Draining the Pool? Carbon Storage and Fluxes in Three Alpine Plant Communities
- 660 Downloads
Shrub communities have expanded in arctic and alpine tundra during recent decades. Changes in shrub abundance may alter ecosystem carbon (C) sequestration and storage, with potential positive or negative feedback on global C cycling. To assess potential implications of shrub expansion in different alpine plant communities, we compared C fluxes and pools in one Empetrum-dominated heath, one herb- and cryptogam-dominated meadow, and one Salix-shrub community in Central Norway. Over two growing seasons, we measured Gross Ecosystem Photosynthesis, Ecosystem Respiration (ER), and C pools for above-ground vegetation, litter, roots, and soil separated into organic and mineral horizons. Both the meadow and shrub communities had higher rates of C fixation and ER, but the total ecosystem C pool in the meadow was twice that of the shrub community because of more C in the organic soil horizon. Even though the heath community had the lowest rates of C fixation, it stored one and a half times more C than the shrub community. The results indicate that the relatively high above-ground biomass sequestering C during the growing season is not associated with high C storage in shrub-dominated communities. Instead, shrub-dominated areas may be draining the carbon-rich alpine soils because of high rates of decomposition. These processes were not shown by mid-growing season C fluxes, but were reflected by the very different distribution of C pools in the three habitats.
Keywordscarbon soil carbon gross ecosystem photosynthesis net ecosystem exchange ecosystem respiration Salix heath meadow Tundra Empetrum
This research was supported by I.K Lykkes fond, Nansenfondet, and The Norwegian Research Council (23060/E10). We gratefully acknowledge help from all our ECOSHRUB field assistants and from the Enquist lab. We thank Aimee Classen’s lab for assistance and collaboration on root and soil samples. We thank Kongsvoll Biological Station and Norsk Villreinsenter for accommodation. We would also like to thank Hanna Lee, Nancy Lea Eik-Nes, James Speed, Stuart Smith, Susanna Karlsson, and the anonymous reviewers for valuable comments on earlier versions of the manuscript.
- Baele A, Sørensen MV, Nystuen KO, Limpens J, Graae BJ, De Frenne P. Shrub encroachment in alpine plant communities: Vegetation canopy effects on microclimate (unpublished manuscript).Google Scholar
- Cornelissen JHC, van Bodegom PM, Aerts R, Callaghan TV, van Logtestijn RSP, Alatalo J, Chapin FS, Gerdol R, Gudmundsson J, Gwynn-Jones D, Hartley AE, Hik DS, Hofgaard A, Jónsdóttir IS, Karlsson S, Klein JA, Laundre J, Magnusson B, Michelsen A, Malou U, Onipchenko VG, Quested HM, Sandvik SM, Schmidt IK, Shaver GR, Solheim B, Soudzilovskaia NA, Stenström A, Tolvanen A, Totland Ø, Wada N, Welker JM, Zhao X, Team MOLT. 2007. Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes. Ecol Lett 10:619–27.CrossRefPubMedGoogle Scholar
- Hodgson JM. 1997. Soil survey field handbook. Silsoe: Cranfield University.Google Scholar
- Hultén E, Fries M. 1986. Atlas of North European vascular plants: north of the Tropic of Cancer. Königstein: Koeltz Scientific Books.Google Scholar
- Lenoir J, Graae BJ, Aarrestad PA, Alsos IG, Armbruster WS, Austrheim G, Bergendorff C, Birks HJB, Brathen KA, Brunet J, Bruun HH, Dahlberg CJ, Decocq G, Diekmann M, Dynesius M, Ejrnaes R, Grytnes JA, Hylander K, Klanderud K, Luoto M, Milbau A, Moora M, Nygaard B, Odland A, Ravolainen VT, Reinhardt S, Sandvik SM, Schei FH, Speed JDM, Tveraabak LU, Vandvik V, Velle LG, Virtanen R, Zobel M, Svenning JC. 2013. Local temperatures inferred from plant communities suggest strong spatial buffering of climate warming across Northern Europe. Global Change Biol 19:1470–81.CrossRefGoogle Scholar
- Moen A. 1998. Nasjonalatlas for Norge: Vegetasjon. Hønefoss: Statens Kartverk.Google Scholar
- Molau U, Alatalo JM. 1998. Responses of subarctic-alpine plant communities to simulated environmental change: biodiversity og Bryophytes, Lichens and Vascular Plants. Ambio 27:322–8.Google Scholar
- Myers-Smith IH, Forbes BC, Wilmking M, Hallinger M, Lantz T, Blok D, Tape KD, Macias-Fauria M, Sass-Klaassen U, Lévesque L, Boudreay S, Ropars P, Hermanutz L, Trant A, Collier LS, Weijers S, Rozema J, Rayback SA, Schmidt NM, Schaepman-Strub G, Wipf S, Rixen C, Ménard CB, Venn S, Goetz S, Andreu-Hayles L, Elmendorf S, Ravolainen V, Welker J, Grogan P, Epstein HE, Hik DS. 2011. Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities. Environ Res Lett 6:1–15.CrossRefGoogle Scholar
- New M, Hulme M, Jones PD. 2000. Global 30-year mean monthly climatology, 1961–1990. http://daac.ornl.gov: Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA.
- NGU. 2015. Berggrunn N250 og Løsmasse N50. Norges Geologiske Undersøkelse.Google Scholar
- R Core Team. 2015. A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.Google Scholar
- Semenchuk PR, Christiansen CT, Grogan P, Elberling B, Cooper EJ. 2016. Long-term experimentally deepened snow decreases growing-season respiration in a low- and high-arctic tundra ecosystem. J Geophys Res Biogeosci 121:1236–48.Google Scholar
- Settele J, Scholes R, Betts R, Bunn SE, Leadley P, Nepstad D, Overpeck JT, Taboada MA. 2014. Terrestrial and inland water systems. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel of Climate Change: 271–359.Google Scholar
- Sistla SA, Moore JC, Simpson RT, Gough L, Shaver GR, Schimel JP. 2013. Long-term warming restructures Arctic tundra without changing net soil carbon storage. Nature 000:1–4.Google Scholar
- Sørensen MV, Strimbeck R, Nystuen KO, Kapas RE, Enquist BJ, Graae BJ. 2017. Data from: draining the pool? carbon storage and fluxes in three alpine plant communities. Dryad Digit Repos. doi: 10.5061/dryad.1n50j.
- Ward SE, Smart SM, Quirk H, Tallowin JRB, Mortimer SR, Shiel RS, Wilby A, Bardgett RD. 2016. Legacy effects of grassland management on soil carbon to depth. Global Change Biol 22:2929–38.Google Scholar
- Wookey PA, Aerts R, Bardgett RD, Baptist F, Bråthen KA, Cornelissen JHC, Gough L, Hartley IP, Hopkins DW, Lavorels S, Shaver GR. 2009. Ecosystem feedbacks and cascade processes: understanding their role in the responses of Arctic and alpine ecosystems to environmental change. Global Change Biol 15:1153–72.CrossRefGoogle Scholar