| Fine root decomposition dynamics contribute significantly to biogeochemical cycling in terrestrial ecosystems. Land use and management may affect root litter decomposition through changes in plant species composition and diversity, effects on the decomposer community and differences in nutrient availability. We have established a large scale root litter decomposition study in three German regions using a standardized litterbag method for forest and grassland sites under different management, soil types and manipulations of the decomposer communities. In one setup of the experiment we used standardized root litter for forest and grassland sites at all 300 plots, and in a second setup root litter collected on-site was used. In total 5112 litterbags were buried at 10 to 40 cm soil depth. The main aims of these experiments are to analyze the links between root litter quality and decomposition rates and to see how these are affected by biotic and abiotic site conditions and soil depth. Quantifying the amount of carbon plants allocate to fine roots and their below-ground residence time is also necessary for the prediction of how ecosystems will respond to environmental change. Therefore we are also interested in measuring the radiocarbon (14C) content of fine roots in order to estimate their mean residence time in different land uses. The decomposition of fine roots is expected to be faster initially for material collected on-site, to differ between land use types, management classes and climatic conditions, and to be influenced by abiotic/biotic soil properties and soil depth. I present the setup of the experiments and the results of the first collections of litterbags in 2012 and of the radiocarbon analysis. |
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