Poster Summaries
Effects of Oxidant Air Pollutants on Pine Litter-fall and the Forest Floor
Rodney J. Arkley and Rudolph Glauser
Oxidant i n j u r y t o western yellow p i n e s (Pinus
ponderosa and P. Jeffrey!)
i n t h e San Bernardino
Mountains r e s u l t s i n n e e d l e i n j u r y followed by
i n c r e a s e d f a s c i c l e m o r t a l i t y and a b s c i s s i o n ,
decreased n e e d l e l e n g t h , branch m o r t a l i t y and
f i n a l l y t r e e m o r t a l i t y . The d e g r e e of i n j u r y h a s
been e s t i m a t e d each y e a r f o r 6 y e a r s by a s c o r i n g
system based on o b s e r v a t i o n of a l l of t h e s e
f a c t o r s w i t h b i n o c u l a r s and combining them i n t o a
s i n g l e o x i d a n t i n j u r y s c o r e (01s). F o l i a g e
d e n s i t y i s d i r e c t l y p r o p o r t i o n a l t o OIS a s
expected. The number of annual needle-whorls
r e t a i n e d (W) i s r e l a t e d t o t h e s c o r e by W = 0.171
x OIS w i t h r = .75** and t h e grams of n e e d l e s p e r
Note t h a t
twig by F = 2.71 x OIS w i t h r = .62*.
OIS d e c r e a s e s w i t h i n c r e a s i n g i n j u r y and a s c o r e
of 0 i n d i c a t e s a dead t r e e . Scores g r e a t e r t h a n
35 i n d i c a t e no obvious i n j u r y .
showed no t r e n d whatsoever.
The response of t h e s e elements i s perhaps due
t o d e c l i n i n g c e l l w a l l t h i c k n e s s w i t h i t s calcium
p e c t a t e and an i n v e r s e d i l u t i o n e f f e c t on N , P,
and K.
The d a t a f o r t h e r e g r e s s i o n l i n e s shown i n
Figure 2 a r e a s follows:
-
,598
N(pct)
P ( p c t ) = .0707
K(pct) = .346
Ca(pct) = .303
p r e s e n t a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
2 ~ o i Morphologist
l
and S t a f f Research A s s o c i a t e ,
r e s p e c t i v e l y , Dept. of S o i l s and P l a n t N u t r i t i o n ,
U n i v e r s i t y of C a l i f o r n i a , Berkeley, C a l i f .
+
.00255
.00034
.00331
.00431
QIS,
OIS,
OIS,
OIS,
r = -.264,
r = -.28,
r = -.37,
r = .58,
n
n
n
n
187
185
= 187
= 147
=
=
1
0 MEAN
EFFECT ON NEEDLE-FALL
The oven-dry weight of n e e d l e s c o l l e c t e d on
0.209 m2 s c r e e n s p l a c e d under p i n e s of v a r y i n g
OIS i s shown i n F i g u r e 1. The average annual
n e e d l e f a l l i n c r e a s e s from 1 3 1 gm/m2 under
h e a l t h y t r e e s t o 357 gm/m2 w i t h OIS of 9 t o 1 4 ,
and d e c r e a s e s a s t h e t r e e n e a r s d e a t h ,
The weight p e r n e e d l e f a s c i c l e i n t h e l i t t e r f a l l decreases progressively with increasing
i n j u r y a s shown a l s o i n F i g u r e 1. (Sig. < .001).
The i n c r e a s e d l i t t e r - f a l l (170 p e r c e n t ) can
b e expected t o i n c r e a s e t h e t h i c k n e s s of l o o s e
d r y l i t t e r on t h e f o r e s t f l o o r w i t h consequent
i n c r e a s e d f i r e hazard and d e c r e a s e d s e e d l i n g
germination.
P l a n t N u t r i e n t Content
L i t t e r - f a l l samples were analyzed t o determine
t h e e f f e c t of o x i d a n t i n j u r y on t h e p l a n t n u t r i e n t
of t h e l i t t e r . The r e s u l t s a r e shown i n F i g u r e
2. The s c a t t e r of p o i n t s ( n o t shown) r e p r e s e n t e d
by t h e r e g r e s s i o n l i n e s i s wide, b u t 187 samples
were analyzed and t h e t r e n d s i n d i c a t e d a r e
c l e a r l y r e a l , s i n c e they a r e highly s i g n i f i c a n t
(P = < .001).
Magnesium was a l s o analyzed b u t
2
-
I
I
^-\+I
/
I
1
./
n
I '
-
\
0
*
\
5
Â
N
.2S'Si
b
1
I
"
RANGE
.20
-2
Â
Ã
-
NEEDLE SIZE
Z
.IS
Oxidont Injury Score
Heolthy
Dead 4
Fig. 1. E f f e c t of o x i d a n t i n j u r y on p i n e n e e d l e
f a l l and n e e d l e s i z e .
3
z
01
Dead
Fig. 2.
<
I
1
I
I
10
20
30
40
1 1
50
Oxidant Injury Score
Needle-fall
Healthy
c o n t e n t of p l a n t n u t r i e n t s .
Regional Air Pollution Impacts on Forest Growth
Thomas V. Armentano, O r i e L. Loucks, and Wayne T. w i l l i a m s 2
Recent s t u d i e s underway i n t h e Ohio R i v e r Basin
Energy Study (Loucks 1980) have shown t h a t c h r o n i c
a i r p o l l u t i o n l e v e l s may b e reducing r e g i o n a l
growth over much of e a s t e r n North America. During
June through August, 1977, monitoring s t a t i o n s
r e p r e s e n t a t i v e of f o r e s t a r e a s recorded h o u r l y
0.10 ppm on 1 4 t o 27 p e r c e n t of t h e days,
maxima
0.05 ppm on 70 t o 93 p e r c e n t of t h e
and maxima
days.
>
>
A survey of e a s t e r n w h i t e p i n e (Pinus s t r o b u s
L.) s t a n d s i n r u r a l and urban l o c a t i o n s throughout
c e n t r a l and s o u t h e r n I n d i a n a showed widespread ozone
damage symptoms: c h l o r o t i c m o t t l i n g , c h l o r o t i c
dwarfing and premature n e e d l e senescence, on a
s c a l e from moderate t o s e v e r e . Sycamore ( P l a n t a n u s
o c c i d e n t a l i s L . ) , s i l v e r m a p l e (&
saccharinum L . ) ,
yellow p o p l a r (Lireodendron t u l i p i f e r a L . ) , and t h e
b l a c k oak group (Quercus s p p . ) a l s o a r e somewhat
s e n s i t i v e . The 37.3 x l o 6 a c r e s of f o r e s t s i n t h e
Ohio Basin y i e l d about 40 f t 3 / a c r e 1 of wood ann u a l l y , b u t a n e s t i m a t e d 25 p e r c e n t of t h e f o r e s t
c o n s i s t s of 0 3 - s e n s i t i v e s p e c i e s , i n d i c a t i n g a
y i e l d r e d u c t i o n from o x i d a n t e f f e c t s (and i n t e r a c t i o n s w i t h o t h e r g a s e s and pathogens), r a n g i n g
from 3 t o 6 p e r c e n t a n n u a l l y (Table 1 ) .
Table I--Total l o s s i n wood p r o d u c t i o n i n Ohio
River Basin f o r e s t s e s t i m a t e d t o r e s u l t from d i r e c t
and i n d i r e c t a i r p o l l u t a n t e f f e c t s upon f o r e s t
growth and m o r t a l i t y r a t e s . T o t a l normal wood
y i e l d f o r t h e r e g i o n i n 1970 was 1 . 5 x 10' f t 3 .
Data e x p r e s s e d i n m i l l i o n s of c u b i c f e e t .
Wood
Annual
Production
Mortality
Loss
T o t a l Loss
Loss
( p e t . ) 1 ( l o b f t 3 ) ( P C ~ . 1)( 1 0 b f t 3 )
(pet.)
1
I
s u g g e s t s t h a t O 3 l e v e l s w i l l c o n t i n u e upward a t
l e a s t through 1985. A t t h e c u r r e n t r a t e of 03 i n c r e a s e , 0.02 ppm p e r decade, wood l o s s e s could
r e a c h 166 x l o 6 f t 3 , t w i c e t h e c u r r e n t e s t i m a t e d
l o s s e s (Table 1 ) .
A p a t t e r n of i n c r e a s i n g t r e e m o r t a l i t y i n t h e
r e l a t i v e l y young e a s t e r n f o r e s t s (30 p e r c e n t mort a l i t y i n c r e a s e i n t h e N o r t h e a s t , and 10 p e r c e n t
i n t h e South from 1962 t o 1970) h a s been r e p o r t e d
d u r i n g a p e r i o d of s i g n i f i c a n t a i r p o l l u t i o n inc r e a s e s i n t h e N o r t h e a s t (U.S. F o r e s t S e r v i c e 1978).
T h i s m o r t a l i t y may b e a t t r i b u t a b l e , a t l e a s t i n
p a r t , t o d e g r a d a t i o n of a i r q u a l i t y . This hypothesis i s supported by n e a r l y c o n s t a n t m o r t a l i t y i n
w e s t e r n f o r e s t s where a i r p o l l u t i o n i s g e n e r a l l y
low, d e s p i t e o v e r m a t u r i t y i n t h e s e f o r e s t s . I f mort a l i t y l o s s e s i n t h e Ohio Basin were i n t e r m e d i a t e
between t h o s e of t h e Northeast and South from 1962
t o 1970, t h e l o s s of wood would b e 4.08 f t 3 / a c r e /
y r l . Proportionately greater losses a r e indicated
f o r 1985 and 2000 (Table 1 ) .
Other s t u d i e s underway i n d i c a t e t h e s e f o r e s t
l o s s e s could b e s i g n i f i c a n t f o r t h e g l o b a l C02
b a l a n c e (Armentano and R a l s t o n 1980). Because of
a f a v o r a b l e s t a n d age d i s t r i b u t i o n brought on by
p a s t h a r v e s t p a t t e r n s , temperate zone f o r e s t s now
s t o r e around 10' t o n s of carbon a n n u a l l y i n longl i v e d t r e e components, 20 p e r c e n t a s much a s t h e
carbon r e l e a s e d from f o s s i l - f u e l combustion. T h i s
s t o r a g e could c o n t i n u e f o r t h e n e x t two decades, b u t
i n c r e a s e d h a r v e s t , f o r e s t m a t u r a t i o n , and a i r p o l l u t i o n e f f e c t s can reduce carbon s e q u e s t e r i n g and wood
p r o d u c t i o n r a t e s . Thus, only management of f o r e s t s
focused on a b a l a n c e between wood p r o d u c t i o n and
wood accumulation can p r o v i d e optimum economic and
ecological benefits. I f present a i r pollution
t r e n d s c o n t i n u e , and i f r e l a t i o n s h i p s t o f o r e s t
growth suggested i n t h i s paper a r e s u b s t a n t i a t e d by
f u r t h e r r e s e a r c h , t h e long-term p r o d u c t i v i t y of f o r e s t s w i l l b e t h r e a t e n e d i n s e v e r a l r e g i o n s of t h e
United S t a t e s .
LITERATURE CITED
Independent s t u d i e s i n d i c a t e 03 l e v e l s w i l l inc r e a s e i n t h e Ohio River Basin o v e r t h e n e x t 20
y e a r s , depending on i n c r e a s e s i n u t i l i t y NOx emiss i o n s . A c o n s e r v a t i v e energy development s c e n a r i o
Armentano, T.V., and C.W. R a l s t o n .
1980. The r o l e of temperate zone f o r e s t s i n t h e
g l o b a l carbon c y c l e . Can. J. For. Res. 10:53-60.
' p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, J u n e 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
Loucks, O.L. (ed.).
1980. Crop and F o r e s t Losses Due t o Current and
P r o j e c t e d Emissions from C o a l - f i r e d Power P l a n t s
i n t h e Ohio River Basin. TIE Report i n review.
Indianapolis.
r e s e a r c h S c i e n t i s t , S c i e n c e D i r e c t o r , and
Research S c i e n t i s t , r e s p e c t i v e l y , The I n s t i t u t e of
Ecology (TIE), I n d i a n a p o l i s , I n d i a n a .
U.S. F o r e s t S e r v i c e .
1978. F o r e s t S t a t i s t i c s of t h e U.S.
partment of A g r i c u l t u r e .
1977.
De-
Canopy Analysis of Pollutant Injured Ponderosa Pine in the San Bernardino
National Forest l 3
M.C. Axelrod, P.I. Coyne, G.E. Bingham, J.R. Kercher, P.R. Miller, and R.C. ~
Nine trees were selected from a ponderosa pine (Pinus ponderosa Laws.! stand which was estab- lished after a fire in the mid-1950's. These trees were classified into three injury groups, [(I) slight, (2) moderate, and (3) severe injury] in accordance with a scoring devised by P.R. Miller. During the summers of 1978 and 1979, a detailed inventory was made of the canopy on each tree. The lengths of all main stem internodes were measured along with the number of primary .
branches radiating from each of these internodes. At roughly every other main stem internode, sev-
eral of the primary branches received a detailed inventory. The length of the primary branch and the number of internodes were recorded. This in- ventory was carried on through to the secondary, tertiary, and quarternary branch levels. The compass angle of each of the inventoried primary branches was also recorded. Whenever needles were found on an internode, the following information was recorded: (1) needle age, (2) needle condi- tion on a scale of 0-4, (3) the number of fasci- cles, (4) the average needle length, (5) the average needle chord width, and (6) the length of the internode bearing the needles. Note that while not all the primary branches at a selected main stem internode were inventoried, the ones selected did receive a complete inventory. A preliminary analysis of the 1978 canopy data has been completed, characterizing the distribu- tion of needle surface area for each tree. The total needle surface area for each inventoried primary branch was computed separately for each needle age. In order to determine the distribu- tion of needle surface area for a whole tree, we estimated the needle area at the main stem inter- nodes where no data was taken. The curve repre- senting needle area as a function of height is approximately bell-shaped. We have developed an algorithm designed to yield estimates of the missing points and a smooth curve. The algorithm is iterative and uses linear interpolation be- presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. ~lectricalEngineer, Lawrence Livermore Natl. Laboratory (LLNL), Livermore, Calif.; Plant Phys- iologist, Southern Plains Range Research Station, uSDA/SEA/AR, Woodward, Okla.; Environmental Scien- tists, LLNL; Research Plant Pathologist, Pacific Southwest For. and Range Exp. Stn., Riverside, Calif.; and Environmental Scientist, LLNL. work performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore Natl. Laboratory under contract number W-7405- ENG-48. u
n
~
~ tween known points to produce a set of initial estimates. The algorithm first computes the cumulative needle surface area as a function of height, then a linearizing transformation is made. Linear interpolation is carried out on this new curve. The transformation is then inverted and first differences taken, resulting in a reproduc- tion of the original data and a new set of esti- mates for the missing data. The new estimates are used as initial values each iteration. A weighted average of the needle conditions for each primary branch was also computed. These averages are then combined to yield an index of the condition of the needles on the whole tree. In table 1A, we see the total leaf area index for each needle age class, with the trees grouped into injury classifications. We can see the leaf area indices decrease across injury classes with- in age groups. There is a pronounced decrease in the retained leaf area with needle age even in the slightly injured group; the severely injured group has essentially no needle area except in the 1 year age category. Table 1B shows the (weighted) average needle condition for the inventoried trees and presents further evidence that ozone injury is dose accumulative with young needles being less affected by ozone than older needles. Since the current year needles were still growing at the time the initial inventory was taken, they were inventoried separately the following year. This data is still being processed and is not yet available, but is expected to add proportionately to the numbers presented here. The trend in leaf area decline indicates the competitive disadvan- tage of an injured tree. Table I--Needle properties by needle age for nine trees under pollution stress.^-
Injury Class
Slight
Moderate
Severe
(A) Leaf Area Index 2 Year
1 Year
9.53
5.23
3.55
4.13
0.73
0.03
3 Year 0.70 0.00 0.00 (B) Average Needle condition2 of Canopy Slight
Moderate
Severe
0.96
2.18
2.63
1.31
2.42
NA
1.28 NA NA " ~ o e snot include data for current year nee- dles. Averages for 3 trees in each injury class. ~ e e d l econdition scale: 0 = green; 2 =
chlorotic mottle. 4 = uniform yellow with
necrosis. Photosynthesis and Stomatal Behavior in Ponderosa Pine Subjected to Oxidant Stress: Water Stress Response
112
Gail E. Bingham and Patrick I. coyne3 Light response curves for net and/or gross photosynthesis, stomatal conductance, and needle xylem potential of ponderosa pine (Pinus ponderosa Laws.) subjected to water and/or ozone stress were studied in the field and laboratory. In the field, measurements were made on a stand of pon- derosa pine in the San Bernardino National Forest, which has experienced long-term oxidant fumiga- tions from the south coast air basin since their establishment following fire in the mid-1950's. These trees were stratified for comparative stud- ies into three groups (slight injury, moderate injury, and severe injury) having similar oxidant symptoms, on the basis of the scoring system of P.R. Miller. Controlled studies using ten healthy, uniform, Oregon-grown, six-year-old saplings growing in 55 1 containers were conducted to elucidate specific field responses. These trees were ap- proximately 2 m tall, and were randomly allocated to positions in two naturally-lighted, mylar- covered, air and humidity conditioned exposure chambers. One chamber was supplied charcoal filtered air and the other with air containing 0.01 ppm ozone for six hours/day during the midday period. Measurements were made at regular intervals from May through October at the forest site and during the fumigation and water stress cycles in the laboratory. During the laboratory study, net photosynthesis (Pn) and stomatal conductance (Cs) measurements were made at constant humidity and temperature using the LLNL developed minicuvette system, with only the fascicle being measured and a few surrounding needles exposed to light. The rest of the tree was surrounded with heavy black cloth from before dawn until after light response curves had been measured on three fascicles. The relationship between needle xylem poten- tial
and maximum stomatal conductance (Cmax) was not single valued, and depended on predawn "presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. 'work performed under the auspices of the U. S. Dept. of Energy by the Lawrence Livennore National Laboratory under contract number W-7405-ENG-48. 3~nvironmentalScientist, Lawrence Livermore
National Laboratory, Livermore, Calif.; Plant Physiologist, Southern Plains Range Research Station, USDA/SEA/AR, Woodward, Okla. When predawn ifiv was in the range from -3 to -5 bars, Cs (and Pn) decreased only slightly dur- ing the normal daily decrease in ifiv due to changes in the diurnal course of irradiance. Minimum ^iy under these conditions seldom exceeded
-14 bars. However, when $x was forced below -15 to -17 bars (by severing the fascicle from the branch) a sharp decrease in Cs occurred, with complete stomatal closure (Cs<O.O1 cm/s) in the range of -36 to -40 bars. When predawn started in the -5 to -8 bar range, however, a bilevel relationship between Cg and ^iy was observed, with Cmax reaching an initial full light value, followed at some later time by a step decrease to a lower value. Conductance and Pn remained at this significantly lower level throughout most of the day, with an accelerated closing trend toward the late afternoon. Late afternoon values were usually only 60 to 70 per- cent of their light corrected morning opening value. qX.
Care had to be taken when interpreting pre-dawn $x measurements in the field. It was often ob- served that at 'a predawn ifiv of -3 to -7 bars, the
stomata would partially open in the predawn hours, resulting in Cs values approaching one-tenth of their full light value. Under these conditions, sufficient transpiration occurred to make predawn qX very sensitive to wind speed. Differences be- tween predawn $x on calm and windy mornings as large as 3 bars were observed. The second factor depended solely on the pre- dawn xylem potential and controlled the maximum stomatal conductance (Cmax) observed during the diurnal cycle. This relationship could not be adequately examined in the forest due to untimely late season rains during the three years that field studies were conducted, and was investigated using potted trees. As predawn $x decreased below -7 bars in control trees and about -10 bars in fumigated trees, a drastic reduction in Cmax and Pn was observed. In trees kept in filtered air, Cmax was decreased from 0.36 to 0.036 cm/s by the decrease of predawn $x from -5 to -15 bars. Since the majority of the tree was kept in the dark dur- ing the measurement, the relationship between Cs and $x at QX values greater than can normally be observed in nature (due to root and xylem resis- tance) were examined. Conductance and Pn of fumi- gated trees in this region was not significantly higher than that observed at potentials associated with full illumination. Reductions in GaX
of 25, 31, and 44 percent were measured for slight, mod- erate, and severely injured needles. Net photo- synthesis for the same needle injury classes was reduced by 38, 54, and 69 percent from the 12.9 mgco2/dir^-h rate measured in trees which had not been exposed to ozone. Oxidant Impact on Ponderosa and Jeffrey Pine Foliage Decomposition1
2
J. N. Bruhn, J. R. Parmeter, Jr., and F. W. Cobb, Jr. Litter decomposition was studied on four plots located along the oxidant dosage gradient in the San Bernardino Mountains (SBNF). Precipitation decreased with decreasing oxidant dosage along this gradient, while forest floor-level solar radiation and temperature ir .eased. Ponderosa (Pinus ponderosa Dougl.) a1.d Jeffrey pine (Pinus Jeffrey! Grev. & Balf.) dominated the most and
least severely impacted sites, respectively. Nylon mesh envelopes of fresh-fallen litter were exchanged among healthy and sick trees on the four study sites. Decomposition was measured as percents overall and nutrient (N, P, K. Ca and Mg) weight loss. During the first two years of decomposition, its rate at each site was directly related to precipitation and oxidant dose. While site mois- ture apparently dominates litter decomposition, evidence suggests that oxidant injury to live needles is directly related to the rate at which they decompose. One year weight loss of ponderosa pine litter was negatively correlated (P .05) with the oxidant injury scores (O.I.S.)(Miller
1973) of litter source trees. One year weight loss by litter of both species was negatively correlated (P .05) with the O.I.S. of litter destination trees. Live needle internal microflora may be initi- ated in the foliar bud and can be thought of as pioneers in a succession of microorganisms re-
sponsible for litter decomposition. Microbial populations involved in foliage decomposition were studied via incubation of surface-sterilized live and litter needles on water agar. Eight trees from each of two central Sierra Nevada sites, Stanislaus National Forest (SNF) and Blodgett Experimental Forest (BEF), were included for com- parison with the 15 SBNF study trees. Both taxo- nomic richness and population density increased with needle age. Both parameters increased simi- larly with age on all four SBNF sites. However, both parameters increased faster on the somewhat less oxidant-impacted BEF, and both parameters developed fastest on the least oxidant-impacted site (SNF). Because not all fungi recorded in incubation studies were identified, they are individually referred to as categories rather than species. Live SNF foliage yielded approximately twice as many fungus categories (60) as foliage from any other site. The two BEF plots harbored a few more categories (29 and 32) than did HV (27), the healthiest SBNF site. HV, in turn, provided more categories than any other SBNF site (15 to 20). Similar effects were not evident in forest floor litter. Oxidants apparently affect live needle microflora in two ways. By reducing needle lon- gevity, internal microflora development is prema- turely truncated. It also seems likely that oxi- dants further reduce the variety of fungi coloniz- ing live pine foliage by eliminating susceptible species. Insofar as community functional pro- perties are stabilized by a combination of species adaptability and community diversity, reduction of live foliage microfloral diversity by oxidants is viewed as weakening the functional stability of these communities. The significance of such weak- ening is unknown. In a growth chamber experiment, propylene oxide- sterilized pine needles were incubated on moist forest floor organic matter from either Che SNF or one of the SBNF sites. No meaningful differences in weight loss developed between treatments over 22 weeks, showing that oxidants to date had not significantly impaired the abilities of study-site microflora to cause litter weight loss. In a sec-
cond growth chamber experiment, propylene oxide- sterilized pine needles were incubated on a uniform moist forest floor organic matter mixture in either filtered air or filtered air enriched with 20pphm ozone 8 hours daily for 14 weeks. The weight loss difference between treatments did not reach signi- ficance ( .05 P .01). Any effect in the field
would be slight and probably limited to surface litter during moderate to severe oxidant episodes. Acknowledgments: This project was funded in part with federal funds from the Environmental Protection Agency (E. P. A.) under contract number 68-03-0273. LITERATURE CITED presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. 2~nstructorof Forest Pathology, Michigan Technological University, Houghton, Mich.; Pro- fessor and Associate Professor of Plant Pathology, respectively, University of California, Berkeley, Calif. Miller, P. R. 1973. Oxidant-induced community change in a mixed conifer forest. In Air pollution damage to vegetation. p. 101-117. Advances in Chemistry Series, Number 122. American Chemical Society. Integrated Lake-Watershed Acidification Study
Carl W. Chen and Robert A.
OBJECTIVES The Integrated Lake-Watershed Acidification Study (ILWAS) was designed to determine the eco- logical effects of acid rain under natural condi- tions (EPRI, 1979, Goldstein et al., 1980). Since the most widely reported effect of acid rain has been the acidification of lake water leading to elimination of fish, it is of interest to learn how and why the ecosystem becomes acidified by acid rain. Three forested watersheds (Panther, Woods, and Sagamore) within 15 km of each other in the Adirondack Park region of New York were selected for investigation. Each watershed has different configurations and characteristics. Principle hypothesis of the study is that these differences may lend to different pH dynamics, i-e., Panther Lake alkaline, Woods Lake acidic, and Sagamore Lake in-between. This research will produce a comprehensive data base for the three watersheds covering a period of almost 4 years, a series of interpretive reports, and a calibrated and verified mathematical model. The wealth of understanding gained and the mathe- matical model developed will be readily applicable to other lake basins. APPROACH ILWAS couples field investigation with theoret- ical modeling. The interactions between the model and the field research are practiced in an inter- active manner, each influencing and strengthening the other. Other research findings on mechanisms and rates of acidification processes are inte- grated into the model formulations. FIELD PROGRAM The watershed ecosystem is envisioned to com- prise a cascade of basic compartments: atmosphere, canopy, snowpack, catchment, soil layers, bogs, stream segment and lake. These are the compart- ments that the acid rain must pass through before it reaches lake outlet. As it passes through each compartment, biogeochemical processes acting in presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. 2~ice-~resident,
Tetra Tech, Inc. , Lafayette,
California; Program Manager, Electric Power Research Institute, Palo Alto, California olds stein' series and in parallel will produce or consume acids and will release chemicals that shift the pH and other chemical equilibrium. 1-
Meteorology
Air duality
Rain Quality
-
Throughfall Chemistry
-Hydraulics
-Geochemistry
Microbial Processes (& Lab)
-
Hydrology
-Aquatic Chemistry
Hydrology
-Aquatic Chemistry
- Paleoecology
Hydrology
Figure 1--Field Program Components Field surveys are being conducted to character- ize the properties of the basic ecosystem compart- ments in each watershed. At selected locations, measurements are made for ambient air quality, the quantity and quality of waters that move through the system from tree top to lake outlet (see fig. 1). Data are collected monthly, weekly, synoptic, and once only, depending on the parameters and their temporal variability. The field program began in 1977 and will be completed in 1981. MODELING The model organizes the data into an integrated theoretical framework (Goldstein et al., 1980). The model also serves as a vehicle to check the consistency of theory and data from rainfall quan- tity to lake outlet quality. Eventually, the model may provide scientific answers to such management questions as: What will and will not happen if a certain air quality standard is im- posed, and if the acidity of precipitation is in- creased or decreased. The model flowchart shows the computation se-
quence (fig. 2 ) . The model calculates dry deposition as a function of ambient air quality and simulates the quantity and quality of water in throughfall, soil horizons, bogs, stream, lake, and lake outlet (Chen et al., 1978). All impor- tant acidification processes are included in the model. The pH at Panther Lake inlet is normally 7.3 to
The pH at the outlet is
similar except during the snowmelt periods. During that period, pH drops to as low as 5.0. Something must have happened in the lake. Alternatively, it was argued that the inlet was only a
small spring, not representative of all inflows.
7.5 throughout the year.
Ambient air quality
Basin properties
Dry deposition
Exudate
Calculate
Throughfall chemistry
Snow accumulation
Snowmelt
Ion-teaching
.
Calculate
Soil moisture
Vertical infiltration
Lateral outflow
Organic decomposition
Nutrient uptake
.Weathering
Cation exchange
Equilibration (At-sys, etc.)
+
Quantity and quality
of H20 through stream
Figure 2--Model Flowchart
The model uses a network of compartments to
account for spatial variability of ecosystem. It
updates meteorological conditions daily and ambient air quality weekly. The calculations are
performed on a daily time step to simulate the
dynamic responses of ecosystem throughout years.
Graphic outputs are provided to facilitate interpretation.
PRELIMINARY FINDINGS
Data indicate that the H+ deposition rates are
seasonal and are approximately the same for all
three watersheds (Johannes and Altwicker, 1980).
The seasonal pattern of H+ deposition seems to
follow that of SO4 deposition (Johannes, 1980).
The deposition rates of various ions in acid rain
as measured at seven ILWAS stations correlate
well with those measured at the nearby MAP3S
stations. This is significant because it suggests
that acid rain data from regional monitoring stations may be used to perform preliminary calculation of acid rain effect for a new site.
The pH profiles measured in the lake show that
only surface water is acidified during the period
of snowmelt (Hendrey et al., 1980). What is the
source of H+ ions that acidify the lake surface?
To resolve the puzzle, the model was used to
help trace the source of water at the outlet. The
model was first calibrated to the Panther Lake
basin (Chen and Goldstein, 1980). After that,
precipitation falling directly on lake surface is
set to zero. This allows estimation of the contributions of this input to the total observed
outflow. Approximately two-fifths of the peak
flow can be accounted for by the direct precipitation to the lake surface. During that period,
lake water is inversely stratified with respect
to temperature. Direct precipitation which has a
pH of 3.8 to 4.2 quite possibly is deposited right
on the surface to acidify the lake surface water
(pH 5.0). Another possible explanation is surface
runoff resulting from snowmelt which has a high
acidity (Galloway et al., 1980).
The significance of the capability to manipulate the model to examine the effect of a single
process on the integrated response of the ecosystem should not be overlooked.
LITERATURE CITED
Chen, C.W., S.A. Gherini, and R.A. Goldstein.
1978. Modeling the Lake Acidification Process.
In Ecological Effects of Acid Precipitation,
Report of a Workshop, Galloway, United Kingdom, September 4-8, 1978, ed. M.G. Wood,
Electric Power Research Institute, Palo Alto,
CA, U.S.A., EA-79-6-LD.
Chen, C.W., and R.A. Goldstein.
1980. "Techniques for Assessing Ecosystem Impacts of Air Pollutants." & Proc. International Conference Air Pollutants and their
Effect on the Terrestrial Ecosystem [May 1017, 1980, Banff, Alberta, Canada].
EPRI Technical Work Statement for the Integrated
Lake-Watershed Acidification Study RP 1109.
1979. Electric Power Research Institute,
Palo Alto, California.
Galloway, J.N., C.L. Schofield, G.R. Hendrey,
and A.J. Johannes.
1980. "Sources of Acidity in Three Lakes Acidified During Snowmelt." In Proc. of International Conference on the Ecological Impact
of Acid Precipitation, [March 11-14, 1980,
Sandefjord, Norway].
Goldstein, R.A., C.W. Chen, S.A. Gherini, and J.D. Dean. 1980. A Framework for the Integrated Lake- Watershed Acidification Study. & Proc. of
International Conference on the Ecological Impact of Acid Precipitation, [March 11-14, 1980, Sandefjord, Norway]. Hendrey, G.R., J.H. Galloway, and C.L. Schofield. 1980. "Temporal and Spatial Trends in the Chem- istry on the Ecological Impact of Acid Pre- cipitation."
Proc. of International Con- ference on the Ecological Impact of Acid Precipitation, [March 11-14, 1980, Sandefjord, Norway]
.
Johannes, A.H., and E.R. Altwicker. 1980. "Atmosphere Imputs to Three Adirondack Lake Watersheds." 3 Proc. of International Conference on the Ecological Impact of Acid Precipitation, [March 11-14, 1980, Sandefjord, Norway]
.
Photosynthesis and Stomatal Response to Light and Temperature in Ponderosa Pine Exposed to Long-Term Oxidant Stress1
P a t r i c k I.Coyne and G a i l E. ~ i n ~ h a m *
Seasonal courses (May t o October 1977) o f
gross p h o t o s y n t h e s i s ( c a l c u l a t e d from
CO2 upt a k e ) and stomatal conductance were c h a r a c t e r i z e d
as a f u n c t i o n o f l i g h t and gross and n e t photos y n t h e s i s were c h a r a c t e r i z e d as a f u n c t i o n o f
temperature (May and J u l y 1978) i n a s t a n d o f
i n t h e San
ponderosa p i n e (Pinus ponderosa
Bernardino N a t i o n a l Forest. The CO2 d i f f u s i o n
pathway was p a r t i t i o n e d i n t o i t s stomatal and
r e s i d u a l (mesophyll , c a r b o x y l a t i o n , e x c i t a t i o n )
r e s i s t a n c e components f o r c o n d i t i o n s o f l i g h t
s a t u r a t i o n and 20 C. These t r e e s have e x p e r i enced l o n g t e r m o x i d a n t f u m i g a t i o n s from C a l i f o r n i a ' s South Coast A i r Basin s i n c e t h e i r e s t a b l i s h
ment f o l l o w i n g f i r e i n t h e mid-1950's.
Nine trees
were s t r a t i f i e d f o r comparative s t u d i e s i n t o t h r e e
chronic i n j u r y classes ( I - s l i g h t i n j u r y , I 1 moderate, I 1 1 - severe) h a v i n g s i m i l a r o x i d a n t
i n j u r y symptoms based on t h e s c o r i n g system o f
P. R. M i l l e r .
m.)
Maximum o r l i g h t s a t u r a t e d gross photosynt h e t i c r a t e s (Pmax) and photochemical conversion
e f f i c i e n c i e s ( d P / d I ) I=o were h i g h e s t i n t h e c u r r e n t needles and decreased w i t h i n c r e a s i n g need l e age and w i t h season. D i f f e r e n c e s among need l e age c l a s s e s w i t h i n an i n j u r y c l a s s d i v e r g e d
as t h e season progressed i n d i c a t i n g an a c c e l e r a t i o n o f senescence b y ozone. Maximum stomatal
conductances (Cmax) and stomatal s e n s i t i v i t y t o
i n c r e a s i n g 1 i g h t (dC/dI) I=o d u r i n g opening f o l lowed a s i m i l a r t r e n d t o Pmax and dP/dI except
i n t h e c u r r e n t needles i n which Cmax and dC/dI
were h i g h e s t i n t h e s e v e r e l y i n j u r e d t r e e s . T h i s
suggests a p o s s i b l e f a c t o r c o n t r i b u t i n g t o d i f f e r e n t i a l ozone s e n s i t i v i t y i n t h i s stand. The
r a t i o o f t h e stomatal r e s i s t a n c e f o r CO2 ( r l ) t o
t h e t o t a l r e s i s t a n c e (r', s t o m a t a l + r e s i d u a l )
decreased w i t h o x i d a n t i n j u r y , i n c r e a s i n g ' n e e d l e
age, and season suggesting t h a t l o s s o f photos y n t h e t i c c a p a c i t y r e s u l t e d more from 1 i m i t a t i o n s
a t t h e c h l o r o p l a s t s than from r e s i s t a n c e t o CO2
d i f f u s i o n t h r o u g h t h e stomata.
Temperature optima (Top ) f o r photosynthesis
were s i m i l a r i n a l l i n j u r y c l a s s e s and averaged
'presented a t t h e Symposium on E f f e c t s o f
A i r P o l l u t a n t s on Mediterranean and Temperate
F o r e s t Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
2 ~ 1 a n tP h y s i o l o g i s t , Southern P l a i n s Range
Research S t a t i o n , USDA/SEA/AR, Woodward, Okla.;
and Environmental S c i e n t i s t , Lawrence Livermore
L a b o r a t o r y , Livermore, Cal i f .
^ h i s work was supported by a U.S. Dept. o f
Energy c o n t r a c t (W-7405-ENG-48) w i t h Lawrence
Livermore L a b o r a t o r y .
about 20° i n May and 25OC i n J u l y . L i g h t r e s p i r a t i o n ( e s t i m a t e d as Pgross-Pnet) was h i g h e s t i n
h e a l t h y younq needles and increased w i t h temperat u r e from 5° t o To t and then l e v e l e d o f f between
Topt and 35OC. ~l
though l i g h t r e s p i r a t i o n was
inversely related t o oxidant i n j u r y , the r a t i o o f
ss tended t o decrease w i t h o x i d a n t injury.
Pnet/P
~ ~ ~ a r e onx itd a? n~t s t r e s s e d t r e e s n o t o n l y had
reduced r a t e s o f CO2 f i x a t i o n , b u t r e t a i n e d a
smal l e r p r o p o r t i o n o f a s s i m i l a t e d carbon a f t e r
r e s p i r a t i o n l o s s e s . Summary data f o r s e l e c t
parameters a r e compared i n Table 1.
Table 1--Comparison o f s e l e c t parameters normali z e d b y d i v i d i n g each mean b y t h e maximum mean v a l u e i n each column.
I n j u r y Needle
1977 Means
Class
Age
Pmax ] Cmax lr;/r1
I
0
1
2
II
0
1
2
III
0
1
Max. value1
1.00
0.61
0.32
0.92
0.53
0.17
'0.79
0.35
8.30
0.89
0.84
0.62
0.92
0.75
0.38
1.00
0.57
0.24
1.00
0.80
0.59
0.82
0.71
0.40
0.59
0.45
0.29
J u l y 1978
Pgross-Pnet
1.00
0.60
0.35
0.95
0.51
0.18
0.94
0.35
2.46
^ p a r meters d e f i n e i n t e x t . U n i t s : P, mg CO2
g -7t-1-1; C, cm s-y ; r, s cm-1; age i n years.
The d i f f e r e n t i a l response i n p h o t o s y n t h e s i s
and stomatal conductance among these f i e l d - g r o w n
ponderosa p i n e t r e e s growing i n a common e n v i r o n ment i n d i c a t e d t h e presence o f e c o t y p i c v a r i a t i o n
i n ozone s e n s i t i v i t y . The d i f f e r e n c e s among
i n j u r y classes were m a n i f e s t as an a c c e l e r a t i o n
o f t h e normal d e c l i n e i n CO2 f i x a t i o n and stomatal
conductance a s s o c i a t e d w i t h needle aging. P a r t i c u l a r l y e v i d e n t were t h e premature senescence and
a b s c i s s i o n o f needles o c c u r r i n g a t about t h e t i m e
gross CO2 uptake dropped t o 10 p e r c e n t o f t h e
p o t e n t i a l f o r c l a s s I c u r r e n t needles w i t h o u t
f o l i a r i n j u r y symptoms. T h i s occurred a t i n t e g r a t e d i n c i d e n t ozone doses as low as 450 ppm-h
i n s e v e r e l y i n j u r e d t r e e s ( c l a s s 111) o r as h i g h
as 800 ppm-h i n s l i g h t l y i n j u r e d t r e e s ( c l a s s I ) .
A probable s c e n e r i o f o r o x i d a n t e f f e c t s can
be described. As f o l i a r i n j u r y symptoms increase,
p h o t o s y n t h e t i c c a p a c i t y and n e t carbon accumulat i o n p e r u n i t l e a f mass o r area, mass and area
p e r needle, needle mass p e r u n i t area, and number
o f needle w h o r l s r e t a i n e d p e r t r e e d e c l i n e .
These f a c t o r s c o n t r i b u t e t o t h e steady l o s s o f
t r e e v i g o r , weakening them t o t h e p o i n t o f v u l n e r a b i l i t y t o pathogenic organisms such as r o o t
r o t t i n g f u n g i and b a r k b e e t l e s .
The Effect of Air Pollution on Western Larch as Detected by Tree-Ring Analysis1
C a r l A . Fox and Thomas H. Nash 1112
The number of p u b l i c a t i o n s i n r e c e n t
y e a r s d e a l i n g w i t h t h e e f f e c t s of a i r
p o l l u t i o n on p l a n t s h a s been voluminous.
A v a s t m a j o r i t y of t h e s e have d e a l t w i t h
t h e e f f e c t s of s h o r t - t e r m ( h o u r s o r d a y s )
f u m i g a t i o n s on p l a n t r e s p o n s e .
I n cont r a s t t o these studies, there is relat i v e l y l i t t l e i n f o r m a t i o n on t h e l o n g term, c u m u l a t i v e e f f e c t s o f a i r p o l l u t i o n
o v e r decades.
To examine t h e s e long-term
e f f e c t s , a dendroecological (tree-ring)
a n a l y s i s was employed t o a s s e s s t h e growth
r e s p o n s e o f w e s t e r n l a r c h ( ----Larix
o-c c i d e n t a l i s N u t t . ) t o s u l f u r d i o x i d e .
U t i l i z a t i o n of d e n d r o e c o l o g i c a l t e c h n i q u e s p r o v i d e d a means f o r q u a n t i t a t i v e l y
r e m o v i n g t h e e f f e c t o f c l i m a t e on t h e
growth response of l a r c h and, t h u s ,
p e r m i t t e d a n e x a m i n a t i o n of t h e r e s i d u a l
growth response i n terms of l o c a l s i t e
f a c t o r s , s p e c i f i c a l l y s u l f u r dioxide.
F i v e w e s t e r n l a r c h s t u d y s i t e s were
l o c a t e d i n t h e Columbia R i v e r V a l l e y n e a r
t h e lead-zinc smelter a t T r a i l , B r i t i s h
Columbia.
This particular location
r e p r e s e n t s a unique study a r e a i n t h a t t h e
s u l f u r d i o x i d e g r a d i e n t has been w e l l
documented, b o t h o v e r s p a c e and t i m e ,
s i n c e s m e l t i n g a c t i v i t y began i n 1896.
S u l f u r e m i s s i o n s from t h e s m e l t e r
i n c r e a s e d i n t h e e a r l y 1 9 0 0 1 s , reached a
maximum i n 1930, and r e s u l t e d i n a concommitant d e c r e a s e i n a n n u a l t r e e growth.
A f t e r 1930, s u l f u r emissions decreased
d r a m a t i c a l l y w i t h t h e i m p l e m e n t a t i o n of
p o l l u t i o n abatement measures.
However,
t h e growth r e s p o n s e of w e s t e r n l a r c h t o
t h e d e c r e a s e d s u l f u r e m i s s i o n s was n o t
immediate, and r e f l e c t e d t h e low f r e q u e n c y
n a t u r e of t h e v a r i a n c e o f t h e s u l f u r
d i o x i d e e f f e c t on t r e e growth.
p r e s e n t e d a t t h e Symposium on E f f e c t s o f
A i r P o l l u t a n t s on M e d i t e r r a n e a n and
Temperate F o r e s t Ecosystems, June 2 2 - 2 7 ,
1980, R i v e r s i d e , C a l i f o r n i a , U.S.A.
^ ~ e s e a r c hS c i e n t i s t , S o u t h e r n C a l i f o r n i a
Edison Company, Rosemead, C a l i f o r n i a ;
A s s o c i a t e P r o f e s s o r o f Botany, Arizona
S t a t e U n i v e r s i t y , Tempe, Arizona.
C o r r e l a t i o n and r e g r e s s i o n a n a l y s e s
were u t i l i z e d t o d e v e l o p m u l t i v a r i a t e
models f o r t h e l a r c h s t u d y s i t e s sampled
a t varying d i s t a n c e s from t h e T r a i l
smelter.
C l i m a t i c models developed f o r
t h e c o n t r o l s i t e ( t r e e - r i n g ) chronology
were a p p l i e d t o s i t e c h r o n o l o g i e s l o c a t e d
within the s u l f u r dioxide affected area t o
remove t h e e f f e c t s o f c l i m a t e on t r e e
growth and examine t h e r e s i d u a l r e s p o n s e
of t h e system.
The p a t t e r n of t h e r e s i d u a l s c l o s e l y resembled t h e s u l f u r emiss i o n s from t h e s m e l t e r with t h e most
n e g a t i v e r e s i d u a l s o c c u r r i n g when s u l f u r
e m i s s i o n s were g r e a t e s t .
F u r t h e r r e g r e s s i o n modeling i d e n t i f i e d t h e r e l a t i v e importance of s u l f u r
e m i s s i o n s , p r i o r y e a r ' s growth, temperat u r e , and p r e c i p i t a t i o n t o a n n u a l f r e e
growth.
I n those s i t e s closest t o the
s m e l t e r , s u l f u r emissions accounted f o r
t h e g r e a t e s t p r o p o r t i o n of t h e v a r i a n c e
As
c a l i b r a t e d b y t h e r e g r e s s i o n models.
d i s t a n c e from t h e s m e l t e r i n c r e a s e d , t h e
variance a t t r i b u t a b l e t o s u l f u r emissions
d e c r e a s e d i n each s i t e model.
I n a l l of
t h e s i t e models, t e m p e r a t u r e , p a r t i c u l a r l y
summer t e m p e r a t u r e , a p p e a r e d t o b e a
primary l i m i t i n g c l i m a t i c f a c t o r .
Prior
growth a l s o accounted f o r c o n s i d e r a b l e
v a r i a n c e i n t h e models w i t h p r e c i p i t a t i o n
v a r i a b l e s a p p e a r i n g t o be o f l e s s e r
importance i n e x p l a i n i n g t h e v a r i a n c e of
the s i t e chronologies.
The r e s u l t s o f t h i s s t u d y demons t r a t e t h e a p p l i c a b i l i t y of t r e e - r i n g
a n a l y s i s i n i d e n t i f y i n g and q u a n t i f y i n g
t h e long-term e f f e c t s o f a i r p o l l u t i o n on
It a l s o p r o v i d e s a
f o r e s t communities.
b a s i s f o r examining t h e i n t e r r e l a t i o n s h i p s
between a i r p o l l u t i o n , c l i m a t e , and t r e e
growth.
Acid Rain: Threshold of Leaf Damage in Eight Species from a Forest Succession1
B.L. Haines, M. S t e f a n i , and F. Hendrix
Eight p l a n t s p e c i e s were s u b j e c t e d t o a r t i f i c i a l a c i d r a i n s of pH 2.5, 2.0, 1.5, 1.0, and
0.5 i n o r d e r t o determine t h e t h r e s h o l d f o r and
symptoms of damage. I n a previous study a r t i f i c i a l a c i d r a i n s of pH 5.5, 4.5, 3.5, and 2.5
f a i l e d t o produce symptoms of damage. The pres e n t s t u d y was designed t o extend t h e pH range.
The p l a n t s were E r e c h t i t e s , Robinia, Pinus,
and Cornus
Quercus, Carya, Liriodendron, &,
from t h e F o r e s t s e r v i c e ' s owee eta ~ ~ d r o l o ~ i c Laboratory n e a r F r a n k l i n , North Carolina. Dup l i c a t e 0.01 m l drops of each of t h e 5 simulated
a c i d r a i n s o l u t i o n s were a p p l i e d t o a s i n g l e
mature l e a f on each of two p l a n t s of seven spec i e s . The e n t i r e experiment was performed twice.
I n Pinus n e e d l e t i p s were immersed i n t h e solut i o n s . The s i z e s of n e c r o t i c s p o t s a r e shown i n
Fig. 1. Droplets of pH 2.0 produced brown necr o t i c s p o t s on a l l s p e c i e s except Pinus w h i l e
d r o p l e t s of pH 1.0 produced necroses on l e a v e s of
a l l s p e c i e s examined. Pinus n e e d l e s were damaged a t pH v a l u e s between 1.0 and 0.5. Damage was
confined t o younger n e e d l e s and was evidenced by
browning and c o l l a p s e . For angiosperms t h e s i z e s
of n e c r o t i c s p o t s i n c r e a s e d w i t h decreasing pH.
This s u g g e s t s t h a t t h e l e a f has some b u f f e r i n g
c a p a c i t y which was p r o g r e s s i v e l y overcome by
i n c r e a s i n g d r o p l e t a c i d i t y . Comparison of r e s u l t s w i t h l i t e r a t u r e s u g g e s t s t h a t developing
l e a v e s a r e more e a s i l y damaged than a r e mature
l e a v e s used i n t h i s study. No s u c c e s s i o n a l
t r e n d s i n s u s c e p t i b i l i t y were observed.
2
The volume weighted average r a i n f a l l pH f o r
Coweeta i s 4.6 w i t h o b s e r v a t i o n s ranging from
3.2 t o 5.9.
Because t h e pH s c a l e i s l o g a r i t h m i c
w i t h a d e c r e a s e i n 1 pH u i t corresponding t o a
?
10-fold i n c r e a s e i n t h e H c o n c e n t r a t i o n , i t i s
apparent t h a t a 100-fold i n c r e a s e
t h e volume
weighted average c o n c e n t r a t i o n of H a t Coweeta
would change t h e pH from 4.6 t o 2.6 which i s
n e a r t h e t h r e s h o l d of damage. However, t h e
extremes may be f a r more c r i t i c a l than t h e volume weighted average. With t h e lowest pH v a l u e
recorded f o r Coweeta being pH 3.2, merely a 10f o l d i n c r e a s e i n a c i d i t y t o pH 2.2 i n a s i n g l e
s p r i n g o r summer storm seems l i k e l y t o b r i n g
damage o r d e a t h t o mature l e a v e s of t h e flowering
p l a n t s a t Coweeta.
in
PLANT SPECIES MD LIFE FORM
pH
0.5
OF DROPLETS APPLIED
1.0
1.5
2.0
-
ERECHTIKS HlEMClFOLIA(L) RAF.
HERBACEOUS WED (N 6)
PUUS STROBUS L.
TREE ( N - 8 )
-
ROBIHIA PSEUDO-ACACIA La
SHRUB TO TREE ( N 6 )
p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
' ~ s s i s t a n t P r o f e s s o r of Botany, Department
of Botany, U n i v e r s i t y of Georgia, Athens, GA
30602; Graduate Research A s s i s t a n t i n P l a n t
Pathology, and Prof. of P l a n t Pathology, Dept.
of P l a n t Pathology and Genetics, U n i v e r s i t y of
Georgia, Athens, Georgia 30602. Research
supported by U.S. EPA Grant R80530510 and NSF
g r a n t s DEB 7619930, DEB 7705324A01 and DEB
7904537 t o t h e U n i v e r s i t y of Georgia.
ACER RUBRUH L.
THE ( N = 0
Figure 1. Average diameter i n mm of n e c r o t i c
s p o t s on l e a v e s s u b j e c t e d t o d r o p l e t s of 5 pH
levels.
(*) Spot diameters n o t measured on
needles, s e e t e x t f o r d e s c r i p t i o n of damage.
2.5
Prioritization of Research on Air Quality Related Resources of the National Parks1
E. A. Howard, L. If. Boyd, W. M. Brock, D. W. Morse, S. S. Shin and K. L. steel-sabo2
The National Park Service (NPS) has the legal responsibility and authority to preserve and pro- tect the resources of lands under its jurisdiction. Air pollution has been recognized as a significant threat to the parks and the 1977 Amendments to the Clean Air Act provided the Service the authority and responsibility to protect resources that are air quality related. The NPS Air Quality Office intends to conduct research programs to determine air pollution effects, t o emphasize the use of sensitive receptors to detect effects, as well as to ensure that scientific evidence is readily a- vailable when NPS must make determinations of adverse effects. These efforts are subject to time and funding limitations and therefore guide- lines on setting research priorities are being developed. The first step in establishing cause and effect relationships is to identify the pollutants that may.affect park resources (fig. 1). Pollutants from existing or planned sources may be identified by monitoring or estimated from permit require- ments. If sources are not known, pollutants must be identified through some early warning process or on the basis of the potential development of re- gional natural resources. Existing sources of air pollutants that may affect the natural or cultural resources of park units must be ranked according to pollutant type, concentration, frequency, and duration of exposure of the resource. The rankine must also incorporate the estimated lead time be- fore new pollutant sources begin operation. The identification and ranking of pollutant sources is necessary to economize the search for potential effects. that are susceptible to the effects of air pollu- tion.
The availability of current research information or literature on susceptibility must be similarly considered in establishing research priorities. Time constraints on recovering infor- mation or research results on air quality effects on natural ecosystems has prompted the development of a quick access annotated bibliography that uses a codin8 system based specifically on natural and cultural resources of NPS units. The bibliography has been used on several occasions to provide lists of references in support of litigation and testimony for hearings. Setting priorities for research on air quality effects is altered by other influences and con- straints (fig. 1). Funding and time limitations must be incorporated into the prioritization. In- sufficient funding may cause postponement of the highest priority research until these requirements can be integrated into the budget cycle. Time constraints also have considerable influence on priority setting. Substantive scientific data on air quality effects cannot be produced within the short time schedules of hearings or litigation. The timing of the budget cycle creates difficulty in obtaining sustained funding for long-term effects research. Political requirements at the Washington level may override the regional pri- oritization. The setting of priorities must be continually updated in conjunction with any change imposed by these influences or constraints. POLLUTANT SOURCES RANKED ACCORDING TO The identified pollutants are then used as a IMMINENCE AND DAMAGE basis of comparison between the list of resources POTENTIAL present on a park unit and the literature or cur- rent research information on resource susceptibility (fig. 1).
The presence or absence of information LISTS OF RESOURCES
LITERATURE AND on park resources must be incorporated into the FOR PARKS OF THE
RESEARCH INFOFNA- setting of priorities. If these data are unavail- able, obtaining information on air quality related REGION
TION ON RESOURCE resources may be the most pressing need. If the SUSCEPTIBILITY resource inventories are available, then the in- formation from these inventories is used in the comparison between resources present and those OTHER INFLUENCES OR CONSTRAINTS presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. 2~hysicalScientist and Environmental Protec- tion Specialists, Denver Service Center, National Park Service, U.S. Department of Interior, Denver, Colorado. PRIORITIZE RESEARCH NEEDS Figure I--Considerations in setting research priorities for air quality related resources. Estimation of Adverse Effects of Air Pollution on Danish Forests1
I b Johnsen
E f f e c t s o f a i r p o l l u t i o n on Danish f o r e s t s do
p r o b a b l y o n l y o c c u r under c o n d i t i o n s , where SO2,
NO,, a n d / o r 0 3 a r e p r e s e n t t o g e t h e r , t h u s r e s u l t i n g in s y n e r g i s t i c a c t i o n on t h e l e a v e s . The
maximum observed monthly a v e r a g e urban immission
o f NOx and SO2 a r e w i t h i n t h e r a n g e f o r synerg i s t i c action hereof. I n r u r a l regions only the
most s e n s i t i v e s p e c i e s may b e a f f e c t e d by combin a t i o n s of S02, NOx and 03. Oxidants, and 0 3 i n
p a r t i c u l a r , p r o b a b l y p l a y a s t r o n g e r r o l e in
r u r a l a r e a s s i t u a t e d in t h e o u t e r p e r i p h e r y o f
c i t i e s . Here l e v e l s exceeding t h e v a l u e s a t
which e f f e c t s on r a t h e r s e n s i t i v e s p e c i e s occas i o n a l l y o c c u r d u r i n g summer time. Unstable
s u p e r a d i a b a t i c c o n d i t i o n s combined w i t h h i g h
i n s o l a t i o n l e a d t o h i g h 0 3 formation r a t e s , and
h i g h ground l e v e l S O ~ / N O l~e v e l s a r e observed
when h i g h s t a c k e m i s s i o n s a r e t r a n s p o r t e d t o t h e
ground r e l a t i v e l y c l o s e t o t h e s o u r c e .
Fluorides a r e only
s t r i c t e d a r e a s around
izer industries etc. ,
i n r e l a t i o n t o Danish
o f importance in v e r y rebrick factories, f e r t i l and o f minor s i g n i f i c a n c e
forestry.
Heavy m e t a l s and hydrogen i o n s r e s u l t i n
i n d i r e c t e f f e c t s a s a d v e r s e e f f e c t s on t h e n u t r i e n t s t a t u s of t h e s o i l and t h e s o i l m i c r o b i a l
p r o c e s s e s . The map shows a r e a s of Denmark
(shaded a r e a s ) where t h e s o i l i s b e l i e v e d t o b e
most v u l n e r a b l e t o a c i d p r e c i p i t a t i o n ; i t i s
r e a s o n a b l e t o b e l i e v e t h a t t h e s e a r e a s a r e coi n c i d e n t w i t h t h o s e e x p e c t e d t o b e most a f f e c t e d
by i n c r e a s i n g heavy m e t a l l e v e l s in t o p s o i l due
t o a t m o s p h e r i c f a l l o u t . The most v u l n e r a b l e
s o i l s a r e i n t e r m e d i a t e between t h e v e r y podz o l i s e d s o i l s o f t h e a l l u v i a l p l a i n s (Western
J u t l a n d ) and brown e a r t h s / c l a y i s h s o i l s w i t h high
b u f f e r c a p a c i t y , and are c h a r a c t e r i z e d by t h e i r
h i g h c o n t e n t o f moraine sand.
2
Areas of woodland in Denmark r e l a t e d t o s p e c i e s .
( Numbers in 1000 ha. )
1976.
Fagus
silvatica
75
Res
Quercus r o b u r
25
Res.
Fraxinus e x c e l s i o r
9
Sens.
5
Res.
Acer psuedoplatanus
Other deciduous spp.
24
Deciduous t o t a l
138
.
Picea abies
Picea s i t c h e n s i s
Abies spp
P i n u s mugo
Other c o n i f e r o u s spp.
Coniferous t o t a l
173
27
30
46
276
Woodland t o t a l
4 14
.
-
Sens.
sens.
Sens.
Res.
Immission l e v e l s and t h r e s h o l d v a l u e s
-
O3
Urban
Rural
Single
-3
(ugm , d i u r n a l means)
40-100.
50-100
25-50
10-40
5-20
25-200
250
100
Comb.
100
500
50
50
100
F
0.5-5
0.2-0.5
1
50
50
p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate
F o r e s t Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
A s s o c i a t e P r o f e s s o r o f P l a n t Ecology,
U n i v e r s i t y of Copenhagen, Denmark.
F i g u r e I--Areas of Denmark (shaded a r e a s )
dominated by moraine sand d e p o s i t s .
Changes in Southern Wisconsin White Pine Stands Related to Air Pollution Sensitivity1 David F. ~ a r n o s k y ~
F i f t e e n e a s t e r n white pine (Pinus strobus L. )
sample p l o t s c o n s i s t i n g of a t o t a l of 1523 t r e e s
were e s t a b l i s h e d within a 1 3 km r a d i u s of t h e
coal-burning 1054 MW Columbia Generating S t a t i o n ,
located 40 km north of Madison, Wisconsin. The
sample p l o t s were e s t a b l i s h e d i n 1971 and observed
f r e q u e n t l y during t h e growing season f o r 4 years
and then annually a t t h e end of each growing season
f o r t h e next 5 years. These p l o t s consisted of
p l a n t a t i o n s with t r e e s having uniform ages within
each p l a n t a t i o n but with t r e e s ranging i n age from
1 0 t o 40 years old across t h e 15 p l o t s . Baseline
study during t h e 4 years 'before t h e p l a n t began
operation i n 1975 showed t h a t some 1 0 percent of
t h e white pine t r e e s were s e n s i t i v e i n some degree
t o ambient a i r p o l l u t i o n a s determined by t h e
presence of needle t i p h r n and/or c h l o r o t i c dwarf
symptoms i n one o r more years. The s e n s i t i v e
t r e e s occurred randomly i n t h e p l o t s .
The most common type of a i r p o l l u t i o n symptom
found i n t h e 'baseline study was tipburn c o n s i s t i n g
of reddish brown dieback (0.1 t o 3 cm i n l e n g t h )
on f i r s t - y e a r needle t i p s . The s e v e r i t y of symptoms v a r i e d from t r e e t o t r e e and from year t o
year. The most severely a f f e c t e d t r e e s had
stunted t o p s , s h o r t needles, poor needle r e t e n t i o n ,
and were c h a r a c t e r i s t i c of an a i r pollution-induced
syndrome c a l l e d t h e c h l o r o t i c dwarf disease.
However, c h l o r o t i c mottling of new needles, common t o t h e c h l o r o t i c dwarf disease., did not occur.
Tipburn symptom development u s u a l l y began during
t h e e a r l y summer when t h e new needles were elongating. Thus, t r e e s 'began showing symptoms i n
e a r l y t o mid June, and symptoms developed throughout t h e growing season.
1
Continuous a i r monitoring f o r s u l f u r dioxide
('SO2) and ozone t o 3 ) , 'begun i n 1973 and continued
t o t h e present time, revealed t h e common occurrence of SO2 and O-; concentrations i n t h e range
of 0.4 t o 5.0 pphm f o r 1 t o 3 hours during t h e
summer months. Maximum one-hour averages recorded
during t h e study were 11 pphm SO2 and 1 3 pphm 03.
These l e v e l s , while low i n terms of a i r q u a l i t y
standards, have "been shown t o be within t h e range
of concentrations of t h e s e p o l l u t a n t s reported t o
i n j u r e g e n e t i c a l l y s e n s i t i v e e a s t e r n white pine
t r e e s i n c o n t r o l l e d fumigations.
p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate Forest
Ecosystems, June 22-27, 2980, Riverside,
C a l i f o r n i a , U.S.A.
o ore st
G e n e t i c i s t , New York Botanical
Garden Cary Arboretum, Millbrook, N.Y.
During t h e 5 years since t h e power p l a n t began
operation, t h e r e have been no d e t e c t a b l e d i f f e r ences i n t h e occurrence o r s e v e r i t y of symptoms.
With only a few exceptions, t h e same t r e e s have
shown symptoms a f t e r t h e p l a n t began operation a s
before it s t a r t e d . However, m o r t a l i t y has reduced
intermediate genotypes (those i n j u r e d i n 1 o r 2
years of t h e 9 year study) by 4.7 percent and t h e
s e n s i t i v e genotypes (those i n j u r e d i n 3 o r more
y e a r s ) by 10.4 percent (Table 1 ) . I n comparison,
only 2.0 percent of t h e t o l e r a n t t r e e s have died
during t h e course of t h e study. Most of t h e mort a l i t y of t h e s e n s i t i v e genotypes was apparently
due t o t h e i r being slower growing and t h u s unable
t o compete f o r l i g h t , water, and n u t r i e n t s with
t h e i r neighboring t r e e s . As a r e s u l t , t h e white
pine stands studied a r e undergoing a gradual t r a n s i t i o n towards having a i r - p o l l u t i o n t o l e r a n t genotypes dominate.
Acknowledgments: This study was supported i n
p a r t by Grant R803971, Environmental Protection
Agency, and by t h e Wisconsin Pi-iblic Service
Corp., t h e Madison Gas and E l e c t r i c Co., t h e W i s consin Power and Light Co., and t h e College of
A g r i c u l t u r a l and L i f e Sciences, University of
Wisconsin.
Table I ~ M o r t a l i t yover a 9-year period of e a s t ern white pine t r e e s d i f f e r i n g i n a i r p o l l u t i o n
sensitivity.
Air
Pollution
sensitivity1
If Trees
Died
Mortality
Tolerant
Intermediate
Sensitive
Totals :
l ~ h es e n s i t i v i t y rankings were based on t h e
following: t o l e r a n t t r e e s did not have a i r pollution-induced t i p b u r n symptoms during t h e
course of t h e study; intermediate t r e e s had
symptoms f o r 1 o r 2 y e a r s ; and s e n s i t i v e t r e e s
had symptoms f o r 3 o r more years.
Effect of Os and Os + NO2 on Growth of Tree Seedlings1
Lance W. ~ r e s s ~
Seedlings of 10 eastern forest tree species were Table 1. Height growth and dry weight expressed as exposed to 0.05, 0.10, or 0.15 pprn 0 and seedlings percent of control for seedlings of 10 tree species of 7 tree species were exposed to 0.10 pprn 0 and/or exposed to 0.05, 0.10, or 0.15 pprn 0 for 6 hr/day 3
3
0.10 pprn NO in 6 hr/day exposures for 28 consecu- for 28 consecutive days. 2
tive days. The exposures were performed when the Percent of control seedlings were 2-4wk-old in indoor exposure chambers of the CSTR design. Species
The Environmental Protection Agency has deter- Loblolly Pine
'100a
looa
lOOa
mined that the threshold for significant growth (Pinus taeda L.)
90ab
82 b
85ab
effects due to extended 0 exposures (7 hr daily 73 b
79 b
72 bc
3
avg. for 2 no) for sensitxve vegetation is between 59 c
74 b
64 c
0.06 and 0.10 ppm. Three species in this study ex- Pitch Pine
lOOa
lOOa
lOOa
hibited a threshold for significant suppressions in rigida Mill. )
96ab
94a
84ab
(P.that range, while three other species exhibited a 77ab
87 b
83a
threshold for significant effects between 0.10 and 68 b
74
c
78a
0.15 pprn (Table 1). However, two species exhibited Virginia Pine
lOOa
lOOa
lOOa
a threshold for significant growth suppressions at 120a
95a
98a
(L
virginiana
or below 0.05 ppm. Those two species, loblolly pine Mill. )
93a
89a
97a
and American sycamore, are probably the most im- 86a
86a
87a
portant of the species tested to the forest industry. Sweetgum
l60a
lOOa
lOOa
The significant effects at 0.05 pprn 0 were not 3
(Liauidambar
88ab
109a
9lab
accompanied by foliar injury. styraciflua L.)
65 bc
71 b
76ab
In previous studies there have been indications 52 c
55 b
60 b
that low concentrations of NO might be stimulatory Sycamore
lOOa
lOOa
lOOa
2
to plant growth or alleviate 0 phytotoxicity.
(Platanus
57 b
104a
84a
3
Similar indications were noted for some of the tree occidentalis L.)
27 b
43 b
73 b
species in this study. Two species (white ash and 19 b
36 b
79 b
green ash) exhibited greater growth in the NO
Green Ash
lOOa
lOOa
lOOa
2
treatment than the control, and the only significant (Lpennsylvanica
86ab
86a
98ab
interactive effects were significantly less than Marsh. )
7lab
75a
76 bc
additive (sweetgum and white ash). 75a
64 b
70 c
White Ash
100 b
lOOab
lOOa
Stimulations of growth at low 0 concentrations
3
{Fraxinus
125a
112a
11la
have been noted in the past, and some species ex- americana L.)
91a
92 b
87 b
hibited growth stimulations in this study (Table 1).
85a
83
b
81 b
However, apparent growth stimulations appear to be 1 OOa
Willow Oak
lOOa
lOOa
dependent in part on the plant species and the (Quercus phellos
99a
99a
94a
parameter being evaluated. 83a
96a
92a
L. )
The relationship that these data have to field 89a
83a
81 b
conditions is not clear. This study demonstrates Sugar Maple
lOOa
100 b
1OOab
the potential for adverse effects at pollutant con- 95 b
88a
161a
(&
saccharum
centrations below the current NAAQS, but future 90a
116ab
108a
L.)
research will have to determine whether such effects 58b
88 c
69 b
can be detected in the field. Yellow Poplar
100 b
100 b
1OOa
(Liriodendron
160a
147a
133a
tulipifera L.1
108 b
11lab
96a
presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, Values for each column/species followed by the California, U.S.A. same letter are not different at p = 0.05 according
to the ~uncan'sNew Multiple Range Test. '~esearch Associate of Plant Pathology, Vir- ginia Tech., Blacksburg, Va. Currently Assistant Ecologist, Argonne National Laboratory, Argonne, 111. Impact of Oxidant Air Pollution on Ponderosa and Jeffrey Pine Cone Production1 Robert F. ~ u c k ~
Cone p r o d u c t i o n by ponderosa and J e f f r e y p i n e
t r e e s 10 cm o r more i n dbh was a s s e s s e d on 19
p l o t s l o c a t e d i n t h e San Bernardino Mountains o f
s o u t h e r n C a l i f o r n i a . These p l o t s were e s t a b l i s h e d along a gradient of oxidant a i r p o l l u t i o n .
Each t r e e was r a t e d a n n u a l l y u s i n g an o x i d a n t a i r
p o l l u t i o n index based upon t h e number o f y e a r
c l a s s e s o f n e e d l e s r e t a i n e d , t h e i r c h l o r o t i c cond i t i o n , t h e i r l e n g t h and t h e amount o f branch
m o r t a l i t y p r e s e n t . T h i s r a t i n g was made i n d e p e n d e n t l y i n t h e upper and lower crown f o r each
t r e e . Other t r e e c h a r a c t e r i s t i c s , e . g . , age,
dbh, h e i g h t , were a l s o measured once d u r i n g t h e
c o u r s e o f t h e 6 y e a r s t u d y . Cones were v i s u a l l y
counted w i t h i n t h e crown o f each t r e e each
September and October.
100
z
3
40
aw 0a
2o
Three p a t t e r n s were observed: (1) I n dominant
J e f f r e y p i n e s 130 y e a r s o r o l d e r fewer s e v e r e l y
i n j u r e d t r e e s b o r e cones t h a n u n i n j u r e d ones
( l b F ( 4 , 25) = 1 1 . 9 8 , p < 0.05) ; (2) i n dominant
ponderosa p i n e s 130 y e a r s o r o l d e r s e v e r e l y i n j u r e d t r e e s b o r e fewer c o n e s / t r e e t h a n u n i n j u r e d
ones (2a x2
= 21.07, p < 0.005) ; and (3) i n
f4l
b o t h dominant and codominant J e f f r e y and ponderosa pines severely i n j u r e d t r e e s bore s i g n i f i c a n t l y fewer cone c r o p s t h a n u n i n j u r e d ones duri n g t h e 6 y e a r s o f t h e s t u d y ( x 2 ' s v a l u e s < 0.01
i n 5 c a s e s , < 0.05 i n 1 c a s e ) .
-
' p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on M e d i t e r r a n e a n and Temperate F o r e s t
Ecosystems, J u n e 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
a s s o c i a t e P r o f e s s o r o f Entomology. D i v i s i o n
of Biological Control, University of California,
Riverside, C a l i f .
z
CÂ¥
O 0-1
4
3
2
5
JEFFREY PINE
¤
M
80
*
a
60
0 U
0" 40
CK
Although s e v e r e o x i d a n t a i r p o l l u t i o n i n j u r y
was a s s o c i a t e d w i t h reduced cone p r o d u c t i o n , t h e
most i m p o r t a n t c o r r e l a t e w i t h cone p r o d u c t i o n
was crown c l a s s , i . e . , t h e p o s i t i o n o f a t r e e ' s
crown r e l a t i v e t o t h o s e o f i t s n e i g h b o r s . Dominant t r e e s bore t h e g r e a t e s t proportion of
cones. I n ponderosa p i n e dominant t r e e s comp r i s e d 32 p e r c e n t o f t h o s e p r e s e n t on t h e 19
p l o t s b u t b o r e 80 p e r c e n t o f t h e cones. When t h e
dominant and codominant crown c l a s s e s were combined t h e y comprised 58 p e r c e n t o f t h e ponderosa
p i n e s b u t b o r e 96 p e r c e n t o f t h e cones. J e f f r e y
p i n e showed a similar p a t t e r n . I n b o t h J e f f r e y
and ponderosa p i n e , cone p r o d u c t i o n i n c r e a s e d
s i g n i f i c a n t l y w i t h age (Ho:b=O: ponderosa p i n e ;
dominant: 7 = -92.33 + 1 . 8 6 (Age), r2 = 0.811**;
codominant: 7 = -74.48 + 1.077 (Age), r2 =
0.4216*: J e f f r e y p i n e ; dominant: 7 = 4.74 + 0.434
(Age), r2 = 0.765**; codominant: 7 = -8.28. +
0.243 (Age), r2 = 0.7456**).
80
60
w
Or
PONDEROSA PINE
0
a -I
Q_
20
0
1
2
3
4
5
100
8 o PONDEROSA PINE
100
JEFFREY PINE
SLIGHT
SEVERE
SMOG INDEX
F i g . 1. P r o p o r t i o n o f t r e e s producing cones
i n a given smog c l a s s .
( a ) Ponderosa p i n e ; (b)
J e f f r e y pine.
F i g . 2. P r o p o r t i o n o f c o n e s / t r e e borne by
t r e e belonging t o a given smog c l a s s . ( a ) Pondero s a p i n e ; (b) J e f f r e y p i n e .
Lichens as Air Quality Monitors1
P.D. Lulman
.
R J . Fessende
9
S.A. McKinnon
The Athabasca t a r s a n d s , l o c a t e d i n a remote
region i n n o r t h e a s t e r n A l b e r t a , i n t h e b o r e a l
f o r e s t r e g i o n o f Canada, c o n t a i n v a s t r e s e r v e s
(approx. 600 b i l l i o n b a r r e l s ) o f bitumen. A t t h e
p r e s e n t time t h e r e a r e o n l y 2 companies o p e r a t i n g
i n t h e r e g i o n , producing s y n t h e t i c crude o i l from
t h i s bitumen, Suncor I n c . and Syncrude Canada Ltd.
Suncor, which began production i n 1967, e m i t s
approximately 200-300 tonnes o f SO2 p e r day.
Syncr-ide, which began production i n 1978 and
which i s l o c a t e d o n l y 10 km from Suncor, h a s been
e m i t t i n g about 50-100 tonnes p e r day. I n t h e
n e x t 10-20 y e a r s t h e r e i s a good p o s s i b i l i t y t h a t
many more companies w i l l begin o p e r a t i n g i n t h e
r e g i o n a s w e l l . T h i s h a s l e a d t o a concern about
t h e e f f e c t s o f changes i n a i r q u a l i t y on t h e
vegetation of the region. Since lichens a r e
known t o be more s e n s i t i v e t o a i r p o l l u t a n t s ,
p a r t i c u l a r l y SO2, t h a n most h i g h e r v e g e t a t i o n , i t
was decided t o monitor changes i n l i c h e n growth
a s an e a r l y warning o f t h e impact o f p o l l u t a n t s
on a l l components o f t h e v e g e t a t i o n .
I n 1976, Syncrude Canada Ltd. i n s t a l l e d a n e t work o f 56 permanent p l o t s i n a r a d i a t i n g p a t t e r n
c e n t e r e d on t h e 2 o p e r a t i o n s and a t d i s t a n c e s o f
up t o 47 km. Within each p l o t 20, 200 cm perman e n t a u a d r a t s c o n t a i n i n a t h a l l i o f Parmelia s u l cats o r Hypogymnia physodes, 2 abundant barkl i c h e n s , were e s t a b l i s h e d and photographed. Most
o f t h e & a d r a t s were e s t a b l i s h e d o n w h i t e s p r u c e
(-P i c e a e l a u c a . a 1thouah a s m a l l e r number w i r e
e s t a b l i s h e d on' balsam f i r (Abies balsamea) and
? photographs
white birch (Betula papyrifera).
were p r o j e c t e d an
surface areas of selected
l i c h e n t h a l l i were measured. I n 1979, a l l o f t h e
q u a d r a t s i n 12 s e l e c t e d p l o t s were rephotographed
and t h e photographs analyzed a s b e f o r e . The obj e c t i v e s o f t h i s p a r t i a l resurvey were ( a ) t o
measure changes i n t h e s u r f a c e a r e a o f t h a l l i o f
P. s u l c a t a , t h e dominant l i c h e n s p e c i e s , i n t h e
3 y e a r p e r i o d 1976-1979, ( b ) t o t e s t t h e s i g n i f i cance o f t h e s e changes a s a f u n c t i o n o f d i s t a n c e
-
-
- -
P r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
~ n v i r o n m e n t a l i s t , Calgary Power L t d . ,
Calgary, A l b e r t a , Canada, formerly, Research
A s s o c i a t e , LGL L t d . , Environmental Research
A s s o c i a t e s , Edmonton, A l b e r t a , Canada; Head,
T e r r e s t r i a l Environment S e c t i o n and Research
A s s i s t a n t , Environmental A f f a i r s Dept., Syncrude
Canada L t d . , Edmonton, A l b e r t a , Canada.
and/or d i r e c t i o n from t h e emission s o u r c e s , and
( c ) t o assess the p r a c t i c a b i l i t y of the l i c h e n
network a s a l o n g term monitoring system f o r
d e t e c t i n g a i r q u a l i t y impacts on v e g e t a t i o n .
There was a s i g n i f i c a n t i n c r e a s e i n p r o j e c t e d
thallus surface area i n 6 plots, a significant
d e c r e a s e i n 2 p l o t s , and no s i g n i f i c a n t change i n
4 p l o t s . I n most c a s e s t h e n e t change i n l i c h e n
s u r f a c e a r e a d u r i n g t h e 3 y e a r p e r i o d was l e s s
than 10%. However, w i t h i n - p l o t v a r i a b i l i t y was
very l a r g e w i t h c o e f f i c i e n t s o f v a r i a t i o n commonl y between 300-400%. The changes i n p r o j e c t e d
t h a l l u s s u r f a c e a r e a were s i g n i f i c a n t l y b u t
weakly, r e l a t e d t o d i s t a n c e ; t h e t h a l l i c l o s e s t
t o t h e emission s o u r c e s i n c r e a s i n g more i n a r e a
than t h o s e a t a d i s t a n c e , where i n f a c t t h e r e was
a n e t d e c r e a s e i n s u r f a c e a r e a on t h e average.F i e l d o b s e r v a t i o n s i n d i c a t e d t h a t t h e r e was no
r e l a t i o n s h i p between l i c h e n c o l o r and/or v i g o r
and d i s t a n c e and/or d i r e c t i o n from t h e emission
s o u r c e . It was e v i d e n t i n a comparison o f t h e
1976 and 1 9 7 9 p a i r e d photographs t h a t t h e r e was
a s i g n i f i c a n t l o s s o f whole t h a l l i and p o r t i o n s
o f t h a l l i from most o f t h e q u a d r a t s . It was n o t
unusual f o r 10-20% o f t h e t h a l l i p r e s e n t i n 1976
t o be m i s s i n g i n 1979. T h i s appeared t o be p r i m a r i l y r e l a t e d t o t h e n a t u r a l p r o c e s s o f bark
e x f o l i a t i o n , although animal a c t i v i t y and i n s e c t
g r a z i n g a r e a l s o suspected c a u s e s .
T h i s technique i s capable o f d e t e c t i n g s i g n i f i c a n t changes i n t h e s u r f a c e a r e a o f P. s u l c a t a
t h a l l i o v e r a 3 y e a r p e r i o d , however, i t r e q u i r e s
c a r e f u l s t a n d a r d i z a t i o n and a l a r g e number o f
samples due t o t h e l a r g e w i t h i n - p l o t v a r i a b i l i t y
i n t h i s c h a r a c t e r i s t i c . The h i g h v a r i a b i l i t y i s
r e l a t e d t o t h e r a t h e r non-uniform arowth o f t h e
P. s u l c a t a t h a l l u s a s w e l l a s t h e v a r i e t y o f
n a t u r a l processes causing l o s s e s of portions of
t h e t h a l l u s . Perhaps o t h e r a t t r i b u t e s o f t h e
t h a l l u s would make b e t t e r i n d i c e s o f growth ( o r
l a c k o f growth), however, none were i n v e s t i g a t e d .
The e x t e n s i v e l o s s e s o f whole t h a l l i r a i s e quest i o n s about t h e permanence o f t h i s system and
hence i t s v a l u e a s a l o n g term monitoring system.
Because t h e predominant reason f o r t h a l l u s l o s s
i s bark e x f o l i a t i o n , t h i s problem i s very much
r e l a t e d t o t r e e s p e c i e s . Spruce a r e p a r t i c u l a r l y
bad i n t h i s r e g a r d . There was very l i t t l e t h a l l u s l o s s from b i r c h o r f i r . Notwithstanding t h e
above d i f f i c u l t i e s , i t was concluded t h a t t h e r e
was no a i r q u a l i t y caused damage t o P. s u l c a t a
between 1976 and 1979 a s i n f e r r e d from t h e relat i o n s h i p s between t h e n e t change i n t h a l l i s u r f a c e a r e a and d i s t a n c e and/or d i r e c t i o n from t h e
e m i s s i o n s o u r c e s . T h i s conclusion i s supported
by f i e l d o b s e r v a t i o n s of l i c h e n c o l o r and v i g-o r .
Acid Precipitation in California and Some Ecological Effects1
John G. McColl and Mary K. Firestone
Wet and d r y p r e c i p i t a t i o n s were monitored on
an event b a s i s i n 1978-9 a t Berkeley and San Jose
( p o l l u t i o n source areas i n t h e San Francisco Bay
area) , Davis and Par1 i e r ( i n t h e c e n t r a l a g r i c u l t u r a l and rangelands) , Chal lenqe ( l o w e r S i e r r a n
f o r e s t ) , and Tahoe C i t y (on t h e shore o f Lake
Tahoe)
Concentrations o f t h i r t e e n i o n i c species
and s p e c i f i c conductance and volume were measured
(Table 1 ) .
A c i d r a i n (pH < 5.6) was common a t a l l e i g h t
s i t e s . Mean pH o f storms v a r i e d from 4.24 a t San
Jose t o 5.20 a t Davis, and t h e l o w e s t pH o f any
storm was 3.71 a t San Jose. The primary cause o f
t h e a c i d i t y was probably t h e a i r p o l l u t a n t NOxy
f o l l o w i n g i t s d i s s o l u t i o n i n wet p r e c i p i t a t i o n .
NO? was t h e anion most c l o s e l y c o r r e l a t e d w i t h H',
and NO3 g e n e r a l l y occurred i n g r e a t e r concent r a t i o n than SO$-.
T o t a l d r y d e p o s i t i o n s o f chemical c o n s t i t u e n t s
between rainstorms were o f t h e same o r d e r as t o t a l
wet d e p o s i t i o n s d u r i n g storms. Dry d e p o s i t i o n
d u r i n q summer would g r e a t l y increase t h e amounts
recorded i n t h i s study which was conducted i n t h e
wet season o n l y . However, more research i s needed
i n procedures f o r q u a n t i f y i n g d r y atmospheric
deposition.
A1 though NOS c o n c e n t r a t i o n (pg/1) and a c i d i t y
(H" c o n c e n t r a t i o n , p g / l ) of wet p r e c i p i t a t i o n were
g r e a t e s t i n p o l l u t i o n source areas, t o t a l depos i t i o n ( k g l h a ) o f NO3 and H+ were g r e a t e s t i n t h e
non-urban r e c e p t o r areas o f Napa and Chal lenqe;
t h i s was l a r g e l y a f u n c t i o n o f t h e g r e a t e r p r e c i p i t a t i o n volumes a t these two s i t e s (Table 1 ) .
Thus e c o l o g i c a l e f f e c t s may be expected i n t h e
coast ranges and S i e r r a s w i t h i n t h e g e n e r a l eastto-west "wash-out f a n " o f wet p r e c i p i t a t i o n , as
w e l l as w i t h i n p o l l ution-source areas.
E f f e c t s o f these a c i d i n p u t s t o C a l i f o r n i a
s o i l s are c u r r e n t l y b e i n g assessed. These invest i g a t i o n s on s o i l e f f e c t s i n c l u d e research on both
t h e i n o r g a n i c phase o f s o i l and on t h e o r q a n i c l b i o l o q i c a l components.
.
'
p r e s e n t e d a t t h e Symposium on Effects of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
~ s s o c i a t eProfessor of S o i l Science and
Associate S p e c i a l i s t i n S o i l Microbiology,
r e s p e c t i v e l y , U n i v e r s i t y o f C a l i f o r n i a , Berkeley,
C a l i f o r n i a , U.S.A.
2
Table 1 --Mean i o n i c concentrations o f wet p r e c i p i t a t i o n d u r i n g the study p e r i o d i n 1978-9 (peqI1).
H' (Lab.)
~ a +
K+
~a2+
kJ2+
~ e3+
~ n2+
cu2+
zn2+
NH;
NO;
ClSO-:
22.1 6.8 10.9
36.9 11.8 15.3
1.5 0.6 1.4
6.0 4.3 8.0
9.6 1.7 3.6
0.3 0.0 0.6
0.1 0.0 0.1
0.1 0.1 0.1
0.3 0.1 0.2
8.0 4.1 40.0
13.0
12.8
2.1
10.9
7.0
0.4
0.6
0.2
0.2
11.9
38.0 7.9 6.3 14.6
33.1 14.5 15.1 22.0
1.5 1.1 1.1 1.4
12.6 3.3 5.6 4.6
9.7 3.8 5.7 5.3
0.8 0.2 0.4 0.4
3.1 0.1 0.1 0.1
0.3 0.1 0.2 0.7
0.6 0.1 0.1 0.2
19.1 9.7 35.5 12.1
13.7 6.7 43.4
40.1 3.7 11.2
10.2 13.3 13.8
19.9 16.4 11.1 22.6 16.4
7.7 38.9 14.2 14.0 -23.1
8.6 10.0 6.2 19.0 11 .7
.
Cond
(pmho/cm) 13.9 .3.9 17.4 10.6 16.2 6.4 9.6 10.7
pH (Lab.) 4.7 5.2 4.7
4.9 4.4 5.1 5.2 4.8
Vol. (cm) 52.7 78.0 19.7 110.7 21.0 64.9 39.7 62.0
'BE Berkeley, TC Tahoe C i t y , KE Kearny ( f i e l d
s t a t i o n a t par1 ier) , CH Challenge, SJ San Jose, HO
Hop1and, DA Davis , and NA Napa
.
I n t h e i n o r g a n i c s o i l -chemical s t u d i e s , s o i l s
c o v e r i n g a wide range o f p a r e n t m a t e r i a l s and age
are b e i n a t r e a t e d w i t h a c i d i n p u t s , and t h e subsequent l e a c h i n g p a t t e r n s o f i o n s ( i n c l u d i n g ~ l + 3 ,
H+, Nat, K+, Mg++, Ca^) are b e i n g determined.
The b i o l o g i c a l i n v e s t i g a t i o n s i n c l u d e assessment o f p o s s i b l e e f f e c t s on t h e s o i l - p l a n t
n u t r i e n t system. The f i r s t 10-week p o t - t r i a l ,
u s i n g a Yolo s e r i e s s o i l and qrowina b a r l e y and
c l o v e r , has j u s t been completed. Prel i m i n a r y
r e s u l t s i n d i c a t e marked qrowth increases i n t r e a t ments where t h e p l a n t s were sprayed w i t h s o l u t i o n s
o f pH 2.0 and 3.0.
This r e s u l t i s a t t r i b u t e d t o
g r e a t e r a d d i t i o n s o f SO^- and NO?, and/or t o
increased a v a i l a b i l it y of s o i l n u t r i e n t s i n these
lower-pH treatments. However, s p o t t i n g o r leaves
by a c i d d r o p l e t s a l s o occurred i n t h e pH 2.0
treatments. N i t r i f i c a t i o n , deni t r i f i c a t i o n and
n i t r o g e n f i x a t i o n a c t i v i t i e s are b e i n g measured i n
b o t h t h e rhizosphere and non-rhi zosphere s o i l
.
Leaf Litter Decomposition in the Vicinity of a Zinc Refinery Emmissions from a large zinc refinery in north- ern Ontario have been monitored for 10 years and an accumulation of zinc, copper, cadmium, arsenic and lead in the soil and vegetation surrounding the refinery complex has been documented. It was considered that decomposition of leaf litter as a part of the nutrient cycling process might be a convenient method to monitor the initial impact of these metals on the environment. This inves- tigation was undertaken in the fall of 1977. Ny-
lon mesh bags containing 10 q (oven-dry weight) of trembling aspen (Populus tremuloides) were set out at several locations around the refinery. Two sources of aspen foliage were utilized inclu- ding foliage from a control location and conta- minated foliage collected near the refinery. The exposure locations for the litter bags included three sites in close proximity to the refinery, (Plot A, B, C ) one site 2.2 km from the refinery
(Plot D) and one at a control location (80 km southwest of the refinery) (Plot E) .
The litter bags were allowed to over-winter and triplicate bags of each litter type were col- lected in May, June and August of 1978 and in May, July and August in 1979. Microarthropods were extracted from the bags in modified Tulgren funnels in the laboratory. The litter was then dried to determine the leaf weight loss and pro- cessed for chemical analysis. It was found that the rate of decomposition of the leaf litter was lower at sites nearest to the refinery and that contaminated foliage de- composed more slowly than control foliage at all sites. The microarthropod population was domi- nated by mites and springtails. The number of microarthropods was generally lower at the sites nearest to the refinery and was also lower in the litter baqs containing the contaminated foliage. The numbers of microarthropods appeared to fluc- tuate with moisture content of the litter. It was found that the concentrations of zinc, copper, cadmium, lead, arsenic, iron, sulphur and sele- nium in the leaf litter increased with time at the sites nearest to the zinc refinery but only a slight increase was noted at the more distant sites. -
'
z
Im
g
60"
PLOT NO
A
CONTAMINATED LITTER ..*-*.
CONTROL LITTER
-
45-
0
a 30I-
z
;
15-
u n NOV
MAY
1977
JUN
AUG
MAY
1978
JUL
AUG 1979
Figure 1. Pattern of decomposition of two types of leaf litter at two sites. presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. plant Pathologist, Ministry of the Environment, 199 Larch Street, Sudbury, Ontario, P3E 5P9. NOV
1977
MAY
JUN
1978
AUG
MAY
JUL AUG 1979
Figure 2. Zinc accumulation is typical of metal accumulation in leaf litter. Effects of Chronic Air Pollution Stress on Allocation of Photosynthate by White Pine
S. B. McLaughlin, R. K. McConathy, and D. Duvick2
A1 location of ^c-photosynthate by in s i t u
branches of nine field-grown white pine trees was
studied t o determine whether distribution patterns
differed between trees with apparent differences
in s e n s i t i v i t y to a i r pollution stress. Three
trees were selected in each of three sensitivity
classes which were differentiated on the basis of
needle length, mottling, and duration of retention. Previous studies (Mann e t a1. 1980) indicated that photosynthetic potential of foliage
from trees in these three classes was not significantly different. Growth ring analysis of
increment cores indicated that average annual
increment of intermediate and sensitive trees was
98% and 47%, respectively, of that attained by
the tolerant trees (7.8 mm y r - l ) over the past
18 years (Fig. 1 ). Sensitive trees showed a
marked decline in annual growth during the past
10 years.
Foliage was labelled with ^COz four times
during the growing season (June, July, August
and November). Of the paired branches from each
tree labelled on each date, one was harvested
a f t e r seven days and the remainder in November
a t the end of the growing season. Photosynthate
allocation patterns were compared by determining
levels of f o l i a r retention and allocation to
nearby branches. In June when elongating needles
were approximately 50%of t h e i r final length, ^ C
movement patterns in needles of three age classes
(Fig. 2 ) indicated that contribution of ^Cphotosynthate by old needles t o new needle growth
was occurring. This process was most rapid in
tolerant trees which retained needles from two
prior years and l e a s t significant in sensi tjve
trees. Lower levels of incorporation of photosynthate into f o l i a r tissues occurred subsequently (X = 35% in June, 27% in July, and 5% in
August a f t e r seven days). There were no d i s t i n c t
differences in f o l i a r retention of 1 4 C between
the three s e n s i t i v i t y classes which could be
associated w i t h the distribution of high levels
of ozone (1h avg > 0.08 ppm) near the study
area. ~ i g nfii c a n t 2-year-old needle retention
on tolerant trees did not extend beyond July.
Presented a t the Symposium on Effects of Air
Pollutants on Mediterranean and Temperate Forest
Ecosystems, June 22-27, 1980, Riverside,
California, U.S.A.
%search Staff llember, Research Associate,
and Technician, respectively, Terrestrial Ecology
Section, Environmental Sciences Division, Oak
Ridge National Laboratory, Oak Ridge, Tennessee,
U.S.A.
Generally higher levels of transfer of 1 4 c from
foliacje into branches were noted in the tolerant
trees throughout the growin season. Higher
levels of trans1 ocation of ^C-photosynthate out
of 1-year-01 d need1 es than current-year needles
were also found for a l l sensitivity classes.
Enhanced current needle elongation (+25%sensitive, +lo%intermediate, and +3% tolerant) compared to the previous year was associated with
lower than average ozone levels and higher than
average rainfall during the growing season. Data
support the hypothesis that growth limitations
in sensitive trees are a function of stressinduced reductions in photosynthate availability
which result from reduced needle length (a function of decreased availability of carbohydrates
for needle growth) and premature needle senescence. The resulting chronic decline of sensitive
trees i s likely a result of interactions between
a i r pollution stress and s i t e factors which may
include secondary belowground pathogens.
Acknowledgments: Research sponsored by the
U. S. Environmental Protection Agency under Interagency AgreementNo. 40-740-78 and the U.S.
Department of Energy under Contract W-7405-eng-26
with Union Carbide Corporation.
Literature Cited
Mann, L.
1980.
pine
Exp.
K., S. B. McLaughlin, and D. S. Shr i ner.
Seasonal physiological responses of white
under chronic a i r pollution stress. Env.
Bot. (in press).
240
1960'62
'â‚
'66 '68 '70 '72 '74 '76 '78 1980
YEAR
1
0
24
168
TIRE SINCE LABtLLIHt (m) F i g u r e I ( l e f t ) - - A v e r a g e annual d i a m e t e r g r o w t h
o f 3 t r e e s i n each o f 3 s e n s i t i v i t y c l a s s e s .
F i g u r e 2 ( r i g h t ) - - D i s t r i b u t i o n o f ^C p h o t o s y n t h a t e
i n f o l i a g e 0, I , and 7 days a f t e r ^cog u p t a k e i n
June.
Effects of SO2 and Ozone on Photosynthesis and Leaf Growth in Hybrid Poplar Reginald D. Noble
and
Keith F. ~ e n s e n 2
P l a n t s i n t h e n a t u r a l environment a r e o f t e n simultaneously exposed t o a combination of many atmospheric p o l l u t a n t s . Thus i t i s of i n t e r e s t t o asc e r t a i n t h e n a t u r e of i n t e r a c t i o n of t h e s e pollut a n t s on p l a n t development and metabolism.
Two poll u t a n t s commonly encountered i n t h e atmosphere which
a r e p a r t i c u l a r l y t o x i c t o p l a n t s and would appear
t o o f f e r p o t e n t i a l f o r i n t e r a c t i o n a r e SO2 and 03.
METHODS
P l a n t s of hybrid p o p l a r #207 (Populus d e l t o i d e s
t r i c h o c a r p a Torr. & Gray) were grown
Bartr. X
from c u t t i n g s under greenhouse c o n d i t i o n s . S i x
week o l d p l a n t s were fumigated i n c o n t r o l l e d environment chambers f o r 12 hours p e r day f o r 24 cons e c u t i v e days. Four s e t s of p l a n t s were used a s
follows : S e t 1-Controls (no fumigation) ; S e t 2-Fumigated with SO2 a t 0.5 ppm; S e t 3-Fumigated with
03 a t 0.25 ppm; S e t 4-Fumigated with SO2 a t 0.5
pprn p l u s O3 a t 0.25 ppm. A t t h e end of t h e 24-day
fumigation p e r i o d , number of l e a v e s p e r p l a n t , l e a f
f r e s h and d r y weight and l e a f a r e a were determined.
During t h e l a t e r s t a g e s of t h e fumigation, photosynt h e s i s measurements were determined f o r s i n g l e a t tached l e a v e s from p l a n t s fumigated with SO2 and
those fumigated with s02+03. Photosynthetic measurements were made a t ambient C02 l e v e l s (300 pprn
C02) and a t 1000 pprn C02.
P.
RESULTS
P l a n t s fumigated with SO2 showed l i t t l e v i s i b l e
evidence of i n j u r y while those fumigated with O3 o r
a combination of t h e two began t o develop t i n y nec r o t i c s p o t s a f t e r 5 t o 7 days of exposure. Soon
a f t e r lower l e a v e s began t o a b s c i s e and by 14 days
e x t e n s i v e i n j u r y was apparent on l e a v e s below t h e
7 t h node from t h e apex. Both O3 and S02+03 t r e a t ments caused a reduction i n t h e number of l e a v e s p e r
p l a n t ; however, t h e r a t e of l e a f formation was n o t
a f f e c t e d f o r t h e f o u r groups. The number of l e a v e s
p e r p l a n t was lower i n t h e O3 treatment group than
i n t h e S02+03 group, suggesting an a n t a g o n i s t i c
_L
Presented a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, Riverside,
C a l i f o r n i a , U.S.A.
p r o f e s s o r of B i o l o g i c a l Sciences, Bowling Green
S t a t e U n i v e r s i t y , Bowling Green, Ohio; Research
S c i e n t i s t , U.S. Department of A g r i c u l t u r e , F o r e s t
S e r v i c e , Delaware, Ohio.
r e l a t i o n s h i p . Fumigation tended t o cause a decrease
i n l e a f a r e a , l e a f dry weight and l e a f f r e s h weight.
This was i n c r e a s i n g l y t r u e a s t h e d i s t a n c e from t h e
p l a n t apex increased. P o l l u t a n t i n t e r a c t i o n evalu a t i o n s revealed an a n t a g o n i s t i c r e l a t i o n s h i p between t h e responses t o O3 and SO2. Ozone which r e tarded growth most had l i t t l e o r no e f f e c t on a r e a ,
dry o r f r e s h weight of l e a v e s above node 5; however,
t h e s e parameters were reduced by 25 t o 40 p e r c e n t
i n l e a v e s fumigated with O3 a t node 9.
These and
r e l a t e d observations demonstrate t h a t O3 r e t a r d s
growth of leaves i n t h i s p l a n t only during t h e l a t e r s t a g e s of t h e i r development.
Ozone fumigated
l e a v e s with v i s i b l e i n j u r y comparable t o t h o s e fumigated with both SO2 and O3 contained l e s s d r y
m a t t e r per u n i t a r e a .
Photosynthetic measurements on c o n t r o l s a s w e l l
a s p l a n t s fumigated with SO2 and S02+03 revealed
l i t t l e d i f f e r e n c e i n r a t e of C02 a s s i m i l a t i o n a t
Even i n l e a v e s of S02+03 fumigated
300 pprn COT
p l a n t s where v i s i b l e i n j u r y was e x t e n s i v e t h e
photosynthetic r a t e was reduced by only 10 t o 20
p e r c e n t . When t h e C02 c o n c e n t r a t i o n was e l e v a t e d
t o 1000 pprn C02 photosynthetic r a t e s f o r c o n t r o l s ,
SO2 fumigated and S02+03 fumigated l e a v e s (with no
v i s i b l e i n j u r y ) were e l e v a t e d three-fold t o approxI n l e a v e s i n which
imately 35 mg C02 dm'-hr-l.
i n j u r y was apparent t h e photosynthetic r a t e i n c r e a s e s were u s u a l l y l e s s than two-fold, t o a l e v e l of
approximately 1 8 mg C02 dm-2hr-1 (whether t h e injury was severe or barely discernable).
DISCUSSION
Ozone, and O3 i n combination with SO2 h a s t e n
senescence and promote r a t e of l e a f drop t o t h e
e x t e n t t h a t c o n t r o l p l a n t s have approximately 50
p e r c e n t more l e a v e s than fumigated ones. Fumigat i o n with SO2 causes no such e f f e c t . Analysis of
a t t a c h e d l e a v e s f o r treatment e f f e c t s c l e a r l y shows
an O3 e f f e c t b u t l i t t l e o r no SO2 e f f e c t .
I n combination these pollutants a t t h i s concentration
i n t e r a c t i n an a n t a g o n i s t i c manner i n r e l a t i o n t o
growth parameters.
Measurements of e f f e c t s of fumigation on photos y n t h e s i s i n d i c a t e t h a t l e a f photosynthesis i s n o t
d r a s t i c a l l y reduced even i n t h e presence of cons i d e r a b l e i n j u r y . I t appears t h a t i n j u r y tends
t o reduce l e a f p o t e n t i a l t o respond t o enhancement c o n d i t i o n s more s o than t h e a b i l i t y t o f i x
C02 under c o n d i t i o n s where C02 may be l i m i t i n g .
Behavior of Airborne Fluorides in Soils'
Janina Polomski, Hannes Flfihler, and P e t e r
Accumulation of airborne f l u o r i d e s i n s o i l s i s
s a i d t o be a s i d e e f f e c t of minor importance i f it
i s compared w i t h t h e p h y t o t o x i c i t y of man-made
gaseous f l u o r i d e . When s o i l f l u o r i d e was considered i n t h e p a s t , F-uptake of p l a n t s , l e a f i n j u r y
o r y i e l d reduction was of prime concern. Not much
i s known about t h e f a t e of F-pollutants a f t e r
being deposited onto t h e s o i l s u r f a c e o r incorporated i n t h e p l a n t l i t t e r l a y e r . Our study aims
a t providing experimental t o o l s and d a t a f o r a
b e t t e r understanding of long-termed e f f e c t s . The
o b j e c t i v e i s t o p i n down t h e most s i g n i f i c a n t ,
c o n t r o l l i n g mechanisms of t h e F-mobility i n s o i l s .
laserâ
Laboratory experiments : What c o n t r o l s the
f l u o r i d e t r a n s p o r t i n s o i l s ? I n case of a noncalcareous s o i l (pH 5.2) the amount of f l u o r i d e
adsorbed within a mixture of s o i l and NaFs o l u t i o n being e q u i l i b r a t e d on a shaker
(3340 \lg ~ / g s) o i l equals approximately t h e
F-adsorption i n t h e course of a p e r c o l a t i o n
through a s o i l s l a b (Fig.)
Breakthrough-Curves of S i b Clay Soil with and without CaCO,
F i e l d experiments: I n t h e v i c i n i t y of a
30000 t Aluminum smelter, b u i l t 1908, we observed t h a t F a c t u a l l y accumulates i n the s o i l
(Table). The s o i l s sampled a t various d i s tances d i f f e r i n many r e s p e c t b u t a r e a l l
calcareous. The F-contents do depend upon
d i s t a n c e from t h e emission source.
distance from
Al-smelter
(km)
total F
1
watersoluble F
(pg F per gram soil)
dissolved F
(pg F per ml
soil solution)
F-content of
1 %-year old
pine needles
( P P ~
Cumulated Outflow [Number of Pore Voluminal
In s o i l s , f l u o r i d e c o e x i s t s i n many d i f f e r e n t
forms which makes t h e t o t a l F-content t o be a
hardly i n t e r p r e t a b l e s o i l c h a r a c t e r i s t i c s .
I n a pine stand, l o c a t e d 1.8 km from t h e
smelter t h e magnitude of t h e annual F-input and
leaching l o s s e s were determined (kg F per y and
ha) : 1-3 kg within dead p l a n t m a t e r i a l , 6-10 kg
atmospheric washout, 40-80 kg adsorption and
sedimentation. The leaching l o s s e s o u t of t h e
r o o t zone were estimated t o be some 80-100 kg.
Under pine canopies t h e F-contents i n t h e
s u r f a c e l a y e r (humus) a r e s y s t e m a t i c a l l y higher
than i n t h e s u b s o i l (mineral horizon) whereas
i n u n c u l t i v a t e d open land under g r a s s cover
f l u o r i d e accumulates i n t h e s u b s o i l .
p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate Forest
Ecosystems, June 22-27, 1980, Riverside,
C a l i f o r n i a , U.S.A.
~ g r o n o m i s t ,s o i l p h y s i c i s t and chemist,
r e s p e c t i v e l y , Swiss F o r e s t r y Research
I n s t i t u t e , Binnensdorf, Switzerland.
The c l o s e agreement between t h e two experiments i n d i c a t e s t h a t adsorption and p r e c i p i t a t i o n a r e f a s t r e a c t i o n s a s compared with t h e
v e l o c i t y of t h e p e r c o l a t i n g s o i l s o l u t i o n .
In calcareous s o i l s , however, the exchange
k i n e t i c s between t h e l i q u i d and s o l i d phase
c o n t r o l s t h e e x t e n t of accumulation and
depletion. The exchange proceeds too slow
t o keep up with t h e pace of t h e moving water.
This explains t h e amazingly high F-mobility
observed i n case of t h e F-contaminated
calcareous s o i l s .
I n t h e course of t h e p e r c o l a t i o n experiments t h e l e a c h a t e s from t h e s o i l columns
contain appreciable amounts of s o l u b i l i z e d
organic matter and aluminum. For a given
s o i l type t h e leaching l o s s e s depend i n t h e
f i r s t p l a c e upon t h e F-content of t h e i n f i l t r a t i n g s o l u t i o n and f u r t h e r upon s o i l type
and t h e F-compounds used t o make up t h e
p e r c o l a t i n g s o l u t i o n . Under f i e l d conditions
with 8-10 ppm F i n the s o i l s o l u t i o n such
phenomena may a l s o occur. A s i g n i f i c a n t amount
of s o l u b l e organic m a t e r i a l can be l o s t which
may r e p r e s e n t an energy s u b s t r a t e shortage
f o r t h e microorganisms, and furthermore t h e
Al-concentrations possibly reach phytotoxic
l e v e l s . A t t h i s p o i n t t h e experimental evidence r a t h e r backs up questions than provides d e f i n i t e answers.
Multiple Pollutant Fumigations Under Near Ambient Environmental Conditions
Using a Linear Gradient Technique1
P.B. Reich, R.G. Amundson, and J.P. L a s s o i e
I n v e s t i g a t i o n s of t h e impact of atmospheric
p o l l u t a n t s on p l a n t s normally i n v o l v e a r t i f i c i a l l y r a i s i n g t h e c o n c e n t r a t i o n of c e r t a i n g a s e s around s t u d y p l a n t s . Such experiments t y p i c a l l y
u t i l i z e e n c l o s u r e s which g r e a t l y modify o t h e r
environmental f a c t o r s . Hence, t h e s e experiments
may n o t a c c u r a t e l y t e s t p l a n t responses under
ambient c o n d i t i o n s . The development of open-top,
f i e l d f u m i g a t i o n chambers (Mandl and o t h e r s 1973)
and a new l i n e a r g r a d i e n t exposure system (Shinn
and o t h e r s 1977) have been a t t e m p t s t o s o l v e
t h i s problem.
I n 1979 we c o n s t r u c t e d a modified l i n e a r grad i e n t system and 6 open-top chambers. The grad i e n t system enabled t h e simultaneous exposure of
numerous s t u d y p l a n t s t o a c o n c e n t r a t i o n g r a d i e n t
of SO2 and 03. S i n c e t h e system does n o t use
e n c l o s u r e s , p l a n t s a r e e a s i l y accessed and exp e r i e n c e near-ambient environmental c o n d i t i o n s .
A p l o t of soybeans (Glycine
v a r . Hark) i n
I t h a c a , NY was used i n a n a t t e m p t t o answer t h e
following questions.
1 ) Can t h e g r a d i e n t system be used t o expose
p l a n t s i n t h e f i e l d t o c o n t r o l l e d l e v e l s of a i r
p o l l u t a n t s without s i g n i f i c a n t l y a l t e r i n g t h e i r
environments?
2) Is p l a n t growth s i g n i f i c a n t l y d i f f e r e n t
i n open-top chambers v e r s u s i n a l i n e a r g r a d i e n t
system?
3) What r e d u c t i o n s i n soybean seed y i e l d w i l l
r e s u l t from exposure t o moderate l e v e l s of SO2
and 03 d u r i n g t h e seed m a t u r a t i o n p e r i o d ?
s.
During t h e seed m a t u r a t i o n p e r i o d , t h e p l a n t s
were exposed t o SO2 and O3 f o r about 55 h o v e r a
20-day p e r i o d .
On a l l o c c a s i o n s , a l i n e a r conc e n t r a t i o n g r a d i e n t was c r e a t e d by t h e system.
Mean c o n c e n t r a t i o n s of SO2 and O3 a t t h e "high"
end of t h e g r a d i e n t were 0.16 and 0.06 ppm, r e s p e c t i v e l y , w h i l e ambient c o n c e n t r a t i o n s of b o t h
p o l l u t a n t s were about 0.02 ppm. Maximum h o u r l y
means a t t h e "high" end of t h e g r a d i e n t were0.50
and 0.17 ppm S O 2 a n d 03, r e s p e c t i v e l y . By monit o r i n g t h e p l o t i n a g r i d d e s i g n , we were a b l e
t o account f o r t h e e f f e c t s of wind on p o l l u t a n t
levels.
I n t h e open-top chambers, p l a n t s were
2
exposed t o 0.30, 0.10, and 0.02 (ambient) ppm SO2
f o r 72 h , over a 30-day p e r i o d , d u r i n g t h e podf i l l i n g stage.
Comparisons of t r e a t m e n t s r e v e a l e d t h a t t h e
g r a d i e n t fumigations reduced t o t a l bean y i e l d p e r
p l a n t and d r y mass p e r bean by a s much a s 39 and
14 p e r c e n t , r e s p e c t i v e l y . I n t h e open-top chamb e r s , t o t a l bean y i e l d p e r p l a n t and d r y mass p e r
bean were reduced by a s much a s 1 0 and 7 p e r c e n t ,
r e s p e c t i v e l y . It i s of i n t e r e s t t o n o t e t h a t
b o t h t h e "high" and "medium" (mean SO2-0.09 ppm,
mean 03-0.04 ppm) t r e a t m e n t s i n t h e g r a d i e n t system caused much g r e a t e r r e d u c t i o n s i n y i e l d t h a n
d i d t h e 0.30 ppm SO2 t r e a t m e n t i n t h e open-top
chamber. I n i n t e r p r e t i n g t h e s e d a t a , one must
remember t h a t t h e p l a n t s i n t h e g r a d i e n t system
did e x p e r i e n c e short-term peaks much h i g h e r t h a n
t h e i r mean c o n c e n t r a t i o n exposures.
I n any c a s e , 03, a l t h o u g h p r e s e n t a t moderatel y low l e v e l s , was ( a l o n e o r s y n e r g i s t i c a l l y w i t h
SO2) probably r e s p o n s i b l e f o r t h e g r e a t e s t r e d u c t i o n s i n seed s i z e and y i e l d .
I n open-topchambers, one can a c c u r a t e l y cont r o l pollutant levels. In contrast, the l i n e a r
g r a d i e n t system a l l o w s f u m i g a t i o n s which v a r y
w i t h time and wind, a s under ambient c o n d i t i o n s .
The l i n e a r g r a d i e n t system proved t o b e a n e f f e c t i v e means of fumigating p l a n t s w i t h m u l t i p l e
p o l l u t a n t s under ambient environmental condit i o n s . Another m o d i f i c a t i o n of t h e g r a d i e n t system i s c u r r e n t l y underway s o a s t o a l l o w f o r
a n a l y s i s of t h e i n t e r a c t i o n s between SO2 and 03,
and t h e e f f e c t s of such on v a r i o u s hardwood t r e e
seedlings.
T h i s s t u d y was supported i n p a r t by t h e Northe a s t e r n F o r e s t Experiment S t a t i o n , F o r e s t S e r v i c e ,
U.S. Department of A g r i c u l t u r e , through t h e Cons o r t i u m f o r Environmental F o r e s t r y S t u d i e s (Fore s t S e r v i c e Grant 23-169) and by t h e C o r n e l l
U n i v e r s i t y A g r i c u l t u r a l Experiment S t a t i o n
(McIntire-Stennis P r o j e c t NY(C)-147556).
LITERATURE CITED
p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
~ r a d u a t es t u d e n t of F o r e s t S c i e n c e , C o r n e l l
U n i v e r s i t y , I t h a c a , NY; P o s t D o c t o r a l A s s o c i a t e ,
Boyce Thompson I n s t i t u t e , I t h a c a , NY; and A s s i s t a n t P r o f e s s o r of F o r e s t S c i e n c e , C o r n e l l
U n i v e r s i t y , I t h a c a , NY.
Nandl, R.H., L.H. Weinstein, D.C. McCune, and
M. Keveny
1973. A c y l i n d r i c a l , open-top chamber f o r t h e
exposure of p l a n t s t o a i r p o l l u t a n t s i n t h e
f i e l d . J. Environ. Qual. 2:371-376.
.
Shinn, J . H . , B.R. Clegg, and I1.L. S t u a r t .
1977. A l i n e a r - g r a d i e n t chamber f o r exposing
f i e l d p l a n t s t o c o n s t a n t l e v e l s of a i r
p o l l u t a n t s . DOE-Preprint UCKL-80411.
Changes in Plant Communities with Distance from an SO2 Source
Paul R. scale2 Investigations were carried out to assess the effects on plant community composition of sulphur dioxide (SO2) emitted from an iron sintering plant in Wawa, Ontario, Canada. Diversity indices and the ordination techniques of Correspondence Analysis (C.A.) and Principal Component Analysis (P.C.A.) were used to discern community level changes. Of special interest were the subtle changes in areas noted to be only slightly affected by SO2 emissions. Over 60 upland birch stands were accessed along a north-easterly transect away from the source at distances of 12 to 55 km. Species specific data was collected on the tree, shrub and ground flora. occurs despite their own greater exposure to S O . The low-bush blueberry (Vaccinium angustifoliumL Ait.) for example, becomes very abundant at dis- tances of 20 to 30 tan yet shows considerable SO2 damage in that area. The first substantial change in species abundance occurs at a distance of 40 km where beaked hazel (Corylus cornuta Marsh.) becomes very abundant before a very rapid decline. This undoubtedly contributes to the drop in the abund- ance of the large leaved aster (Aster macrophyllus L.) at that distance.
Dealing collectively with all species of a com- munity to discern changes caused by a pollutant is, for theoretical reasons and from experience, a Changes in species composition are dramatic as more satisfactory approach than changes in indivi- the 30 year SO2 source is approached. The total dual species abundance. Diversity indices have percent cover of the dominant, predominantly boreal, been used extensively for this purpose. However, ground flora species are shown in Figure 1. They the data from Wawa indicates that although diver- reflect the complex pattern of species abundance sity indices can deal with spatial/structural which occurs along the transect. Characteristic is changes in the community, they do not adequately the transitory increase in abundance which occurs reflect the subtler changes in species composition. in most species. What is particularly evident is Ordination techniques, such as C.A. and P.C.A., are the ability of many species to take advantage of better suited for this purpose. For example, the the increasing damage caused first to the tree Shannon-Weiner Diversity index has a transitory increase between 20 and 30 km before declining at canopy and subsequently to the shrub layer. This distances below 20 km. In contrast, the first axis of C.A. using ground flora data shows a simple, (Figure 2). C.A. linear change from 12 to 33 km
is most effective in reflecting overall trends whereas P.C.A. is particularly useful in discerning differences in stands of very similar composition. On the basis of P.C.A. using shrub density data, the separation of sites in intermediate areas from controls can be achieved. The boundary between the two groups in Figure 2 corresponds well with the line designated in 1973 and 1974 as separating areas which do and do not show visible leaf damage. Figure 1--Changes in ground flora species abundance with distance using a running average of percent cover: Am, Aster macrophyllus; An, Aralia
nudicaulis; Df, Deschampsia flexuosa; Dl, Diervilla lonicera; Me, Maianthemum canadense; Va, Vaccinium angustifolium. presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. ~ r a d u a t eStudent, Institute for Environmental Studies, University of Toronto, Toronto, Ontario, Canada. Figure 2~Distancevs Axis 1 of ground flora (percent cover) and shrub density (number of stems under 5 cm diameter at breast height) data using C.A. and P.C.A., respectively. Lichens as Ecological Indicators of Photochemical Oxidant Air Pollution1
Lorene L. S i g a l and Thomas H. Nash 111~
From t h e l a t e 1 9 6 0 ' s t o t h e p r e s e n t , both t h e
c o n c e n t r a t i o n and dose of photochemical oxidant a i r
p o l l u t a n t s (ozone and peroxyacetyl n i t r a t e o r PAN)
have continued t o i n c r e a s e i n t h e mountainous a r e a s
surrounding t h e Los Angeles Basin. Since 1972, a
m u l t i - d i s c i p l i n a r y team of e c o l o g i s t s has monitored
and analyzed t h e e c o l o g i c a l consequences of t h i s
p o l l u t i o n i n t h e c o n i f e r f o r e s t ecosystem of t h e
San Bernardino Mountains. Our l i c h e n study p a r a l l e l s and expands t h e parameters of t h e aforement i o n e d s t u d y and a l l o w s a comparison of t h e r e l a t i v e s e n s i t i v i t y of l i c h e n s v e r s u s higher p l a n t s
t o oxidants.
H i s t o r i c a l l y , l i c h e n s have been demonstrated t o
be s e n s i t i v e i n d i c a t o r s of a i r p o l l u t a n t s such a s
s u l f u r d i o x i d e . More r e c e n t l y , t h e r e i s s t r o n g
evidence t h a t l i c h e n s a r e a l s o s e n s i t i v e t o hydrogen f l u o r i d e and heavy m e t a l s . The p r e s e n t
s t u d y documents f o r t h e f i r s t time t h a t l i c h e n s a r e
a l s o s e n s i t i v e t o ozone and peroxyacetyl n i t r a t e .
F i e l d i n v e s t i g a t i o n s were conducted i n f o u r
mountain ranges surrounding t h e Los Angeles Basin.
A f i f t h s i t e i n Cuyamaca Rancho S t a t e Park, e a s t of
San Diego, was chosen a s t h e c o n t r o l a r e a . R e s u l t s
of sampling l i c h e n s on Quercus k e l l o g g i i Newb. and
c o n i f e r s showed o v e r a l l s p e c i e s r i c h n e s s decreased
by 38 p e r c e n t i n t h e h i g h l y impacted San Bernardino
Mountains. Cover v a l u e s f o r s p e c i e s on Q. kellogdecreased by 16 p e r c e n t ; f o r l i c h e n s on coni f e r s t h e d e c r e a s e was 78 p e r c e n t . The l a t t e r dec r e a s e i s l a r g e due t o t h e f a c t t h a t t h e "sens i t i v e " f r u t i c o s e l i c h e n s p e c i e s a r e found mainly
on c o n i f e r s . There was an i n v e r s e r e l a t i o n s h i p
between t h e cover of l i c h e n s a t b r e a s t h e i g h t on
c o n i f e r s and t h e oxidant dose e s t i m a t e s a t s i t e s i n
t h e San Bernardino Mountains ( f i g . 1 ) . A t h r e s h o l d
i s seen a t 180 ppm-hrs above which t h e l i c h e n s a r e
almost a b s e n t .
Fumigation s t u d i e s i n t h e l a b o r a t o r y provided a
d e f i n i t i v e way of t e s t i n g t h e response of f i e l d
s e n s i t i v e and f i e l d t o l e r a n t s p e c i e s t o c o n t r o l l e d
c o n c e n t r a t i o n s of ozone and PAN s i m i l a r t o those
o c c u r r i n g i n t h e f i e l d . I n j u r y was documented a s a
s i g n i f i c a n t r e d u c t i o n i n g r o s s photosynthesis.
Parmelia s u l c a t a Tayl. e x h i b i t e d g r e a t e r s e n s i t i v i t y t o ozone and PAN than Hypogymnia enteromorpha
(Ach.) Nyl. These r e s u l t s were c o n s i s t e n t w i t h
f i e l d observations.
A s a r e s u l t of c o l l e c t i o n s made by H. E . Hasse
and t h e subsequent p u b l i c a t i o n of h i s "Lichen
F l o r a of Southern C a l i f o r n i a " i n 1913, t h e p r e s e n t
d i s t r i b u t i o n and v i t a l i t y of a number of l i c h e n s
was compared t o t h e i r d i s t r i b u t i o n a t t h e t u r n of
t h e century. There was a 50 p e r c e n t d e c r e a s e i n
I n a d d i t i o n , marked morphospecies richness.
l o g i c a l d e t e r i o r a t i o n was s e e n i n t h e t h a l l i of
e x i s t i n g f o l o s e s p e c i e s such a s Hypogymnia e n t e r omorpha. Forty-two p e r c e n t of t h e t h a l l i c o l l e c t e d
i n t h e San Bernardinos were bleached and 44 p e r c e n t
were convoluted i n c o n t r a s t t o no bleaching o r conv o l u t i o n i n c o l l e c t i o n s made i n t h e Cuymacas.
T h a l l u s dimensions were decreased by approximately
50 percent i n t h e San Bernardino c o l l e c t i o n s .
The importance of l i c h e n s t u d i e s l i e s i n t h e i r
s e n s i t i v i t y t o a i r p o l l u t i o n and t h e i r p o t e n t i a l
u s e a s b i o i n d - i c a t o r s . By monitoring t h e abundance
and d i s t r i b u t i o n of s e n s i t i v e l i c h e n s , i t i s poss i b l e t o e s t i n a t e t h e magnitude of a i r p o l l u t i o n .
u s e of l i c h e n s i n t h i s m a t t e r may be f e a s i b l e n o t
only a s c u r r e n t l y a p p l i e d i n n o r t h e r n Europe w i t h
s u l f u r d i o x i d e a i r p o l l u t i o n , b u t a l s o over l a r g e
geographical a r e a s impacted by photochemical
oxidant a i r p o l l u t i o n .
Acknowledgment: This s t u d y was supported by
National Science Foundation Grant DEB-7610244 t o
D r . Thomas H. Nash 111, Dept. of Botany/Microbiology, Arizona S t a t e U n i v e r s i t y , Tempe, Arizona
85281.
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p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
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Research A s s o c i a t e , Oak Ridge National Labo r a t o r y , Environmental Sciences Division, P.O. Box
X, Oak Ridge, Tenn.
37830. Operated by Union
Carbide Corporation under c o n t r a c t W-7405-eng-26
w i t h t h e U.S. Department of Energy; and A s s o c i a t e
P r o f e s s o r of Ecology and Lichenology, Arizona
S t a t e U n i v e r s i t y , Tempe, Ariz. 85281.
F i g u r e 1--Percent l i n e a r cover a t b r e a s t h e i g h t of
L e t h a r i a v u l p i n a (1.) Hue and Hypop-ymnia
enteromorpha (Ach.) Nyl. a s a f u n c t i o n of t h e
oxidant dose e s t i m a t e s (ppm - h r s . = t h e mean
oxidant c o n c e n t r a t i o n i n ppm m u l t i p l i e d by t h e
time of exposure) a t s i t e s i n t h e San Bernardino
Mountains.
The Effects of Air Pollutants on Forest Ecosystems in S.R. Slovenia1
Marjan Solar
INTRODUCTORY DATA
S l o v e n i a w i t h i t s s u r f a c e o f 20,251 km2 represents 8% o f t h e t e r r i t o r y o f Yugoslavia (255,804
km2). I t i s s i t u a t e d i n t h e extreme northwestern
p a r t o f t h e s t a t e between t h e Alps, t h e Pannonian
p l a i n , t h e A d r i a t i c sea and t h e D i n a r i c o r o g r a p h i c
system. H a l f o f t h e s u r f a c e i s covered by f o r e s t s
(1,000,000 ha), 2/3 o f which a r e p r i v a t e l y owned.
The p o r t i o n o f c o n i f e r s amounts t o 56%, t h e average
wood mass i s n e a r l y 200 m3/ ha. The t o t a l increment
per year i s 4,000,000 m3, t h e c u t t i n g 3,000,000 m3.
Two-thirds o f t h e wood h a r v e s t possess a t e c h n i c a l
value. The p o r t i o n o f f o r e s t r y w i t h i n t h e n a t i o n a l
income i s 4% and i n d i c a t e s w e l l t h e l e v e l o f t h e
i n d u s t r i a l development o f Slovenia.
S l o v e n i a i s d i v i d e d up i n t o 15 f o r e s t management
areas and each o f those i n t o t h e s o c i a l l y and p r i v a t e l y owned s e c t o r s . The p r i n c i p l e s o f management
a r e u n i f i e d . The b a s i c p r i n c i p l e i s t o manage as
much p r o n a t u r a l l y as p o s s i b l e t o secure t h e permanency o f y i e l d and f u n c t i o n s o f t h e f o r e s t . The f o r e s t s e r v i c e e n j o y s i n some places a 200-year
tradition.
The study o f e f f e c t s o f a i r p o l l u t a n t s on t h e
f o r e s t s goes back t o t h e year 1926, and systematic
i n v e s t i g a t i o n s were s t a r t e d i n 1969.
OBJECTIVES OF INVESTIGATION
We w i s h t o determine t h e parameters, i n t e n s i t y
and p e r s p e c t i v e s o f t h e e f f e c t s o f a i r p o l l u t i o n on
t h e f o r e s t s i n Slovenia, w i t h t h e aim t o secure
r e l i a b l e f o u n d a t i o n s f o r t h e p l a n n i n g o f t h e indust r i a l development r u n n i n g p a r a l l e l l y w i t h t h e p r e servation o f the multifunctional forest, f o r the
r e g u l a t i o n o f i n d e m n i t i e s and t h e e l a b o r a t i o n o f
c o r r e c t n o r m a t i v e concerning t h e maximum t o l e r a b l e
concentrations valuable f o r t h i s s p e c i f i c f o r e s t
area.
PRELIMINARY FOUNDATIONS REQUIRED
Ecology (geology, s o i 1 s , phytocoenology , c l imate)
as bases f o r t h e d e t e r m i n a t i o n o f f o r e s t ecosystems
n o t s t r e s s e d by emission, f o r e s t i n v e n t o r y as a bas i s f o r t h e d e t e r m i n a t i o n o f t h e normal management
P r e s e n t e d a t t h e Symposium on E f f e c t s o f A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
~ r a d u a t ef o r e s t engineer, h i g h e r research
c o o p e r a t o r o f t h e I n s t i t u t e f o r t h e F o r e s t and
Wood Economy a t t h e B i o t e c h n i c a 1 F a c u l t y i n
L j u b l j a n a , Yugoslavia.
s i t u a t i o n o f t h e f o r e s t s and a r e g i s t e r o f e m i t t e r s .
METHODS OF ASSESSING THE EFFECTS
OF POLLUTED AIR ON FORESTS
Symptomatics, chemical analyses, increment a n a l yses, b i o i n d i c a t o r s , presence o f d i f f e r e n t l y aged
needles, presence o f secondary p e s t s , i n f r a c o l o r aerophotographs.
SPECIFIC FEATURES OF THE TERRITORY OF SLOVENIA
Accentuated ~ o n f i g u r a t i o n ~ i n d u s t royf t e n l o c a t e d
i n narrow v a l l e y s , temperature i n v e r s i o n , extremely
h i g h emission values (shocks), h i g h p r o p o r t i o n o f
s u s c e p t i b l e c o n i f e r s , e r o d i b l e s o i l s , predominancy
o f SO2 and HF.
RESULTS OF INVESTIGATION
The t o t a l s u r f a c e o f v i s i b l y damaged f o r e s t s i n
S.R. Slovenia amounts t o 22,000 ha i . e . 2.2% o f t h e
t o t a l f o r e s t area ( s i t u a t i o n i n 1977). The i n t e r n a l
d i v i s i o n o f damaged f o r e s t s i s t h e f o l l o w i n g :
Group A-the narrower emission area- t h e f o r e s t dest r o y e d and e x i s t e n s i a l l y threatened, o r s u r f a c e s
under t h e impact o f c r i t i c a l emission c o n d i t i o n s
e n t a i l i n g t h e t o t a l d e s t r u c t i o n o f a11 f o r e s t
f u n c t i o n s - d e s t r u c t i o n o f t h e f o r e s t ecosystem.
Surface 4,000 ha.
Group B-the w i d e r emission a r e a - f o r e s t under p e r manent emission impact, y e t t h e e x i s t e n c e o f t h e
f o r e s t i s n o t threatened, i t s f u n c t i o n s a r e however
reduced, o r surfaces under t o heavy emission cond i t i o n s t o a l l o w a normal t h r i v i n g o f t h e f o r e s t .
The emission causes an i n s t a b i l i t y o f f o r e s t ecosystems. Surface 16,000 ha.
Group C-Periodic emission a r e a - p e r i o d i c occurrence o f
damages, p o s s i b l y a c u t e ones, b u t between i n d i v i d u a l emission i n f l u e n c e s i n every case l o n g e r normal
s i t u a t i o n s a r e i n t e r c a l a t e d d u r i n g which t h e f o r e s t can recover. Surface 2,000 ha.
Based on t h e chemical analyses o f Spruce needles
as t o t h e increased c o n t e n t o f sulphur and f l u o r i d e ,
t h e s u r f a c e o f f o r e s t s w i t h hidden i n j u r i e s i s est i m a t e d t o 25,000 ha. Survey and d e t a i l e d maps o f
i n j u r e d f o r e s t have been made f o r a11 b i g g e r emiss i o n s areas. On t h e b a s i s o f r e l a t i v e r e s i s t a n c e
c a p a c i t y o f f o r e s t t r e e s and o f t h e i r p r o p o r t i o n a l
presence i n t h e f o r e s t v e g e t a t i o n communities a
categorization o f f o r e s t s w i t h respect t o t h e i r
s u s c e p t i b i l i t y t o a i r p o l l u t i o n has been c a r r i e d o u t .
The process o f a f u r t h e r improvement o f t h e
emission damages i n t h e f o r e s t s observed d u r i n g t h e
l a s t t h r e e years i s n o t l i k e l y t o proceed because
o f t h e increase o f consumption o f c o a l possessing
h i g h c o n t e n t s o f combustible s u l p h u r .
CONCLUSIONS
On t h e b a s i s o f i n v e s t i g a t i o n s c a r r i e d o u t i n
t h e t o t a l f o r e s t area o f Slovenia i n f l u e n c e d by
emission, o f knowledge concerning t h e ecology o f
t h i s t e r r i t o r y and t h e p a r t i c u l a r i t i e s o f e f f e c t s
o f t h e p o l l u t e d a i r , we a r e a b l e t o p r e d i c t exactl y t h e f u t u r e o f a c e r t a i n f o r e s t under c e r t a i n
emission i n f l u e n c e .
The s t a n d p o i n t o f f o r e s t e r s i s always t h e f o l lowing: Wherever t h e f o r e s t has been destroyed
o r i s on t h e way o f d e s t r u c t i o n , t h e a i r i s 10c a l l y oolluted t o a r e l a t i v e l y c r i t i c a l extent.
The a i r p o l l u t i o n i s t o o h i g h a l s o i n places
where t h e f o r e s t i s hampered i n i t s development.
Appealing t o t h e normatives f i x e d by law and
concerning t h e maximum emission values allowed
means n o t h i n g b u t t h a t t h e normatives a r e s e t
t o o h i g h and t h a t t h e f o r e s t e r s a r e bound t o
lower them.
The R e s o l u t i o n issued on t h e xth ~ e e t i no f~ t h e
IUFRO Group 2.09-Air P o l l u t i o n , L j u b l j a n a 1978 i s
proposing t h e normatives i n s u r i n g t h e normal
t h r i v i n g o f a11 k i n d o f f o r e s t s on average and
extreme s i t e s . The values f o r SOi a r e f o l l o w i n g
( i n pg/m3/air) : 50 as y e a r l y average, 100 as 24 h
average, 150 as & h value, and f o r HF ( i n
ug/m3/air) 0.3 as y e a r l y average and 0.9 as & h
value. For extreme s i t e s t h e normatives a r e t w i c e
as sharp.
I f we compare t h e normatives f i x e d by Resolut i o n t o those f i x e d by law i n d i f f e r e n t c o u n t r i e s
we r e a l i s e t h e l a s t ones a r e much t o o h i g h .
Population Differences in Response to Sulfur Dioxide: a Physiological Analysis1
G.
E. Taylor, Jr. and D. T. Tingey
The environment e x e r t s a profound i n f l u e n c e on
a p l a n t ' s a b i l i t y t o s u r v i v e and reproduce, and
consequently v e g e t a t i o n i n a g i v e n a r e a w i l l
p o s s e s s a s e t of morphological and p h y s i o l o g i c a l
t r a i t s t h a t enhance f i t n e s s . A t t h e l e v e l of
populations, these site-specific a t t r i b u t e s a r i s e
through e i t h e r a m o d i f i c a t i o n of t h e phenotype
(phenotypic p l a s t i c i t y ) o r a change i n t h e gene
pool (ecogenetic adaptation).
Both r e s p o n s e s a r e
common s t r a t e g i e s among n a t u r a l p o p u l a t i o n s experi e n c i n g d i s p a r a t e c l i m a t i c , e d a p h i c and b i o t i c
It is h y p o t h e s i z e d t h a t e l e v a t e d l e v e l s
stresses.
of a t m o s p h e r i c p o l l u t a n t s have e l i c i t e d i n a comp a r a b l e manner a v a r i e t y of t r a i t s t h a t enhance
s u r v i v a l and r e p r o d u c t i o n i n n a t i v e p l a n t s inhabi t i n g pollution-stressed areas.
One example of e c o g e n e t i c a d a p t a t i o n i n
r e s p o n s e t o a i r p o l l u t i o n i s t h e e v o l u t i o n of
s u l f u r d i o x i d e r e s i s t a n c e w i t h i n p o p u l a t i o n s of
Geranium c a r o l i n i a n u m , a n herbaceous w i n t e r a n n u a l
common i n d i s t u r b e d h a b i t a t s i n t h e S o u t h e a s t e r n
United S t a t e s .
I n comparison w i t h t h e i r counterp a r t s from p o l l u t i o n - f r e e r e g i o n s , p o p u l a t i o n s
sampled from a r e a s e x p e r i e n c i n g v a r i a b l e SO2
s t r e s s f o r 3 1 y e a r s were c o n s i s t e n t l y more r e s i s t a n t t o SO2 under c o n t r o l l e d exposure c o n d i t i o n s .
This i n f r a s p e c i f i c v a r i a t i o n is g e n e t i c a l l y determined and q u a n t i t a t i v e l y c o n t r o l l e d . P l a n t s of
c o n t r a s t i n g SO2 r e s i s t a n c e were used t o invest!+
g a t e t h e p h y s i o l o g i c a l b a s i s of t h i s a d a p t a t i o n .
I n d i v i d u a l p l a n t s were p l a c e d i n a whole-plant
gaseous exchange system i n which c o n c u r r e n t s t e a d y
s t a t e measures of l e a f r e s i s t a n c e t o w a t e r vapor
e f f l u x and SO2 i n f l u x were monitored i n t h e d a r k
and l i g h t a t p o l l u t a n t c o n c e n t r a t i o n s o f 0.4, 0.6,
and 0.8 u l 1 - l .
For r e s i s t a n t and s e n s i t i v e
p l a n t s a t each c o n c e n t r a t i o n , e s t i m a t e s of t o t a l
SO2 f l u x (pg c m 2 h r l ) a s a f u n c t i o n of l e a f
r e s i s t a n c e t o Hz0 e f f l u x were modeled u s i n g l i n e a r
r e g r e s s i o n t e c h n i q u e s . From e s t i m a t i o n p r o c e d u r e s ,
t o t a l f l u x was p a r t i t i o n e d i n t o l e a f s u r f a c e and
internal fractions.
2
however t h e r a t i o o f i n t e r n a l t o t o t a l f l u x dec r e a s e d s t e a d i l y . The a b s o l u t e v a l u e s f o r i n t e r n a l SO2 f l u x were s t r i k i n g l y s i m i l a r f o r b o t h
p l a n t groups a t each c o n c e n t r a t i o n . T h e r e f o r e , i n
s p i t e of t h e v a r i a t i o n i n t o t a l SO2 f l u x t o t h e
p l a n t , t h e r a t e of SO2 absorbed i n t o t h e l e a f
i n t e r i o r was e q u i v a l e n t f o r r e s i s t a n t and s e n s i t i v e plants.
Since l e a f r e s i s t a n c e t o water vapor
e f f l u x i s t h e same f o r a l l p l a n t s i n b o t h ambient
and S02-polluted atmospheres, o v e r t p l a n t - t o - p l a n t
d i f f e r e n c e s i n t h e i r r e s p o n s e t o SO2 r e f l e c t
d i s p a r a t e i n t e r n a l biochemical p r o c e s s e s a f f e c t i n g
pollutafit t o x i c i t y , perturbation or c e l l u l a r
repair.
The f a c t t h a t p l a n t d i f f e r e n c e s i n r e s p o n s e t o
SO2 a r e g e n e t i c a l l y c o n t r o l l e d and n o t a r e s u l t of
p o l l u t a n t exclusion is relevant t o an understanding
of t h e r a p i d e v o l u t i o n of p o p u l a t i o n r e s i s t a n c e i n
G. carolinianum. T h i s s p e c i e s i s a n a n n u a l t h a t
t h r i v e s f o r s i x months a s a w i n t e r r o s e t t e d u r i n g
which new l e a f growth i s minimal and y e t t r a n s p i r a t i o n remains a c t i v e .
This h a b i t coupled w i t h
t h e p l a n t ' s i n a b i l i t y t o t r a c k and e x c l u d e e l e v a t e d l e v e l s of SO2 may p r e d i s p o s e t h i s s p e c i e s
t o accumulate more SO2 d e r i v a t i v e s t h a n o t h e r
co-occurring s p e c i e s t h a t a r e e i t h e r more ephemeral
o r c a p a b l e of a v o i d i n g SO2 u p t a k e
increasing
stomata1 resistance.
These s p e c i e s ' a t t r i b u t e s
may e x p l a i n t h e c o n s i s t e n t f i e l d o b s e r v a t i o n s t h a t
show
carolinianum t o b e a s e n s i t i v e b i o l o g i c a l
i n d i c a t o r of e l e v a t e d SO2 l e v e l s .
c.
Acknowledgments: Research sponsored by t h e
N a t i o n a l Academy of Sciences-National Research
Council through a P o s t d o c t o r a l Research A s s o c i a t e s h i p t o t h e s e n i o r author.
S e n i o r a u t h o r acknowl e d g e s s u p p o r t f o r manuscript p r e p a r a t i o n under
C o n t r a c t W-7405-eng-26
by t h e Department of Energy
w i t h Union Carbide Corporation, a t Oak Ridge
N a t i o n a l Laboratory, Oak Ridge, Tennessee.
--
6.0
,
t
RESISTANT PLANTS
r
1
SENSITIVE PLANTS
T o t a l SO2 f l u x v a r i e d a s a f u n c t i o n of l e a f
r e s i s t a n c e and d i d n o t d i f f e r among r e s i s t a n t and
s e n s i t i v e p l a n t s a t 0.4 and 0.6 u l l 1 SOz. Conv e r s e l y , a t t h e h i g h e s t c o n c e n t r a t i o n t o t a l SO2
f l u x was n o t t h e same f o r t h e 2 p l a n t groups a s a
consequence of d i s p a r a t e s l o p e parameters.
Irres p e c t i v e of c o n c e n t r a t i o n t h e l e a f s u r f a c e and
i n t e r i o r were major s i n k s f o r SO2 (Fig. 1 ) . Each
f r a c t i o n increased l i n e a r l y with concentration,
' p r e s e n t e d a t t h e Symposium on E f f e c t s of A i r
P o l l u t a n t s on M e d i t e r r a n e a n and Temperate F o r e s t
Ecosystems, J u n e 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
2 ~ o s t d o c t o r a lA s s o c i a t e and P l a n t P h y s i o l o g i s t ,
T e r r e s t r i a l D i v i s i o n , U.S. Environmental Protect i o n Agency-Corvallis Environmental Research
Laboratory, C o r v a l l i s , Oregon, U.S.A.
SULFUR DIOXIDE CONCENTRATION ( p l I"')
F i g u r e I--Absolute v a l u e s f o r t o t a l , s u r f a c e and
i n t e r n a l l e a f f l u x of SO2 a s a f u n c t i o n of
p o l l u t a n t c o n c e n t r a t i o n i n r e s i s t a n t and' s e n s i t i v e
plants.
Ozone Injury to Pines in the Southern Sierra Nevada of California1
D e t l e v R. Vogler and John Pronos
The F o r e s t S e r v i c e began e v a l u a t i n g t h e impact
o f ozone on S i e r r a Nevada f o r e s t s i n 1974. Evalu a t i o n e f f o r t s were expanded and i n t e n s i f i e d i n
1977, and s i n c e then t h e primary methods o f
assessment have included, ( 1 ) m o n i t o r i n g ambient
ozone levels, and (2) r a t i n g i n j u r y t o p i n e f o l iage i n permanent t r e n d p l o t s .
A i r p o l l u t i o n i n j u r y t o commercial p i n e stands
located between 4000 and 8000 f e e t e l e v a t i o n
occurs q u i t e u n i f o r m l y along most o f t h e southern
S i e r r a Nevada f r o n t range adjacent t o t h e San
Joaquin V a l l e y and up i n t o t h e major r i v e r d r a i n ages. Symptoms a r e n o t confined t o l o c a l i z e d
areas downwind from major p o l l u t a n t sources.
Rather, ozone i s c a r r i e d down t h e e n t i r e San
Joaqu i n A i r Basin and eastward i n t o t h e S i e r r a .
Metropo I i t a n areas c o n t r i b u t i n g t o t h e ozone dose
inc I ude Stockton, Modesto, Merced, Fresno,
Visa1 i a B a k e r s f i e l d , and perhaps even Sacramento
and t h e San Francisco Bay Area.
OZONE MONITORING
F i v e f o r e s t e d l o c a t i o n s i n t h e southern S i e r r a
were moni+ored f o r season-long ozone dosages
Whitaker
between 1977 and 1979. One s i t e
was monitored c o n t i n u o u s l y d u r i n g t h i s
Forest
3-year period. The s i t e s ranged i n e l e v a t i o n
from 5400 f e e t t o 7540 f e e t , and a l l were a t
l e a s t 50 m i l e s from suspected m e t r o p o l i t a n sources
of a i r pollution.
--
--
2
Trend p l o t data were co I l e c t e d f o r t h r e e cons e c u t i v e years beginning i n 1977. I n 1977 and
1978 ozone i n j u r y r a t i n g s of p l o t s s c a t t e r e d
throughout a sampl i n g area o f over 1 m i I l i o n acres
ranged between no i n j u r y and moderate i n j u r y . A l though t h e m a j o r i t y o f 1978 p l o t s showed more o x i dant symptoms t h a n 1977 p l o t s , t h e r e was no stat i s t i c a l l y s i g n i f i c a n t t r e n d evident. The change
between 1977 and 1979, however, was more dramatic.
Nineteen o f 27 p l o t s evaluated i n 1979 showed
a d d i t i o n a l i n j u r y o v e r 1977 levels, and seven o f
these p l o t d i f f e r e n c e s were s t a t i s t i c a l l y s i g n i f i I n 1979, f o r t h e f i r s t time,
c a n t (P = 0.05).
several p l o t s f e l I i n t o t h e severe i n j u r y category.
The t r e e s i n these p l o t s averaged 2 years o f
needle r e t e n t i o n w i t h ozone symptoms on Z-yearol'd needles.
T h i s obvious increase i n i n j u r y was n o t expect e d because measured ozone l e v e l s i n 1979 were
g e n e r a l l y lower than i n e i t h e r 1978 o r 1977.
Considerable p h y s i o l o g i c a l s t r e s s from a 2-year
drought (1976-1977) c o u l d account f o r p a r t o f t h e
observed increase i n f o l i a r i n j u r y . One v i s i b l e
response o f pines t o t h e drought was a dramatic
decrease i n needle r e t e n t i o n , which tended t o
produce more severe ozone i n j u r y r a t i n g s . F u t u r e
recovery o f t r e e s from drought stress, i n t h e form
o f increased needle r e t e n t i o n , may r e s u l t i n a
r e l a t i v e r e d u c t i o n o f measureable a i r p o l l u t i o n
i n j u r y d u r i n g t h e n e x t few years.
CONCLUSIONS
Ozone l e v e l s a t each s i t e exceeded both t h e
Federal (0.12 ppm) and S t a t e (0.10 ppm) Standards
each year they were recorded. Based on t h e numb e r o f hours exceeding t h e Standards, 1977 was
t h e w o r s t year f o r ozone, w h i l e l e v e l s d e c l i n e d
s t e a d i l y i n 1978 and 1979. During t h e summer o f
each year d a i l y peak ozone values commonly ranged
between 0.10 ppm and 0.14 ppm. These values can
be compared t o those i n t h e San Bernardino Mount a i n s o f southern C a l i f o r n i a , where maximum d a i l y
ozone l e v e l s f r e q u e n t l y range from 0.20 t o 0.33
ppm, and where i n j u r y t o p i n e f o r e s t s i s correspondingly more severe.
TREND PLOTS
Presented a t t h e Symposium on E f f e c t s o f A i r
P o l l u t a n t s on Mediterranean and Temperate Forest
Ecosystems, June 22-27, 1980, Riverside,
C a l i f o r n i a , U.S.A.
'plant P a t h o l o q i s t s , P a c i f i c Southwest Region,
F o r e s t Service, Ui s .
partment of A g r i c u ture,
San Francisco, Ca I i f o r nia.
~e
The o v e r a l l l e v e l o f forest-wide i n j u r y i n t h e
south'ern S i e r r a Nevada can be termed s l ight, w i t h
some l o c a l p o p u l a t i o n s o f s u s c e p t i b l e pines showing moderate o r worse i n j u r y . Unexpectedly h i g h
amounts o f i n j u r y detected i n c e r t a i n areas i n
1979 placed some p l o t s i n t o t h e severe category.
I t i s p r e s e n t l y u n c l e a r whether t h i s i s a permanent t r e n d of increasing impact, o r j u s t a shortterm r e s u l t o f drought stress.
With o n l y 3 years o f m o n i t o r i n g data, t r e n d s
i n annual ozone dose a r e d i f f i c u l t t o assess.
Ozone l e v e l s seemed t o decrease s l i g h t l y each year
between 1977 and 1979, even though v i s i b l e i n j u r y
t o pines increased. Measured v a r i a t i o n s i n seasonal ozone dose may be associated more w i t h
weather p a t t e r n s than w i t h decreased pol I u t a n t s
a t t h e source. Maximum d a i l y ozone values i n t h e
S i e r r a s t i l l remain about 1/2 o r less of those
o c c u r r i n g i n southern C a l i f o r n i a . As ozone cont i n u e s t o be t r a n s p o r t e d i n t o t h e western slopes
o f t h e S i e r r a Nevada, s e n s i t i v e pines w i l I cont i n u e t o show a d d i t i o n a l i n j u r y and w i l I s l o w l y
decl lne.
Modifications of Chemical Contents of Precipitation
by Passage through Oak Forests1
George T. Weaver and Jon D.
Bulk precipitation monitored within oak forests in the Ozark Physiographic Province in Illinois was strongly acidic (pH<4.5) throughout most of . 1978. Exceptions occurred during late summer and
early autumn when pH rose to 5.8. This pattern with similar pH values reoccurred during the au- tumn and winter of 1979-80 and differs from sea- sonal trends usually reported from the northeast- ern United States where periods of greatest and least acidity are summer and winter, respectively. During the 1979-80 period, the highest concentra- ~
~ durin~
autumn, and on an tions of ~ 0 occurred
equivalence basis, exceeded H concentrations by a factor of 10. Concentrations of ~
a ~ , g and
, K+ were also high during autumn. It is hypothe- sized that considerable neutralization of strong acids occurred in the atmosphere due to the pre- sence of airborne dust which normally exists dur- ing autumn. Additional neutralization occurred as precipi- tation passed through the forest canopy, especial-
ly during autumnal leaf senescence. At this time canopy drip pH exceeded bulk precipitation
, by up to 0.7 units. The concentrations of Ca2qH
and ~ 0 in~canopy
~ drip
increased M g 2 ,,'K
804
markedly compared to bulk precipitation, particu-
larly during autumn. During the winter, canopy drip pH decreased to values as low as 3.8 and dif- fered little from bulk precipitation pH. In 1978, 68 percent of the precipitation reaching the for- est floor as canopy drip was acidic (pH<5.6). The removal of nutrient ions from the canopy also de- presented at the Symposium on Effects of Air Pollutants on Mediterranean and Temperate Forest Ecosystems, June 22-27, 1980, Riverside, California, U.S.A. ~ s s o c i a t eProfessor of Forestry, Southern Illinois University, Carbondale, 111.; Forestry Aide, Baruch Science Institute, Georgetown, S.C. ones^ creased during winter. In the spring of 1980 maximum bulk precipitation pH was 6.6 but passage through the canopy caused a decrease in pH as great as 0.8 units. Soluble organic compounds, apparently leached from some oaks, were present in sufficient quantities to impart a dark stain to canopy drip during this period and may be as- sociated with the reversal in H exchange in the canopy. The concentrations of ions in soil water fonn- ed three distinct patterns relative to concentra- tions in bulk precipitation and canopy drip. Hy-
drogen ion concentration was decreased markedly by passage through these ecosystems and the quan- tity remaining in soil water was only about 10 percent as great as in bulk preci itation. The m 3 - , ca2+concentrations of four ions -,-:oS
- increased as water passed through these
and W2+
ecosystems. The levels of these ions in soil wa-
ter were as great as 37 times and 9 times the levels in bulk precipitation and canopy drip, re- spectively, although major differences occurred among seasons and between ions. The contents of K+ and ~
0 in ~
bulk-precipitation
also were in- creased by up to 25 times by passage through the forest canopy. However, concentrations of these particular ions either decreased or remained simi- lar to concentrations in canopy drip after passage through the soil. Between October 1979 and April 1980, ca2+ and the predominant ions (equivalence basis) associated with meteorologic and hydrologic proc- esses in these ecosystems. The importance of Ca2+ in these ecosystems was anticipated since it is selectively accumulated by some species of oaks in these forests. It is also apparent that elevated levels of 'H are being deposited in association with
in these ecosystems, but the impacts remain undetermined. sod2- were
Seasonal Variation of Inorganic and Organic Sulfur in Coniferous Needles
Intensified by SO2 Pollution
'
2
Karl Friedrich Wentzel und SUnther Gasch
Method:
Needles front 50
-
70 year old Norway spruce from 1. gardens and
parks of Wiesbaden town (slight damage), and 2. Wiesbaden forests
(no v i s i b l e injury) were used as bioindicators f o r $0.-uptake.
I n octobre we picked 05.,
1.5
and 25.
year old needles, i n m y
we picked 1, 2 and 3 year old needles fro@the tops of the sam
trees. Inorganic and organic sulfur was determined according t o
JSger und Steubing (1970).
Results:
1. Air pollution measuremnt 1976
-
1979. Datas i n microgram
fig. 1 :Map of Wiesoaden/FRG
SO per cbw air. 11 = annual average, 12 = 95 percentile of
2
30 win. values:
Zone
Industrial Area
Town
Forests
II
120
-
140
7 0 - 90
<50
1 2
400
- 500
200-300
< 120
2. Total sulfur content increases with needle age as shown i n
Fig. 2. I n town the S contents d the needles are 100
-
200 ppm
higher than those froa the forests.
3. The inorganic fraction of a l l needle samples surmounts the
-- - - 300
organic fraction. The difference i s greater i n autumn than i n
spring and more apparent i n town than i n the forests.
4. The v a l i d i t y of using coniferous needles as indicator of a i r
- Wiesbaden Town
500.
0.5
1.0
1.5
2.0
25
Needle4 e
Fig. 2 :Sulfur content ( p p of dr. wt.) i n spruce needles from
Wiesbaden town (means of 39 tree samples) and forests (mans of
16 tree samples).
pollution effects i s best when octobre datas of inorganic S are
Oclobre- deltas
. . . .
used.
5. Organic sulfur content decreases during the vegetation period
Wiesbaden Forest
3D
1
A
-
May deltas
Decrease of inoro. S
while the inorganic fraction increases. During winter time the
opposite occurs (Fig. 3).
From t h i s i t i s suggested that i n
spring t i n e a part of the organic sulfur d m n d i s covered by
remvinq the inorganic amount, which p a r t i a l l y i s of air-borne
origin.
1 Presented a t t h e I n t e r n a t i o n a l Symposium on
E f f e c t s o f A i r P o l l u t a n t s on Mediterranean and
Temperate Forese Ecosystems, June 22-27, 1980,
Riverside, C a l i f o r n i a , U.S.A.
2 Forest E c o l o g i s t and chemist, r e s p e c t i v e l y ,
Hessische Landesanstalt f u r Umwelt, Wiesbaden,
West Germany
I
Wiesbaden Town
-
39 trees in casualorder
Fig. 3 : Seasonal alteration of inorganic and organic S i n spruce
needles frw Wiesbaden town (mans of 6 semi-annual needle sets).
Sulfur Dioxide and Oxidant Effects on Californian Coastal Sage Scrub1
W.E. Westman and K.P. p r e s t o n z
Two f i e l d s t u d i e s have r e l a t e d o x i d a n t and
s u l f u r dioxide p o l l u t i o n t o a deterioration i n
t h e s t r u c t u r e and f u n c t i o n o f s o u t h e r n C a l i f o r n i a ' s drought-deciduous shrublands ( c o a s t a l sage
scrub).
I n a s t u d y o f 67 s i t e s (0.63ha) f r o m
San F r a n c i s c o t o E l R o s a r i o ( B a j a C a l i f o r n i a ) ,
d a t a were c o l l e c t e d on s p e c i e s c o v e r and 43
h a b i t a t v a r i a b l e s d e s c r i b i n g topography, s o i 1 ,
c l i m a t e , v e g e t a t i o n s t r u c t u r e , age s i n c e f i r e ,
g r a z i n g i n t e n s i t y , and a i r p o l l u t i o n o f s i t e s .
The v a r i a b l e which showed t h e h i g h e s t s i q n i f i c a n t c o r r e l a t i o n w i t h p e r c e n t f o l i a r cover o f
n a t i v e species was t h e mean annual o x i d a n t
c o n c e n t r a t i o n (r=-.58, P<.001).
E l e v a t i o n and
mean maximum temperature o f t h e warmest month
a l s o showed h i g h l y s i g n i f i c a n t c o r r e l a t i o n s
(r=-.52).
The p a r t i a l c o r r e l a t i o n c o e f f i c i e n t s
o f o x i d a n t s w i t h p e r c e n t cover remained h i g h
when c o v a r i a t i o n s w i t h e l e v a t i o n , mean maximum
temperature o f t h e warmest month ,and d i s t a n c e
f r o m t h e c o a s t were e x t r a c t e d ( r = - .41,- .35,- .42
respectively)
The i n t e r r e l a t i o n s h i p s o f these
v a r i a b l e s were i n v e s t i g a t e d f u r t h e r by means o f
p a t h a n a l y s i s . A p a t h model ( c h i - s q u a r e p r o b a b i l i t y = .87) r e l a t e d environmental f a c t o r s t o a
r e d u c t i o n i n t h e p e r c e n t c o v e r o f n a t i v e species.
The p a t h model suggested t h a t o t h e r f a c t o r s c o r r e 1 a t e d w i t h d e c l in i ng c o v e r were a c t i n g p r i m a r i 1y t h r o u g h t h e i r i n f l u e n c e on o x i d a n t concentrat i o n i n p r e d i c t i n g t h e d e c l i n e i n cover o f n a t i v e
scrub species.
I n c r e a s i n g c o n c e n t r a t i o n s o f o x i d a n t s were
a l s o a s s o c i a t e d w i t h a d e c l i n e i n species r i c h ness (r=-.23; P<.05) and i n c r e a s e i n e q u i t a b i l i t y ( W h i t t a k e r ' s Ec i n d e x ; r=.24; P<.05).
Diversity i n f l o r i s t i c a l l y s i m i l a r s i t e s o f high
and low annual o x i d a n t c o n c e n t r a t i o n s was
compared. H i g h l y p o l 1u t e d s i t e s have fewer
species p e r abundance c l a s s and a l o w e r t o t a l
species r i c h n e s s ("7=18 v . T=29 a t l e s s p o l l u t e d
s i t e s ) . C o n c e n t r a t i o n of dominance i n c r e a s e s i n
t h e more p o l l u t e d s i t e s . M a j o r r e s u l t s have been
r e p o r t e d i n Wes tman ( 1979).
I n a second f i e l d study, t h e e f f e c t s o f s u l f u r
d i o x i d e emissions (up t o 0.13 ppm f o r a p e r i o d o f
25 y e a r s ) from an o i l r e f i n e r y were s t u d i e d n e a r
Santa Maria, on t h e r u r a l c e n t r a l c o a s t o f C a l i f o r n i a . Stands o f c o a s t a l sage s c r u b w i t h b l a c k
sage (Sal v i a me1 1if e r a ) downwind o f t h e r e f i n e r y
were compared w i t h stands i n r e l a t i v e l y p o l l u t i o n -
f r e e upwind s t t e s . I n j u r y t o i n d i v i d u a l S a l v i a
shrubs and changes i n community s t r u c t u r e and
f l o r i s t i c c o m p o s i t i o n were recorded. Stomata1
r e s i s t a n c e was found t o be s i g n i f i c a n t l y l o w e r
on t h e p o l l u t e d s i t e s w i t h a concomitant 35 p e r c e n t i n c r e a s e i n mean t r a n s p i r a t i o n r a t e s o f
S a l v i a . F l o w e r i n g c a p a c i t y o f S a l v i a , measured
by t h e number o f f l o w e r w h o r l s p e r f l o w e r s p i k e ,
was a l s o s i g n i f i c a n t l y reduced. S i g n i f i c a n t
decreases i n t h e h e i g h t / w i d t h r a t i o o f S a l v i a
were h y p o t h e s i z e d t o be caused by s u l f i t e mediated d e s t r u c t i o n o f i n d o l e a c e t i c a c i d (Yang
and Saleh, 1973) and p o s s i b l e i n h i b i t i o n o f
a p i c a l dominance. S i g n i f i c a n t r e d u c t i o n s i n
photos.ynthetica11.y a c t i v e t i s s u e o f S a l v i a
r e s u l t e d f r o m i n c r e a s e d d e f o l i a t i o n and r e d u c t i o n
i n l e a f s i z e a s s o c i a t e d w i t h SO2 s t r e s s . The
evidence i n d i c a t e s t h a t these f a c t o r s decreased
t h e s h r u b s ' a b i l i t y t o compete w i t h t h e more rs e l e c t e d annuals. As such, t h e number o f
species, p r i m a r i l y annuals, i n c r e a s e d c o n s i d e r a b l y i n t h e most o o l l u t e d s i t e s (X=27 v. 7=18.on
c o n t r o l s i t e s ) . These SO2 - a s s o c i a t e d changes
i n community s t r u c t u r e and f l o r i s t i c c o m p o s i t i o n
suggest t h a t r e t r o g r e s s i o n i s o c c u r r i n g , c a u s i n g
t h e 26-year o l d s t a n d t o resemble a 7-year o l d
p o s t - f i r e sera1 'stage. R e s u l t s a r e r e p o r t e d
more f u l l y i n P r e s t o n ( 1 980). L a b o r a t o r y s t u d i e s
a r e i n progress t o assess s e n s i t i v i t y o f sage
scrub species t o SO2 i n j u r y .
Â¥'Â¥presenta t t h e Symposium on E f f e c t s o f A i r
P o l l u t a n t s on Mediterranean and Temperate F o r e s t
Ecosystems, June 22-27, 1980, R i v e r s i d e ,
C a l i f o r n i a , U.S.A.
Whi t t a k e r , R.H.
1972. E v o l u t i o n and measurement o f species
d i v e r s i t y . Taxon 21 :213-251.
' ~ s s o c i a t e P r o f e s s o r o f Geography and graduate
student, r e s p e c t i v e l y , U n i v e r s i t y o f C a l i f o r n i a ,
Los Angeles, Cal i f o r n i a.
Yang, S.F. and S.A. Saleh.
1973. D e s t r u c t i o n o f i n d o l e - 3 - a c e t i c a c i d
d u r i n g t h e a e r o b i c o x i d a t i o n o f s u l fit e .
Phytochemistry 12:1463-1466.
.
Preston, K.P.
1980. E f f e c t s o f s u l f u r d i o x i d e p o l l u t i o n on
c o a s t a l sage scrub. M.A. Thesis. Department
o f Geography, U n i v e r s i t y o f C a l i f o r n i a , Los
Angel es
.
Westman, W.E.
1979. O x i d a n t e f f e c t s on C a l i f o r n i a n c o a s t a l
sage scrub. Science 205:1001-1003.
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Miller, Paul R., technical coordinator.
1980. Proceedings of the symposium on effects of air pollutants on Mediterranean
and temperate forest ecosystems, June 22-27, 1980, Riverside, California,
U.S.A. Gen. Tech. Rep. PSW-43,256 p. Pacific Southwest Forest and Range Exp.
Stn., Forest Sew., U.S. Dep. Agric., Berkeley, Calif.
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These proceedings papers and poster summaries discuss the influence of air pollution on
terrestrial and related aquatic ecosystems. They describe single species-single pollutant
relationships; interactions of producers, consumers, and decomposers under pollutant
stress; and the use of ecological systems models for interpreting and predicting pollutant effects.
Retrieval Terms: air pollution injury, acidic precipitation, pollutant stress, terrestrial
habitats, species-pollutant relationship. mathematical models.
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