Abstract
The overall aim of the present proposal is to increase our understanding of microbial communities for recalcitrant organic matter formation and nutrient turnover in soils under different scenarios of nitrogen (N) deposition, with a focus on forest soils. N deposition is a global change component which, contrary to sulphur deposition, still is high in large parts of northern Europe. Increased N input to forests initially lead to increased carbon (C) sequestration, and fertilization, including N amendments, has been proposed as a mean to sequester C in forest ecosystems. However, on a longer term increased N input may result in N saturation with N leaching and deterioration of the forest as a C sink. We will use a combination of different approaches – from detailed mechanistic experiments on organisms in well defined laboratory systems to studies on microbial communities in natural soils – to identify the microorganisms that carry out C and N turnover in soils, characterize some of these processes at molecular levels, and identify how they are regulated under different environmental scenarios. On a larger scale, we will use a network of sites in northern Europe. Our research programme is essential in order to improve C cycling models and to understand how elevated N input influence C sequestration and risks of nutrient leaching from soils. A Centre for Soil Microbial Ecology will be established to accomplish this interdisciplinary research program.
Sweden