B2.1 Organic matter and microbial community structure in soils
PI(s) for this project:
Organic matter and microbial community structure in soils
The objectives of the proposed project are to quantify organic matter turnover in top soils in relation to organic matter quality, activity and community structure of soil microorganisms under different land-use in the mountain rain forest region of southern Ecuador. The effects of clean-burning, fertilisation and litter quality in pastures will be investigated and key factors controlling efficient re-colonization of burned and heavily used soils towards natural conditions in succession determined. In the fertilisation experiment effects of 14C- and 15N-labelled urea and rock phosphate will be used in order to quantify the effects on soil organic matter (SOM) turnover in connection to changes in soil microbial community structure. Phospholipid fatty acid (PLFA) analysis together with ergosterol determination will be used for characterising the soil microbial community. The degradability of plant litter typical of the respective land-use system will be measured and referred to litter quality (C, N, P, lignin content). Using the different delta 13C signature of pasture and forest vegetation, the source of SOM mineralised preferentially by soil microorganisms will be identified. Thus, a detailed acquisition of processes and mechanisms in the soil organic matter cycle in soils of the mountain rainforest region of Ecuador will be obtained and SOM turnover modelled.