, Volume 21, Issue 8, pp 1623–1638 | Cite as

Total C and N Pools and Fluxes Vary with Time, Soil Temperature, and Moisture Along an Elevation, Precipitation, and Vegetation Gradient in Southern Appalachian Forests

  • Jennifer D. KnoeppEmail author
  • Craig R. See
  • James M. Vose
  • Chelcy F. Miniat
  • James S. Clark


The interactions of terrestrial C pools and fluxes with spatial and temporal variation in climate are not well understood. We conducted this study in the southern Appalachian Mountains where complex topography provides variability in temperature, precipitation, and forest communities. In 1990, we established five large plots across an elevation gradient allowing us to study the regulation of C and N pools and cycling by temperature and water, in reference watersheds in Coweeta Hydrologic Laboratory, a USDA Forest Service Experimental Forest, in western NC, USA. Communities included mixed-oak pine, mixed-oak, cove hardwood, and northern hardwood. We examined 20-year changes in overstory productivity and biomass, leaf litterfall C and N fluxes, and total C and N pools in organic and surface mineral soil horizons, and coarse wood, and relationships with growing season soil temperature and precipitation. Productivity increased over time and with precipitation. Litterfall C and N flux increased over time and with increasing temperature and precipitation, respectively. Organic horizon C and N did not change over time and were not correlated to litterfall inputs. Mineral soil C and N did not change over time, and the negative effect of temperature on soil pools was evident across the gradient. Our data show that increasing temperature and variability in precipitation will result in altered aboveground productivity. Variation in surface soil C and N is related to topographic variation in temperature which is confounded with vegetation community. Data suggest that climatic changes will result in altered aboveground and soil C and N sequestration and fluxes.


aboveground belowground C sequestration fluxes long-term data N sequestration pools 



We thank the investigators of Coweeta LTER 3 (1990–1996) for contributions to the design of the original gradient study, the technicians and graduate students who have made measurements on these plots periodically throughout the last 20+ years, and Coweeta Analytical Lab managers, Dr. Barbara (Kitti) Reynolds, James Deal and Cindi Brown who have insured high quality control of all analyses. We also thank Drs. Rich Bowden and Luke Nave for helpful comments on the manuscript. This work was funded by NSF Grants DEB0218001 and DEB0823293 to the Coweeta LTER program at the University of Georgia and by USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory project funds. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the authors and do not necessarily reflect the views of the USDA Forest Service.

Compliance with Ethical Standards

Conflict of interest

The authors declare that experiments complied with the current laws of the USA and there is no conflict of interest.

Supplementary material

10021_2018_244_MOESM1_ESM.docx (1 mb)
Supplementary material 1 (DOCX 1049 kb)
10021_2018_244_MOESM2_ESM.docx (16 kb)
Supplementary material 2 (DOCX 15 kb)


  1. Aber J, McDowell WH, Nadelhoffer K, Magill A, Berntson GM, Kamakea M, McNulty S, Currie WS, Rustad L, Fernandez I. 1998. Nitrogen saturation in temperate forest ecosystems. BioScience 48:921–34.Google Scholar
  2. Adams MB, Knoepp JD, Webster JR. 2014. Inorganic nitrogen retention by watersheds at fernow experimental forest and coweeta hydrologic laboratory. Soil Sci Soc Am J 78:S84–94.Google Scholar
  3. Akselsson C, Berg B, Meentemeyer V, Westling O. 2005. Carbon sequestration rates in organic layers of boreal and temperate forest soils—Sweden as a case study. Glob Ecol Biogeogr 14:77–84.Google Scholar
  4. Alban DH. 1982. Effects of nutrient accumulation by aspen, spruce, and pine on soil properties. Soil Sci Soc Am J 46:853–61.Google Scholar
  5. Allison SD, Wallenstein MD, Bradford MA. 2010. Soil-carbon response to warming dependent on microbial physiology. Nat Geosci 3:336–40.Google Scholar
  6. Argerich A, Johnson S, Sebestyen S, Rhoades C, Greathouse E, Knoepp J, Adams M, Likens G, Campbell J, McDowell W. 2013. Trends in stream nitrogen concentrations for forested reference catchments across the USA. Environ Res Lett 8:014039.Google Scholar
  7. Bani A, Pioli S, Ventura M, Panzacchi P, Borruso L, Tognetti R, Tonon G, Brusetti L. 2018. The role of microbial community in the decomposition of leaf litter and deadwood. Appl Soil Ecol. 126:75–84.Google Scholar
  8. Bardgett RD, Bowman WD, Kaufmann R, Schmidt SK. 2005. A temporal approach to linking aboveground and belowground ecology. Trends Ecol Evol 20:634–41.PubMedGoogle Scholar
  9. Bardgett RD, Mommer L, De Vries FT. 2014. Going underground: root traits as drivers of ecosystem processes. Trends Ecol Evol 29:692–9.PubMedGoogle Scholar
  10. Berg B, Dise N. 2004. Validating a new model for N sequestration in forest soil organic matter. Water Air Soil Pollut Focus 4:343–58.Google Scholar
  11. Boot CM, Hall EK, Denef K, Baron JS. 2016. Long-term reactive nitrogen loading alters soil carbon and microbial community properties in a subalpine forest ecosystem. Soil Biol Biochem 92:211–20.Google Scholar
  12. Brookshire ENJ, Valett HM, Thomas SA, Webster JR. 2007. Atmospheric N deposition increases organic N loss from temperate forests. Ecosystems 10:252–62.Google Scholar
  13. Caldwell PV, Miniat CF, Elliott K, Swank WT, Brantley ST, Laseter SH. 2016. Declining water yield from forested mountain watersheds in response to climate change and forest mesophication. Glob Change Biol 22:2997–3012.Google Scholar
  14. Carney KM, Matson PA. 2005. Plant communities, soil microorganisms, and soil carbon cycling: does altering the world belowground matter to ecosystem functioning? Ecosystems 8:928–40.Google Scholar
  15. Clark JS, Vose JM, Luce CH. 2016. Forest drought as an emerging research priority. Glob Change Biol 22:2317.Google Scholar
  16. Cole DW. 1995. Soil nutrient supply in natural and managed forests. Plant Soil 168–169:43–53.Google Scholar
  17. Cromack J, K., Monk CD. 1975. Litter production, decomposition, and nutrient cycling in a mixed hardwood watershed and a white pine watershed. In: Howell FG, Gentry JB, Smith MH, Eds. Mineral cycling in southeastern ecosystems proceedings. Augusta (GA): US Energy Research and Development Administration, pp 609–24.Google Scholar
  18. Cross A, Perakis SS. 2011. complementary models of tree species-soil relationships in old-growth temperate forests. Ecosystems 14:248–60.Google Scholar
  19. Crow SE, Lajtha K, Filley TR, Swanston CW, Bowden RD, Caldwell BA. 2009. Sources of plant-derived carbon and stability of organic matter in soil: implications for global change. Glob Change Biol 15:2003–19.Google Scholar
  20. Crowley KF, McNeil BE, Lovett GM, Canham CD, Driscoll CT, Rustad LE, Denny E, Hallett RA, Arthur MA, Boggs JL, Goodale CL, Kahl JS, McNulty SG, Ollinger SV, Pardo LH, Schaberg PG, Stoddard JL, Weand MP, Weathers KC. 2012. Do nutrient limitation patterns shift from nitrogen toward phosphorus with increasing nitrogen deposition across the northeastern United States? Ecosystems 15:940–57.Google Scholar
  21. Davidson EA, Ackerman IL. 1993. Changes in soil carbon inventories following cultivation of previously untilled soils. Biogeochemistry 20:161–93.Google Scholar
  22. Dixon RK, Brown S, Houghton RA, Solomon A, Trexler M, Wisniewski J. 1994. Carbon pools and flux of global forest ecosystems. Science (Washington) 263:185–9.Google Scholar
  23. Douglass JE, Hoover MD. 1988. History of Coweeta. In: Swank WT, Crossley DA Jr, Eds. Forest hydrology and ecology at Coweeta. New York: Springer. p 469.Google Scholar
  24. Du Y, Guo P, Liu J, Wang C, Yang N, Jiao Z. 2014. Different types of nitrogen deposition show variable effects on the soil carbon cycle process of temperate forests. Glob Change Biol 20:3222–8.Google Scholar
  25. Eisenlord SD, Freedman Z, Zak DR, Xue K, He Z, Zhou J. 2013. Microbial mechanisms mediating increased soil C storage under elevated atmospheric N deposition. Appl Environ Microbiol 79:1191–9.PubMedPubMedCentralGoogle Scholar
  26. Elliott KJ, Miniat CF, Pederson N, Laseter SH. 2015. Forest tree growth response to hydroclimate variability in the southern Appalachians. Glob Change Biol 21:4627–41.Google Scholar
  27. Elliott KJ, Swank WT. 2008. Long-term changes in forest composition and diversity following early logging (1919–1923) and the decline of American chestnut (Castanea dentata). Plant Ecol 197:155–72.Google Scholar
  28. Elliott KJ, Vose JM. 2011. The contribution of the Coweeta Hydrologic Laboratory to developing an understanding of long-term (1934–2008) changes in managed and unmanaged forests. For Ecol Manag 261:900–10.Google Scholar
  29. Elser JJ, Bracken ME, Cleland EE, Gruner DS, Harpole WS, Hillebrand H, Ngai JT, Seabloom EW, Shurin JB, Smith JE. 2007. Global analysis of nitrogen and phosphorus limitation of primary producers in freshwater, marine and terrestrial ecosystems. Ecol Lett 10:1135–42.PubMedGoogle Scholar
  30. Fahey T, Siccama T, Driscoll C, Likens G, Campbell J, Johnson C, Battles J, Aber J, Cole J, Fisk M. 2005. The biogeochemistry of carbon at Hubbard Brook. Biogeochemistry 75:109–76.Google Scholar
  31. Federer CA. 1984. Organic matter and nitrogen content of the forest floor in even-aged northern hardwoods. Can J For Res 14:763–7.Google Scholar
  32. Fernández-Martínez M, Vicca S, Janssens IA, Sardans J, Luyssaert S, Campioli M, Chapin FSIII, Ciais P, Malhi Y, Obersteiner M. 2014. Nutrient availability as the key regulator of global forest carbon balance. Nat Clim Change 4:471–6.Google Scholar
  33. Fernandez IJ, Simmons JA, Briggs RD. 2000. Indices of forest floor nitrogen status along a climate gradient in Maine, USA. For Ecol Manag 134:177–87.Google Scholar
  34. Fox S, Jackson B, Jackson S, Kauffmann G, Koester MC, Mera R, Seyden T, Van Sickle C, Chipley S, Fox J, Hicks J, Hutchins M, Lichtenstein K, Nolan K, Pierce T, Porter B. 2011. Western North Carolina report card on forest sustainability. Asheville, NC: USDA Forest Service, Southern Research Station. pp 1–198.Google Scholar
  35. Frangi JL, Barrera MD, Richter LL, Lugo AE. 2005. Nutrient cycling in Nothofagus pumilio forests along an altitudinal gradient in Tierra del Fuego, Argentina. For Ecol Manag 217:80–94.Google Scholar
  36. Franzluebbers AJ, Haney RL, Honeycutt CW, Arshad M, Schomberg HH, Hons FM. 2001. Climatic influences on active fractions of soil organic matter. Soil Biol Biochem 33:1103–11.Google Scholar
  37. Frey S, Ollinger S, Nadelhoffer K, Bowden R, Brzostek E, Burton A, Caldwell B, Crow S, Goodale C, Grandy A. 2014. Chronic nitrogen additions suppress decomposition and sequester soil carbon in temperate forests. Biogeochemistry 121:305–16.Google Scholar
  38. Friedrichs DA, Trouet V, Büntgen U, Frank DC, Esper J, Neuwirth B, Löffler J. 2009. Species-specific climate sensitivity of tree growth in Central-West Germany. Trees 23:729.Google Scholar
  39. Garten CT. 2009. A disconnect between O horizon and mineral soil carbon–implications for soil C sequestration. Acta Oecol 35:218–26.Google Scholar
  40. Gessner MO, Swan CM, Dang CK, McKie BG, Bardgett RD, Wall DH, Hättenschwiler S. 2010. Diversity meets decomposition. Trends Ecol Evol 25:372–80.PubMedGoogle Scholar
  41. Guo LB, Gifford R. 2002. Soil carbon stocks and land use change: a meta analysis. Glob Change Biol 8:345–60.Google Scholar
  42. Harmon ME, Bible K, Ryan MG, Shaw DC, Chen H, Klopatek J, Li X. 2004. Production, respiration, and overall carbon balance in an old-growth Pseudotsuga-Tsuga forest ecosystem. Ecosystems 7:498–512.Google Scholar
  43. Harmon ME, Franklin JF, Swanson FJ, Sollins P, Gregory SV, Lattin JD, Anderson NH, Cline SP, Aumen NG, Sedell JR, Lienkaemper GW, Cromack JK, Cummins KW. 1986. Ecology of coarse woody debris in temperate ecosystems. In: MacFadyen A, Ford ED, Eds. Advances in ecological research. Cambridge: Academic Press. p 133–302.Google Scholar
  44. Hedde M, Aubert M, Decaëns T, Bureau F. 2008. Dynamics of soil carbon in a beechwood chronosequence forest. For Ecol Manag 255:193–202.Google Scholar
  45. Hessen DO, Ågren GI, Anderson TR, Elser JJ, de Ruiter PC. 2004. Carbon sequestration in ecosystems: the role of stoichiometry. Ecology 85:1179–92.Google Scholar
  46. Hobbie EA, Macko SA, Shugart HH. 1999. Interpretation of nitrogen isotope signatures using the NIFTE model. Oecologia 120:405–15.PubMedGoogle Scholar
  47. Hobbie EA, Macko SA, Williams M. 2000. Correlations between foliar δ15N and nitrogen concentrations may indicate plant-mycorrhizal interactions. Oecologia 122:273–83.Google Scholar
  48. Hobbie SE. 2015. Plant species effects on nutrient cycling: revisiting litter feedbacks. Trends Ecol Evol 30:357–63.PubMedGoogle Scholar
  49. Hooker TD, Compton JE. 2003. Forest ecosystem carbon and nitrogen accumulation during the first century after agricultural abandonment. Ecol Appl 13:299–313.Google Scholar
  50. Hooper DU, Bignell DE, Brown VK, Brussard L, Mark Dangerfield J, Wall DH, Wardle DA, Coleman DC, Giller KE, Lavelle P. 2000. Interactions between aboveground and belowground biodiversity in terrestrial ecosystems: patterns, mechanisms, and feedbacks: we assess the evidence for correlation between aboveground and belowground diversity and conclude that a variety of mechanisms could lead to positive, negative, or no relationship-depending on the strength and type of interactions among species. BioScience 50:1049–61.Google Scholar
  51. Jacobs LM, Sulman BN, Brzostek ER, Feighery JJ, Phillips RP. 2018. Interactions among decaying leaf litter, root litter and soil organic matter vary with mycorrhizal type. J Ecol 106:502–13.Google Scholar
  52. Jenny H. 1941. Factors of soil formation: a system of quantitative pedology. New York, NY: McGraw-Hill Book Company Inc.Google Scholar
  53. Johnson DW, Knoepp JD, Swank WT, Shan J, Morris LA, Van Lear DH, Kapeluck PR. 2002. Effects of forest management on soil carbon: results of some long-term resampling studies. Environ Pollut 116:S201–8.PubMedGoogle Scholar
  54. Kang S, Lee D, Lee J, Running SW. 2006. Topographic and climatic controls on soil environments and net primary production in a rugged temperate hardwood forest in Korea. Ecol Res 21:64–74.Google Scholar
  55. Keiser A, Knoepp JD, Bradford M. 2013. Microbial communities may modify how litter quality affects potential decomposition rates as tree species migrate. Plant Soil 372:167–76.Google Scholar
  56. Kelly J, Mays P. 2005. Soil carbon changes after 26 years in a Cumberland Plateau hardwood forest. Soil Sci Soc Am J 69:691–4.Google Scholar
  57. Knicker H. 2011. Soil organic N-An under-rated player for C sequestration in soils? Soil Biol Biochem 43:1118–29.Google Scholar
  58. Knoepp JD, Coleman DC, Crossley DA Jr, Clark JS. 2000. Biological indices of soil quality: an ecosystem case study of their use. For Ecol Manag 138:357–68.Google Scholar
  59. Knoepp JD, Reynolds B, Crossley DA Jr, Swank WT. 2005. Long-term changes in forest floor processes in southern Appalachian forests. For Ecol Manag 220:300–12.Google Scholar
  60. Knoepp JD, Swank WT. 1994. Long-term soil chemistry changes in aggrading forest ecosystems. Soil Sci Soc Am J 58:325–31.Google Scholar
  61. Knoepp JD, Swank WT. 1997. Forest management effects on surface soil carbon and nitrogen. Soil Sci Soc Am J 61:928–35.Google Scholar
  62. Knoepp JD, Swank WT. 1998. Rates of nitrogen mineralization across an elevation and vegetation gradient in the southern Appalachians. Plant Soil 204:235–41.Google Scholar
  63. Knoepp JD, Swank WT. 2002. Using soil temperature and moisture to predict forest soil nitrogen mineralization. Biol Fertil Soils 36:177–82.Google Scholar
  64. Knoepp JD, Swank WT, Haines BL. 2014. Long- and short-term changes in nutrient availability following commercial sawlog harvest via cable logging. In: Swank WT, Webster JR, Eds. Long-term response of a forest watershed ecosystem: clearcutting in the southern Appalachians. London: Oxford University Press. p 57–84.Google Scholar
  65. Knoepp JD, Vose JM. 2007. Regulation of nitrogen mineralization and nitrification in southern Appalachian ecosystems: separating the relative importance of biotic vs. abiotic controls. Pedobiologia 51:89–97.Google Scholar
  66. Knoepp JD, Vose JM, Swank WT. 2008. Nitrogen deposition and cycling across an elevation and vegetation gradient in southern Appalachian forests. Int J Environ Stud 65:389–408.Google Scholar
  67. Lal R. 2004. Soil carbon sequestration to mitigate climate change. Geoderma 123:1–22.Google Scholar
  68. Lal R. 2005. Forest soils and carbon sequestration. For Ecol Manag 220:242–58.Google Scholar
  69. Lal R, Follett RF, Kimble JM. 2003. Achieving soil carbon sequestration in the United States: a challenge to the policy makers. Soil Sci 168:827–45.Google Scholar
  70. Laseter SH, Ford CR, Vose JM, Swift JLW. 2012. Long-term temperature and precipitation trends at the Coweeta Hydrologic Laboratory, Otto, North Carolina, USA. Hydrol Res 43:890–901.Google Scholar
  71. Leppälammi-Kujansuu J, Salemaa M, Kleja DB, Linder S, Helmisaari H-S. 2014. Fine root turnover and litter production of Norway spruce in a long-term temperature and nutrient manipulation experiment. Plant Soil 374:73–88.Google Scholar
  72. Liese R, Lübbe T, Albers NW, Meier IC. 2018. The mycorrhizal type governs root exudation and nitrogen uptake of temperate tree species. Tree Physiol 38:83–95.PubMedGoogle Scholar
  73. Lovett GM, Goodale CL. 2011. A new conceptual model of nitrogen saturation based on experimental nitrogen addition to an oak forest. Ecosystems 14:615–31.Google Scholar
  74. Luce CH, Vose JM, Pederson N, Campbell J, Millar C, Kormos P, Woods R. 2016. Contributing factors for drought in United States forest ecosystems under projected future climates and their uncertainty. For Ecol Manag 380:299–308.Google Scholar
  75. Luyssaert S, Schulze E-D, Börner A, Knohl A, Hessenmöller D, Law BE, Ciais P, Grace J. 2008. Old-growth forests as global carbon sinks. Nature 455:213–15.Google Scholar
  76. Maaroufi NI, Nordin A, Palmqvist K, Gundale MJ. 2017. Nitrogen enrichment impacts on boreal litter decomposition are driven by changes in soil microbiota rather than litter quality. Sci Rep 7:4083.PubMedPubMedCentralGoogle Scholar
  77. Markewitz D, Sartori F, Craft C. 2002. Soil change and carbon storage in longleaf pine stands planted on marginal agricultural lands. Ecol Appl 12:1276–85.Google Scholar
  78. Martin-Benito D, Pederson N. 2015. Convergence in drought stress, but a divergence of climatic drivers across a latitudinal gradient in a temperate broadleaf forest. J Biogeogr 42:925–37.Google Scholar
  79. Martin JG, Kloeppel BD, Schaefer TL, Kimbler DL, McNulty SG. 1998. Aboveground biomass and nitrogen allocation of ten deciduous southern Appalachian tree species. Can J For Res 28:1648–59.Google Scholar
  80. Midgley MG, Brzostek E, Phillips RP. 2015. Decay rates of leaf litters from arbuscular mycorrhizal trees are more sensitive to soil effects than litters from ectomycorrhizal trees. J Ecol 103:1454–63.Google Scholar
  81. Miltner A, Bombach P, Schmidt-Brücken B, Kästner M. 2012. SOM genesis: microbial biomass as a significant source. Biogeochemistry 111:41–55.Google Scholar
  82. NADP. 2017. (NRSP-3). National Atmospheric Deposition Program Office, Illinois State Water Survey, 2204 Griffith Dr., Champaign, IL 61820.Google Scholar
  83. Oliverio AM, Bradford MA, Fierer N. 2017. Identifying the microbial taxa that consistently respond to soil warming across time and space. Glob Change Biol 23:2117–29.Google Scholar
  84. Portmann RW, Solomon S, Hegerl GC. 2009. Spatial and seasonal patterns in climate change, temperatures, and precipitation across the United States. Proc Natl Acad Sci 106:7324–9.PubMedGoogle Scholar
  85. Prescott CE. 2005. Do rates of litter decomposition tell us anything we really need to know? For Ecol Manag 220:66–74.Google Scholar
  86. Qiao Y, Miao S, Silva LCR, Horwath WR. 2014. Understory species regulate litter decomposition and accumulation of C and N in forest soils: a long-term dual-isotope experiment. For Ecol Manag 329:318–27.Google Scholar
  87. Raich JW, Russell AE, Kitayama K, Parton WJ, Vitousek PM. 2006. Temperature influences carbon accumulation in moist tropical forests. Ecology 87:76–87.PubMedGoogle Scholar
  88. Reich PB, Luo Y, Bradford JB, Poorter H, Perry CH, Oleksyn J. 2014. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots. Proc Natl Acad Sci 111:13721–6.PubMedGoogle Scholar
  89. Richter DD, Markewitz D, Trumbore SE, Wells CG. 1999. Rapid accumulation and turnover of soil carbon in a re-establishing forest. Nature 400:56–8.Google Scholar
  90. Ryan MG, Vose JM, Hanson PJ, Iverson LR, Miniat CF, Luce CH, Band LE, Klein SL, McKenzie D, Wear DN. 2014. Forest processes. Climate change and United States forests. Berlin: Springer. pp 25–54.Google Scholar
  91. SAS. 2013. SAS/STAT 9.3 User’s Guide. Cary, NC USA: SAS Institute Inc.Google Scholar
  92. Schlesinger WH, Dietze MC, Jackson RB, Phillips RP, Rhoades CC, Rustad LE, Vose JM. 2015. Forest biogeochemistry in response to drought. Glob Change Biol 22:2318–28.Google Scholar
  93. Stewart CE, Paustian K, Conant RT, Plante AF, Six J. 2008. Soil carbon saturation: evaluation and corroboration by long-term incubations. Soil Biol Biochem 40:1741–50.Google Scholar
  94. Swank WT, Vose JM. 1997. Long-term nitrogen dynamics of Coweeta forested watersheds in the southeastern United States of America. Glob Biogeochem Cycles 11:657–71.Google Scholar
  95. Swift LW Jr, Cunningham BB, Douglass JE. 1988. Climatology and hydrology. In: Swank WT, Crossley DA Jr, Eds. Forest hydrology and ecology at Coweeta. New York, NY: Springer. p 35–55.Google Scholar
  96. Tipping E, Somerville CJ, Luster J. 2016. The C: N: P: S stoichiometry of soil organic matter. Biogeochemistry 130:117–31.Google Scholar
  97. Vadeboncoeur MA. 2010. Meta-analysis of fertilization experiments indicates multiple limiting nutrients in northeastern deciduous forests. Can J For Res 40:1766–80.Google Scholar
  98. Vadeboncoeur MA, Hamburg SP, Blum JD, Pennino MJ, Yanai RD, Johnson CE. 2012. The quantitative soil pit method for measuring belowground carbon and nitrogen stocks. Soil Sci Soc Am J 76:2241–55.Google Scholar
  99. Van Miegroet H, Moore PT, Tewksbury CE, Nicholas NS. 2007. Carbon sources and sinks in high-elevation spruce-fir forests of the Southeastern US. For Ecol Manag 238:249–60.Google Scholar
  100. Wardle DA, Bardgett RD, Klironomos JN, Setala H, van der Putten WH, Wall DH. 2004. Ecological linkages between aboveground and belowground biota. Science 304:1629–33.Google Scholar
  101. Webster J, Knoepp J, Swank W, Miniat C. 2016. Evidence for a regime shift in nitrogen export from a forested watershed. Ecosystems 19:1–15.Google Scholar
  102. White LL, Zak DR, Barnes BV. 2004. Biomass accumulation and soil nitrogen availability in an 87-year-old Populus grandidentata chronosequence. For Ecol Manag 191:121–7.Google Scholar
  103. Yanai RD, Arthur MA, Siccama TG, Federer CA. 2000. Challenges of measuring forest floor organic matter dynamics: repeated measures from a chronosequence. For Ecol Manag 138:273–83.Google Scholar
  104. Yanai RD, Vadeboncoeur MA, Hamburg SP, Arthur MA, Fuss CB, Groffman PM, Siccama TG, Driscoll CT. 2013. From missing source to missing sink: long-term changes in the nitrogen budget of a northern hardwood forest. Environ Sci Technol 47:11440–8.PubMedPubMedCentralGoogle Scholar
  105. Yount JD. 1975. Forest-floor nutrient dynamics in southern Appalachian hardwood and white pine plantations ecosystems. In: Howell FG, Gentry JB, Smith MH, Eds. Mineral cycling in southeastern ecosystems proceedings. Augusta, GA: U.S. Energy Research and Development Administration, p 898.Google Scholar
  106. Zak DR, Holmes WE, Burton AJ, Pregitzer KS, Talhelm AF. 2008. Simulated atmospheric NO3—deposition increases soil organic matter by slowing decomposition. Ecol Appl 18:2016–27.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature (this is a US Government work and not under copyright protection in the US; foreign copyright protection may apply) 2018

Authors and Affiliations

  • Jennifer D. Knoepp
    • 1
    Email author
  • Craig R. See
    • 2
    • 3
  • James M. Vose
    • 4
  • Chelcy F. Miniat
    • 1
  • James S. Clark
    • 5
  1. 1.USDA Forest Service, Southern Research Station, Center for Forest Watershed ScienceCoweeta Hydrologic LaboratoryOttoUSA
  2. 2.Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensUSA
  3. 3.Department of Ecology, Evolution and BehaviorUniversity of MinnesotaSt. PaulUSA
  4. 4.USDA Forest Service, Southern Research Station, Center for Integrated Forest ScienceNorth Carolina State UniversityRaleighUSA
  5. 5.Department of Statistical Science, Nicholas School of the EnvironmentDuke UniversityDurhamUSA

Personalised recommendations