Warming and increased precipitation frequency on the Colorado Plateau: implications for biological soil crusts and soil processes
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Changes in temperature and precipitation are expected to influence ecosystem processes worldwide. Despite their globally large extent, few studies to date have examined the effects of climate change in desert ecosystems, where biological soil crusts are key nutrient cycling components. The goal of this work was to assess how increased temperature and frequency of summertime precipitation affect the contributions of crust organisms to soil processes.
With a combination of experimental 2°C warming and altered summer precipitation frequency applied over 2 years, we measured soil nutrient cycling and the structure and function of crust communities.
We saw no change in crust cover, composition, or other measures of crust function in response to 2°C warming and no effects on any measure of soil chemistry. In contrast, crust cover and function responded to increased frequency of summer precipitation, shifting from moss to cyanobacteria-dominated crusts; however, in the short timeframe we measured, there was no accompanying change in soil chemistry. Total bacterial and fungal biomass was also reduced in watered plots, while the activity of two enzymes increased, indicating a functional change in the microbial community.
Taken together, our results highlight the limited effects of warming alone on biological soil crust communities and soil chemistry, but demonstrate the substantially larger effects of altered summertime precipitation.
KeywordsColorado Plateau Biological soil crusts Climate change Soil chemistry
Thanks to DOE PER program and Jeff Amthor for providing funding for this project. Thomas R. Weicht, Nicholas LeValley, Henrietta Oakley and Koela Ray provided technical support in conducting extracellular enzyme assays and Kelly Ramirez provided helpful suggestions for extracellular enzyme analyses. We also thank S. Phillips, M. Turner, P. Ortiz, A. Atchley, A. Collins, J. Aylward, B. Graham, K. Markland, T. Orbiz, and many more for help in the field and with lab analyses. We are grateful to M. Bowker and two anonymous reviewers for suggestions that greatly improved the manuscript.
- Belnap J (1994) Potential role of cryptobiotic soil crusts in semiarid rangelands. In: Monsen SB, Kitchen SG (eds). Proceedings: Symposium on Ecology, Management, and Restoration of Intermountain Annual Rangelands, May 18–22, 1992, Boise, ID. General Technical Report INT-GTR-313, pp. 179–185Google Scholar
- Castenholz RW, Garcia-Pichel F (2000) Cyanobacterial responses to UV-radiation. In: Whitton BA, Potts M (eds) Ecology of cyanobacteria: Their diversity in time and space. Kluwer Acad. Publ, Dordrecht, pp 591–611Google Scholar
- Christensen JH, Hewitson B, Busuioc A, Chen A, Gao X, Held I, Jones R, Kolli RK, Kwon WT, Laprise R, Magaña Rueda V, Mearns L, Menéndez CG, Räisänen J, Rinke A, Sarr A, Whetton P (2007) Regional Climate Projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate Change 2007: The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USAGoogle Scholar
- Kimball B (2005) Theory and performance of an infrared heater for ecosystem warming. Glob Chang Biol 11:2041–2056Google Scholar
- Lange O (2001) Photosynthesis of soil-crust biota as dependent on environmental factors. In: Belnap J, Lange O (eds) Biological soil crusts: structure, function, and management. Ecological studies series 150. Springer, Berlin, pp 217–240Google Scholar
- Maestre FT, Bowker MA, Escolar C, Puche MD, Siliveres S, Maltez-Mouro S, García-Palacios P, Castillo-Monroy AP, Martínez I, Escudero A (2010) Do biotic interactions modulate ecosystem functioning along stress gradients? Insights from semi-arid plant and biological soil crust communities. Phil Trans R Soc B 365:2057–2070PubMedCrossRefGoogle Scholar
- Medlyn BE, McMurtrie RE, Dewar RC, Jeffreys MP (2000) Soil processes dominate the long-term response of forest net primary productivity to increased temperature and atmospheric CO2 concentration. Can J For Res 30:872–888Google Scholar
- Mishler BD, Oliver MJ (2009) Putting Physcomitrella patens on the tree of life: the evolution and ecology of mosses. Annu Plant Rev 36:1–15Google Scholar
- [NAST] National Assessment Synthesis Team, U.S. Global Change Research Program (2000) Climate change impacts on the United States: The potential consequences of climate variability and change. Cambridge University Press, New YorkGoogle Scholar
- Pepper DA, del Grosso SJ, McMurtrie RE, Parton WJ (2005) Simulated carbon sink response of shortgrass steppe, tallgrass prairie and forest ecosystems to rising [CO2], temperature and nitrogen input. Global Biogeochemical Cycles 19, GB 1005: doi: 10.1029/2004GB002226
- Schwinning S, Belnap J, Bowling D, Ehleringer J (2008) Sensitivity of the Colorado Plateau to change: climate, ecosystems, and society. Ecol Soc 13:1–28Google Scholar
- Sinsabaugh RL (2010) Phenol oxidase, peroxidase, and organic matter dynamics of soil. Soil Biol Biochem 42:391–404Google Scholar
- Sinsabaugh RL, Lauber CL, Weintraub MN, Ahmed B, Allison SD, Crenshaw C, Contosta AR, Cusack D, Frey S, Gallo ME, Gartner TB, Hobbie SE, Holland K, Keeler BL, Powers JS, Stursova M, Takacs-Vesbach C, Woldrop MP, Wallenstein MD, Zak DR, Zeglin LH (2008) Stoichiometry of soil enzyme activity at global scale. Ecol Lett 11:1252–1264PubMedGoogle Scholar
- Smith SD, Charlet TN, Fenstermaker LF, Newingham BA (2009) Effects of global change on Mojave Desert Ecosystems. In: Webb RH, Fenstermaker LF, Heaton JS, Hughson DL, McDonald EV, Miller DM (eds) The Mojave Desert: Ecosystem processes and sustainability. University of Nevada Press, Reno, pp 31–56Google Scholar
- Vose R, Easterling D, Gleason B (2005) Maximum and minimum temperature trends for the globe: an update through 2004. Geophys Res Lett 32:1–23Google Scholar