Resolving the Dryland Decomposition Conundrum: Some New Perspectives on Potential Drivers
Decomposition of organic matter is a crucial component of biogeochemical cycles that strongly controls nutrient availability, productivity, and community composition. The factors controlling decomposition of litter in arid and semi-arid systems remain poorly understood, with an unresolved disconnect between measured and modeled decay rates. In contrast, decay rates in mesic systems are generally quite successfully predicted by models driven by climatic variables. Here, we explore the reasons for this disconnect by reviewing literature on the biotic and abiotic controls over dryland decomposition. Recent research on decomposition in drylands suggests that several key drivers of dryland decomposition have been historically overlooked and not included in models. In particular, UV photodegradation and soil transport processes, both a function of vegetation structure, may strongly influence dryland decomposition dynamics. We propose an expanded framework for studying dryland decay that explicitly addresses vegetation structure and its influence on decomposition. Spatial heterogeneity of vegetation in dryland systems necessitates considering how the spatial and temporal context of vegetation influences soil transport patterns and UV photodegradation, both of which may in turn affect abiotic and biotic decomposition processes.
KeywordsDecomposition Rate Litter Decomposition Soil Deposition Sonoran Desert Glob Change Biol
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- Ekaya W, Kinyamario J (2001) Production and decomposition of plant litter in an arid rangeland of Kenya. Afr J Range Forage Sci 18:125–129Google Scholar
- Fryrear DW (1985) Soil cover and wind erosion. Trans Am Soc Agric Eng 28:781–784Google Scholar
- Johnson KA, Whitford WG (1975) Foraging ecology and relative importance of subterranean termites in Chihuahuan desert ecosystems. Environ Entomol 4:66–70Google Scholar
- Pancotto VA, Sala OE, Robson TM, Caldwell MM, Scopel AL (2005) Direct and indirect effects of solar ultraviolet-B radiation on long-term decomposition. Glob Change Biol 11:1982–1989Google Scholar
- Rozema J, Tosserams M, Nelissen HJM, van Heerwaarden L, Broekman RA, Flierman N (1997) Stratospheric ozone reduction and ecosystem processes: enhanced UV-B radiation affects chemical quality and decomposition of leaves of the dune grassland species Calamagrostis epigeios. Plant Ecol 128:285–294CrossRefGoogle Scholar
- Schlesinger WH (1997) Biogeochemistry: an analysis of global change, 2nd edn. Academic Press, San Diego.Google Scholar
- Toy TJ, Foster GR, Reynard KG (2002) Soil erosion: processes, prediction, measurement and control. Wiley, New York.Google Scholar
- Wetterer JK, Himler AG, Yospin MM (2001) Foraging ecology of the desert leaf-cutting ant, Acromyrmex versicolor, in Arizona (Hymenoptera: Formicidae). Sociobiology 37:633–649Google Scholar
- Whitford W (2002) Ecology of desert systems. Academic Press, San Diego, CA.Google Scholar