Effects of bioturbation on rates of vertical and horizontal sediment and nutrient fluxes

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Ground-dwelling animals act as ecosystem engineers that affect the structure and composition of the vegetation and thereby also ecosystem processes like soil formation, decomposition and carbon storage. Bioturbation has also links to the redistribution of solid and soluble particles and increases the patchiness of water and nutrient availability with consequences for plant assemblages and for soil organisms. However, most published studies on bioturbation have a local perspective and comprehensive, spatially explicit analyses of the influence of ground-dwelling organisms on rates of sediment and nutrient redistribution in the weathering zone and on hill slopes covering a broad climatic gradient are lacking. We thus aim to i) estimate the spatial distribution, abundance and functional type of the bioturbators in the EarthShape primary focus areas and along its climate gradient, ii) quantify the vegetation along this gradient and determine its relation to distribution and abundance of burrowing animals, iii) quantify effects of bioturbators on soil, nutrients and sediment redistribution, and iv) derive catchment-wide redistribution and erosion rates of the effects of bioturbators by using remote sensing and modelling techniques based on plot-derived transfer functions between climate, vegetation and abundance of species.