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Unexpected ecological advances made possible by long‐term data: A Coweeta example

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C. Rhett Jackson, Jackson R. Webster, Jennifer D. Knoepp, Katherine J. Elliott, Ryan E. Emanuel, Peter V. Caldwell, Chelcy F. Miniat

Published Online: Jan 09 2018

DOI: 10.1002/wat2.1273

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In the 1970s, Forest Service and academic researchers clearcut the forest in Watershed 7 in the Coweeta Basin to observe how far the perturbation would move the ecosystem and how quickly the ecosystem would return to its predisturbance state. Our long‐term observations demonstrated that this view of resistance and resilience was too simplistic. Forest disturbance triggered a chain of ecological dynamics that are still evolving after 40 years. Short‐term pulses in dissolved inorganic nitrogen (DIN) (3 years) and streamflows (4 years) were followed by several years in which the system appeared to be returning to predisturbance conditions. Then however, changes in forest composition triggered a regime change in DIN dynamics from biological to hydrological control as well as persistent high stream DIN levels mediated by climatic conditions. These forest composition changes also led to later reductions in streamflow. These long‐term observations of streamflows, stream DIN concentrations, stream DIN exports, and stand composition have substantially advanced our understanding of forest ecosystem dynamics; and they demonstrate the value of long‐term observational data in revealing ecosystem complexities and surprises, generating new hypotheses, and motivating mechanistic research. Shorter observational records from this experiment would have produced incomplete or erroneous inference. WIREs Water 2018, 5:e1273. doi: 10.1002/wat2.1273 This article is categorized under: Science of Water > Hydrological Processes Science of Water > Water Quality Water and Life > Nature of Freshwater Ecosystems

Percent aboveground biomass for the whole watershed in WS 7 through time (Boring, Elliott, & Swank, ). Species code are ACRU, Acer rubrum; BELE, Betula lenta; CARY, Carya spp.; LITU, Liriodendron tulipifera; QUCO, Quercus coccinea; QUPR, Quercus prinus; QURU, Quercus rubra; QUVE, Quercus velutina; and ROPS, Robinia pseudoacacia. Robinia became dominant early in succession then diminished substantially but remained well above preharvest levels 30 years after harvest

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Changes in annual water yield (Q) from WS7 between water years 1967 and 2016 (bars), and the prediction intervals evaluated at α = .05 (lines). Changes in Q that lie outside prediction intervals are significant. Predicted WS7 yield in the absence of treatment was estimated by fitting a linear model of treatment to reference watershed Q during the calibration period and using this model to predict what would have been WS7 Q in the posttreatment period. Data are previously published (Swank et al., ) but updated to include 2013–2016

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Map of WS7 nitrate‐N concentrations (μg/L) across the stream network in 2008. Numbers in parentheses are tributary concentrations, and numbers not in parentheses are concentration in the main stream. Patterns were basically the same in sampling that occurred in post treatment sampling in 1977–1978, 1999, 2004, and 2008. The increase in nitrate at the headwater spring was first observed in April 1977, just after logging in January–February. The 2004 samples were taken as part of the LINX project(LINX Colaborators, )

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Progression of annual DIN and discharge deviation between Coweeta Watersheds 7 (treatment) and 2 (reference) from 1973 to 2013. The discharge deviation is the difference between the observed WS7 flow and that predicted from WS2 based on the pretreatment model. The DIN deviation is WS7 DIN–WS2 DIN. Each point is marked by the last two digits of the year. Symbol colors denote separate clusters identified by k‐means clustering by year. Green points encompass the initial watershed response (1977–1979) featuring large increases in water yield and moderate nitrogen release after harvest. Red points encompass the preharvest period (1972–1976), but also a period when the watershed seemed to be returning to preharvest conditions (1980–1988) after the initial response. Light blue points encompass the period of high DIN concentrations (1990–1998) due to nitrogen fixation following the emergence of Robinia as a dominant forest tree. Dark blue points encompass the most recent period (1999–2013) featuring lower streamflows and DIN. These latter two periods suggest interactions between droughts and DIN. The data do not yet indicate a move back to the initial condition

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Mean annual disolved inorganic nitrogen (DIN) concentration in Coweeta watersheds 7 (WS 7, logged 1977) and 2 (WS 2, reference) and annual discharge from WS 7. The gray bars represent periods of drought.(Reprinted with permission from Webster, Knoepp et al. ()

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References

Aber,, J. D., Nadelhoffer,, K. J., Steudler,, P., & Melillo,, J. M. (1989). Nitrogen saturation in northern forest ecosystems. Bioscience, 39, 378–386.
Adams,, M. B., & Kochenderfer,, J. N. (2014). Recovery of central Appalachian forested watersheds. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem. Clearcutting in the southern Appalachians (pp. 194–212). New York: Oxford University Press.
Andreassian,, V. (2004). Waters and forests: From historical controversy to scientific debate. Journal of Hydrology, 291, 1–27.
Argerich,, A., Johnson,, S. L., Sebestyen,, S. D., Rhoades,, C. C., Greathouse,, E., Knoepp,, J. D., … McDowell,, W. H. (2013). Trends in stream nitrogen concentrations for forested reference catchments across the USA. Environmental Research Letters, 8, 014139.
Bailey,, S. W., Brousseau,, P. A., McGuire,, K. J., & Ross,, D. S. (2014). Influence of landscape position and transient water table on soil development and carbon distribution in a steep, headwater catchment. Geoderma, 226, 279–289.
Boring,, L. R., Elliott,, K. J., & Swank,, W. T. (2014). Successional forest dynamics 30 years following clearcutting. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem: Clearcutting in the southern Appalachians (pp. 11–35). New York: Oxford University Press.
Boring,, L. R., Swank,, W. T., Waide,, J. B., & Henderson,, G. S. (1988). Sources, fates, and impacts of nitrogen inputs to terrestrial ecosystems—Review and synthesis. Biogeochemistry, 6, 119–159.
Bosch,, J. M., & Hewlett,, J. D. (1982). A review of catchment experiments to determine the effects of vegetation changes on water yield and evapotranspiration. Journal of Hydrology, 55, 3–23.
Caldwell,, P. V., Miniat,, C. F., Elliott,, K. J., Swank,, W. T., Brantley,, S. T., & Laseter,, S. H. (2016). Declining water yield from forested mountain watersheds in response to climate change and forest mesophication. Global Change Biology, 22, 2997–3012.
Clark,, J. S., Bell,, D. M., Kwit,, M. C., & Zhu,, K. (2014). Competition‐interaction landscapes for the joint response of forests to climate change. Global Change Biology, 20, 1979–1991.
Clark,, J. S., Nemergut,, D., Seyednasrollah,, B., Turner,, P. J., & Zhang,, S. (2017). Generalized joint attribute modeling for biodiversity analysis: Median‐zero, multivariate, multifarious data. Ecological Monographs, 87, 34–56.
Coweeta. (2016). Coweeta Hydrologic Laboratory quality assurance protocol. Retrieved from: http://www.srs.fs.usda.gov/coweeta/tools-and-data/qa-protocol_revised-2016-01-08.pdf.
Dodds,, W. K., Robinson,, C. T., Gaiser,, E. E., Hansen,, G. J. A., Powell,, H., Smith,, J. M., … McDowell,, W. H. (2012). Surprises and insights from long‐term aquatic data sets and experiments. Bioscience, 62, 709–721.
Edmondson,, W. T. (1991). The uses of ecology: Lake Washington and beyond. Seattle, Washington: University of Washington Press.
Elliott,, K. J., Boring,, L. R., Swank,, W. T., & Haines,, B. R. (1997). Successional changes in plant species diversity and composition after clearcutting a southern Appalachian watershed. Forest Ecology and Management, 92, 67–85.
Elliott,, K. J., Caldwell,, P. V., Brantley,, S. T., Miniat,, C. F., Vose,, J. M., & Swank,, W. T. (2017). Water yield following forest‐grass‐forest transitions. Hydrology and Earth System Sciences, 21, 981–997.
Ford,, C. R., Hubbard,, R. M., & Vose,, J. M. (2011). Quantifying structural and physiological controls on variation in canopy transpiration among planted pine and hardwood species in the southern Appalachians. Ecohydrology, 4, 183–195.
Ford,, C. R., Laseter,, S. H., Swank,, W. T., & Vose,, J. M. (2011). Can forest management be used to sustain water‐based ecosystem services in the face of climate change? Ecological Applications, 21, 2049–2067.
Gillin,, C. P., Bailey,, S. W., McGuire,, K. J., & Gannon,, J. P. (2015). Mapping of hydropedologic spatial patterns in a steep headwater catchment. Soil Science Society of America Journal, 79, 440–453.
Goldman,, C. R., Jassby,, A. D., & Hackley,, S. H. (1993). Decadal, interannual, and seasonal variability in enrichment bioassays at Lake Tahoe, California‐Nevada USA. Canadian Journal of Fisheries and Aquatic Sciences, 50, 1489–1496.
Gooseff,, M. N., Barrett,, J. E., Adams,, B. J., Doran,, P. T., Fountain,, A. G., Lyons,, W. B., … Wall,, D. H. (2017). Decadal ecosystem response to an anomalous melt season in a polar desert in Antarctica. Nature Ecology %26 Evolution, 1, 1334–1338.
Gurtz,, M. E., & Wallace,, J. B. (1984). Substrate‐mediated response of stream invertebrates to disturbance. Ecology, 65, 1556–1569.
Hewlett,, J. D., & Hibbert,, A. R. (1963). Moisture and energy conditions within a sloping soil mass during drainage. Journal of Geophysical Research, 68, 1081–1087.
Hewlett,, J. D., & Hibbert,, A. R. (1967). Factors affecting the response of small watersheds to precipitation in humid areas. In W. E.Sopper, & H. W.Lull, (Eds.), Forest hydrology (pp. 275–290). Oxford, England: Pergamon Press.
Hewlett,, J. D., Lull,, H. W., & Reinhart,, K. G. (1969). In defence of experimental watersheds. Water Resources Research, 5, 306–316.
Hicks,, B. J., Beschta,, R. L., & Harr,, R. D. (1991). Long‐term changes in streamflow following logging in western Oregon and associated fisheries implications. Journal of the American Water Resources Association, 27, 217–226.
Hornbeck,, J. W., Martin,, C. W., & Eagar,, C. (1997). Summary of water yield experiments at Hubbard Brook experimental forest, New Hampshire. Canadian Journal of Forest Research, 27, 2043–2052.
Kelly,, C. N., McGuire,, K. J., Miniat,, C. F., & Vose,, J. M. (2016). Streamflow response to increasing precipitation extremes altered by forest management. Geophysical Research Letters, 43, 3727–3736.
Knoepp,, J. D., Coleman,, D. C., Crossley,, D. A., & Clark,, J. S. (2000). Biological indices of soil quality: An ecosystem case study of their use. Forest Ecology and Management, 138, 357–368.
Knoepp,, J. D., & Swank,, W. T. (1998). Rates of nitrogen mineralization across an elevation and vegetation gradient in the southern Appalachians. Plant and Soil, 204, 235–241.
Knoepp,, J. D., Swank,, W. T., & Haines,, B. L. (2014). Long‐ and short‐term changes in nutrient availability following commercial sawlog harvest via cable logging. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem: Clearcutting in the southern Appalachians (pp. 57–84). New York: Oxford University Press.
Knoepp,, J. D., Taylor,, R. S., Boring,, L. R., & Miniat,, C. F. (2015). Influence of forest disturbance on stable nitrogen isotope ratios in soil and vegetation profiles. Soil Science Society of America Journal, 79, 1470–1481. https://doi.org/10.2136/sssaj2015.03.0101
Knoepp,, J. D., Vose,, J. M., & Swank,, W. T. (2008). Nitrogen deposition and cycling across an elevation and vegetation gradient in southern Appalachian forests. International Journal of Environmental Studies, 65, 391–410.
Laseter,, S. H., Ford,, C. R., Vose,, J. M., & Swift,, L. W. (2012). Long‐term temperature and precipitation trends at the Coweeta Hydrologic Laboratory, Otto, North Carolina, USA. Hydrology Research, 43, 890–901.
LINX Colaborators (2014). The lotic intersite nitrogen experiments: An example of successful ecological research collaboration. Freshwater Science, 33, 700–710.
Manning,, D. W. P., Rosemond,, A. D., Gulis,, V., Benstead,, J. P., Kominoski,, J. S., & Maerz,, J. C. (2016). Convergence of detrital stoichiometry predicts thresholds of nutrient‐stimulated breakdown in streams. Ecological Applications, 26, 1745–1757.
Manning,, D. W. P., Rosemond,, A. D., Kominoski,, J. S., Gulis,, V., Benstead,, J. P., & Maerz,, J. C. (2015). Detrital stoichiometry as a critical nexus for the effects of streamwater nutrients on leaf litter breakdown rates. Ecology, 96, 2214–2224.
McClain,, M. E., Boyer,, E. W., Dent,, C. L., Gergel,, S. E., Grimm,, N. B., Groffman,, P. M., … Pinay,, G. (2003). Biogeochemical hot spots and hot moments at the interface of terrestrial and aquatic ecosystems. Ecosystems, 6, 301–312.
Meyer,, J. L., Webster,, J. R., Knoepp,, J. D., & Benfield,, E. F. (2014). Dynamics of dissolved organic carbon in a stream during a quarter century of forest succession. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem: Clearcutting in the southern Appalachians (pp. 102–117). New York: Oxford University Press.
Monk,, C. D., Crossley,, D. A., Swank,, S. T., Todd,, R. L., Waide,, J. B., & Webster,, J. R. (1977). An overview of nutrient cycling research at Coweeta Hydrologic Laboratory. In D. L.Correll, (Ed.), Watershed research in eastern North America (pp. 505–526). Washington, DC: Smithsonian.
Nippgen,, F., McGlynn,, B. L., Emanuel,, R. E., & Vose,, J. M. (2016). Watershed memory at the Coweeta Hydrologic Laboratory: The effect of past precipitation and storage on hydrologic response. Water Resources Research, 52, 1673–1695.
Perry,, T. D., & Jones,, J. A. (2017). Summer streamflow deficits from regenerating Douglas‐fir forest in the Pacific Northwest, USA. Ecohydrology, 10. https://doi.org/10.1002/eco.1790
Price,, K., Jackson,, C. R., Parker,, A. J., Reitan,, T., Dowd,, J., & Cyterski,, M. (2011). Effects of watershed land use and geomorphology on stream low flows during severe drought conditions in the southern Blue Ridge Mountains, Georgia and North Carolina, United States. Water Resources Research, 47. https://doi.org/10.1029/2010WR009340
Rosemond,, A. D., Benstead,, J. P., Bumpers,, P. M., Gulis,, V., Kominoski,, J. S., Manning,, D. W. P., … Wallace,, J. B. (2015). Experimental nutrient additions accelerate terrestrial carbon loss from stream ecosystems. Science, 347, 1142–1145.
Schindler,, D. W. (1998). Replication versus realism: The need for ecosystem scale experiments. Ecosystems, 1, 323–334.
Singh,, N. K., Emanuel,, R. E., & McGlynn,, B. L. (2016). Variability in isotopic composition of base flow in two headwater streams of the southern Appalachians. Water Resources Research, 52, 4264–4279.
Singh,, N. K., Reyes,, W. M., Bernhardt,, E. S., Bhattacharya,, R., Meyer,, J. L., Knoepp,, J. D., & Emanuel,, R. E. (2016). Hydro‐climatological influences on long‐term dissolved organic carbon in a mountain stream of the southeastern United States. Journal of Environmental Quality, 45, 1286–1295.
Swank,, W. T., Douglass,, J. E. (1975). Nutrient flux in undisturbed and manipulated forest ecosystems in the southern Appalachian mountains. In: Association Internationale des Sciences Hydrologiques Symposium, 117:445–55.
Swank,, W. T., Knoepp,, J. D., Vose,, J. M., Laseter,, S. N., & Webster,, J. R. (2014). Response and recovery of water yield and timing, stream sediment, abiotic parameters, and stream chemistry following logging. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem clearcutting in the southern Appalachians (pp. 36–56). New York: Oxford University Press.
Swank,, W. T., & Vose,, J. M. (1997). Long‐term nitrogen dynamics of Coweeta forested watersheds in the southeastern United States of America. Global Biogeochemical Cycles, 11, 657–671.
Swank,, W. T., Vose,, J. M., & Elliott,, K. J. (2001). Long‐term hydrologic and water quality responses following commercial clearcutting of mixed hardwoods on a southern Appalachian catchment. Forest Ecology and Management, 143, 163–178.
Swank,, W. T., & Webster,, J. R. (Eds.) (2014). Long‐term response of a forest watershed ecosystem: Clearcutting in the southern Appalachians. New York: Oxford University Press.
Velbel,, M. A. (1988). Weathering and soil‐forming processes. In W. T.Swank, & D. A.Crossley, (Eds.), Forest hydrology and ecology at Coweeta (pp. 93–102). New York: Springer‐Verlag.
Vitousek,, P. M., & Melillo,, J. M. (1979). Nitrate losses from disturbed forests: Patterns and mechanisms. Forest Science, 25, 605–619.
Wallace,, J. B., Eggert,, S. L., Meyer,, J. L., & Webster,, J. R. (1997). Multiple trophic levels of a forest stream linked to terrestrial litter inputs. Science, 277, 102–104.
Wallace,, J. B., Eggert,, S. L., Meyer,, J. L., & Webster,, J. R. (1999). Effects of resource limitation on a detrital‐based ecosystem. Ecological Monographs, 69, 409–442.
Wallace,, J. B., Eggert,, S. L., Meyer,, J. L., & Webster,, J. R. (2015). Stream invertebrate productivity linked to forest subsidies: 37 stream‐years of reference and experimental data. Ecology, 96, 1213–1228.
Wallace,, J. B., & Ely,, D. (2014). Stream macroinvertebrate response to clearcut logging. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forest watershed ecosystem: Clearcutting in the southern Appalachians (pp. 177–193). New York: Oxford University Press.
Webster,, J. R., Knoepp,, J. D., Swank,, W. T., & Miniat,, C. F. (2016). Evidence for a regime shift in nitrogen export from a forested watershed. Ecosystems, 19, 881–895.
Webster,, J. R., Newbold,, J. D., & Lin,, L. (2016). Nutrient spiraling and transport in streams: The importance of instream biological processes to nutrient dynamics in streams. In J.Jones, & E.Stanley, (Eds.), Stream ecosystems in a changing environment (pp. 181–239). London, England: Academic Press.
Webster,, J. R., Swank,, W. T., Vose,, J. M., Knoepp,, J. D., & Elliott,, K. J. (2014). Bridging the gap between ecosystem theory and forest watershed management: A synthesis of 30+ years of research on WS 7. In W. T.Swank, & J. R.Webster, (Eds.), Long‐term response of a forested watershed ecosystem: Clearcutting in the southern Appalachians (pp. 229–247). New York: Oxford University Press.
Webster,, J. R., Waide,, J. B., & Patten,, B. C. (1975). Nutrient recycling and the stability of ecosystems. In F. G.Howell,, J. B.Gentry,, & M. H.Smith, (Eds.), Mineral cycling in southeastern ecosystems. ERDA Symposium Series. CONF‐740513 (pp. 1–27). Springfield, VA: National Technical Information Service.
Wilm,, H. G. (1943). Statistical control of hydrologic data from experimental watersheds. Eos, Transactions American Geophysical Union, 24, 618–624.

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