Climate change alters growing season flux dynamics in mesic grasslands
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Changing climate could affect the functioning of grassland ecosystems through variation in climate forcings and by altering the interactions of forcings with ecological processes. Both the short and long-term effects of changing forcings and ecosystem interactions are a critical part of future impacts to ecosystem ecology and hydrology. To explore these interactions and identify possible characteristics of climate change impacts to mesic grasslands, we employ a low-dimensional modeling framework to assess the IPCC A1B scenario projections for the Central Plains of the United States; forcings include increased precipitation variability, increased potential evaporation, and earlier growing season onset. These forcings are also evaluated by simulations of vegetation photosynthetic capacity to explore the seasonal characteristics of the vegetation carbon assimilation response for species at the Konza Prairie in North Central Kansas, USA. The climate change simulations show decreases in mean annual soil moisture and and carbon assimilation and increased variation in water and carbon fluxes during the growing season. Simulations of the vegetation response show increased variation at the species-level instead of at a larger class scale, with important heterogeneity in how individual species respond to climate forcings. Understanding the drivers and relationships behind these ecosystem responses is important for understanding the likely scale of climate change impacts and for exploring the mechanisms shaping growing season dynamics in grassland ecosystems.
KeywordsKonza Prairie Ecohydrology Low-dimensional modeling Nonlinear interactions Soil moisture feedback
We would like to thank the National Science Foundation EPSCoR 0553722 and KAN0061396/ KAN006263 for funding this research, and also Laura Kangas, for field support.
- Angert A, Biraud S, Bonfils C, Henning C, Buermann W, Pinzon J, Tucker C, Fung I (2005) Drier summers cancel out the CO2 uptake enhancement induced by warmer springs. PNAS 31(102):10,823–10,827Google Scholar
- Cowan I (2002) Fit, fitter, fittest; where does optimisation fit in? Silva Fenn 3(36):745–754Google Scholar
- Harpole W, Tilman D (2006) Non-neutral patterns of species abundance in grassland communities. Ecol Lett 9:15–23Google Scholar
- Knapp A, Briggs J, Hartnett D, Collins S (eds) (1998) Grassland dynamics: long-term ecological research in tallgrass prairie. LTERGoogle Scholar
- Laio F, Porporato A, Ridolfi L, Rodriguez-Iturbe I (2001) Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress - II. Probabilistic soil moisture dynamics. Adv Water Resour 24(7):707–723Google Scholar
- Monson R, Sparks J, Rosentiel T, Scott-Denton L, Huxman T, Harley P, Turnipseed A, Burns S, Backlund B, Hu J (2005) Climatic influences on net ecosystem CO2 exchange during the transitions from wintertime carbon source to springtime carbon sink in a high-elevation, subalpine forest. Oecologia 146:130–147CrossRefGoogle Scholar
- Porporato A, Laio F, Ridolfi L, Rodriguez-Iturbe I (2001) Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress - III. Vegetation water stress. Adv Water Resour 24(7):725–744Google Scholar
- Ridolfi L, D’Odorico P, Porporato A, Rodriguez-Iturbe I (2000b) Impact of climate variability on the vegetation water stress. J Geophys Res–Atmospheres 105(D14):18,013–18,025Google Scholar
- Riley W, Biraud S, Torn M, Fischer M, Billesbach D, Berry J (2009) Regional co2 and latent heat surface fluxes in the southern great plains: measurements, modeling, and scaling. J Geophys Res 114Google Scholar
- Teuling A, Seneviratne S, Williams C, Troch P (2006b) Observed timescales of evapotranspiration response to soil moisture. Geophys Res Lett 33:1–5Google Scholar
- Williams Jr C, Vose R, Easterling D, Menne M (2006) United states historical climatology network daily temperature, precipitation, and snow data. Tech rep ornl/cdiac-118, ndp-070, carbon dioxide information analysis center, Oak Ridge National Laboratory, Oak Ridge, TennesseeGoogle Scholar