Changes in soil carbon pools and microbial activity along land-use gradients in grassland and forest ecosystems

• Applicant: Dr. Marion Schrumpf
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 37904809

Microorganisms are the main decomposers in the soil and their activity strongly affects soil carbon storage. Extracellular enzymes play an important role in the mineralization of soil organic matter. While almost all carbon in soils is potentially degradable, a considerable part of carbon in soils is not easily accessible to microbes and their growth is often limited by available energy or nutrient sources. Especially the sorption of substrates to soil particles of the clay fraction seems to reduce their availability to microorganisms. Land use and environmental changes affect the amount and composition of new substrates entering the soil as well as the distribution of carbon between free and mineral associated fractions. This also influences microbial activity and enzyme production, which in turn affects soil carbon storage. While small changes in soil carbon are hard to identify in field studies, shifts in the activities of specific enzymes can be early indicators for changes. The aim of this project is to link microbial composition and activity to soil carbon storage as affected by land use on the main sites of the exploratories. We intent to analyse carbon storage in particle size fractions of different age and sensitivity to land use changes as well as the activities of a range of extracellular enzymes in those fractions. Enzyme activities are an indicator for functional soil biodiversity and will be related to results about species diversity and enzyme encoding gene analyses.

• DFG Programme: Research Grants
• Participating Person: Dr. Annette Freibauer