DECOMPOSITION AND DISAPPEARANCE O F
ORGANIC DEBRIS IN THREE REPLICAT E
STREAMS WITH DIFFERENT NITRATE INPU T
by
F . J . Triska and J . R . Sedel l
Department of Fisheries and Wildlif e
Oregon State University
Completion report for research project A-029-ORE sponsored by
The Office of Water Research and Technology, USDI, and in par t
by the National Science Foundation, Coniferous Fores t
Biome I . B . P . Grant .
WATER RESOURCES RESEARCH INSTITUT E
Oregon State University
Corvallis, Oregon 9733 1
.
WRRI-37
October 1975
W-ee.A.Mxa-')
DECOMPOSITION AND DISAPPEARANCE OF ORGANIC DEBRI S
IN THREE REPLICATE STREAMS WITH
,
DIFFERENT NITRATE INPUT
by
T
F . J . Triska and J . R . Sedell
Department of Fisheries and Wildlife
Oregon State University
4.
Completion report for research project sponsored by th e
Office of Water Research and Technology, USDI .
..
it
.
•
The heterotrophic nature of small woodland streams elaborate d
by Teal (1957) has been tested and confirmed on numerous occasions b y
aquatic ecologists . More recently, stream ecologists have concentrate d
their studies on larger (third to fourth order, Strahler 1964) streams wher e
the interplay of autotrophic and hetrotrophic energy pathways, habi t
diversity and fluctuation of physical and chemical parameters frombasi c
groundwater states are maximized . Such environmental diversity result s
in a biological diversity and production not equalled in first order streams .
Nonetheless, first and second order streams are significant since 70% o f
all stream miles in the continental U . S . are of these small streams .
Furthermore, the physical and chemical parameters which facilitat e
biological diversity and production in midsized streams are a cumulativ e
product of a watershed's lower order streams to which the biology of th e
headwaters significantly contributes . In first order drainages, the biolog y
of the stream is most intimately tied to the terrestrial landscape . Tall, old growth forests of Douglas-fir and hemlock shade the water, inhibit strea m
autotrophy and contribute up to 65% of the annual energy now throug h
abscission of needle litter . Understory vegetation, including alder, vin e
maple and big-leaf maple, contribute deciduous litter to the stream ecosystem .
Tree boles and limbs felled by age, wind, or disease contribute tremendou s
amounts of large, woody debris which form dams incapable of being moved
by the small water volume of headwater streams . Debris dams retain litte r
for microbial processing which, in turn, prepares it for invertebrate consumptio n
or export to downstream biological communities . A major characteristic of
small headwater drainages in the Cascade Mountains of the Pacific Northwest ,
U .S .A., is the presence of low concentrations of inorganic nitrogen in stream
water . The low nitrogen concentration of groundwater is the result of bot h
nutrient conservation of old growth forests and the geological nature of bedroc k
materials . A major characteristic of litter debris in streams is also lo w
nitrogen concentration of naturally abscissed litter, particularly fro m
coniferous species . Numerous studies have indicated the necessity fo r
preparation of litter material by the microbial community prior to passage o f
energy and nutrients through the processing machinery of higher trophic levels .
Thus, microbial processing indirectly affects the biological productions o f
small forested streams where heterotrophic processes control such production .
High C/N ratios of abscissed litter material and low inorganic nitroge n
concentrations in stream water led to the following hypotheses : 1) The
ability of the microbial community to process the energy base (leaf litter )
and prepare it for passage to higher trophic levels will be determined by th e
nitrogen concentration of stream water ; and 2) if any nutrient is limiting t o
biological production in small forested streams, it is nitrogen .
To test the effect of nitrate addition on litter processing, a controlle d
experiment was undertaken in three replicate stream channels . Themagnitude
of nitrate addition stimulated the effect of nitrogen fertilization or logging o n
small watershed streams . The objectives of the first year's research were
as follows :
2.
To determine if decomposition rates in streams are increase d
by nitrate additions such as might occur in clearcut or fertilize d
watershed .
b) To monitor the change in carbon quality of leaf litter as i t
decomposed .
c) To compare respiration rates of decomposing litter betwee n
treatment and control streams, for four litter species .
During the second year, complimentary research was undertaken :
a) To compare nitrogen concentration of four species of lea f
litter as decomposition proceeds in three streams wit h
different nitrate input .
b) To determine if litterfall debris in streams acts as a short ter m
nutrient sink . In effect, to estimate the capacity of leaf materia l
to capture and exchange cations .
c) To monitor changes of micronutrient content on decomposing plan t
material .
The study was undertaken in conjunction with Weyerhaeuser Corp . scientifi c
personnel who had previously begun their own investigations in the same
streams . These streams were ideal to test certain aspects of leaf decomposition since they provided control not usually found in more natural strea m
systems :
1) The streams were well studied both biologically and in terms o f
water chemistry ;
2) The temperature was constant, thereby removing it as a variable ;
3) The current and water volume were also constant, thus removin g
another two variables . The fact that these streams do not flood i n
the winter greatly minimizes possible fragmentation of litter due to
mechanical means, e .g ., current and physical abrasion by suspende d
sediment ;
4) Since there is no vegetative material falling into these stream s
there are no insects present which feed primarily on intact leaves .
This absence of leaf shredders also permitted focusing on the microbia l
decomposition processes in the streams . Furthermore, the levels of nitrat e
addition were realistic in terms of those reported by Fredricksen (1971 ,
personal communication) in other clearcut watersheds of the Pacific Northwest .
A more complete description of the study site is provided in Triska and Sedel l
(1975).
a)
Materials and Method s
To accomplish the above objectives, leaf litter of four commo n
streamside species, vine maple, big-leaf maple, red alder, and Douglas-fi r
was collected at abscission and dried at 50 0 C . Leaf packs were used as a
method of investigation . Rates of weight loss were calculated by fitting the
data to the exponential model Yt = Yo e-kt derived from Olson (1963) an d
Peterson and Cummins (1974) . Lines were fitted by linear regression and
logarithmetic transformation . The second objective, measurement of carbo n
quality, was assessed by comparing changes in lignin composition to change s
in acid detergent cell wall material according to the method of Van Soes t
(1963) . The third objective, comparison of respiration rates between treatment
3.
•
•
and control streams, was undertaken on a 14 station Gilson respiromete r
(Gilson 1963) by measurement of oxygen consumption . A more detaile d
explanation of the above methods is presented inTriska and Sedell (1975) .
During the second year, the capacity to retain and hold nitrogen a s
decomposition proceeds was also examined . Measurements of nitroge n
concentration were undertaken by the micro-Kjeldahl method . To calculate
C/N ratios, carbon concentrations were spot checked on a Burell tota l
carbon analyzer . Analysis for other nutrients including potassium,phosophorus ,
calcium magnesium and fine micronutrients were conducted on a Perkin Elmi r
IM Emission Spectrophotometer . In order to obtain an estimate of the capacit y
of organic material to bind nutrients, cation exchange capacity was measure d
according to the procedure of Jackson (1958) . Determinations of cation
exchange capacity by this method involves extraction with ammonium acetat e
at a pH of 7 .0 . Since nitrate addition did not significantly accelerat e
decomposition, litter from streams where decomposition proceeds rapidl y
(Mack Creek), and a stream where decomposition proceeds slowly (WS 10)
were chosen for this comparison . Both streams are located in the H . J .
Andrews Experimental Forest in the Cascade Mountains of Oregon . A complete
diagram of the experimental design for both years is provided on Figure 1 .
Results and Discussion
First Year Research Summary : As noted previously, the experimen t
was undertaken in three replicate channels . During the course of the study ,
one stream received a chronic input of 100 ppb nitrate above base level ; one
stream received nitrate of 100 ppb when precipitation amounted to .65 cm or
more ; and, one stream remained as a control at 30 ppb nitrate . During th e
course of the study, actual nitrate concentrations fluctuated around a mean o f
37 ppb for the control stream, 59 ppb for the intermittent stream, and 138 ppb
for the continuous nitrate stream . A graph of actual nitrate concentration s
throughout the study is provided inTriska and Sedell (1975) . Despite
differences in nitrogen concentration, the slopes of weight loss regression s
were not significantly different between treatment and control streams . The
lack of significant differences in weight loss was true for all four specie s
tested . Significant differences in weight loss have been reported by Hyne s
and Kaushik (1969) and Howarth and Fisher (1976) at nitrate levels 100 time s
those used in this study . Of the four species tested, two disappeared rapidl y
(vine maple and red alder), while two disappeared more slowly (big-leaf mapl e
and conifer) . Previous studies (Sedell, et al . 1975 and Triska, et at . 1975)
indicate that the constant cold temperature (6°C± .5°) supplied sufficient
degree days to avoid a temperature limitation to leaf pack weight loss . The
effect of a similar thermal regime (equal number of degree days) but with a
diurnial temperature fluctuation could not be tested as a determinant o f
litter decomposition rates .
Because of mechanical breakage and leaching losses, determination s
of carbon quality and leaching losses were also undertaken . As expected ,
lignin composition increased and acid detergent cell wall decreased a s
decomposition proceeded . The two litter species which decomposed fastest,
4.
vine maple and alder, showed the greatest increase inlignin and decrease i n
acid detergent cell wall . The two slowest decomposing species, big-leaf
maple and Douglas-fir, exhibited the least increase in lignin content an d
decrease in acid detergent cell wall . Differences in percent composition
between the nitrate treated streams and the control stream were not observed .
Like weight loss and carbon quality, respiration activities tracked
well with time in all three streams regardless of nitrogen treatment .
Respiration rates increased as leaf packs became colonized in autumn an d
decreased as packs were reduced to refractory lignified residues by spring .
Since stream temperature remained essentially constant, seasonal temperatur e
effects have been eliminated . Leaf packs of vine maple, which lost weigh t
most rapidly, also had the highest rates of oxygen consumption . Needl e
packs of Douglas-fir which disappeared most slowly had the lowest rates o f
oxygen consumption, but over a more extended time period . Overall, no
significant effects of nitrate addition could be concluded from the respiratio n
measurement of oxygen consumption . As in the other measured parameters ,
species differences of litter material were greater than treatment difference s
in all three streams .
Second Year .
During the second year research effort focuse d
on a comparison of nitrate concentration between treatment and contro l
streams, measurements of phosphorus, and other nutrient concentrations ,
and measurements of cation exchange in decomposing litter debris . The
results of nitrogen analyses were converted to absolute nitrogen content i n
order to provide a comparison with litter prior to stream incubation and betwee n
the two treatment streams and the control stream . Increase in nitroge n
concentration is a well known phenomena in decomposing litter . Such a
capacity to retain and hold nitrogen may be based on four possible processes :
1) Nitrogen immobilization . Nitrogen may be immobilized by incorporatio n
into fungal and microbial protein as carbon is mineralized . Nitroge n
immobilization has commonly been demonstrated in both agricultural investigations and for many species of leaf litter and wood in soil studies . Whe n
nitrogen immobilization occurs, the nitrogen percentage concentration increase s
while the absolute amount of nitrogen remains unchanged . 2) Uptake of
nitrate from stream water . If absolute amounts of nitrogen increase by uptak e
of nitrate from the water, then litter from the two streams with nitrat e
treatments might be expected to contain higher absolute amounts of nitroge n
than the control stream . 3) Nitrogen fixation . This microbial process results
in an increase in nitrogen content by fixation of molecular nitrogen . Both o f
the latter two processes could result in an absolute increase in the amount o f
leaf pack nitrogen . 4) Exchange of ammonia on organic substrates . The last
possible source of nitrogen was considered nonsignificant since ammonia wa s
not detectable in the spring water source and increased to only 1 .5 ppb at the
foot of the experimental channels .
Absolute increases in nitrogen content, in addition to increases i n
concentration, as litter decomposes on soils have been reported by Gilber t
and Bocock (1960) and Bocock (1964) . In flowing water systems, Mathew s
and Kowalczewski (1969) reported increases in nitrogen concentration through-
r
5.
•
•
out decomposition, and absolute nitrogen increases during initial stage s
of decomposition of willow and sycamore litter in coarse mesh bags fro m
the River Thames . Iversen (1973) has also found both absolute increas e
and increase in concentration of nitrogen in beech leaves decomposing in a
Danish stream .
In this study, absolute increases in nitrogen content were used sinc e
they establish a basis of comparison with leaf litter at the time of initia l
incubation and were normalized to an initial leaf pack of 10 grams dry weight .
All species of litter leached approximately 50% of their initial nitrogen content
during the first four days (Fig .2 ) . Within 40 to 70 days, leaf packs containe d
a greater nitrogen content than when the packs were initially incubated in the
respective streams . Nonetheless, the final absolute content of nitrogen wa s
not related to nitrate treatment .
Absolute content of nitrogen was considered in relation to weight loss ,
to determine the capacity of leaf packs to retain nitrogen as the weight of th e
leaf packs decreased (Fig . 3) . More than 100% of the initial nitrogen conten t
remained although more than 50% of the pack had disappeared . For alder an d
vine maple, peak nitrogen content was attained within 40 days of leaf pac k
incubation . Packs of big-leaf maple attained maximum nitrogen conten t
within 110 days, and conifer within 173 days . The mechanisms for thi s
dramatic increase in nitrogen in both concentration and absolute amoun t
following leaching is not understood at this time but may be related to complexin g
of nitrogenous compounds with lignin, to be discussed later .
It was curious to note that peak nitrogen content occurred at incubatio n
times near those at which litter material became palatable to aquatic detritu s
consuming invertebrates in previous studies (Sedell, et al . 1975, Anderson
and Grafius 1975) . This observation lends support to the recent finding of a
microbial conditioning prerequisite to insect consumption and has importan t
implication for both decomposition and energy flow to higher trophic levels .
If detritus consuming invertebrates are stripping microbial biomass as a
major source of nutrition, then it is unlikely that detrital carbon is ever a
limiting element in energy flow of stream ecosystems, except for the influenc e
of carbon quality on detrital breakdown by the microbial community . Evidence
from previous studies suggests that consumer invertebrates are willing t o
sacrifice carbon quality for microbial biomass . This loss of carbon quality
may be measured by the proportional decline of acid detergent cell wal l
materials, and increase in percent composition of lignin during the tim e
required for microbial growth (conditioning) . The sacrifice in carbon quality ,
results in a net gain in nitrogen, through immobilization by microbial biomas s
or other processes considered earlier . The rate of microbial processing is in
turn dependent on the factors of lignin and nitrogen concentrations . These two
substances are thus the key factors for microbial growth, organic matte r
breakdown, and energy now to higher trophic levels in streams dominate d
by heterotrophic processes .
Plant tissues, in this case leaf litter, vary greatly in their concentration s
of total fiber (lignin + cellulose) and nitrogen (Table 1 ) . Red alder, which
6.
decomposed very rapidly, was characterized by low total fiber conten t
• (18 .5%) and nitrogen (2 .16%) . Douglas-fir, which decomposed most slowly ,
had the highest total fiber content (38 .5)% and lowest nitrogen concentratio n
( .64%) at the time of abscission . When thenitrogen content of litter detritu s
is high and in a form readily utilized, then microbial colonization and accompanying decomposition will proceed at a rapid pace and conditioning time will b e
short . When the substrate is poor in nitrogen, however, decomposition i s
retarded . In aquatic systems, massive leaching of nitrogen presents
additional obstacles to microbial decomposition (Table 2 ) . Leaching losses
of nitrogen averaged 52% for all four species in all three streams . The
recovery of nitrogen to levels near initial concentrations indicates tha t
decomposing leaf material does have a capacity to remove nitrate from th e
water . The capacity to achieve nitrogen concentrations significantly abov e
this level, however, would depend upon a massive influx of nitrogen far abov e
levels usually experienced as a result of land management practices .
The carbon concentration of most litter detritus is approximately 45 %
and does not change significantly as litter is decomposed through time . As
a result, the C/N rates serves as an indicator of susceptibility to decay ,
and an index of food quality for detritus consuming invertebrates . During the
decomposition of litter material, the C/N ratio decreases with time (Table s
4-7 ) . The decrease in C/N ratio was observed in all four litter species i n
all three streams . This results from both theuptake of nitrogen from water
and immobilization of litter tissue nitrogen in microbial biomass as carbon i s
oxidized to 002 . Accoring to Alexander (1961), C/N ratio of tissue nitroge n
will continue to approach 10/1 as decomposition proceeds . The ratio of 10/ 1
represents the average composition of microbial cells . In this study, only
red alder with a mean C/N of 14 approached a ratio of 10/1 following recover y
from losses due to leaching . In vine maple, the C/N ratio averaged 30/1 ,
in big-leaf maple 31/1, and in Douglas-fir litter 45/1 . Because the C/N rati o
of vine maple, big-leaf maple, and Douglas-fir never approached a C/N rati o
of 10/1 , it is reasonable to assume that nitrogen was limiting to decompositio n
in these three species for the full decomposition period . Under such conditions ,
bacteria and fungi can remain metabolically active as available nitrogen i s
utilized either by biological immobilization or by complexing with organi c
residues such as lignin . With the passage of time, nitrogen is returned to the
ecosystem by mineralization following cell death or by leaching from living ,
microbial tissue . The remainder is passed on to a succession of microbia l
communities mandated by a deterioration of carbon quality and seasonal change s
in water temperature .
Just as C/N ratios approach 10/1 , the average constituents of microbial
protoplasm, N/P ratios also approach an approximate ratio of 10/1 . In
this study, vine maple had the lowest N/P ratio at 6/1 (Tables 4-7 ) . Re d
alder had a mean N/P ratio of 17, bigleaf maple had a mean ratio of 8/1,
I
and Douglas-fir a ratio of 9/1 . Such data reveal two aspects of phosphorus
concentration in relation to nitrogen . First, the data confirm the poverty o f
nitrogen in litter of vine maple, big-leaf maple and Douglas-fir . Secondly, the
mean N/P ratio of alder at 17, indicates that this was the only one of the fou r
leaf species in which phosphorus may have been immobilized . In the other
7.
•
.
•
three species, phosphorus was being mineralized to the environment . Like
the other parameters tested there were no significant differences betwee n
the control and treatment streams .
The relationship of carbon to phosphorus as a factor in microbial
decomposition is obtained from the carbon to phosphorus or C/P ratio . A t
C/P ratios of 200/1 or less, mineralization processes will predominat e
while at levels greater than 300/1 immobilization is most likely to occu r
(Alexander 1961) . In this study, C/P ratios approxirrated those which woul d
favor mineralization (Tables 4-7). During the study, vine maple exhibited a
mean C/P ratio of 205 . Alder had a C/P ratio of 266, Big-leaf maple a rati o
of 304, and Douglas-fir was 555/1 . Since, as emphasized previously, th e
carbon concentration remains essentially constant through time as litter i s
decomposed, C/P ratios like C/N ratios, provide some index of decomposition .
Vine maple which decomposed most rapidly, also had the lowest C/P ratio ,
followed by alder, big-leaf maple and Douglas-fir, the same order in whic h
leaf litter decomposed in the experimental streams . As in the case of the
C/N ratios, C/P ratios dropped dramatically following the four-day sample .
C/P ratios also exhibited a general trend of becoming lower as decompositio n
proceeded . This trend was exhibited by all four species tested and in all thre e
streams . Significant differences between the two treatment streams and
control stream were not observed . Except possibly for litter of Douglas-fir ,
the data indicate a balance between mineralization and immobilization o f
phosphorus between litter and the water column, and, thus, no phosphoru s
limitation to decomposer activity .
Data on cation exchange capacity was undertaken based upon the hypothesi s
that leaf species with the lowest base saturation tend to accumulate cation s
such as magnesium and calcium at sometime during decomposition . This
hypothesis was verified by our studies . Douglas-fir needles began with both a
lower cation exchange capacity and a lower percentage base saturation tha n
vine maple leaves (Tables 8-9 ) . In both streams tested (Watershed 10 an d
Mack Creek) Douglas-fir needles accumulated a higher base saturation an d
calcium, magnesium, and potassium cations . On the other hand, vine mapl e
leaves which started with a high base saturation, low lignin content, and whic h
also decomposed faster did not show an increase in base saturation or catio n
exchange capacity . The stream in which decomposition proceeded most rapidl y
also demonstrated a more rapid rise in cation exchange capacity (Fig . 4 ) .
The increase in cation exchange capacity is, therefore, a function of decomposition, probably through the increase in lignin concentration , as the hemicellulose, cellulose, and acid detergent cell wall fractions are oxidized . Thus ,
the chemical composition of the litter material is altered as litter detritus
undergoes decomposition . As decomposition proceeds, nutrients are hel d
increasingly by microbial biomass and by complexing to lignin . Due in part
to complexing, and in part to microbial activity, lignin in particular i s
chemically modified through time . Among the important chemical changes ar e
removal of side chains of the aromatic nucleus and a decrease in the number
of methoxyl groups . Alexander (1961) postulated that increase in cation
exchange may result from the loss of methoxyl groups and replacement by
N.,
8.
.
•
•
carboxyl groups, which provides free hydroxyls to retain cations . Since
the lignin of deciduous trees may contain 20% methoxyl groups, the capacit y
for an increase in cation exchange capacity as a result of lignin alteratio n
is substantial . In WS 10, where decomposition, per se, is slower, demethoxylation as a result of biological and chemical activity, was also slowed an d
cation exchange capacity rose at a slower rate than Mack Creek (Fig . 4) .
Change in cation exchange capacity is also a function of pH . Under
acid conditions, hydrogen ions are tightly bound to organic particles and ar e
not easily replaced by other cations . Therefore, as pH rises, the cation
exchange capacity also increases . Such an increase was observed in ou r
studies . As Douglas-fir litter decomposed through time, the pH of the litter
material rose from an initial value of 4 .2 to a high of 5 .7 in both stream s
(Table 14) . The high value of 5 .7 was attained in Mack Creek about two month s
earlier than in Watershed 10 where decomposition proceeded at a slower rate .
In vine maple both pH of the litter and cation exchange capacity began at a
higher initial level . In Watershed 10 the pH of vine maple litter rose fro m
5 .3 to 6 .1, but cation exchange capacity did not change appreciably . Neithe r
the pH or cation exchange capacity changed significantly on litter of vine
maple decomposing in Mack Creek .
As mentioned previously, the lignin molecule undergoes extensiv e
modification through time in conjunction with biological activity . In fact ,
the degredation of litter material in water is similar to that of humificatio n
in soils . Like organic matter in soils, lignin residues and various microbia l
transformation products may become complexed with amino acids to for m
highly resistant ligninlike complexes . Waksman (1938) concluded that humus
consists largely of complexes of lignin and protein . However, the inabilit y
of Bremner (1965) to isolate significant quantities of protein from soils, ha s
led to a gradual disregarding of the lignoprotein concept of humus formation .
More generally accepted is the idea of humus formation by complexing o f
protein degredation products of amino acids and lignin residues first propose d
by Schreiner and Dawson (1927) . The formation of nitrogen lignin complexe s
in stream systems has been observed by Subercropp and Klug (persona l
communication) . In this study, significant accumulation of nitrogen in the
lignin fraction was also observed . As one might expect, the litter specie s
with the lowest concentration of lignin also had the lowest proportion of
available nitrogen tied up by lignin complexing (Tables 10-13) . Vine maple
was lowest with an average of 25% litter nitrogen in such lignin complexes .
Alder had 34% of the litter nitrogen complexed with lignin, followed by
conifer with 53% and big-leaf maple with 62% . The lignin used for thi s
determination was derived by Van Soest (1963) methodology, and the nitroge n
concentrations were measured by the micro-Kjeldahl determination . The
data indicate a definite increase in the nitrogen concentration due to nonbiological immobilization . The mechanism remains obscure but may b e
attributed to at least three possible causes : 1) nitrogen in lignin is an anti fact of the method ; 2) it results from either ammonia or amino acids, o r
peptides from microbes or, possibly, aquatic invertebrates ; 3) the source
9.
is organic nitrogen or nitrite from the water . Van Soest (1965) warns o f
the possibility of protein lignin complexing if , for instance, litter materia l
is dried at temperatures in excess of 500C . Although the cautions of
Van Soest were meticulously heeded, some nitrogen may have, nonetheless ,
occurred as a result of lignin isolation . Numerous workers who have studie d
humus formation in soils, confirm the ability of nitrite and ammonia to reac t
with the lignin molecule . Neither nitrite or ammonia is commonly availabl e
in stream water, although ammonia is the waste product of aquatic invertebrates ,
who colonize and use litter accumulations as a source of food and habitat .
Thus, some ammonia may be made available in dense leaf accumulation s
where water volume is slow and invertebrate biomass is high . As stated
earlier, it is generally believed that most nitrogen complexed with ligni n
is in the form of protein degredation products such as amino acids and pep tides . Such materials as peptides could be generated by fungi in th e
process of litter protein degredation, or could be formed from the conversio n
of inorganic nitrate from water . The formation of extracellular organi c
nitrogen in the form of peptides resistant to microbial assimilation, fro m
ammonia, nitrate and organic nitrogen, have been confirmed in culture studie s
of Scopulaniopsis brevicaulis by Morton and Broadbent (1955) . The proportio n
of such resistant extracellular peptide nitrogen in the dissolved organi c
nitrogen pool of streamwater is a matter of conjecture, but a potentia l
source of nitrogen for lignin complexing .
In addition to carbon, nitrogen and phosphorus, the concentration o f
many other macronutrients and macronutrients were measured during th e
course of the study . Among the more important were aluminum, calcium ,
magnesium and potassium, the ions most likely to be involved in catio n
exchange capacity . Of these, calciumis present inthe highest concentratio n
in all four species of litter detritus . Calcium concentration increased abov e
initial concentration (Table 3 ) for all litter species in all streams (Table s
15-26) .
Calcium concentrations began to drop below initial values onl y
after 41 days of stream incubation . Aluminum which held even more tightl y
in the process of cation exchange, increased dramatically in concentratio n
for all test situations throughout the decomposition period . Thiswa s
especially true in the two maple species where aluminum concentration s
exhibited a 20-25 fold increase as decomposition proceeded . The magnesiu m
concentrations declined dramatically from initial levels, particularly i n
vine maple and alder . This trend was evident to a lesser extent in big-lea f
maple and Douglas-fir in all three streams . Potassium, among the most
mobile of all cations, also decreased dramatically as decomposition proceede d
in all four species . Concentrations of all nutrients tested were remarkabl y
similar in all three experimental channels and gave no indication of faste r
processing rates in the control versus treatment streams . Despite leaching
of nutrients such as potassium and magnesium, concentrations were al l
sufficiently high not to impose a nutrient limitation on the microbia l
decomposition .
10 .
.
•
-.
Summary and Conclusion :
Completion of the study provided important data as to the mechanism s
of decomposition in flowing waters, and to a lesser extent about the transfe r
of energy and nutrients to higher trophic levels in systems dominated b y
heterotrophic processes . The immobilization and mineralization of nitroge n
and phosphorus, the complexing of nitrogen with lignin residues, and change s
in the cation exchange capacity in aquatic detritus, mimic similar processe s
of humus formation on land . Such findings have implications on the siz e
classing and microbial activity of detrital particles . They raise questions as
to the time required and the size attained of particles when they becom e
biologically inert as "aquatic" humus . The role of this debris as surfac e
for microbial colonization, as a prelude to stripping by invertebrates whic h
feed on fine particles , may well be different if the organic particle is
incapable of providing a source of energy and nutrients to surface microflora .
The quality of such particles should be investigated, as it is exported throug h
successive biological communities .
The general health of both streams and forested areas and the effect s
of land management practices are most often assessed by examination o f
stream water . Investigations over the past two years have indicated a
capacity for litter and other organic debris to accumulate concentrations of
certain elements in relation to decomposition . Rapidly decomposed debris ,
such as litter, both retains and accumulates nitrogen in the process of
decomposition which may be necessary to maintain decomposition rates ,
and provide sources of essential nutrients for the biotic community .
Refractory debris, such as needles and possibly bark and woody debris ,
also appear to accumulate cations at sometime during decomposition . The
understanding of how such organic debris may influence water quality i s
necessary to properly interpret such data . This is especially true in th e
interpretation of water quality data from small watershed streams where
organic debris constitutes a major carbon and nutrient sink .
Acknowledgements
This research was funded in part by the Office of Water Research an d
Technology, U . S . Department of Interior, under the provisions of Publi c
Law 88-379, Grant Number 30-262-4034-W12, and in part by the National
Science Foundation, Coniferous Forest Biome I .B .P . , Grant GB36810X .
We would like to express special gratitude to Barbara Buckley for her
help and support throughout the project . We express appreciation to Rud y
Thut, Bob Herman and the Weyerhaeuser Corporation for permission to use
the experimental channels, and to E . Holcomb of the U . S . Forest Service
Laboratory for her special help and assistance .
t I
•
Literature Cited :
Alexander, M . (1961) . Introduction to soil microbiology . John Wiley and
Sons, New York . 472 pp .
Anderson, N . H ., and E . Grafius . (1975) . Utilization and processing o f
allochthonous material by stream trichoptera . Vert . Int . Ver .
Limnol . 19 (in press) .
Bocock, K . L . (1964) . Changes in the amountsof dry matter, nitrogen, carbon ,
and energy in decomposing woodland leaf litter in relation to th e
activities of the soil fauna . J . Ecol . 52, 273-283 .
Bremner, J . M . (1965) . Organic nitrogen in soils . In : N . V . Bartholome w
and F . E . Clark (eds .) . Soil Nitrogen . Agronomy 10 :93-149 .
Fredriksen, R . L . (1971) . Comparative chemical water quality - natural an d
disturbed following logging and slash burning . In : Forest Land Uses and
Stream Environment, pp 125-137 . Oregon State Univ . Dept . of
Printing, Corvallis .
Gilbert, O ., and K . L . Bocock . (1960) . Changes in soil litter when placed
on the surface of soils with contrasting humus types . II . Changes i n
nitrogen content of oak and ash litter . J . Soil Sci . 11, 10-19 .
Gilson, W . E . (1963) . Differential respirometer of simplified and improve d
design . Science 141, 531-532 .
Howarth, R . W ., and S . G . Fisher . (1976) . Carbon, nitrogen and phosphoru s
dynamics during leaf decay in nutrient enriched stream ecosystems .
Freshwater Biology (in press) .
Hynes, H . B . N ., and N . K . Kaushik . (1969) . The relationship betwee n
dissolved nutrient salts and protein production in submerged autumna l
leaves . Verh . Int . Ver . Limnol . 17, 95-103 .
Iversen, T . M . (1973) . Decomposition of autumn-shed beech leaves in a
springbrook and its significance for the fauna . Arch . Hydrobiol .
72, 305-312 .
Jackson, M . L . (1958) . Soil chemical analysis . Prentice Hall, Inc . ,
Englewood Cliffs, N . J . pp 84-97 .
Olson, J . S . (1963) . Energy storage, and the balance of producers and
decomposers in ecological systems . Ecology 44, 322-331 .
•
Mathews, C . P ., and A . Kowalczewski . (1969) . The disappearance of leaf
litter and its contribution to production in the river Thames . J . Ecol .
57, 543-552 .
12 .
.
Morton, A . G ., and D . Broadbent . (1955) . The formation of extracellula r
nitrogen compounds by fungi . J . Gen . Microbiol . 12 :248-258 .
Petersen, R . C ., and K . W . Cummins . (1974) . Leaf processing in a
woodland stream ecosystem . Freshwater Biol . 4 :343-368 .
Schreiner, O ., and P . R . Dawson . (1927) . The chemistry of humu s
formation . Trans . Int . Congr . Soil Sci . , 1st, Comm . 3 :255-263 .
Sedell, J . R ., F . J . Triska, and N . S . Triska . (1975) . The processin g
of conifer and hardwood leaves in two coniferous forest streams .
Verh . Int . Ver . Limnol . 19 (in press) .
Strahler, A . N . (1964) . Quantitative geomorphology of drainage basin s
and channel networks . In : Chow, V . T ., (ed .) Handbook of Applie d
Hydrology (McGraw-Hill, New York) Section 4-11 .
Teal, J . M . (1957) . Community metabolism in a temperate cold spring .
Ecol . Monogr . 27 :283-202 .
Triska, F . J . , and J . R . Sedell . (1975) . Decomposition of four species o f
leaf material in three replicate streams with different nitrate input .
Report 29 . Water Resources Research Institute, Corvallis, Orego n
97331 . 14 pp .
Triska, F . J ., J . R . Sedell, and B . Buckley . (1975) . Processing of conife r
and hardwood leaves in two coniferous forest streams . II . Biochemica l
and nutrient changes . Vert . Int . Ver . Limnol . 19 (in press) .
Van Soest, P . J . (1963) . A rapid method for the determination of cellulos e
and lignin . Journal A .O .A .C . 46 :829-835 .
Van Soest, P . J . (1965) . Use of detergents in analysis of fibrous feeds .
III . Study of the effects of heating and drying on yield of fiber and ligni n
in forages . Journal of A .O .A .C . 48 :785-790 .
Waksman, S . A . (1938) . Humus . WilliamsandWilkins, Baltimore, Md .
2nd ed . 526 pp .
.
U
■
■
1
1
1•
r
1
_
►
I,
I I
.
-
-
1I
J
-
I
•I
1
I
_
~
11`
■
I
+;
■
1
Cl
-
L
-1
I
A
- 1
■
1
-
4
:-
1
I
I
-I
-
}
_ ,
' '
-
TABLE S
.
an d
■I
.
FIGURES
1
P
J
I
I
r
r.
4
■
■
J
Ir
r
■
i
}
I
' !
F .,
T
4
I%
J
a1
It_
I I
I
h
Z
CM
o
• a•
'b•
0•
%
N "0
I~
N - I
-
It)
N
0
o
r)
C)• l~C
t[)
C'r)
"It
It) It) CI) .
CP. CO
1>
.-
"0 0 .
co
•
Q
W
0
0
I
•
;o
N
N
.
•
8;
0
0)
0
0
C
a)
m
O
L
u
Z
a
C
•
ti
(0
W
N
(o
•
sir
T
a)
05
L
4JC
4-)
J- ,
C
a)
w (~
C
CD
q -C
L
C-0
U)
C E
▪
L
L
N
*-
E
W
U.)
D
a)
)
0
•
U)
O
+L) v
U SL
C +'
l~ C
L (n
q ).,
-0 (0
L
U)
4a
q
(
a)
)
I
• I
T
C
o
0 ,-
Z
U) 'U
U) 0
q .rC
N
T
al
u)
N r
N
u)
a)
U
a)
a
n 0)
U
Z
a
C
N
CC
D
U
N
o•
o
"n
T.'
(NI
N
o c
o
8 8 0 8
N LO d N
oo▪ 0
0
. 0 8•
dr-
o•
N
o
LO
M -qt
.-
r-
O O O
.
o•
O O 0
8 O O.
0
•
C"7
N
~--
0..
8•
E
0
2
~t
L.
a)
0
4-
0
d-.
C
C
N C']
co
O
0)
▪
i1
O
• N.
r-
d.
0
U
▪
Op.
Y
N
a)
a)
0
•
.
N C')
.O
•
▪
C')
f•
N N.
(N Q• f•
.
a)
aO
E
a)
C
as
00
E
a)
C
7
7
0 N
N 0
•
N N N
i w
co
I'
T
Lo
0
CO
(0
N r r
C
O
)
0
O
L
a- +
N
0
L
C
O
NN N-
r (r0
d
(0
(D
(0
U)
N-
to
N-
co
(U
co
r-
co .
N
(0
LU
II)
(0
(0
(0
•
N
N
0) 00))
OI'
0 C
N r N
r
(Y
r
(0
r
(U
Z
T
0
U
z
•
as
3
)
U
(C
C
a)
)
0
0
L
0)
z
E
)
u) 0
0
L a- 1
q U
)
C
0
U
a)
a)
L
LC)
Q
0
0
•
-c
E
•
C
• 0
a)
L
q
Z
d-
0) co
•
a
O
co
o
co
c
m
m
to
N
)
Q
C
q
U
0) w
O -p
L
Z
\
0
c
of
C) N
N CO N
CO
CON N
0)
0)
co
N
co
N.
co
(0
N
CO
T
C~')
N
d
r
d'
Ckf
CD
N
C
CO
.0 CO
T
I1
N
r T r r N
()
N
CO
L
C
Z
q L
C] Cl)
L 0
n) C
0 D
OL
0
\C 0)
N
y
0
0
N. T
N
CO
O
M N N N N N N
N
N
0)
.C
0
0)
L-
M r
os
os
.O
N
lc) Nn 0%
N N N N 0%
r CM
a)
c')
C
D
L.
(1)
0
a
0
o
4C
-
L
N
0
N N N
NN
.
N
U
0
L
4a)L
H
0
}
O
r M
r N
In O.
r r
Z
a
U
c
G
O's
r
N
LO
N Os O. .
-
M
N
NO
r (V 'oo►
r r
R M
~--~Lr)
~--~.-mot
r r
A M N N
Lr) Lo Lr)
0
U
•
s
0_
E
C
}vii
aa)
0)
q
G)
m
a)
Lr)
'Tr LC)
OQ r
M
r
Lr)
C
C
q
.E
a
E
0
()
0
co
2
C
O
cM~
M M
c-
'I
d
so tr)
r
u r r•
r
U
d ~O n - N r r
I
r
o
C
o
•
•
U
U
a)
O
L
N
(0
N
(D
U)
CO N
N
N
N
•
0)
T
al
N
in
T
CCo
N
N-
.-
N
co • CO
7t
N
C)
.
N
N
0))
r-
T
(0
CO
C()
T
N
N
Z
O
L
C
O
CO
CO
CO
T
•
CO
CO N
N
0
CO
CO
N
0
q L;
L
L
C
7 4J
L C
0
0
-
CL
C
0
Z
-2
rd
0i
F
Cl3
•
L
L
a
(1)
q
r
N
CO
N-
CO
1'
0
T
o
T
CO
in
CO
cc
CO
0)
co
m
co
co
o
T
co
co
cc
n
r
CO
N
N
N
C
n)
0
L
C
O
(u
.L
C3)
0
in
ill
•
N-
Z
sl:$
-0
•
co co
L
a
O
£
•
N
q
0
c
C
0
2
q)
C o
(u a
0) E
co
m
Lo
co
(
0
O
o)
01
(\
oi
N
co
o
N
N
N
1n
N
t
N
CO
r
co
O
Z
0
C
a)
01
0
L
to
o
2
N
()
(
N
co
N
co
CO
N
t
(0
CO
(0
CO
N
(O
co
CO
co
1CO - (O
•
CO
'J
Z
0
L
C
(0
U
a)
0
id
H
N-
C co
T
T
• T
N
O
C
co
f
f~
O
CO
0)
0
(T)
1In
0)
(r)
r
OD
CO
0)
T
CO
(")
v-
f
LN
C+)
r
CO
CO
0
d'
CO
0
0
I
0)
(D
CT)
NACO
CO
0)
0)
N
C
a
a)
CU
U
L
Z
N
A-
U)
N
c
O
9
L
0
O
4-1
L
4J
C
0
=0
U)
CU
CO
C')
3
a
L
.a
N
z
0
0
co
0)
0) 0 0) CO T 0 0)
C
a)
a
0
L
z
T
a0
0
T
CO
0)
0)
00
r
T
r-
CO
CO
co
•
0)
d
0
•
0)
fCO C') rt
OD
d-
1-
0)
1-
0L
C
0
T
T
U
0)
�
z
o
c
a) 0
O) a)
O a
L
4-1
N
0)
C
. O
N
C C)
o
1)
ca)
c
U
CO
0
C
a)
0
L
J
4
LO
OD
•
CO
1f)
Ln
0
LC)
LI
f)
•
((0 I~ CO
A
C
T)
Z
O
i
C
0
0
r
t
o co
1
U
a)
as
I
-
r co
N co
()
r T r •
r CV C U
,. -
rti]
f
1
•
1
M
-11.
44
LI
.•
.1 1
S =+ I ` 1
5 .
4r40
a
vi cd
CD O
b2
a)
U
a)
a)
C
V-.
w
O
C
fI
O
r4
\O
1f \
N
O
H
CO O 0\
lc\
1
H
\O
ON N \O \0
.
to 4\O N CO Nto in 4
0
H
N \O
CO
COK\
In to
O
tcl '.K1
O\
N\O
Kl
111 0
CO
N NCO
IA CO
H
O
a\
N N H rn
H
i N- N
f
N
H a\ \O
N
N \O 0\
CO
00
dO
at
\O m 0\
\O
Cp
OtZ
in a
N
O\ N -.
IA
O
•
T-
0
a)
C
tU
A
H- M
4
s
N
H
tc\ 4\o
COH N
0
N
ti
If'.
N• 111• N. I1 ~• O
N N IA IN M 11
\O•
4-*
0
'0
H
M
N- H H 0 H N
N
CO
1c\ CO
\o
t-- N
In 4Kl -?
K\ OK1 in
tcl CO
i\
In
H
O
\O
N
H
ao
\O
H D
V M H O i -I- H H IN 0
H 4- \ 4O- 0 H
• O• O O O O O O O O O O O O O
0
O
O\ 0\ 0\
O O O O O O O O O O O O O O
O O
fi o
CO
Ifs
IA H H II) O .. M \0 Cam- N
O
H N N 4- M Ifl tc1 -7 -1Icl NO N\ K1
4-
H
4
-
0\
In CO 0
N- H N
tf)
0 4•
4- \0 N N
In CO
N r-f 4•
N1
N CO
4-N H
`0 N H H N CO
IA• Icl• 4-• H
\O
0
In
H
\o
u-t
O\ N 4-•
H• • r4 N Ic•1 IA• U1• to 4'• •
in
In
z
0 N H 4
. IA
Ill
44- N \D
pp
03
0\
N
ti N \ O
H to
'-0
N
In
\O NN
)-O f\ 0K\ H
Il'\ O\ '
. H co
N ~N N 4 CO N O 0 CO
i-I H r-I H r-i r~I N N I N H . N CM M to
•
N
in O\
N
O\. CT
N 0 LA Ic \
O 0\
N CO
N1 N 0 O\ N N H IA
tD
to CO
4- In
to H
LA N
In
K1 CO
Ic\ H N 4- 0
N 0 CO H \D N H- N N 0 \O H CO 0 IA
In
^- Ic \ r• 111 K1 N N K1 CO CO to, H K1 \D r-I CO
.~
Ic1 Icl K1 Ifs to \O \0 In 4- CD iC1 \O \0
H 0
rI
Ua,
tf\
111
\O
Icl
Nl
\CI
..
IC'. Ib
CO
In
IA
\D
IO
C\
ttn
rMI
•
H
ti N- O
4-
4-
CV
H•
CO
tc1
H
00\•
H
d
It\ 4 N N O) CO
CO \O CO
If\
\O
\O
n•
• H• H In• i
M
N
N \
\O
O\
I
N
~rl
N
N
•
C aO
G
•
N
N
N
NCT
N
O• NO• N
O• N
O• 0
S• O 4
O• O• 4
O•
O
O
O
O
CE
In
O a
ti
N
N
•
0
M
0
N
0
0
IfM
O\
CD N \O \o \D \O \O
•
•
•
•
•
•
•
. •
N 0\
IA \o
t--rIin4coN
11
H N 4- \0 N 0) O\ N O'.
CO \O
re\
to
\O H
.-
N \O
t^ IC\
4- In N tc\ tc1 4- H N1 CO .
4 \0
CO
4N
to N
o If\ m K.\ • - 4 to N. If\ 0\ N N
N• •N
CM
N
N
N
N
4
4
4If\
LA
\D
\O
CO
•
•
•
•
•
•
•
•
•
•
•
•
•
• IA•
O CO O\ .4• O\ H OQ
c\al IA f~
CO
• • 4 •N N
• N
• N• t 1• l1• 4•
N
CD \0 I•'1 0\ IA ti \p IA I c1 CA0
4 \O ri .CO
H 4 N cl Ic1 tf\ \O 0\ C
N- to
r-4 D
N N CV IA
0
4
•4 N M
f
I
0
0 \O H Ic \ H N O\ \O 0 H \O N C O
N 111 M
r 1 N N rl C s,\!..
N
r-I
N N N rl
O
H H H cm cm c H 4 N In .4In In \O N CO a\
O\
r-1
10f1 ti H
O \O r-1 ic1 gal N O\
N
N \
-4 N
M
H
H r\
1.1 r♦ CV
H ri
T
O
a)
•rl
PI
;d
Fa
w-p
•
bik -P
0
U1
K\
0
co
CO co
In -4- .- .4N --I- C- CO
In H co t` K1
ON 0 ON C- 0
0
CO
.- In N
C- ti N
10 ON In
\0 10 C-
CO
C-
O\ co
0 C
H
O
CO
4-
Ul
N
ON
0
N
K\
\O
K\
\O
C\O
CO
In
C\O
0
H
OJ
Pr\
(\I
H
0
tn O
a)
■D i
O\ H N 4- N
In \0 C- \O .'0
CO 4- CO
H H
O
1-1 10-1 H-I
ON 4- 0 0
tr\ ON
O
r-1
ti
CO
•
r-1
H
r-1
ti
U1
If\ .'O
.
•
OD
H
H
'O
.
4-
ON
8.
H
O
C
4- C- O C - ri N QO
K\ C-• '‘O. N• H• O• N•
In Cs- C- U1 C- In It\
4- 0 4K\ CO
CQO
4N
tr.\
co
0
r0.1 H rri r-1
a
0 0
0
0
0
0
0
0
0 0
0 0
0
0
0
0
n
r
0
0
U1
0 0 CH• O• . N• 0•
O
N
H H
K\ 0
0• H•
Ul \O co
N
O\ N
O• 0• H•
In CO
~ N a
0\. K\. K\. H•
H
t0
.
I
.
a)
E
.
H ONO O
O\
O\
CO
N H N- 00 N 0 CO
U1 \O CO CO Cs- CO 0..1
4- 0 O CO \O CO U1 O H \O N
ON C- N H \p. OD• 10. C-• O\• O\
• ON•
CO
tr\
.#
. a\ I(1 10n
. t ~ l'
0
C-
CO
N
O\
O .- 1-1
O\ In U1
CO
r-l U\ U1 N i
n
ON
\O
~ ~ If l
0
a)
U1
\0 CO tl\ CIn N OD H
H
N ~~Op N
Cs- \O \0
K\
rN-i 0
rHi
ON
ON
0
ln
H
.
N
CO
0 0 0 0
O\ CO
0 ri
0 0
0 0
0
CO
CO
CO CO
H 0 ON
O\ 4•
•
•
•
•
CO IA a\ IA 0 CO
N
OO
O\9
9
9
U\ i
n i
t
-4- I \ Pe \
O O CO
H N VD9
ON In In U\
K\
4- K\
~O
H
0
0
H
0
0
0
0
2
0
0
0
0
0
0
0
H C- ~D
U\ \0 0 0
H
• --• ri•
O\ ri
0
r1 H
r -1
a
In
.-
C- CO
H H
r-1•
in U1 \O
K\. N. 0
t J•
a)
a1
C
saU
x
a
.
H
O E
H H
aU 40C
if\ a\
H
4N .4-
N
C
4
.4-
t
i
.A-
-4'
am
ti
C.
N
K\
-4-
t1
(
K\
1
t11
K\
O
0\
K\
N
N
.
Cs
00.
N
•
Pr\
H
•
'
in U\
N
U\ lp
ff\
O
fr \
L\ O
H
O
C- \O
0
K\
.4-
aa\
U
H
CO \
ri ri
IH
n
N
H
H
N
N
ON
\O 0
ri
In U1
\0
.
in
in
.
N
Cs- H tO
ri
O
N•
U\ ri
CO
•
8
O\
CO CO
O
.•
•
N
t•
i
0 03 CO
N Ln \O
10
•
0•
O\ 4'
.4•
4
•
In 'O
a
\O
•
a) o
0) 4-
a
C
O
V E
a)
o) o
H
co
pt-\
H
N
Ul
ri
0
N
VD
C'.
H
ri
1+\
N
N
N
N
('
H
H
A a
K
0
o
~ I~\ ri
o)
I-
a)
-N
O\
0 N
r1 H
cn ri
H
ri
ri
r
ri
.-
N
O \O ri N
IA CV N
N
U r\
i N N N N )-f
ri H H r♦
A
a\
N
A
O
O
rnCO rN rto 0)CO N-10
OQC
0) (0 0) CO T
T T T N N
C
o
•qL aE Daa)
!
u)
C
• o a)
O- U (A
-
D)
•q 0
)
L
•
q
C
a)
O
r
3
L
D
C
u)
r,
C
015
C
q
•
RS
L
•
C
•
1_
°
Tt
O
N 0)
N
(0
W
(3)
T
CO
V
•
r
CO)
C
r- N
0
v
C
CX C
CD m C)l
a
L E
a
.r Q S
.,..
O
L
4 4-4
O
r
4-
c
a)
^
a) _ a)
C
N-
O
•~' w
C
N N CO
CO CO t`
C
C
'D
(CS
E
o
z
L
a)
U
a)
C
q a
a)
)
0
O
L
Z 0 3
0
• ~ a
D 0
0
C
C
•C C ,
~ .r
r
N N 1.0 (0 (3)
N
(Y) LO (3)
u J T T 0) In
N N (~) C') N
0
C
a)
)
0
o
L o
I
LI)
N
ID
CO)
N F 1.0 (*) N
I~ ti CO 0) t- CO
z
C
C
0)
•~
J
10(. 0vr d' O 1,0 N 10
0) T T C~ d 0
T N N N N Cr)
0
N
(Or)
(D )
0
N
T
CO
T
D
OO
r
C
(1)
0)
0
L
to CO CO
O If) O) N (O
a)
C
w
0
c0 co
co
CO N N co co
0
E
C
0
U)
U
U)
U
C- 0 a)
0
a) a
a
E U)
0 L
C U U)
(U U )
3
N
C
0
. r.
Qf
L
C
a)
0
C
0
0
C
U)
r1
U)
a)
L
U
IO O) 1
N
N
d' O d
N T N N (~
U
U)
C E
1
2
0 U)
Cn L
L
a) Cl)
U as
C
3
C
L
U)
0
D
CO O CO N
q CO d N O)
[O O) CO CO CO
N N N CO CO
a)
L.
uC 0
C
0
a)
L
U
C
(1)
U
C
O
C
C
Q)
t
U
U)
O
C
C
0)
3
O
U)
U)
U
0
a
rr
L
O
O
O
)
a
Q
a
E
U
L.
U)
.C
3
CO'
1 '
I
t
C
a)
)
u
w
N
(0
U
a a
0
C0 a E0 L
N U)X .UU)0
0U)
L.
a)
ro
a a
z U 3
U
O
v-
CI) OD 0
LC)) CO OOD 0)
Q)
U
0
L
a
0)
0
z
q
IC) 1' CO
q O CO N
N
T
CO
NNN
v
C
C
O i-,
Jo
1'
am
NN
N
0.1
10 1'
N CO
I
C
O
CO
N CO t (0 L0 CO O
r C') In 0)
IC) CO
T T T
CO CO
(D
0) <t
t
0) O N r
0)
•
CO
CO 00
d' CO
r
CO CO (0 (O
r
tf)
C
a)
0)
0
3 (~ co Lo co (O f
co co
o)oo o
z
ca 0
E E
oU oU L
a
0)
CO W I
0)
Er) to
-Kr o
CO N r CO O
Co
(a
O
•
• L L
C
.0
O
•r
L
c
as
L
q O
w
t
L
as
0
co CD O W
O
(O r co
o
N to co (0
co
>,
O
to
tntotnLo
o
•
q U)
a)
a
(tj
d-
3
(CS
a) •r 0
0) 0 C
o 0) (
f~ to r CO to
Z 0
3
to
(t}
1
J
(L)
a)
o
a
N- r o r h- o
I`Wrn
r
O
Z v
C 0
a >,
L ~
E
o a
•
0 3 -aa
CC
a)
r I• tD I~ CO LO
W r (O O r t o
(O O N (~ to W
CO
d
cf.
N
T
0)
a)
C
o .-
N Co W tD c
o
co In Q) N W co
•
r r r
E
C al
0 (1)
•
-p 0
L
-0
a)
C)
(I)
C
w •~
o C
0
O
a
E
o
•
Q) +, a
)
q N "0
ro
L
^C
a)
U
C
O
C
(0 O
N CO CO T Co
a
E ~
0 .r
N T O O) LO 0) CO
O 0) (0 I- CO O 0)
LO CO CO
LO C+D
C
0)
0 o
4
N- (0 T I~
(0 CO (0 0) 0) I ~
Z0 3
a •a o
°a 0
C
o
O
V
L
5z
0) (D
C
M
ot3) (!)
J
4
a
C
•
L
cd
_ W ~J T y)
LO
In
CO 0) U) 0) O
(a
• CO 0) N u) O O O
U) If) L )
CO CO
o
v
D
a)
CX C
a) a) a)
In'
-C
a)
L
L
a)
U L
O
L
a
E
O CO LO N N 0) O
N N O CO 0)
LO N Cu to a) (D 0)
'd- (0 t lf) (D N ~t
Z U
3
U
c
0
2
0
C
a)
0
Vxnl
'-
4_)
O L
Z
0
v
W 0)
LO
CO
If) If) If) If) CO (0 N
U ID0-
)
a) a0
C
C
N U
O
2
0) /1
J
3
(3) tr) O .- t O Cr)
O COMW O r T T
0) to (0 0) (1) V "CO CO CO CT) 1''
d'
CO
N
a)
U
-
C
0 .'r a
N O 0) (0 «) CO 0
CO L() 0) N (0 CO
r T T
1
U
q
co
W
a)
a)
O
t
0)
0)
0)
CO
r
(D
CO
t
0)
U)
CV
L0
N
U)
CO
CO
U)
C
(0
N
0)
-
lf)
d'
LO
LO
t
O
N)
sr
a
0
(d
E
t
r
a~
C
N
2
a'
Lci
.
N
(O
CO
lri
lri
C
L
u-.
I
+.,
us
a)
N N
a
0
0)0
D0
0
to-"
.
0)
co
N
N
N
In
CO -
N
CO
0
(0
CO
N
O
D
CO
CO
OD
t
r
0 C
L
m
(1)
4-)
4-)
m
E
.~
L
L()
to
aD
q
T
U)
lf)
Lf)
Lf)
UO
UO
CO
(h
CO
N
N
N
N
CO
tf5
CO
O
O
N-
N
q
00
T
(r)
t
to
to
to
10
O
N
N'
OD
I(0
OD
0)
C')
N
N
N
C
to
CO
CO
(0
CO
CO
0D
LU
U)
U)
0
N
0
t
CO
N
2a
0
I
a
•. W
X
W
0
0
(A '
a)
c 4'
o)
- 1I
N
S Oi
o N
N E
0)
OO
D
0)
O
d'
0)
LO
CO
d•
Up
N
l!)
In
tf)
0)
CO
0)
N
q
0
0)
tf)
C9
N
0)
N
q
r
0)
(0
CO
CO
O)
r
d'
N
d•
0
to
CO
ct
lf)
LO
T
LO
N.
tf)
C us
o L
n
t0 (
o
O
us
L
2
,o
s=
a)
m
O
a)
m
L
•
a
E
'
W
0
N
2a
U'O
CO
(f)
I-
Up
'
lf)
CO
N
N
CO
('')
LO
q
0
r
U)
N
1.()
UO
to
N
(O
h
t[)
to
tf)
I-
CO
lf)
LC)
tf)
Lf)
LO
U)
N
N
N
N\
. CO
N
\
0
N\
CO
CO
t'7
CO
[r)
C')
CO
N
~
CO
ti
\
t•
\
f•
\
q
N
N
r
CO
0)
q
q
'mot
OD
N-
O
U
0 -o
Tt.
N
N
\
0)
N
a)
gI
C
.
T
T
N
N
\
LA
0
N
T
r
N
r
N
N
r
CO
N.
\
N
r
r
N
r
T
0
CO
CAS
\
\
N
\
F\
N
CV
N
r
r
0
N
O
N
CO
N
r
CO
N
[')
q
0)
0
r
07
N
if)
0
LU
[0
0
O
(0
q
N
(')
N
\
CO
os
sO
V
CO
Z
Lo
CV
'-▪
co
co oo
Oq t
CO I O
M M C") C") N M M▪ M
d
OM
O N.
.p~
'Os
C
N
0
0
$
O
0
o
°
0 O Os O
N
s •~
CO O C')
Co0 Co O Cos0
0 $
o $ $•
~:
•
_
O
p $ $ p $ p
$ $ p_ $
6
O
p
O
0
0
0
$
•
E
0
.
L
4-
d' M ~O Os C')
Gd
2
4
4..
C
0
U
0
.C
0
D
U
°
o
E
O
U
_U
0
S
0)
C
0
0)
CD
0
•
•
4-
•
•
1-
O.
CO CT.
0
0
O 0
• $• $• o
•
•
•
0
•
CO
Os a
CO N 'N
CO
N
4C
0 O N. O O 0O co
lf
j
(NI
0
C
0
0
CL
4
CO
C
-
c :)
In "O f) Os
p
8
8
8
8
O
8
8
0
C
D
L-
a)
0
0
2
La-
0
L.
d)
4-
Os
O
N
CU•MNN
U-
O
•
r
r
N
. N• tV•
N.
LC)
'51''
N.
(NI
M ^▪ M▪ M
r r r r
a▪
C
N
d)
0)
C
0
S
U
O CO N 0 Os
•
•
•
•
4-
C
.O
L
4-
Z
U)
CNI
if)
'0 f~ CO
rI--
N
co
1
N N
; co
~ 0
C")
. O O'.
r
N co
Nr ~
V_
O
U
0
/0'
z
^i
r
Q
C
N
°chi
d- "1- nt
0°
~-- M M M M M M M
o
00 tf) p ~OrOrN(O
N
N CO r
d
o 0
•
0
0 0 0
Csl
M
Nr
(NI
CO Os
MaN
~O
O_ ~O a
00 0 °o H
'0 S o H S 0
Lt-)
CO
►c ) dp
M N
N'0
0 r
NO
N 'O
r N
r 'O
r N
It)
CCI
0
C
C
O
}
U
00 *0 M O . 0 %O O' It'
0
0
p
N
'
CO
O N M M
p
H O H
O
H
O
0
0
.
.
.
.
.
. 0.
C)
IL
M M O~ M
,O
M r .-p M
.
N
.
.'.p00 o
o
0 00
00 0 0 0 c
a)
C
C
(NI
(N
0' sO
0
C
p
I O *0 '0 `pd N Mp 0
0. a
H O H H O S 8`'' 0 0
O
0
0E
O
U
u)
.O
)
o
_
C
C
ON
O r 0 r O0.
r 0o
0 r r
0
l[) sO O 0 0 O• N CO pp
N 1~• d ('~ N (NI M N
3 r r r . . . .
a
Os
.
Q 00
r IN
rNO
r CO
r N ~`j
Q NN
U
C
U,a)
a1
C
0
S
U
8 M r O M M O O
Q Q
d' r N '0 ON r M
N. CO
c•1
(D
LC)
U
S
4
0
M
N NN
r
0
1 1 1 1
r r N M
Os
r
1..
o O
1
d'
s
In
CO
N
U
Z
Q
N
C
Cd
N
C)
00
0
N
N
0
0.
0'
.
0
a
U
O
0`
CO
CO
O
C7
S
'O
LO
.O
CO
)
C
0'
co
N M
8 o 0 0
.
•
•
N
0
•
M
N
0
•
8
M
0 0
N
0
ON
COCV
.-
CO
LO
8
s
°
0
•
N
N`
LC)
)
00
(C )
O
•
O
O
O
CO
d
'O
CO
0
8
O
%O
O
.
N
I
CO
O
M
O.
O•
0•
N
co
O O
LC)
LC)
•
0
M
0
.
a
o 8
N
O
CO
NI-
O
a
E
a)
C
'>
O
Co 0
O
cf)
O
8
`d'
M
CD
O•
U
a)
0.
0
O
O
.
■t
C•4
S
N
M
CO
CO
•
.
0
O
CO
•
'
CO
.
•
C'4
N
.-
r
O N
N
N
•
N.
N
.
sd)
44-
C
N
d
a)
C
0
sU
M
' Os.
O
•
•
CO
Ci
LC)
I-
LC)
.
•
•
i-• N
N
a
1
N
1
r-
^
I
co
T
IO
N M
O..
T
co
O
O..
O
d-
c()
M
d'
U
Z
a
•
CD
O0
N
C
0•0
0
U)
.
N
m
U
-
C
M
Nt'
(N M
O•
a
•
Z
O.
CO OO
°
O
0
0
N
O
s
U)
o
CD
0
M CO U '1p
p8
O8
O
O
O
.
.
It)
O
CO
N.
(`7 `'OO
O
O
f
S 8 S
Ns
O
CO
▪
U)
S
t1
LO
.-~ r•
•
M M
0 0
1f
C
O
.
N
0
Ip~ Q ~
O
V
.
U
NO
r
•
C"
•
O
.
CO
8
N .
.
O.
.-8.
0
S b 0 0
N
0
. O.
.
a
s
O
.
a
Os
0%
O CD 0
.
.
.
000
U)
0 d
0
o
O O
O O
0
a
Cr)
00
O
CO O
Os M O
.- M
N
.- N 'mot.
.
a
U
N
CO
O
.
N..
O
M
M•
C
i
N•
0
•
CO
a-
.
N
8
8
. O NIr•-
^
Q)
0)
C
0
u
C
v
•-
N.
U
)
O
D
Z
N
co co
O
r
I.
N rN.
O
.-
A
N,
Os
O
CD
Q Cr) ~- U)
U
S
Z
N
N
Oo
O.
C
N
Ix"
LO
CO
8
.O
Os
CD
%O
LO
o
O
CD
D
CO
O
N,
CO
.
•O
CN
CD
o
00
U-
O
O
o
'mo
CN
co
8
Os
Os
U-
0
LO
to
r
M
O'
U)
I
A
Cl
0
E
O
L
C4
O
O
0
L
4-
O
CD
O
O
S
CO
Q
O
p
O
O
p
O
sO
0
CO
O
O
8
O 1,-
CD
D
C
o
0
U
O
D
U
C
0
4-
N.
Cl
O
O
O
CD
0
CO
co
CO
to
~O
N
0
E
G)
U.
D 00
.-
S
C
O
CO
<)
O
LI-)
--
CD
CD
N
O
N
N
•
CO
C•
CD
•
•
•
N
CO
Os.
to
M
dC')
f`")
N
•-
N
sO
Os
a
0
CO
O
CD
M
N
o
t
(N
•-
Of.
f
O
N
•-
Ce)
Os
Cl
CO
LO
(NI
NI-
CD
O
0
O
0'
N
u
.
o)
o
2)
C
C
0
N
O
a)
O)
O
•
N.
.
O
•
N.
O
0
O
U
Os
~--
N.
.
CD
Co
.
M
C'~)
•
N
N
N
N
N
N
N
N
d'
N
(NI
10
`O 1- CO
~-
N 'NI-
r
N
4C
O-
sO
N
N
a)
O
s
N
N.
Z
O
.~
N.
CO
N.
N ^-
'O
CD
^
co
I-
1
O
N
co
N
N
U
S
Z
c%
N
C
a
N O
O O
hC
0
U
a)
.c
>
C
N
(1)
LL
C
'd'
Co
CO
C
O
CC
~ a CO
0 0 0
0
M
r
0
0
0
0 O
.
•
N
p
0
O.
LO
0 0 O O▪
CO
-0
O
.
LO
CD
0
N
•
0•
•
u-
C)
L.
a
U
44-
!1
r-
0
0 C
D
U 0
0
M
0.
Ns
0
Os
0
r.
0 M pp
r
M
N
0
0
0
0
0.
.
.
.
.
0)
E
a)
C
.>
N
r r r (V
N °T Co
0
r
CO
0 CD
r
r
to
to
Ns
C'')
0
(NI
d'
N
r
sO
Ns
I~
O
CD
0
0\
CD•
Os
O
to
.
U
c%
0
Ns.
- o
t
r
0
C)
CO
r
LO
N '0 LC)
0
.
C)
.
M r
r
r
N
P.". O
0
•
to
CO
r
r
N ^ to
r
O -0 M N.
0 0 v
0
C)
sO Cs Lr
O
0 0
. •
•
.
Oro s Os ) 0 CD
•
• • •
•
C-N
r
U-r
C
a
a)
a)
C
0
a
-C
U
C
a)
`
D
C
▪
N CO CO
N.
.
.
N
r.
C7 O CO CO
to
r r r N Co
•
0
4j
LO
N •
•
C
D
O
a
(NI
LC)
Cs
`0 I~ CO
0
4ri
a
. cOo
.N N N
I
r CV
r
()
i~ CA
r
I
N M
O
_
L
~.
Cs
N
01
to ' 01
p
U
z
a
C
N
1
Os
U
co
8
N.
C7 O O
Q
p~
O
0
O'
O N
M
Csi O
M0 s
ce) '
M
0
O
N
0
0
CD
CO 0 O M M N Os M
M
.
N
C7
S
.
r
CT.
O O
O
CD
CD
O O O 0
pr p O r r r
O
O
O
O
O
C.4
CD'
O• Ch
8
. 0. O. O. O.
cf.)
csi
LC) CO
CV
0
0 rr
LO
.O
q
P.,'
to
r
C)
r
CO
r
o
CO
()
NN
O
O
r
S
CV 'd'
O.
O
0.
0
.
to
co
CD 0 0 O CD CD CD CD C D
•
C
0)
C
a)
LC)
CD
C)
_Q
a
U
r)
L.
Cl)
44.
c~ 'Tt Co CD
r
q
0 r
0
0
CD
CD
.
.
.
.
O.
.
N
.
CO
<L
a)
0)
O
.
Os
00
0
CD
.
•
tc)
~O
CD
O
t_
CD}
~
B
CD CD C)
.
.
•
N
i
8•
•
•
N
▪
O
.
^
M
r
r
I
.
t
o
•
LC
)N
r
N
r
. Os CD
N
D
C
p
C ~)
to
•
r
r
to
Os
N. CO Co C
o
•
.
.
N N
▪
N
O
)
U
a
CO
r
•
O'
N
r
r
r
C
a
s
U
4-
C
W
L.
D
Z
•
a)
Cl
U)
a)
. C
N
O
o .E
o
0_
.
N N
CC')
1 1 1 1
r N r r
r r
1
N
cc)
-t
N
"O
O
•O
tf)
If)
V
I
U)
Z
Co Cut?)
.
Q
.
ao
O
a)
NC
Lr)
0•
O
O.
CO
(▪)
U
.S
.
0
~
.
.
.
.
O' I- $
`t
.
.
.
CO
O
- C
N
co
O
E
0 O.
p O-
0%
~
O O
O
•
• O O O O O
O
V
N. %O ~ N
.^- 0% •oO 0%
g 8
r r N N
O O O O O
CO
N
O
IL
`dN M N
N
O c
O O
N
CO
W...
•
g
0
a)
L.
U)
0
C
C
a)
0
▪
0 LO
C%l
0%
N a- O
O
• O O O o o O O
a
E
O
a)
i
0)
)
0
0
a)
V
n
LC' 0 N 0• o
0.
N r r r
. r r •
C
N
a)
0)
C
0
U
a
3
3
l[) C')
r r
a- R
• N• M•
s
4C
CD
a- N
•
•
•
4-
N.
a-•
•
r
N•
0
O
4
O
O-
Z •E
•O
4
a
N
1
r1
N
r r
N C
o0
f\
t
!
r r1
C') O r
a O 0.
r
Cf)
r
r
r
U
I
Z
8
0
b
Y:0
Os - .
O O
C
N
CO
D
U
M
N
^
4')
N
Q
O p
O O O C) 0
0
N p
0 CD
I-
N
C'sl
-
co
Os
In
11-.0
t() O
.
S S• O
• S• S
Os
0
6-
O• 00
0
(NI
st:)
O O
•
•
C
O
00 O
_
• O• 0
. S.
0O
•
•O
. O. CO.
O.
U
CO O0. M
•
N .-
•
d
.
0
co
CO
ca
..<
Os
00
Os
O p 0 O
•
•
•
•
N
0
0
CO
CNI
O
o.
N
CV
N
a- N'
O
0)
-
in
CO hs.
O O O O O
M
0
0
M
O
.
•O
d-
O•
CO
•
O•
O•
.I
-
%CI CO
. O••
N N
N
N• (V
0
0
0
N
O
O
CO
. CO
Os
.
.O CO
0
(
co
(N
.p
It)
N
N (NI
o O
O
CD
•O 1, N
10 O.-.
.-- r-1~
• .-• ..
•
•
CO
less
vs.
C
UI
a)
CNI
Os
•O 1~ CO
N
C') 0 O. O 0 a
1 N1 ^ C')
1
N
CY)
M
.p
V1
U
g
M
U
co
Z
•
Q
C
N
'Tr
0
O~ O O N
•
.
.
.
a O }} N
te~
O
O
N
^
.N
CO
N
0
0
0
.
O
8
8
N
8
8
eN.
O
O
U
O
.-
a)
N
D
LL
C
O
a)
N
~} C')
O O
N
O
O
LO
(NI
0.
0
1.r)
CD
a
U
O
CD
O
'Cr
LO)
8
so
so
N
O
.p
0
.'
O
.
CD
0 0
O
O
•
sO 0
0 O
8
C■
^lO
i")
O
Q
^
o
8
tf)
CT CO
C)
.
Os
0
M
0
8
O
p
L
CO
so
8
. 8
C')
O
O
O
03
CO LO CO CT
C ) N CO I~
0
CL
^
'rLO 03 ~
8
p 8 8 8 8
N N
8• 8 8
O
8 8 0
(Y) O
O
• 8• 8. O. 0.
-
co
0.
N
s
s-• CD
C') LI)
LC)
-. M N N
O•
(NI
N
•
r
-
`O Os
LO
E
C
O
N
LC)
O OT
^
.
N. NO
0 CO
0
m
U
.= a
-1'
N-
CN,l
LO
LI)
^
•
N N h OM
~1
1
1
I
.-
Ch
I
^
OT
O
I
d'
I
O_ 0.
I
0
I
M
N
C' )
(N
I~
.-
I
I
0
n
I
8
0
'0
O O
O•
8
N
O
i-
esl
M
M
I
aD
O
Os
N
M
•
co
D
V
N
LL.
C
O)
O
r-
.-
M
^
CO
O
CO
d
O
0
O
I.
n
I
N
.r-
CO
.-
O
.-
N0
8
I-
Os
N
0
OD
CO
0
O
0
O
0
O
~
•
0
•
0
.
N
.
•
.
.
.
.O
r-
r•
M
p
N
'O
•-
O
O~
O
0
'--
S
~
p
O
O
N
.
o.
co
1r)
MI
n
I
sO
0
~O
I
CY)
O
CO
0
s
o
M
0
0
cN
°O
LO
O
c" )
~--
r
0
M N
CD
0
CD
.
S
S
Ce)
CN
pp
.
°o
N M M -'
S S C) 0
S
N
N1
1
o
M
r
I -•
4-
O
0 • LC)
1r
O.
S
•
C)
0
.
▪
p
eF
0
•
C■l
0
N
N
O
O
• O
. O
. O
N
Q
0 0
'--
SS
S S O
CO
Os
N
0
CO
9 S S S S
03
0 '-
N
M
1
N
N
o1
C
M
1
M
.
-
.
~
O O'
ci)
I.
t[)
.0
yp'
g
'o
V
N
O..
Z i1 1
N•
om.
Q
•
O
M
C
L
0
0
a.a-0
'0
'p
8•
LC)
N
0
N..
0
OD
N.
0
O•
.
CO
ci• .
LO
O
• O• O•
CV
O•
N
it))
8 8
L
8
O• O• 8•
~O N
0
Cf) '•O Os
Nt
.' 0 0 G
• O•
0
O•
I
L
O
8 8 8 8 8 8 8 8
i
'
O
I N O
•
w O.
8
CO
O O•
•
O.
N O 00 CO . CO 0 `~t C^
d.
. O~
. ~O
. ~O
. f.. CQ
. 'O.
0
N
~p
O C>
N
o
CI .
N
CO C) - ; N
•
•
•
cR'
8 8 8 8 8
(NI
•
8
• 8• 8• 8• 8•
88
,
C
'0 '0
L() I-
C 8 8
LL
O
•
OOO
C)
p7
•
O O
e• o•
N
N
N•
•
M
.
a
d..
4
0
e}
LC) C'~)
1' •
• .r
• I•
.)
.
'0
. N
.' .
~--•
Ix)
ps,
Cv)
CO
O
'0
-4a
0
C) N N
r N
IL
CO
M •? O N co co~'
0
(C)
N.
a-
'O f~
Process
•
Figure 1 . Flow Diagram
EXPERIMENTAL DESIGN
WEYERHAEUSER STREAM S
(1 )
Leaf collection at leaf abscissio n
(alder, vine maple, conifer, big lea f
maple)
(2)
Leaf material strung into packs usin g
monofilament nylon line .
(3)
Leaf packs dried at 50°C and weighed .
(zero time reading )
(4)
Leaf packs rehydrated, tied to brick s
and incubated in three stream s
November l g
Streaml
Control
Stream II
Constant nitrate
addition
Stream II I
Intermittant nitrat e
addition
144 leaf packs
incubated (36 packs
of each species)
144 leaf packs
incubated (36 packs
of 'each species )
144 leaf packs incubate d
(36 packs of each species )
(5) Collection of 36 leaf packs for each sampling interval (3 leaf packs o f
each leaf species from each stream)
O
(6) Processing of leaf packs for each leaf species from each stream is identical .
(6A)
Leaf Pack 1 .
remainder of
10 gram (wet weigh t
leaf material subsample for bacteria l
analysis {total viabl e
counts )
handwashing t o
remove insect s
and associate d
debris
•insect preservation
in alcohol
dried at 50°C
(6C )
Leaf Pack 3 .
(6B)
Leaf Pack 2 .
remainder o f
leaf materia l
handwashing to handwashing t o
remove associated remove associdebris and insects ated debris an (
insect s
50 leaf disk s
(1 .5)cm remove d
from each pac k
insect preserva of alder, vine
and conifer ;
tion in ethano l
insects removed dried at 50°
C
by han d
respiration
measurements t o
obtain estimate s
of carbon mineral izatio n
insect preservation i n
ethano l
leaf gisks drie d
at50 C
dried at 50° C
leaf pack weigh t
loss (correcte d
for bacteriologica l
subsample)
total leaf pack weight
loss
leaf pack
weight los s
(7) Dried leaf material from each leaf pack ground separately on a Wiley mil l
(40 mesh )
•
410
(8)
Subsampling of dried leaf material for chemical . Chemical analysis o f
each leaf pack of each species from each stream is identical .
Subsample a (300 mg )
Biochemical analysis fo r
lignin, cellulose, noncel l
wall constituents by acid detergent method
Subsample b (100 mg )
Total nitrogen content b y
micro-Keldahl metho d
Subsample c (100 mg )
Subsample d (500 mg )
Carbon content by combustion
on a Burell total carbon
analyze r
Other nutrient analysis on a
Perkin Elmir IM Emissio n
Spectrophotometer for :
second year
Cation exchange capacity
(1 gram)
Litter material fro m
Mack Creek an d
Watershed 1 0
potassium
phosphorus
magnesium
manganes e
iro n
coppe r
boro n
zin c
aluminum
second year
second year
10
1/
1''
Absolute nitrogen content (mg) for,leaf packs of : (a) vine maple, (b) big-leaf maple ,
(c) alder, and (d) Douglas-fir, in relation to weight loss resulting from litter disappearance in three streams with different intrate input . Control stream (A), continuous nitrate input stream (0), and , intermittent nitrate input stream (0) . Initia l
leaf pack weight normalized to 10 grams . Dashed line indicates original nitrogen content .
410
80 --
60 -
40 vI
E
A
1- 20 -
20 0
0
1
20
I
I
I
60
I
1
100
I
20
80 -
I
I
60
1
100
D
q
60 -
160 -
40 -
80 -
20 -
I
•
20
I
I
60
I
1
100
20
WEIGHT LOSS (%)
Figure 2
I
I
60
I
1
00
C
Percent of original nitrogen concentration present in leaf packs of :
(a) vine maple, (b) big-leaf maple, (c) alder, and (d) Douglas-fir ,
from three streams with different nitrate input . Control stream (14
continuous nitrate input stream (0), and intermittent nitrate inpu t
strean (0) .
,
C
1
1
1
40
I
7
80
1
1
I
I
I20
DAYS IN PLACE
Figure 3 .
I
160
I
I
200
I
I
24 0
t t`
J
70-
• WS10
Conifer
4
o MACK
•
0
0
60-
•
50-
0
00
40"
0
•
e
.
0
•
•
•
0
3
Vine Mapl e
•
•
70-
9
•
Z
0
0
o$
•
60-
•
0
50 -
40-
300
•
40
80
120
160
200
24 0
DAYS IN PLAC E
Figure 4. Change in cation exchange capacity for litter of conifer, and vine maple ,
in a stream where decomposition proceeds slowly, Watershed 10 (0) and a
stream where-decomposition proceeds rapidly, Mack Creek (0 ) .
28 0