INTER-HEMISPHERIC COMPARISON OF SOIL CARBON QUALITY RESPONSES TO WARMING AND ELEVATED ATMOSPHERIC [CO2] MANIPULATIONS IN TEMPERATE GRASSLANDS

(WYO-00602)

This project will examine organic matter chemistry as altered by elevated CO2 and warming in native grasslands in southeastern Australia and Wyoming, USA. Future sustainability of agricultural productivity depends on adequate soil resources, including stocks of soil organic matter (SOM) that provide long-term C sequestration and potentially mineralizable N. Stability of SOM pools is related to their chemical composition, and may be enhanced or diminished by climate changes including elevated [CO2] and warming, depending on feedback processes between plant litter chemistry and microbial decomposition. Advances in specialized spectroscopic methods can potentially improve predictive understanding of changes in SOM quality under future climate change. Application of these quantitative techniques to SOM studies was pioneered at the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Adelaide, Australia, and has elucidated mechanisms of SOM formation and stabilization. Stable forms of SOM have been identified to be related to compounds derived from roots. Decomposition of roots supplies the majority of organic matter to SOM pools in grasslands. By investigating chemistry and decomposition of roots and SOM pools, this research will fill a major gap in understanding feedbacks between climate change and soil C stability.

USDA CRIS Project Information Link: 0214901