Parameters influencing infrared reflectance of a vegetational canopy
by Mark William Hoard
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in
Range Science
Montana State University
© Copyright by Mark William Hoard (1985)
Abstract:
The objectives of this research are to determine the correlation, if any, among chlorophyll a and b
concentration, plant cell shape and size, plant and soil moisture, total vegetative cover and an observed
reduction in color intensity on photographic records of native vegetation that has been exposed to
sulfur dioxide fumigation. There were positive correlations between increasing sulfur dioxide levels
and reduced chlorophyll concentration, reduced photographic color intensity and reduced vegetational
cover. There were positive correlations between reduced photographic intensity and reduced
chlorophyll concentration and reduced vegetative cover; these correlations occurred at different stages
of the canopy's growth cycle. During the canopy's active growth stage chlorophyll concentration had a
high degree of correlation with reduced color intensity. Later in the season the chlorophyll-color
intensity correlation was not significant. At no point in the vegetational canopy's growth cycle were
there any correlations between plant cell shape and size, plant or soil moisture and reduced color
intensity on the photographic records. Total vegetative cover did not correlate well with reduced color
intensity during the early growth stages of the vegetational canopy. During the later growth stages the
total vegetational cover-color intensity correlation was significant. PA R A M ETER S IN F L U E N C IN G IN F R A R E D REFLECTANCE
OF A V E G E T A T IO N A L CANOPY
by
Mark William Hoard
A thesis submitted in partial fulfillm ent
o f the requirements for the degree
of
Master of Science
in
Range Science
M O N T A N A STATE U N IV E R S IT Y
Bozeman, Montana
May 1985
U 3T&
Nb t) I
ii
A PPR O VA L
of a thesis submitted by
Mark William Hoard
This thesis has been read by each member of the thesis committee and has been found
to be satisfactory regarding content, English usage, format, citation, bibliographic style,
and consistency, and is ready for submission to the College of Graduate Studies.
ns; / T
Date
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Approved for the Major Department
V -VxtKivA
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Date
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Head, Major Department
Approved for the College of Graduate Studies
r~ ' 2 *
Date
/ 2 / ^ 0^
Chairperson, Graduate Committee
Graduate Dean
S T A T E M E N T OF PERM ISSION TO USE
In presenting this thesis in partial fulfillm ent of the requirements for a master's degree
at Montana State University, I agree that the Library shall make it available to borrowers
under rules of the Library. Brief quotations .from this thesis are allowable without special
permission, provided that accurate acknowledgment of source is made.
Permission for extensive quotation from or reproduction of this thesis may be granted
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Signature
Date
A C KNO W LEDG M ENTS
I would like to express my great appreciation for the assistance given by the following:
Dr. Sharon Eversman, Dr. Clancy Gordon, Dr. John Rumely, and Dennis Neuman.
/
V
TA B LE OF CO NTENTS •
Page
A P P R O V A L .....................................................................................................................
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S T A T E M E N T OF PERM ISSION TO USE................................................. ; .........................
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A C K N O W L E D G M E N T S ___ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iv
TA B L E OF C O N T E N T S ..............................
v
L IS T O F TA B L E S .............................................................
vii
LIST OF F IG U R E S ............ ...........................
vii I
A B S T R A C T ......................................................
jx
IN T R O D U C T IO N ............ ..
I
DESC R IPTIO N O F S T U D Y A R E A . . . . . . . . . _____ . . . . . . . . . . . . . . . . . . . . . . . . . .
3
L IT E R A T U R E R E V IE W ....................
7
. Infrared Reflectance ( I R ) .................................................................................................
Sulfur Dioxide E ffects........................
Remote Sensing.......................................................................................................
M ETH O DS A N D P R O C E D U R E ........................................................
Aerial Photography ...................................
Film Processing and Printing...............................................................................................
Aerial Photo A nalysis..................
Chlorophyll E xtraction..................
Microscopic E xam in atio n ................
V
.
„
Field Measurements..................................................................................................... : . . .
RESULTS A N D D IS C U S S IO N .............................................................
Aerial Photo A nalysis.........................
J u n e .............. ............................i . . . .
August..............................
Chlorophyll Analysis................
Correlation Analysis
..." „ . . . . . . . . . . . . . . . .
Canopy Coverage Analysis......... ................................................... . . ; .................: .
8
9
10
12
12
12
13
13
14
15
16
16
18
18
18
22
26
vi
TA B L E OF C O N T E N T S -C o n tin u ed
------- ;--------
V
Page
Correlation A n alysis..............................................................................................................
Microscopic Analysis.....................................................................................................’
Plant M oisture................................................................................................................. ]
Soil M oisture................................................................................................................... /
29
29
29
3 1
S U M M A R Y A N D C O N C L U S IO N S ..................................................
34
L IT E R A T U R E C I T E D .................................................................................................................
36
A P P E N D IX
40
vii
LIS T OF TA B LES
Tables
Page
1.
Rendition o f Subject Colors in CIR F i l m ...................................................................
18
2.
June 29: Chlorophyll-Color Intensity Correlation Coefficients ( r ) ......................
22
3.
August 16: Chlorophyll-Color Intensity Correlation Coefficients (r)...................
23
4.
Total Vegetational Cover-Color Intensity Correlation Coefficients (r)..................
29
5.
Total Vegetational Cover-Color Intensity Correlation Coefficients (r)..................
29
Appendix Table
6.
Species Encountered on the ZAPS S ite ................................................
41
viii
L IS T O F FIG URES
Figures
Page
1.
Aerial photography study site in Southeastern Montana . . . . . . ___ . . . . ____
4
2.
Zonal A ir Pollution Site, aerial view August, 1976 ................
5
3.
The electromagnetic, energy spectrum (from Scherz and Stevens,
1970) .................................................................... ............................; ..............................
Ii
4.
Densitometric readings on ZAPS; June 1979.................................................
16
5.
Densitometric readings on ZAPS; August 1 9 7 9 ..............
17
6.
Chlorophyll a and b concentrations on ZAPS; June 1 9 7 9 .......................................
19
7.
Chlorophyll a and b concentrations on ZAPS; August 16, 1979 ...........................
20
8.
Chlorophyll a and b concentrations on ZAPS; August 3 1 ,1 9 7 9 . . . . . . „ . . . . „
21
9.
Chlorophyll a — Color intensity June 29, 19 7 9 ............
23
10.
Chlorophyll a — Color intensity August 16, 1 9 7 9 .....................................................
24
11.
Chlorophyll b — Color intensity August 16, 19 7 9 ............... .... ................................
25
12.
Total vegetational cover on ZAPS; June 1 9 7 9 ...........................................................
26
13.
Total vegetational cover on ZAPS; August 16, 1 9 7 9 .......................................................28
14.
Vegetational cover — Color intensity August 16, 1979
15.
Microsections of western wheatgrass leaves under four levels of
sulfur dioxide fu m ig a tio n ....................
31
16.
Plant moisture...............................................................................................
32
17.
Soil moisture
33
..'..
30
ix
A BSTRACT
The objectives o f this research are to determine the correlation, if any, among chloro­
phyll a and b concentration, plant cell shape and size, plant and soil moisture, total vegeta­
tive cover and an observed reduction in color intensity on photographic records of native
vegetation that has been exposed to sulfur dioxide fumigation. There were positive correla­
tions between increasing sulfur dioxide levels and reduced chlorophyll concentration,
reduced photographic color intensity and reduced vegetational cover. There were positive
correlations between reduced photographic intensity and reduced chlorophyll concentra­
tion and reduced vegetative cover; these correlations occurred at different stages of the
canopy's growth cycle. During the canopy's active growth stage chlorophyll concentration
had a high degree of correlation with reduced color intensity. Later in the season the
chlorophyll-color intensity correlation was not significant. A t no point in the vegetational
canopy's growth cycle were there any correlations between plant cell shape and size, plant
or soil moisture and reduced color intensity on the photographic records. Total vegetative
cover did not correlate well with reduced color intensity during the early growth stages of
the vegetational canopy. During the later growth stages the total vegetational cover-color
intensity correlation was significant.
I
IN T R O D U C T IO N
The grasslands of southeastern Montana overlie coal which is becoming increasingly
important to the nation's energy needs. A likely result of this need will be the increased
rate of mining and burning of this coal to generate electricity for large urban areas of the
midwest and Pacific coast. The sulfur dioxide pollution that will result from the burning
of this coal could have an effect on the grasslands of this region.
In an effort to determine the effect of sulfur dioxide on the grasslands of this region
the United State Environmental Protection Agency sponsored field experiments designed
to assess the impact of energy producing activities on the environment of southeastern
Montana. These experiments were initiated in May 1975 and were designed to test the
effect of sulfur dioxide upon plant and animal (arthopods) biomass dynamics, plant com­
m unity structure, insect and fungal diseases of plants, pollination systems, sensitivities of
lichens, and upon a number of physiological and biochemical functions (Lee and Lewis,
1978). These experiments have been supplanted by aerial photography from the onset
(Taylor and Leininger, 1977, 1978).
The objectives of this research were to determine the relationships, if any, among
chlorophyll a and b concentration, plant cell shape and size, plant and soil moisture, and
total vegetational cover and the color intensity o f the infrared photographic records of the
study area.
The above mentioned environmental parameters were chosen because of their ability
to influence a canopy's spectral properties. In addition, chlorophyll concentration, cellular
integrity, plant moisture, and vegetational cover can be adversely affected by sulfur
dioxide.
2
The importance of this type of research is related to the use of aerial photography as
a remote sensing technique. The major advantages o f aerial photography are: ( I ) reliability,
(2) favorable vantage point. (3) resolution o f detail, (4) completeness of coverage, (5) ease
of interpretation, (6) opportunity to extend ground observations, (7) ease of measure­
ments, (8) ease of checking error, (9) opportunity of observations at any time, (10) rapid­
ity of data collection, (11) usefulness for comparative studies, (12) application in "discrete
appraisals," and (13) economy. Major limitations are: ( I) photographs can be rapidly out­
dated, (2) they may emphasize the wrong features, (3) one photograph may not show the
total area of study, (4) it does not eliminate field work, and (5) intensive training is neces­
sary for proper interpretation. Regardless of the limitations of aerial photography, proper
correlation of photographic records with prevailing physiological, structural and commun­
ity aspects of the photographic subject can increase its usefulness to natural resource
management.
3
DESC R IPTIO N OF S T U D Y A R EA
The study area lies within the unglaciated Missouri plateau section of the Great Plains
Geomorphic Province. Specifically, it is located 86 Km. southeast of Ashland, Montana
(Fig. I ) in the west half of Section 9, Township 7 South, Range 47 East, M.P.M. Located
within the study area is a 10.8 hectare grassland exclosure which is called the Zonal Air
Pollution System (ZAPS) (Fig. 2). The exclosure has a six to eight percent southwest­
facing slope, and the elevation is about 1220 meters. The study area has a continental
climate that is cold in winter, warm in summer, and has large variation in seasonal precipi­
tation. The warmest month, July, has an average temperature of 22 degrees centigrade.
Annual precipitation is 360 millimeters with approximately 50 percent received during
April, May, and June (Dodd et al., 1979). The plant community at the site is composed of
a mixed grass prairie association. The site is dominated by western wheatgrass Agropyron
smithii, a cool season grass and an important forage species throughout the Northern Great
Plains. Other important plant species present are Sandberg bluegrass {Poa sandbergii),
prairie junegrass (Koeleria cristata), needle-and-thread {Stipa comata), common dandelion
[Taraxacum officionale) and western yarrow [Achillea lanulosa) (a complete species list is
shown in Appendix I ) . Soils at the site are derived from colluvium and parent material
weathered in place.
These soils consist of shallow clay loams that are underlain by clayey, silty, and sandy
clay loams (Soil Survey of Powder River County, 1971). The dominant taxonomic class on
the site has been described as a fine silty mixed Typic Argibordll.
The field design for the Zonal A ir Pollution System consisted of four 0.40 hectare
plots within the exclosure. These plots were experimentally stressed by different sulfur
CANADA
NORTH
DAKOTA
ORCAT FALLS
• MISSOULA
MILES CITY
COLSTRlP
BUTTE
BILLINGS
SOUTH
DAKOTA
V ASHLAND
Zofna I
IDAHO
WYOMING
Figure I . Aerial photography study site in Southeastern Montana.,
A ir
Pc I l u t l o n
5
Figure 2. Zonal Air Pollution Site, aerial view August, 1976.
6
dioxide concentrations. A constant 30 day median concentration was planned for each
growing season for the duration of the field experiments. Each plot was supplied with a
0.50 hectare network of 2.5 centimeter pipe supported above ground by pipe stakes. The
centers of the plots were located along a line, with buffer zones between plots. Different
concentrations of sulfur dioxide were bled into a continuous flow of air, while on the con­
trol plot only air was bled onto the site. Sulfur dioxide was monitored by recording output
on a sulfur analyzer for ten of every eighty minutes, from eight sample points (Lee and
Lewis, 1978). The system was designed to apply 10 pphm sulfur dioxide on the high fumi­
gation plot, 5 pphm on the medium fumigation plot, 2 pphm on the low fumigation plot,
and 0 pphm on the control plot. Sulfur dioxide drift due to wind movement and diurnal
temperature fluctuations made the actual fumigation rates vary, but the proportional dif­
ferences were relatively constant. Subsequent references to the fumigation plots will be
made with the designations A, B, C, D (control, low, medium, and high, respectively).
7
L IT E R A T U R E R EVIEW
Aerial photographs of the ZAPS site have shown a general trend toward decreasing
color intensity in red, green, and blue wavelengths. Although these values varied at the
intermediate levels of sulfur dioxide fumigation there were significant differences between
the control and high fumigation rates. Early in the experiment these photographic differ­
ences were difficult to demonstrate with ground monitoring. This was believed to be caused
by the initial positive response of the vegetation to the absence of grazing pressure. Later
ground monitoring has shown a reduction in color intensity with increased sulfur dioxide
and a corresponding decrease in ground cover (Taylor and Leininger, 1977, 1978). Ground
studies have shown that long-term exposure of the system to sulfur dioxide has not signifi­
cantly altered above or below ground biomass dynamics, net primary production, forage
quality or species composition (Dodd et al., 1978, 1979). Total living vegetation, total
graminoids, western wheatgrass, lichens and perennial species all showed decreasing cover
with increasing sulfur dioxide rates. Western wheatgrass was shown to accumulate sulfur
dioxide in a linear relationship to both tim e and concentration. Chlorophyll a and b con­
centrations significantly decreased in the absence of visible necrosis but chlorophyll a was
more sensitive than chlorophyll b. The sensitivity of chlorophylls to sulfur dioxide changed
as the season progressed, suggesting cumulative effects and/or interactions with normal
senescence.
The lichen species Usnea birta and Parmelia chlorochroa exhibited reduced photosyn­
thetic rates, disrupted chloroplast structures, and increased algal plasrriolysis, while respira­
tion rates and relative chlorophyll extract absorbance were not changed (Eversman, 1978,
1979).
8
Infrared Reflectance (IR )
To better understand the observed reduction in color intensity it is necessary to under­
stand the factors which affect the ability of a plant to reflect, transmit, and absorb radiant
energy. The leaf of a plant is the primary organ for conversion of solar energy. This con­
version through the process of photosynthesis occurs in the chloroplasts. Thechloroplasts
are situated along the walls of the parenchyma cells comprising the 'mesophyll or middle
section of the leaf. The chloroplasts are suspended within the cellular protoplasm and are 5
to 8 microns in diameter and about I micron in width. Within the chloroplasts are long
slender strands called grana. The grana are generally 0.5 microns in length and about 0.05
microns .in diameter. These dimensions are within th e dimensions of the wavelength of
light and may produce considerable reflectance of light entering the chloroplasts. It seems
that near-infrared reflectance is a function of cell shape and size and the amount of inter­
cellular space. The predominant pigments in most plants are chlorophyll a, chlorophyll b,
alpha-carotene, and lutein (xanthophyll).
All these pigments absorb radiation in the vicinity of 445 nm in the blue, but only
chlorophyll absorbs in the red, around 645 nm (Gates et al., 1965). It has been shown that
reflection of light from a leaf is generally reduced over all wavelengths when the leaf is
infiltrated with water (Gausman and Allen, 1973). In addition to plant moisture, the
moisture content of the nonfoliage background can affect the spectral signature of a vegetational canopy (Gates, 1965). The compactness of a vegetational canopy will also affect
its spectral properties. The reflectance of a vegetational canopy viewed against a soil back­
ground increases as the number of plant leaf layers in the canopy increases (Gausman et al.,
1976).
9
Sulfur Dioxide Effects
Sulfur dioxide can affect a plant's physiological and anatomical integrity. These effects
can have both deleterious and beneficial consequences: The deleterious effects fall into
three categories; acute, chronic, and physiological and/or biochemical injury. Acute and
chronic effects are characterized by visible mottled or chlorotic foliage while physiologicalbiochemical injury is characterized by alterations in a plant's photosynthetic rate (Severson,
1974). The green palIisade and spongy parenchyma cells contain the bulk of the leaf cells
most susceptible to air pollution-induced injury. Injury may occur when pollutants react
with cell constituents and disrupt their structural and functional integrity (Bennett, Hill,
and Gates, 1973).
These disruptions can take the form of swelling of chloroplastic membranes and
altered permeability of cell membranes due to disrupted structural proteins (Godzik and
Knabe, 1973; IMeibor et al., 1975). There is general agreement among plant physiologists
that net photosynthesis is inhibited by sulfur dioxide (Thomas, 1961). The photosynthetic
rate and photosynthetic efficiency of a plant are closely related to the integrity of the
primary and secondary pigments present in the plant's light harvesting mechanism, i.e.,
chlorophylls, carotenoids, and xanthophylls (Severson, 1974). Reductions in photosyn­
thetic rates have also been correlated with sulfur dioxide-induced alterations of the chloroPlast ultrastructure (Wellburn et al., 1972). The results of long term suppression of photo­
synthetic rates due to chronic levels of sulfur dioxide will be reduced plant yields (Godzik
and Knabe, 1973). It has also been reported that sulfur dioxide reacts with chlorophyll to
yield pheophytin, a related compound w ithout biological activity (Roa and LaBIanc, 1965),
Sulfur dioxide pollution can also cause damage to plants by suppression of plant growth
without visible injury ( Heggestad, 1968; Adedipe et al., 1972). Although the deleterious
10
effects far outweigh the beneficial effects, it has been noted that on sulfur-deficient soils
sulfur dioxide can increase plant yields (Cowlins et aI0, 1973).
Remote Sensing
The photographic records of the ZAPS site do indicate changes in native vegetation
due to sulfur dioxide fumigation. The ability to sense these changes is due to the specific
interaction between various photographic film emulsions and the electromagnetic spectrum.
In the visible portion of the electromagnetic spectrum (400-700 nm) differences in the
amount of light reflected by objects are apparent to the eye and can be recorded photo­
graphically as differences in color (using color film ) or variations in tone (using black and
white film ) (Laboratory for Agriculture Remote Sensing, 1967). Those portions of the
electromagnetic spectrum which are not visible to the human eye extend into the ultravio­
let and infrared regions of the spectrum and beyond, as shown in Figure 3.
Even though these portions of the spectrum are not visible to the human eye some
can be recorded through photography and other systems. The "bands" which are most use­
ful in remote sensing are those sets of wavelengths that allow data collection in the "atm o­
spheric windows" or portions of the electromagnetic spectrum in which the atmosphere is
transparent. For example, beyond 14,000 nm most thermal radiation is absorbed by water
and carbon dioxide in the atmosphere, but between 8,000 and 14,000 nm very little radia­
tion is absorbed. With black and white infrared film , as with panchromic film , the image is
black and white with intermediate tones of grey (Sherz and Stevens, 1970). The sensitivity
range of this film is from 360-900 nm (Colwell, 1968). Ordinary color film is composed of
three layers of emulsions which are sensitive to blue, green, and red light (Sherz and
Stevens, 1970). It is possible, with color photography, to make accurate distinctions
among 200,000 colors on the basis of hue, value, and chroma (Myers and Allen, 1968).
By extending the sensitivity of photographic emulsions into the near-infrared portion of
11
Black Body al SBOO1K
BLACK BODY RADIATION
and
SUN'S RADIATION
CURVES
X - Z S u n 1I energy
Block body al IZOO1K
Block body Ol BOO1K
Black body Ol SOO1K
2
4 0 60
.3
TO
ZO
40 60
IOO 200
5mm Imm
cm
Im
IOmlOOm
Blocking effect
of
e o rlh 'i
atmosphere
SPECTRAL RANGE OF OPERATION FOR COMMON REMOTE SENSING INSTRUMENTS
Rodor
M v lti- Spectral
4
6 B i 1O
Sconners
Passive Microwave
)
IO
20
40 60
100 200 Srnmlmm
WAVELENGTH, MICRONS
(N ot To S e a l:)
Icm
Im
IOmiCOm
Figure 3. The electromagnetic energy spectrum (from Scherz and Stevens, 1970).
the spectrum, a photograph can be produced which is induced by reflected energy to
which the eye is not sensitive (Laboratory for Agriculture Remote Sensing, 1967).
12
M ETH O DS A N D PROCEDURE
Aerial Photography
In 1979 two aerial missions were flown, the first on June 6 and the second on August
31. A Cessna 182 airplane was used for the missions. The plane was leased from Miles City
Aero Service, Miles City, Montana. The aircraft was modified by addition of a 30.5 cm
diameter belly port, to accept a special camera mount designed by W. E. Woodcock of
Miles City (Woodcock, 1976). The camera was fitted with a 50 or 80 mm lens depending
on the desired photo scale. The scale used for this paper is 1:3,800, which is obtained by
flying 305 meters above the ground with an 80 mm lens. Film types used for the missions
were Color and Color Infrared (C IR ). For optimum description o f infrared reflectance, CIR
film requires a minus blue filter; in this study a Wratten # 15 was used because it cuts off
slightly more yellow-orange portions of the spectrum than a # 12 as recommended by
Eastman Kodak Company. This allows for better separation of the infrared reflectance,
which shows up on CIR as tones of red (Taylor and Leininger, 1978).
Film Processing and Printing
All Cl R film was sent to Precision Photo in Dayton, Ohio, for processing. An optical
density wedge is exposed onto the film edge before processing for density and color cali­
bration. The Cibachrome process for all infrared color printing is used, and can be pro­
duced in the Montana State University Range Science photo lab. The color negative film
is processed within the state and prints are made in the lab or by commercial firms.
13
Aerial Photo Analysis
A Macbeth T D 524 (Status A )* densitometer with a I mm aperture was used to read
the density of aerial transparencies in the red, blue, and green spectral ranges. A total dens­
ity value was also obtained from each aerial transparency. The density values obtained are
expressed as the common logarithm of opacity, which is defined as the reciprocal of trans­
mittance, and are therefore related to color saturation of the wavelength being studied.
Chlorophyll Extraction
Chlorophyll content was sampled on June 29, July 25, August 16, and August 31 dur­
ing the field season. The ZAPS plots were divided into "N o rth " and "South" subdivisions
for sampling. Equal samples were collected from each half. No samples were taken in microtopographic depressions or in areas less than one meter from a sulfur dioxide delivery pipe
(Taylor and Leininger, 1977). A total of four points were sampled for the June 29 sample
date. In order to reduce sample variation a total of ten points were sampled in each half for
subsequent sample dates. The plant material from the June 29 and July 25 sample dates
were analyzed using the following technique: three grams of fresh western wheatgrass leaf
tissue was placed in a Waring blender. Fifty milliliters of 80 percent acetone was added and
this mixture was blended for two minutes.
The resulting solution was filtered through a #1 Whatman filter paper. The filtrate
was then analyzed in a Beckman model 25 spectrophotometer at 663 nm and 645 nm. The
resulting absorption values were used to calculate chlorophyll a and b concentrations
(Arnpn, 1949; MacKinney, 1941). In the June sample undissected leaf tissue was used. For
the July sample the leaf tissue was cut into one centimeter segments. This dissection led to
an unsatisfactory extraction and for this reason the July sample was discarded. A more
*N o endorsement of specific brand names is implied.
14
satisfactory technique was used fo r subsequent samples. The collected western wheatgrass
was dried then ground in a hammermill until it could pass through a 40 mesh screen. Three
grams of the disintegrated plant material was placed in a mortar with approximately 0.1
grams of sodium bicarbonate. Five milliliters of 85 percent acetone was then added and the
mixture was ground using a pestle. The extract was then filtered through a #1 Whatman
filter paper. This process was repeated until the filtrate was colorless. The filtrate was then
transferred to a volumetric flask and diluted to volume with 85 percent acetone. Twentyfive milliliters of the filtrate was then transferred to a separatory funnel containing 50 m illi­
liters of purified ether. This mixture was agitated and the acetone layer was drawn off. The
ether was washed with 100 m illiliter portions of distilled water. The washed ether layer
was then analyzed on the spectrophotometer at 660 nm and 642.5 nm. The resulting
absorption values were used to calculate chlorophyll a and b concentrations (Horwitz,
1975).
Microscopic Examination
Samples of western wheatgrass taken from each o f the four fumigation plots were
placed in a fixing solution of 70 percent ethyl alcohol, proprionic acid, and formalin. After
fixing, the plant material was cut into four millimeter segments and dehydrated. After
dehydration the plant material was imbedded in paraffin. The imbedded material was then
placed in a microtome and ten-micron sections were cut and mounted in microscopic slides
for analysis (Johansen, 1940). The prepared microscopic slides were photographed using
color film at various f-stops for optimum exposure. Color slides of the color negatives were
prepared commercially within the state. The color slides were examined visually for any
anatomical abnormalities. Particular attention was given to cell size, shape and intercellular
space.
15
Field Measurements
Canopy cover was sampled twice during this study, June 3-5 and August 28-30. The
ZAPS plots were divided into "N o rth " and "South" subdivisions for sampling. Sample
lines were randomly placed in each half. Care was taken to avoid microtopographic depres­
sions or areas less than one meter from a sulfur dioxide delivery pipe. A 1/10 square meter
grid was used to sample at one meter intervals along each sample line. Plant species present
within the sample grid were given a canopy coverage value based on the polygon method
(Daubinmire, 1959).
Plant moisture measurements were taken by randomly locating four 0.223 square
meter sample points within each o f the four fumigation plots. All vegetation at these points
was clipped to the ground, separated into life form class (grass, forb, or shrub), weighed and
dried. Wet and dry weights were used to calculate the percent moisture for each sample.
Soil moisture was obtained by random sampling of four sample points within each of
the four fumigation plots. Each sample point was cleared of all plant material and the soil
was removed to a depth o f five centimeters. The soil was then placed in a metal container,
sealed, and weighed. The soil was then dried and weighed again. Wet and dry weights were
used to calculate the percent moisture for each sample.
16
RESULTS A N D DISCUSSION
Aerial Photo Analysis
Photographic density values for the two aerial missions are shown in Figures 4 and 5
(June and August flights, respectively.
0 - -------------- ©
BLUE DENS I TY
-© RED
DENSI TY
■0 GREEN DENSI TY
0
TOTAL DENSI TY
2- 96 -
£ 2 .5 2 -
2.98 -
1.64 -
1. 20
-
F U M IG A T IO N
PLOTS
Figure 4. Densitometric readings on ZAPS; June 1979 (1:3700 CIR film ). Means, within
lines, followed by the same letter are not significantly different (P =0.5).
17
©------------e b l u e
density
® ------------------- ® RED
DENSI TY
© ---------
© GREEN DENSI TY
® -------- «-------- © TOTAL
FU M IG A T I O N
DENSI TY
PLOTS
Figure 5. Densitometric readings on ZAPS; August 1979 (1 :3700 CIR film ). Means, within
lines, followed by the same letter are not significantly different (P=O0B).
The colors quantified by the densitometer are produced in C lR film . The relation­
ships among original and Cl R colors and some examples used in interpretations are given
in Table I.
18
Table I . Rendition o f Subject Colors in CIR Film.
Original (natural) Color
Wave Lengths
(nanometers)
630-700
500-600
400-500
CIR Rendition
Color Rendition
Infrared Rendition
Predominant Wave Length
in Densitometer
green
blue
—
646
54.5
460
red
green
blue
Examples o f CIR records:
• Healthy, vigorous vegetation
Mature or diseased vegetation
Litter
Bare ground
Turbid water
Clear water
Red
Greenish
Green to yellow
White or green
Light blue
Black
June
There was an overall decrease in density with fumigation for all colors. The decrease
was significant when comparing the C and D plots with the. A and B plots for red and green,
but not for blue and total density.
August
The recorded color densities are lower than June values, but this could be due to d if­
ferences in film , exposure, film processing, and plant and substrate reflectance. Therefore,
comparisons of color intensities among dates are not appropriate. As with the June sample
the overall trend is a decrease in density with fumigation. These decreases are more pro­
nounced than in the June sample, and are significant for all colors and total density.
Chlorophyll Analysis
Chlorophyll a and b concentration values for the three 1979 sample dates are shown
in Figures 6, 7, and 8 (June 29, August 16, and August 31 sample, respectively). In the
June 29 sample, there is a significant decline in chlorophyll a and b concentration from
19
a
Ch I o r o p h y I I
b
&- -
—
—
—©
CHLOROPHYLL CONCENTRATION ( „ a / L )
Chlorophyll
0
A
FUMIGATION PLOTS
Figure 6. Chlorophyll a and b concentrations on ZAPS; June 1979 (m g/L). Means, within
lines, followed by the same letter are not significantly different (P =0.05).
20
.0
Chlorophyll
a
° ------------------- ©
C hlorophyll
b
O - — — — -O
“
FUMIGATION PLOTS
Figure 7. Chlorophyll a and b concentrations on ZAPS; August 16, 1979 (mg/L). Means,
within lines, followed by the same letter are not significantly different (P=O0OB)0
fumigation plots A through C. The chlorophyll a concentration on plot D was not signifi­
cantly different from that found on plots B or C. There appears to be an increase in chloro­
phyll b on the D plot. This could be due to sampling error. These results are summarized in
Figure 6.
The August 16 sample shows a general decline in chlorophyll concentration with
increasing sulfur dioxide fumigation (Figure 7).
21
Total levels of chlorophyll a and b and the observed decline of these levels across the
fumigation plots were not as pronounced as in the June sample. This is due to lower overall
chlorophyll concentrations in plant tissue with advancing growth stages (Gausman and
Allen, 1973).
The general decline in chlorophyll concentration observed in the June 29 and August
16 samples was not found in the August 31 sample (Figure 8).
Ch l o r o p h y I I
a
Chlorophyl I b
(•>■
(Sy™ — — — -^S)
FUMIGATION PLOTS
Figures. Chlorophyll a and b concentrations on ZAPS; August 31, 1979 (m g/L). Means,
within lines, followed by the same letter are not significantly different (P=0.05).
22
The August 31 sample was influenced by the same physiological factors as explained
by Gausman and Allen (1973). The fact that the chlorophyll levels were almost identical
across the fumigation plots is due to the cessation of chlorophyll synthesis and accelerated
destruction of existing chlorophyll during late summer or early autumn.
Correlation Analysis
Simple correlation coefficients were calculated for each color and total density and
chlorophyll a and b concentrations for all sample dates. Linear regressions were calculated
for all significant correlations. In the June 29 sample, chlorophyll a had a significant corre­
lation (0.1 level) with photographic density for all colors and total density (Table 2). The
relationship of these correlations is shown in Figure 9. This correlation was not observed
with chlorophyll b. This is due to the inherent resistance of chlorophyll b to sulfur dioxide
damage ( Lauenroth and Dodd, 1980). This resistance may be due to the fact that in higher
plants photosystem I contains a relatively greater proportion of chlorophyll a than chloro­
phyll b while this relationship is less pronounced in photosystem II. Since photosystem Il
is more resistant to external reductants such as sulfur dioxide the net effect is a greater
reduction of chlorophyll a when compared the reduction of chlorophyll b (Kok, 1976).
Table 2. June 29: Chlorophyll-Color Intensity Correlation Coefficients (r)*.
Red
Chlorophyll a
Chlorophyll b
0 .5 4 *
-0 .2 7
Green
0 .5 6 *
-0 .1 9
Blue
Total
0 .5 7 *
0 .5 5 *
0.22
0.23
*r values followed by x are significant at the 0.1 level.
The August 16 sample showed significant correlations of chlorophylls a and b when
each was compared to all colors and total density (Table 3).
The relationship of these correlations is shown in Figures 10 and 11. The reason why
the chlorophyll b-color intensity relationship is significant in the August 16 sample and not
23
a
a - Green
a - Keil
a - T otal
1 .4 5
y
= 1 .8 5
y
=
2 . Nti
1 .5 5
♦ 0 .0 2 6
♦
0 .0 1 9
0 .0 3 6
+ 0 .0 2 3
r
r
r
r
= 0 .5 4
= 0 .5 6
- 0 .5 7
= 0 .5 5
IfY
C h lo ro p h yll
C h lo ro p h yll
C h lo ro p h yll
C h lo ro p h y ll
I _______________,_______________
________________,_______________
,_______________ I_
I
I
I
I
O
4
8
12
16
20
CHLOKOFHYLL A < » t i / L )
Figure 9. Chlorophyll a — Color intensity June 29, 1979.
Table 3. August 16: Chlorophyll-Color Intensity Correlation Coefficients (r)*„
Red
Green
Blue
Total
Chlorophyll a
0 .5 4 *
0 .6 6 *
0 .6 6 *
0 .6 2 *
Chlorophyll b
0.91Y
0.90Y
0.91 Y
0.89y
*r values followed by x and y are significant at the 0.1 and 0.01 level, respectively.
24
2.0
C h lu r o p h y ll
a - B lu e
W •
0 .3 3
f 0 . OS I
C h lo r o p h y ll
a - G reen
u *
0 .3 ?
+ 0 ,0 5 6
C h lu r u p li y ll
a - Rod
y = 0 .3 9
+ 0 .0 5 5
C h lo r o p h y ll
a- T o ta l
u *
+ 0 .0 5 5
0 .3 6
0.66
CHLOROPHYLL A ( m a / L )
Figure 10. Chlorophyll a — Color intensity August 16, 1979.
in the June sample may be a reduction in overall chlorophyll concentration due to senes­
cence (Gausman and Allen, 1973).
In the August 31 sample there was no significant correlation between chlorophyll a
and any color or total density. There were significant correlations between chlorophyll b
and the colors blue and green. Since the colors blue and green represent absorption at wave
lengths of 400-500 nanometers (nm) and 500-600 nm, respectively, and chlorophyll b
25
2.0
“I
C h lo r o p h y ll b - B lu e
C h lo r o p h y ll b - G reen
C h lo r o p h y ll b - Ked
C h lo r o p h y ll b -
1.0
T o ta l
-
CHLO RO PHYLL
b
< e iH /L )
Figure 11. Chlorophyll b — Color intensity August 16, 1979.
shows absorption of radiant energy at 645 nm, the correlations in the August 31 sample are
probably a reflection of secondary plant pigments such as xanthophylls and carotenoids.
Both the August 16 and 31 sample extracts were analyzed for free magnesium ions.
The presence of these ions would suggest the formation of pheophytins (Roa and LaBIanc,
26
1965). Since pheophytins are formed from the reaction between sulfur dioxide and chloro­
phyll one would expect to find magnesium ions present at the higher levels of sulfur dioxide
fumigation; no such relationship was found.
Canopy Coverage Analysis
There were no definite trends observed in the June sample. The mean coverage
obtained on plot C was significantly higher than the means found on all other plots (Figure
12).
®
0
ad
A
fumigation
plots
Figure 12. Total vegetational cover on ZAPS; June 1979 (%). Means, within lines, not fol­
lowed by the same letter are significantly different (P=CLOS).
27
There were no significant differences between plots A and D. The mean coverage on
plot 8 was significantly different than that of plot A but not plot D. The absence o f a
downward trend in canopy coverage with increasing levels of sulfur dioxide, during June,
suggests that during the canopy's early growth stages plants are able to produce enough
new growth to effectively mask any adverse effects that sulfur dioxide may have on total
vegetative cover. In the absence of any significant differences in canopy cover across the
fumigation plots the question remains does sulfur dioxide have an adverse effect on higher
plants? It has been shown in this study and others at the ZAPS site that chlorophyll con­
tent will decline with increasing rates of sulfur dioxide fumigation ( Lauenroth and Dodd,
1980). It is also known that higher plants synthesize more chlorophyll than they need
(Gausman and Allen, 1973). The reduced levels of chlorophyll found with sulfur dioxide
fumigation are not biologically significant unless they effect other physiological processes
within the plant. Since photosynthesis is the ultimate source of energy for the plant, a
reduction o f chlorophyll content by sulfur dioxide to levels which adversely effect carbo­
hydrate production could ultimately be seen in a reduction of plant growth and canopy
coverage.
In August there was an overall decline in total vegetative cover across the fumigation
plots (Figure 13).
•
'
There was no significance between the value found on plot A when compared with
the values obtained on plots B and C, and plot C when compared to plot D„ There were
significant differences when comparing either plots A or B to plot D0 It is interesting to
note that early aerial coverage of the ZAPS site did not show decreases in canopy cover­
age with fumigation while reduced chlorophyll levels were apparent from the onset (Taylor
and Leininger, 1978; Dodd et al., 1979). Observable declines in canopy coverage were not
noticed until after at least tw o years o f fumigation. These results may be explained by the
cumulative effects of carbohydrate suppression due to reduced chlorophyll levels.
TOTAL VEGEl ATl ONAL COVER ( Z )
28
FUMIGATION PLOTS
Figure 13. Total vegetational cover on ZAPS; August 16, 1979 (%). Means, within lines,
not followed by the same letter are significantly different (P =0.005).
29
Correlation Analysis
Simple correlation coefficients and linear regressions were calculated for each color
and for total density and total vegetative cover for both sample dates. Linear regressions
were calculated for all significant correlations. There were no significant correlations
between the June total coverage values and any color or total density (Table 4).
Table 4. Total Vegetational Cover-Color Intensity Correlation Coefficients (r)„
June
Red
Green
Blue
Total
0.003
-0 .1 3
. -0 .0 6
-0 .0 5
There were significant correlations among all colors and total density and the August
coverage values (Table 5). The relationship of these correlations is shown in Figure 14.
Table 5. Total Vegetational CoverCoIor Intensity Correlation Coefficients (r)*.
August
Red
Green
Blue
Total
0.72z
0.76z
0.77z
0.73z
* r values followed by z are significant at the 0.05 level.
Microscopic Analysis
There was no evidence to suggest that sulfur dioxide had any effect on cell size, shape,
or intercellular space. Although there were examples of collapsed cell space and disrupted
cell walls, they were observed on all plots. An example from each of the four fumigation
plots are shown in Figure 15.
Plant Moisture
The percent plant moisture for the June sample showed no significant differences
among the moisture contents of the forbs harvested from each of the four fumigation plots.
30
V e g e ta c io n a l
V e g e t a t io n a l
V e g e t a t io n a l
V e g e t a t io n a l
C o ve r
Cover
C o ve r
C o ve r
TO TAl
- B lu e
- G reen
- Red
- T o ta l
UFOFT A T I ONAl
COVER
U>
Figure 14. Vegetational cover — Color intensity August 16, 1979.
but the moisture content of the grasses on the D plot was significantly higher than that of
the grasses clipped on the other plots (Figure 16). This significance can be explained by a
rain shower which occurred while the D plot was being harvested.
31
Figure 15. Microsections of western wheatgrass leaves under four levels of sulfur dioxide
fumigation. A=O, B = 2, C =5, D = IO pphm.
Soil Moisture
There were no significant differences among the soil moisture indices from the four
fumigation plots for either the June or August sample dates (Figure 17).
32
O- —
50
~
40
—
30
-
O—
Grasses
O------- -
20
—
-O
Forbs
-
FUMIGATION PLOTS
Figure 16. Plant moisture (%). Means, within lines, not followed by the same letter are
significantly different (P =0.05).
33
6 . 0 ~l
June
o—
5.0
-
4.0
-
-
-o
August
3.0 -
1 .0
-
FUMIGATION PLOTS
Figure 17. Soil moisture (%). Means, within lines, not followed by the same letter are sig­
nificantly different (P=O=OB).
34
S U M M A R Y A N D CONCLUSIONS
This research has shown that exposure o f native vegetation to sulfur dioxide fumiga­
tion has reduced chlorophyll concentration and total vegetative cover. These reductions
were directly proportional to the level of sulfur dioxide fumigation. The methods by which
these sulfur dioxide-induced changes were monitored and quantified were aerial photogra­
phy and ground truth data collection. Aerial photographs showed a decrease in the color
intensity of photographic records of the Zonal A ir Pollution System. As with chlorophyll
and vegetative cover color intensity decreased in direct proportion to sulfur dioxide fumi­
gation. The reduction in photographic color intensity was noted after the first fumigation
season in 1973, although ground observations did not indicate a change in the vegetational
canopy until 1976. The cause of the observed reduction in color intensity is the adverse
effects sulfur dioxide has on those parameters which affect a plant's ability to reflect, trans­
m it, and absorb radiant energy. By comparing those factors which are adversely affected
by sulfur dioxide and affect a plant's spectral properties; factors were identified which
might explain the reduced color density on the photographic records o f the ZAPS site. In
this study there were significant correlations between reduced chlorophyll a concentration
in the June 29 sample and reduced color intensity on the photographic records of the
Zonal A ir Pollution System. The August 16 sample showed a significant correlation between
reduced chlorophyll b and b concentrations and reduced color intensity on the August
photographs.
These correlations were not present when chlorophyll a o rb concentrations from the
August 31 sample date were compared to photographic color intensity. These results indi­
cate that reduced color intensity on photographic records duringthe canopy's growth stages
35
are due to reduced chlorophyll concentration. The lack o f correlation between chlorophyll
concentration (and color intensity in the August 31 sample date is probably due to the
natural reduction in chlorophyll as the canopy approaches winter dormancy. There was
no observable correlation between cellular integrity and reduced color intensity for either
sample date. Although disrupted cells were observed, they were present in all samples and
could have been caused by sulfur dioxide or faulty preparation. Comparisons of June 29
and August 16 total canopy coverage values with the color intensity values on June photo­
graphs showed no significant correlations. The reduction in total canopy coverage in the
August 31 sample showed a significant correlation to reduced color intensity on the August
photographs. This suggests that reduced color intensity during the later growth stages of a
canopy are due to reduced canopy coverage. A t no time of the season did plant moisture
or soil moisture show any significant relationship to reduced color intensity on photogra­
phic recores of the ZAPS site. This study demonstrates that both chlorophyll concentra­
tion and total vegetative cover will influence the color intensity on photographic records of
the ZAPS site, but their relative contribution will be a function of the physiological activ­
ity of the canopy. The higher the physiological activity (i.e., chlorophyll production, high
rates of photosynthesis) the greater the contribution chlorophyll concentration will have
on the color intensity of a photograph. As the physiological activity of a canopy slows
down the greater total canopy coverage will contribute to the color intensity of a photo­
graphic record. These research points toward the sensitivity of aerial photography as a
remote sensing technique. It shows that aerial photography can be used to sample both
physiological and community aspects of a vegetational canopy. This sensitivity combined
with aerial photography's non-destructive mode of supplying a permanent, reliable source
of environmental record points toward its usefulness to the natural resource manager.
36
L IT E R A T U R E C ITE D
37
L IT E R A T U R E C ITED
Adedipe, IN, O., R. E. Barrett, and D. P. Ormrod. 1972. Phytotoxicity and growth of orna­
mental bedding plants to ozone and sulfur dioxide. J. Amer. Soc. Hort. Sci. 97:341345.
A m on, D. I. 1949. Plant Physiol. 24:1-15.
Ben net, J. H., A. C. Hill, and D. M. Gates. 1973. A model for Gaseous Pollutant Sorption
by Leaves. A ir Pollut. Cont. Assoc. J. 23:957-962.
Cowling, D. W., L. H. P. Jones, and D. R. Lockyer. 1973. Increased yield through correc­
tion of sulfur deficiency in ryegrass exposed to sulfur dioxide. Nature 243:479-480.
Daubenmire, R. F. 1959. A Canopy-Coverage Method of Vegetational Analysis. Northw.
Sci. 33(1 ):43-64.
Dodd, J. L., W. K. Lauenroth, G. H„ Thor, and M. B, Coughenour. 1978. Effects of Chronic
Low Level Sulfur Dioxide Exposure on Producers and Litter Dynamics. In: The Bioenvironmental Impact of a Coal-Fired Power Plant, Fourth Interim Report, Colstrip,
Montana. E. M. Preston and T. L. Gullett (eds.), EPA-600/3-79-044 U.S. Environmen­
tal Protection Agency, Corvallis, Oregon, pp. 384-493.
Dodd, J. L., W. K. Lauenroth, and P. K. Heitschmidt. 1979. Effects of Controlled Sulfur
Dioxide Exposure on Net Primary Production and Plant Biomass Dynamics. In: The
Bioenvironmental Impact of a Coal-Fired Power Plant, Fifth Interim Report, Colstrip,
Montana. E. M. Preston and D. 0 . Guinn (eds.),’ U.S. Environmental Protection
Agency, Corvallis, Oregon, pp. 172-194.
Eversman, S. 1978. Effects o f Low-Level Sulfur Dioxide Stress on Two Lichen Species. In:
The Bioenvironmental Impact of a Coal-Fired Power Plant, Third Interim Report,
Colstrip, Montana. E. M. Preston and R. A. Lewis (eds.), EPA-600/3-78-021 U.S.
Environmental Protection Agency, Corvallis, Oregon, pp. 385-398.
Eversman, S„ 1979. Effects of Low-Level Sulfur Dioxide Stress on Two Native Lichen
Species. In: The Bioenvironmental Impact of a Coal-Fired Power Plant, Fourth
Interim Report, Colstrip, Montana. E. M. Preston and T. L. Gullett (eds.), EPA-600/379-044 U.S. Environmental Protection Agency, Corvallis, Oregon, pp. 642-672.
Gates, D. M., H. J. Keegan, J. C. Schleter, and V . R. Weidner. 1965. Spectral Properties of
Plants. Applied Optics, Vol. 4 , no. I , pp. 11-19 Jan. 65.
Gausman, H. W. and W. A. Allen. 1973. Optical parameters of leaves of 30 plant species.
Plant Physiol. 52:57-62.
38
Gausman, H. W., R„ R. Rodriquez, and A. J. Richardson. 1976. Infinite Reflectance of
Dead Compared with Live Vegetation, biblio. il Argro. J. 68:295-296 Mr. 76.
Godzik, S., and W. Knabe. 1973. Comparative electron microscopic investigation of the
fine structure of chIoroplasts of certain Pinus species from the Ruhr and upper Silesian
industrial areas. Proc. Inti. Clean Air Congr., 3rd. Duesseldorf, W0 Germ., pp. A164A l 70.
Heggestad, A. E. 1968. Diseases o f crops and ornamental plants incited by air pollutants.
Phytopathology 58:1089-1097.
Horwitz, W. (Ed.). Official Methods of Analysis. Assoc, of Official Analytical Chemists.
Tw elfth edition, 1975.
Johansen, D. A. 1940. Plant Mictotechnique. McGraw-Hill, New York and London.
Kok, B. 1976. Photosynthesis: The Path of Energy, In: Plant Biochemistry. Third Edition,
J. Bonner and J. E. Varner (eds.). Academic Press, Inc., pp. 846-883.
Laboratory for Agriculture Remote Sensing. 1967. Interpretation of Remote Multispec­
tra I Imagery of Agriculture Crops. Purdue Univ. Agr. Res. Bull. 831.
Lauenroth, W. K., and J. L. Dodd. 1980. Chlorophyll reduction in western wheatgrass
exposed to sulfur dioxide. In: The Bioenvironmental Impact o f a Coal-Fired Power
Plant, Fifth Interim Report, Co !strip, Montana. E. M. Preston and D. 0 . Guinn (eds.),
U.S. Environmental Protection Agency, Corvallis, Oregon, pp. 197-203.
Lee, I. J., and R. A. Lewis. 1978. Zonal Air Pollution System. In: The Bioenvironmental
Impact of a Coal-Fired Power Plant, Third Interim Report, Colstrip, Montana. E. M.
Preston and R. A . Lewis (eds.), EPA-600/3-78-021 U.S. Environmental Protection
Agency, Corvallis, Oregon.
MacKinney, G. 1941. J. Biol. Chem. 140:315-322.
Nieboer, E., D. H. S. Richardson, K. J. Puckett, and F. D. Tomassini. 1975. The phyto­
toxicity of sulfur dioxide in relation to measurable responses in lichens. In: Effects
of Air Pollutants on Plants. Edited by T . A. Mansfield. Cambridge Univ. Press.
Parker, J. L , L R. Guptill, Jr., K. M. Bajema, W. A. Berg, L. Logan, and R. E. Adams.
1971. Soil Survey of Powder River Area Montana. U.S. Dept, of Agr. and the Interior
in cooperation with the M t. Agr. Exp. Sta.
Roa, D. N., and F. LeBlane. 1965. Effects on the lichen algae of sulfur dioxide with special
reference to chlorophyll. Bryologist. 69:69-75.
Scherz, J. P., and A. R. Stevens. 1970. An Introduction to Remote Sensing for Environ­
mental Monitoring. Univ. of Wisconsin, Remote Sensing Program, Report No. I ,
80 pp.
39
Severson, J. G., and S. J„ Dina. 1974. Effects of airborne pollutants on physiological, eco­
logical, and biochemical processes of plants. In: Protocol for a biological (ecological)
effects monitoring system. U.S. Environmental Protection Agency, Corvallis, Oregon,
pp. 241-306.
Taylor, J. E., and W. C. Leininger. 1977. Remote Sensing of Sulfur Dioxide Effects on
ZAPS. In: The Bioenvironmental Impact of a Coal-Fifed Power Plant, Third Interim
Report, Co !strip, Montana. E. M. Preston and R. A . Lewis (eds.), EPA-600/3-78-021
U.S. Environmental Protection Agency, Corvallis, Oregon.
Taylor, J. E., and W. C. Leininger. 1978. Remote Sensing of the Bioenvironmental Effects
of Stack Emissions in the Colstrip V icinity. In: The Bioenvironmental Impact of a
Coal-Fired Power Plant, Fourth Interim Report, Colstrip, Montana. E. M. Preston and
T. L. Gullett (eds.), EPA-600/3-79-044 U.S. Environmental Protection Agency, Cor­
vallis, Oregon.
Taylor, J. E., W. C. Leininger, and M. W. Hoard. 1980. Remote Sensing of Sulfur Dioxide
Effects on ZAPS. In: The Bioenvironmental Impact of a Coal-Fired Power Plant,
Fifth Interim Report, Colstrip, Montana. E. M. Preston and D. 0 . Guinn (eds.), U.S.
Environmental Protection Agency, Corvallis, Oregon, pp. 292-303.
Thomas, 1961. Effects of A ir Pollution in Plants, in "A ir Pollution," pp. 233-278. W.H.O.
(Geneva) Monogr. no. 46.
Wel!burn, A. R., 0 . Majernik, and F. Wellburn. 1972. Effects of sulfur dioxide and nitro. gen oxide polluted air upon the ultrastructure of chloroplasts. Environ. Pollut. 3:3749.
Woodcock, W. E. 1976. Aerial Reconnaissance and Photogrammetry with Small Cameras.
Photogrammetric Eng. and Remote Sensing 4 2 :5 0 2 -5 1 1.
40
A PPEN D IX
41
Table 6. Species Encountered on the ZAPS Site
Plot
Species
Graminoids
Agropyron smith//
A. spicatum
Aristida iongiseta
Bouteloua gracilis
Bromus japonicus
B. lsctorum
Buchloe dactyloides
Caiamagrostis montanensis
Carex fHi folia
C. pennsyivanica
Danthonia unispicata
Festuca idahoensis
Juncus interior
Koeieria cristata
Muhienbergia cuspidata
Phieum pratense
Poa p ra ten sis
P. sandbergii
Schedonnardus panicuiatus
Sporobolus cryptandrus
Stipa comata
S. viriduia
Vuipia octo flora
A
B
D
C
------X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Forbs
Achillea m illefolium
Agoseris g/auca
AHium textile
Ambrosia psilostachya
Androsace occidenta/is
Antennaria species
A. neglecta
A. rosea
Arabis hoiboeiHi
Arnica sororia
Artemisia iudoviciana
Asciepias pumiia
Aster species
Medicago sativa
Meiiiotus aiba
M. officinalis
Mertensia species
M. obiongifoiia
Monardafistulosa
Opuntia fragiiis
0 , po/ycantha
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
42
Table 6 (continued).
Plot
Species
A. falcatus
Astragalus species
A. crassicarpus
A. drummondii
A. giM fIorus
A. purshii
Bahia oppositifolia
Besseya wyomingensis
Camelina microcarpa
Cafochortus nuttallii
Cerastium arvense
Chenopodium album
Chorispora tenella
Cirsium unduiatum
Coiiomia linearis
Conyza canadensis
Crepis species
Delphinium bicoior
Descurainia species
Draba species
Enchinacea pallida
Erigeron divefgens
E. pumilus
Erysimum asperum
Gaura coccinea
Geum trifiorum
Grindeiia squarrosa
Hapiopappus spinulosus
Hedeoma hispida
Heterotheca villosa
Lactuca serriola
Lappuia echinata
Lepidium densiflorum
Leucocrinum montanum
Lithospermum incisum
L. ruderaie
Lomatium species
L orientale
Lupinus species
L sericeus
Mammiiiaria missouriensis
Orthocarpus Iuteus
Oxytropis sericea
Penstomon species
P. nitidus
A
B
C
X
X
X
X
X
X
X
X
X
X
XX
X
D
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
43
Table 6 (continued).
Plot
Species
Petalostemon purpureum
Phlox hoodii
Plantago patagonica
P. splnu/osa
Polygonum viviparum
Psoralea argophylla
Pc esculenta
Ranunculus glaberrimus
Ratibida columnifera
Senecio species
Sisyrinchium angustifolium
Solidago species
S. missouriensis
Sphaeralcea coccinea
Taraxacum officinale
Thlaspi arvense
Tragopogon dubius
Vicia americana
Viola nuttallii
Zygadenus venenosus
A
B
C
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
D
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Shrubs and half-shrubs
Artemisia cana
A. dracuncu/us
A. frigida
A. tridentata
A tripiex nuttallii
Ceratoides ianata
Xanthocephaium sarothrae
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