> - 

{&) Department of 

Agriculture 

Forest Service 

Northeastern Forest 

Experiment Station 

Research Paper NE-584 

~nput-output Budgets 

of Selected Nutrients on an 

Experime.ntal Watershed 

Near Parsons, West Virginia 

J. D. Helvey 

Samuel H. Kunkle 
The Authors 

J. D. Helvey is research hydrologist, USDA Forest Service, Timber and Watershed 

Laboratory, Parsons, WV 26287; Samuel H. Kunkle is hydrologist, Water Resources Division, USDI, National Park Service, Colorado State University, Fort 

Collins, CO 80523. This research was funded as part of the National Acid Precipitation Assessment Program by the USDA Forest Service. 

Manuscript received for publication 22 May 1985 

Abstract 

The objectives of this 3-year study were to determine (1) budgets of H+, Ca+ +, 

CI-, NOS-N, NH3-N, and S04= for a 38.9-ha forested watershed and (2) changes 

in concentration of these constituents that occur in the tree canopy, the soil and 

bedrock, and the stream channel. Sampling points were two forest openings for 

bulk precipitation, 20 throughfall sites, four springs where water first seeps out of 

the soil, and the main stream at the watershed outlet. The most important conclusion was that sulfate is accumulating in the watershed. Average annual kglha of 

sulfate were: bulk precipitation = 39.9, throughfall = 53.0, and stream = 25.1. 

Sulfate budgets are compared with published results from five other study sites in 

the hardwood region of the Eastern United States and with some results from 

Germany. 
Precipitation in the central Appalachians is among the most 

acidic in the United States. Average annual pH is 4.20, but 

pH readings below 4.0 are common in the summer months 

(Helvey et a1.1982). The 15-year average pH of streamflow 

from an undisturbed watershed is 5.85. Thus, major chemical changes occur as water from precipitation passes 

through the ecosystem. Some scientists believe that acid 

precipitation will accelerate nutrient leaching from the forest 

foliage (Tukey 1980) and the soil profile (Hutchinson 1980). 

The long-term consequences could be a decrease in forest 

productivity. 

We started a study in 1980 to determine changes in the 

chemistry of precipitation as it filters through an undisturbed 

watershed on the Fernow Experimental Forest. Our specific 

objective was to determine the chemical characteristics of 

bulk precipitation, throughfall, spring water, and streamflow. 

By establishing current budgets of the common nutrients 

within the ecosystem, changes in these budgets over time 

can be determined. Although similar studies have been 

reported for New England (Likens and others 1977), the 

southern Appalachians (Swank and Douglass 1977), and 

eastern Tennessee (Kelly 1979), this is the first nutrient 

balance study to be reported for the high-precipitation zone 

of the central Appalachians. 

Study Area and Methodology 

The Fernow Experimental Forest, located near Parsons, in 

north-central West Virginia, is typical of much wooded land 

in the central Appalachians. Elevations range from 650 to 

almost 1,000 m, slopes from 10 to 60 percent, with 20 to 30 

percent most common. The soils are derived from acid shale 

and sandstone of the Hampshire series, with Calvin channery silt loam (loamy-skeletal, mixed, mesic typic Dystrochrepts) prevalent. Soil pH averages 4.3, 4.6, and 4.7 for the 

A, B, and C horizons, respectively (Tomkowski 1983). Soil 

depth averages about 120 cm. 

The study was conducted on watershed 4 (38.9 ha), which 

has served as a control, catchment since the research program began in 1951. Forest vegetation, little disturbed since 

a high-grading operation in 1909, consists of several hardwood species including yellow-poplar (Liriodendron tulipifera 

L.), sugar maple (Acer saccharum Marsh.), black cherry 

(Prunus serotina Ehrh.), white ash (Fraxinus americana L.), 

sweet birch (Betula lenta L.), yellow birch (Betula alleghaniensis Britt.), red oak (Quercus rubra L.), American beech 

(Fagus grandifolia Ehrh.), black locust (Robinia pseudoacacia L.), and hickories (Carya spp.). 

Average basal area, determined from a 100 percent cruise 

in 1984, was 30.3 m2/ha for stems greater than 12.7 cm 

at breast height. The utjderstory contains reproduction of 

overstory species along with a scattering of flowering dogwood (Cornus florida L.) and other shrubby species. During 

the growing season, the forest floor is almost covered with 

stinging nettles (Laportea canadensis (L.) Wedd.), which 

often reach 120 cm in height. 

Annual precipitation averages 150 cm, evenly distributed 

through the year. Annual streamflow averages 60 cm, but 

the distribution is strongly seasonal. Seventy-five percent occurs during the dormant season and 25 percent during the 

growing season. The watershed seems to have very limited 

buffering capacity because annual stream alkalinity averages 

less than 2 mg/L as CaC03. 

Annual leaf fall biomass averages about 4.2 metric tonstha 

(Kochenderder and Wendel 1982). Litter decomposition, 

although not measured, seems to be very rapid because the 

previous year's accumulation virtually disappears by the 

end of each growing season. 

Figure 1 shows the experimental watershed with plotted 

sampling points. Bulk precipitation was sampled with two 

Figure 1 .-The experimental watershed with the location of 

sampling sites. Forest opening sites: OP-A and OP-6; 

throughfall sampling sites: TA, TB, TC, and TD; and spring 

water sampling sites: SA, SB, SC, and SD. 
gauges in each of two forest openings. In addition to the 

gauges for collecting samples for chemical analysis, standard and recording precipitation gauges are located in each 

forest opening. Records from these gauges were used for 

total amounts and timing of precipitation events. Throughfall 

was sampled with five randomly located gauges on each 

of four plots (40 m2). Spring water was sampled at the four 

locations where water first seeps out of the soil. Streamflow 

was sampled about 10 m above the 120" V-notch weir. 

Deep seepage, water leaving the catchment without flowing 

across the weir blade, is a concern when input-output budgets are computed. Although the amount of deep seepage 

is impossible to determine, it is not believed to be a serious 

problem for the experimental watershed. Nutrient input as 

stemflow, which was not measured, at least partly compensates for unmeasured nutrient losses by deep seepage. 

During the snow-free season, gauges for throughfall and 

bulk precipitat'ion consist of polyethylene funnels, with a 

diameter of 17 cm, mounted on 2-L polyethylene bottles. A 

piece of fiberglass was placed across the opening of each 

funnel to help prevent sample contamination by insects and 

plant debris. After each throughfall or precipitation sample 

was collected, the funnels were scrubbed and thoroughly 

rinsed with distilled water, and a new piece of fiberglass was 

installed. Also, bottles that had been scrubbed with soapy 

water, then thoroughly rinsed with distilled water, were installed to sample the next storm. 

During the months when snow normally falls (DecemberFebruary), bulk precipitation and throughfall were sampled 

with one 120-L container at each throughfall plot and at 

each open site. A new plastic liner was installed each week 

after the preceding week's sample was collected. 

A test of precipitation catch efficiency was made among the 

funnels, containers, and standard precipitation gauges located in the two forest openings. There was no significant 

difference (P= 0.05) in the performance of these three collectors. 

Grab sampling was used for the spring and stream sites. 

Chemically clean polyethylene bottles were-rinsed 3 times 

with water at the sampling site prior to sample collection. 

During the snow-free season, bulk precipitation, throughfall, 

spring flow, and streamflow samples were usually collected 

within 15 hours after each storm. The exceptions were 

storms that occurred on weekends; those samples were 

collected the following Monday morning. During the snowy 

season, samples were collected on Tuesday of each week. 

Stream and spring samples were collected at frequent intervals during selected storms in order to better define the 

relationship between flow rate and the concentration of 

chemical constituents. The sampling interval varied depending on changes in stage. 

On rare occasions, a throughfall sample was lost because of 

animal disturbance or because it was obviously contaminated by insects or plant material. These missing values 

were estimated by averaging values from the remaining 

samples. 

Collected samples were transported about 12 km to the 

laboratory where they were composited by plots and subsequently analyzed for various chemical constituents. During 

the first year of the study (May 1980-April 1981), the samples were analyzed for pH, specific conductance, and the 

concentration of sulfate. Samples collected after May 1981, 

were analyzed for pH, specific conductance, nitrate nitrogen 

(N03-N), sulfate (S04=), chbride (CI-), calcium (Ca++), and 

ammonia nitrogen (NH3-N). pH was determined with a 

Corningi 10 meter and specific conductance with a temperature compensating Markson meter. Anions were measured 

with a Dionex 10 ion chromatograph, except that the Hach 

Chemical Company (1977) method was used for sulfate 

between May 1980 and May 1, 1981. Calcium was measured with a 503 Perkin Elmer Atomic adsorption Spectrophotometer. Ammonia nitrogen (NH3-N) was measured by the 

Hach Chemical Company (1977) method using a Bausch 

and Lomb spectrometer with digital readout for color comparisons. 

pH and specific conductance were measured within 24 

hours, anions within 7 days, and cations (including NH3-N) 

within 30 days after sample collection. Each sample for 

anion analysis was injected through an individual 0.2-pm 

filter, but samples were not filtered prior to the other analyses. No preservatives were used because of the short time 

between sample collection and analysis. All samples were 

refrigerated at 4°C until they were analyzed. 

Data Analysis 

Each chemical constituent was averaged by dates for each 

sampling site before input-output budgets were computed. 

Chemical inputs were computed by first converting depth of 

measured precipitation and throughfall for each event to 

volume per hectare. Next, the concentration of each ion was 

multiplied by the computed volume to give kglha of that ion 

for that event. Finally, the kglha values per event were accumulated for growing season (May l-October 31 ), dormant 

season (November 1-April 30), and hydrologic year (May 1- 

April 30). 

'The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. 

Such use does not constitute an official endorsement or 

approval by the US. Department of Agriculture or the Forest 

Service of any product or service to the exclusion of others 

that may be suitable. 
The intensive sampling during storms showed only minor 

and inconsistent changes in the concentration of measured 

constituents as flow rate increased. Therefore, chemical 

outputs were computed by first determining the volume of 

streamflow represented by each collected stream sample. 

This volume was defined as the measured flow occurring 

midway between the time of the previous sample and the 

current sample and between the current sample and the 

next sample. This outflow volume, in Uha, was multiplied, in 

turn, by the concentration of each chemical constituent. 

Finally, the individual output values were accumulated by the 

same time periods as the input values. 

Results 

Output budgets at the springs could not be computed because flow rates were not measured. A total of 87 storms in 

the growing season and 72 in the dormant season was 

sampled during the 3-year study. Table 1 shows average 

concentration of each measured chemical constituent by 

season and the standard error (Sic) ofmeach mean. Several 

conclusions can be drawn from the table: 

During the growing season, hydrogen ion concentration 

decreases dramatically from bulk precipitation to 

throughfall and to springs and streams. Throughfall 

contains about 38 percent fewer hydrogen ions than bulk 

precipitation. Of the hydrogen ions in throughfall, 85 

percent are neutralized in the soil and bedrock, and about 

8 percent are neutralized in the open stream channel. 

Specific conductance of throughfall is greater than 

conductance of bulk precipitation during both seasons, 

presumably because of nutrients added by the forest 

canopy. Average conductivity and the variability between 

samples are much less for streamflow than for the other 

sampling sites. 

The neutralization capacity of the tree canopy is much less 

during the dormant than during the growing season. 

However, the soil and bedrock continue to neutralize 

incoming acids, and the pH of streamflow during both 

seasons averaged 5.85. 

Water is enriched in the canopy and soil with respect to 

most ions and slightly diluted in the stream channel. 

Exceptions are SO,= and NH3-N, which are greatly 

enriched in the canopy but are diluted within the soil and 

bedrock. 

Concentration of SO,=, Ca", and NH3-N in bulk 

precipitation is higher during the growing than during the 

dormant season. However, there is no significant 

difference (P = 0.05) in the streamflow concentration of 

these nutrients between seasons. 

Table 1 .-Simple averages and standard errors of measured chemical parameters by season and sampling sites 

Site H+ Conductivity CI - N03-N SO,= Ca+ + NH3-N pH 

weqlL pslcrn .............................................. mg/L ............................................. 

GROWING SEASON (May 1-Oct. 31) 

Bulk 

Sic 

Throughfall 

sic 

Springs 

Sic 

Stream 

sic 

Bulk 

Sic 

Throughfall 

sic 

Springs 

Sic 

Stream 

sic 

DORMANT SEASON 
Concentration of most ions differ very little from the time 

water appears at springs until it exits the watershed. An 

exception is NO3-N, which decreases in concentration from 

about 1.35 mg/L at the springs to 1.05 mg/L at the 

watershed outlet. 

Budgets of the measured ions are presented in Table 2. As 

suggested by Shaffer and Galloway (1 982) these relationships can be divided into the following classes: input > 

output, input < output, and input = output. The ions falling 

into each of these categories are as follows: 

Table 2.-Annual budgets of measured nutrients 

greater than the loss as streamflow (9.3 kglha). Total nitrogen budgets could not be computed because organic nitrogen was not measured. 

input < output (Ca'+) 

Calcium input as precipitation averaged about 4 kg/ha/yr 

less than the loss in streamflow during the 2 years of record. 

An enrichment occurred in the canopy, and throughfall contained almost double the calcium measured in bulk precipitation samples. 

Years Site CI- NO3-N S04= Ca++ NH3-N H+ N03-N + NH3-N Water depth 

........................................ kg/ha .............................................. cm 

1980-81 Bulk - - 38.6 - - 0.84 - 107.1 

Throughfall - - 47.2 - - .63 - 97.3 

Stream - - 19.9 - - .O1 - 57.2 

1981 -82 Bulk 0.9 7.2 48.5 7.4 8.5 0.95 15.7 160.0 

Throughfall 1.0 8.8 65.0 15.7 15.2 .75 24.0 139.2 

Stream .7 10.5 31.5 13.7 .8 .02 11.3 83.4 

1982-83 Bulk 0.3 . 4.9 32.6 8.3 6.8 0.68 11.7 140.2 

Throughfall .6 6.1 46.9 14.2 12.8 .53 18.9 124.0 

Stream .3 6.6 23.9 10.9 .6 .01 7.2 69.0 

Average for Bulk 0.6 6.0 39.9 7.9 7.7 0.82 13.7 135.8 

period of Throughfall .8 7.5 53.0 15.0 14.0 .64 21.5 120.2 

record Stream .5 8.6 25.1 12.3 .7 .01 9.3 69.9 

aThe hydrologic year begins May 1 st and ends the following April 30th. 

input > output 

(H', SO,=, NH,-N, Total inorganic N) 

lnput of hydrogen ions was 0.8, 1 .O, and 0.7 kglha for the 

first, second, and third year of the study, respectively. 

Losses in streamflow were only 0.01 kglha for each year. 

Therefore, as pointed out earlier, this watershed effectively 

neutralizes acid received in precipitation. Annual sulfate 

input averaged 40 kg/ha during the 3 years of record and 

ranged from 32.6 to 48.5 kglha. During the 3 years of study, 

sulfate in throughfall averaged 33 percent more than the 

amount measured in bulk precipitation samples. The sulfate 

export by streamflow averaged 14.8 kglha less than the 

input as bulk precipitation and 27.9 kglha less than throughfall. 

The annual input of NH3-N averaged 7.7 kglha during the 2 

years of complete record. Almost double this amount was 

delivered to the forest floor as throughfall (14 kglha), but 

water flowing from the drainage contained almost no nitrogen as NH3-N. 

input = output (CI-, NO,-N) 

lnput and losses of chloride are expected to roughly balance 

over the long term because chloride is not involved significantly in biological processes (Shaffer and Galloway 1982). 

A slight enrichment of NO3-N occurs in the forest canopy 

and a greater enrichment occurs within the soil and bedrock. 

However, NO3-N export by the stream differed only slightly 

from the input in bulk precipitation. 

Discussion 

One concern of all studies involving precipitation and 

throughfall sampling is the difficulty (or impossibility) of computing error terms for estimated values. The problem is 

even greater when collected samples are analyzed for the 

concentration of various ions from which nutrients budgets 

are computed. Because of these problems, the uncertainty 

of estimated values is rarely mentioned in research papers 

that present nutrient budgets. 

When NO3-N and NH3-N are combined, the annual input of 

inorganic nitrogen as precipitation (13.7 kglha) is slightly 
Potential sources of error include: (1) the accuracy of estimated volumes of precipitation, throughfall, and streamflow, 

(2) the representativeness of precipitation, throughfall, and 

streamflow samples with respect to the chemical characteristics of the respective populations, (3) the accuracy of 

chemical determinations in the laboratory, and (4) computation errors. 

The study design used here for volumes of precipitation and 

throughfall meets the recommendations of Helvey and Patric 

(1965) for numbers of samplers needed to ensure that estimates are within + 5 percent of true values for a given 

storm. Since many storms were sampled in this study, the 

errors should tend to cancel out and annual values should 

be more accurate than individual storm values. Streamflow 

measurements with the 120" V-notch weir have an accuracy 

of + 5 percent (Hornbeck 1965). As stated earlier, the volume and chemical characteristics of deep seepage is impossible to quantify accurately, but nutrient losses by this 

pathway are partly compensated by the unmeasured inputs 

by stemflow. Quality control in the laboratory and double 

checking of all computations minimizes these sources of 

error. 

Although it is impossible to know for sure, we believe that 

the values in Tables 1 and 2 are within 10 percent of actual 

values. 

The input-output relationships of S04= and Ca+ + (Table 2) 

raise an important question: Is the enrichment of throughfall 

caused by ions being leached from plant surfaces, the 

washoff of dry depositions that accumulated between 

storms, or a combination of these processes. In other words, 

when computing input-output budgets, is bulk precipitation 

or throughfall the proper input value? 

If leaching is the dominant process in throughfall enrichment, 

bulk precipitation would be the proper input value because 

leaching simply cycles the nutrients between the canopy and 

soil. Without leaching, these nutrients would reach the forest 

floor with leaf fall. If washoff is the dominant process, 

throughfall is the proper input term because throughfall 

would include dry deposition. Bulk precipitation gauges, although open to the atmosphere at all times, are inefficient 

dry deposition collectors. For example, the National Atmospheric Deposition Program no longer uses buckets on a 

routine basis for estimating dry deposition because buckets 

do not accurately simulate the surfaces of vegetation. 

The answer to the question is important because, as with 

calcium, leaching would mean a net loss of these ions to the 

ecosystem, while washoff indicates a net gain. A net watershed accumulation of sulfate is indicated whether leaching 

or washoff is the dominant process. However, the magnitude 

of the accumulation is almost double if washoff is dominant. 

Others who have addressed this question concluded that the 

dominant process varies between ions. Leaching is the dominant process for throughfall enrichment of potassium because potassium is an extremely mobile ion (Mayer and 

Ulrich 1980; Johnson et al. 1982). Washoff is believed to be 

the dominant process for throughfall enrichment of most 

other ions (Eaton et al. 1973; Mayer and Ulrich 1980). Smith 

(1981) stated that forest trees can be extremely efficient at 

trapping sulfur compounds in their foliage because leaf surface area is about 5 times greater than the ground surface. 

Perhaps the most important finding of this research is that 

annual sulfate input exceeds annual streamflow losses. 

Shaffer and Galloway (1 982) succinctly evaluated the implications of sulfate accumulation: "Sulfate adsorption capacity 

of soils is finite; as these sites become saturated, sulfate 

output will rise until input and output are equal, resulting in a 

major increase in total anion concentration. Simultaneously, 

there is currently a net export of base cations from the watersheds; at current loss rates and in the absence of significant primary weathering, we estimate depletion of the base 

cation pool within 50-200 years. As sulfate output increases, 

this time period will shorten accordingly." 

There is no evidence of accelerated cation leaching from the 

Fernow watershed because calcium losses are approximately balanced by input at the forest floor (throughfall). Although there has been no significant change in pH of 

streamflow from the experimental watershed during the past 

15 years (Helvey et al. 1982), some fishery biologists believe that other streams in the central Appalachians are 

becoming more acidic because of increased acid deposition 

(Zurbuch 1984). 

Since sulfate budgets are extremely important to the chemical stability of watersheds, Table 3 compares the sulfate 

budget for this study site with published budgets from other 

watersheds in the Eastern United States where mixed hardwoods are the dominant forest types. The input values are 

remarkably uniform considering the wide geographical area 

covered by the studies. The north-south range is from New 

Hampshire to North Carolina. The slightly lower deposition 

reported by Shaffer and Galloway (1982) could be caused 

by a combination of lower annual precipitation amounts and 

slightly lower concentrations of S04=. 

Although the S04= deposition values in Table 2 are greater 

than would be expected in the absence of atmospheric pollution, they are much less than reported sulfate deposition in 

certain parts of Europe. For example, sulfate input at three 

study sites in the Federal Republic of Germany was 69 

kglha on bare soil, 141-153 kglha for throughfall in a birch 

forest, and 240-258 kglha for throughfall in a spruce forest 

(Mayer and Ulrich 1978). 

Sulfate losses in streamflow (Table 3) range from 53.8 kglha 

at Hubbard Brook (Likens and others 1977) to only 9 kg/ha 

in the Blue Ridge Mountains of Virginia (Shaffer and Galloway 1982). Undoubtedly, this range is caused by the great 

diversity in soil types and parent material. 
Table 3.-Input and output budgets of S04= on catchments in the 

Eastern United States 

Bulk 

Authors precipitation Throughfall Streamflow 

kg/ha .......................... 

This study 39.9 53.0 25.1 

Shaffer and Galloway (1 982)" 26.8 - 9.0 

Likens et al. (1977) 38.4 - 53.8 

Lindberg et al. (1979) 39.6 96.0 - 

Kelly (1 979) 33.9 42.0 - Swank and Douglass (1 977)b 36.8 - 9.1 

aComputed from sulfate concentration and water volume data presented 

by authors. 

*These are the averages for seven control watersheds at the Coweeta 

Hydrologic Laboratory. 

More research is needed on the sulfate adsorption capacity 

of the common soil types in the Eastern United States where 

sulfate deposition is greatest. By knowing the sulfate adsorption capacity of a given site, we can predict from current 

sulfate deposition rates the number of years required to 

reach that capacity. A start toward a better understanding of 

sulfate adsorption capacity of several soils has been made. 

Johnson and others (1 980) concluded that watershed sulfur 

accumulation in soils from five sites in the Eastern United 

States is due to inorganic sulfate adsorption. Fitzgerald and 

others (1983) and Swank and others (1984) suggest that 

microbial conversion of sulfate to organic-sulfur forms is an 

additional important process influencing sulfate accumulation 

and mobility in forest ecosystems at the Coweeta Hydrologic 

Laboratory. These authors also suggest that microbial processes may be important at other locations and that further 

research into this question is warranted. 

Conclusions 

The control watershed at the Fernow Experimental Forest is 

currently effective in neutralizing the acids received in precipitation. The accumulation of sulfate within the ecosystem 

could cause watershed acidification and cation depletion 

in future years. Research is in progress to better understand 

the internal cycling of sulfate within the soil profile. Future 

research will attempt to define sulfate adsorption capacity of 

the major soil types on the Experimental Forest. 

Literature Cited 

Eaton, John S.; Likens, Gene E.; Bormann, Herbert F. 

Throughfall and stemflow chemistry in a northern 

hardwood forest. Ecology. 61 : 495-508; 1973. 

Fitzgerald, J. W.; Ash, J. T.; Strickland, T. C.; Swank, W. T. 

Formation of organic sulfur in forest soils: a biologically mediated process. Canadian Journal of Forestry 

Research. 13(6): 1077-1 082; 1983. 

Hach Chemical Company. Drinking water analysis handbook. Ames, IA: Hach Chemical Company; 1977. 219 p. 

Helvey, J. D.; Hubbard, John; Dewalle, David R. Time 

trends in pH and specific conductance of streamflow 

from an undisturbed watershed in the central Appalachians. In: Proceedings Canadian Hydrology Symposium; 

1982 June 14-1 5; Fredericton, New Brunswich; Canada. 

National Research Council of Canada; 1982: 637-651. 

Helvey, J. D.; Patric, J. H. Design criteria for interception 

studies. In: Design of Hydrological Networks: Proceedings 

of a symposium; 1965 June; Quebec City Canada. International Association of Scientific Hydrology; 1965; 67: 

131-137. 

Hornbeck, James W. Accuracy in streamflow measurements on the Fernow Experimental Forest. Res. Note 

NE-29. Broomall, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment Station; 

1965. 8 p. 
Hutchinson, T. C. Effects of acid leaching on cation loss 

from soils. In: Hutchinson, T. C.; Havas, M., eds. Effects 

of acid precipitation on terrestrial ecosystems: NATO Conference Series 1: Ecology 4 New York, NY: Plenum Press; 

1980: 481 -497. 

Johnson, Dale W.; Hornbeck, J. W.; Kelly, J. M.; Swank, W. 

T.; Todd, D. E. Regional patterns of soil sulfate accumulation: Relevance to ecosystem sulfur budgets. 

In: Shriner, David S.; Richmond, Chester R.; Lindberg, 

Steven E. Atmospheric sulfur deposition, environmental 

impacts and health effects. Ann Arbor, MI: Ann Arbor 

Science Publishers, Inc.; 1980: 507-51 9. 

Johnson, Dale W.; Turner, John; Kelly, J. M. The effects of 

acid rain on forest nutrient status. Water Resources 

Research. 18(3): 449-461 ; 1982. 

Kelly, J. M. Camp Branch and Cross Creek experimental 

watereshed projects; objectives, facilities and ecological characteristics. 60017-79-053 Washington, DC: 

Environmental Protection Agency; 1979. 153 p. 

Kochenderfer, J.N.; Wendel, G. W. Effects of fertilization 

and aspect on leaf biomass, leaf size, and leaf area 

index in Central Appalachian hardwood stands. In: 

Muller, Robert N., ed. Fourth Central Hardwood Forest 

Conference; 1982 November 8-1 0; Lexington, KY. University of Kentucky, Department of Forestry; 1982: 102-1 12. 

Likens, Gene E.; Bormann, F. Herbert; Pierce, Robert S. 

(and others). Bio-geo-chemistry of a forested ecosystem. New York, NY: Springer-Verlag; 1977. 146 p. 

Lindberg, E. E.; Harriss, R. C.; Turner, R. R. (and others). 

Mechanisms and rates of atmospheric deposition 

of selected trace elements and sulfates to a deciduous forest watershed. Environ. Sci. Div. Publ. No. 

1299. ORNL-TMl6674 Oak Ridge, TN: Oak Ridge National 

Laboratory; 1979. 514 p. 

Mayer, R.; Ulrich, B. lnput of atmospheric sulfur by dry 

and wet deposition to two central European forest 

ecosystems. Atmospheric Environmental Great Britain: 

Pergamon Press; 1978; 12: 375-377. 

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of vegetation in intercepting and modifying inputs-- 

A review. In: Hutchinson, T. C.; Havas, M., eds. Effects of 

acid precipitation on terrestrial ecosystems: NATO Conference Series 1 : Ecology 4 New York, NY: Plenum Press; 

1980: 173-1 82. 

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The impact on two headwater streams in Shenandoah 

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the 80's. Proceedings of the AWRA, international Symposium on Hydrometerology, 1982 June; Colorado. American Water Resources Association, Bethesda, Maryland; 

1982: 43-53. 

Smith, William H. Air pollution and forests. Interactions 

between air contaminants and forest ecosystems., New 

York, NY: Springer-Verlag; 1981. 379 p. 

Swank, Wayne T.; Fitzgerald, John W.; Ash, Jaru T. Microbial transformations of sulfate in forest soils. Science. 

223: 182-1 84: 1984. 

Swank, W. T.; Douglass, J. E. Nutrient budgets for undisturbed and manipulated hardwood forest ecosystems 

in the mountains of North Carolina. In: Correll, David L., 

ed. Watershed research in eastern North America, Vol. 1; 

A workshop to compare results; 1977 Edgewater, MD. 

Smithsonian Institution, Washington, DC; 1977: 343-464. 

Tomkowski, Anthony C. A study of the effects of acid 

rainfall on forest soil acidity. West Virginia Forestry 

Notes. 10: 17-18; 1983. 

Tukey, H. B., Jr. Some effects of rain and mist on plants, 

with implications for acid precipitation. In: Hutchinson, 

T. C.; M. Havas, eds. Effects of acid precipitation on terrestrial ecosystems: NATO Conference Series 1 : Ecology 

4 New York, NY: Plenum Press; 1980: 141-1 50. 

Zurbuch, Peter E. Neutralization of acidified streams in 

West Virginia. Fisheries Bulletin. 9(1): 42-47; 1984. 
Helvey, J. D.; Kunkle, Samuel H. Input-output budgets of selected nutrients on an experimental watershed near Parsons, West Virginia. 

Res. Pap. NE-584. Broomall, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station; 1986. 7 D. 

A control watershed at the Fernow Experimental Watershed effectively neutralizes acids received in precipitation. However, sulfate input by precipitation 

greatly exceeds sulfate losses as streamflow and watershed acidification is 

a real concern. 

I ODC 1 16.1 (754) 

Keywords: Central Appalachians; acid precipitation; nutrient cycling; sulfate 

budgets 
Headquarters of the Northeastern Forest Experiment Station are in 

Broomall, Pa. Field laboratories are maintained at: 

Amherst, Massachusetts, in cooperation with the University of 

Massachusetts. 

Berea, Kentucky, in cooperation with Berea College. 

Burlington, Vermont, in cooperation with the University of 

Vermont. 

Delaware, Ohio. 

Durham, New Hampshire, in cooperation with the University of 

New Hampshire.. 

Hamden, Connecticut, in cooperation with Yale University. 

Morgantown, West Virginia, in cooperation with West Virginia 

University, Morgantown. 

Orono, Maine, in cooperation with the University of Maine, 

Orono. 

Parsons, West Virginia. 

Princeton, West Virginia. 

Syracuse, New York, in cooperation with the State University of 

New York College of Environmental Sciences and Forestry at 

Syracuse University, Syracuse. 

University Park, Pennsylvania, in cooperation with the 

Pennsylvania State University. 

Warren, Pennsylvania.