Climate Change Impacts on Soil Processes in Rangelands

Abstract

Changing climates are expected to increase the vulnerability of the world's rangelands to ecosystem degradation. Rising temperatures and altered rainfall patterns are likely to substantially affect plant processes and thus the maintenance of healthy soils and functional soil processes. Changing climates are likely to reduce the ability of rangeland soils to sequester carbon, resist erosion and maintain infiltration and nutrient production processes. This chapter describes the projected changes in climate for the world's major rangelands and the effects on soil processes and ecosystem functions. We use two examples of climate-induced changes in rangelands; woody thickening from the western USA and grassland degradation in eastern Australia to demonstrate the tight interconnections between climate, altered plant and invertebrate communities, and reduced soil function. There is still considerable uncertainty associated with the assessment of soil organic carbon stocks, the magnitude of current emissions and sinks, and the possible flow-on effects to other processes in rangelands. The maintenance of plant cover, including woody cover, will be critical for carbon storage and ecosystem stability in the face of climate change, and as an aid to adaptation to the stressors of forecasted change.