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

陆栖动物是生态系统的工程师，它们影响植被的结构和组成，从而影响土壤形成、分解和碳储存等生态系统过程。生物扰动还与固体和可溶性颗粒的再分配有关，并增加了水和养分可用性的斑块性，从而对植物群落和土壤生物产生影响。然而，大多数已发表的关于生物扰动的研究都是从局部角度出发的，缺乏对风化带和山坡上覆盖广泛气候梯度的地表生物对沉积物速率和营养物质再分配的影响的全面、空间明确的分析。因此，我们的目标是i)估计地球形状主要关注区域及其气候梯度的生物扰动器的空间分布、丰度和功能类型；ii)量化该梯度沿线的植被，并确定其与穴居动物的分布和丰度的关系；iii)量化生物扰动器对土壤、养分和沉积物再分布的影响。iv)利用基于气候、植被和物种丰度之间的图源传递函数的遥感和建模技术，得出生物扰动效应在流域范围内的再分配和侵蚀率。

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.