DecAlp refers to the abbreviated title of the proposed project dealing with the effects of climate on coarse woody debris Decay dynamics and incorporation into the soils of forested Alpine areas. The investigation area is located in Val di Rabbi in the south Alpine belt in northern Italy (Trentino).

Work package 1 (WP1) is carried out by the Laboratory of Soil and Vegetation at the University of Neuchâtel (CH), headed by Prof. Jean-Michel Gobat, in collaboration with the Institute for Applied Soil Biology (IFAB GmbH) in Hamburg, Germany.

WP1 is focusing on the interrelationship between vegetation cover, soil fauna and humus formation as a function of climate. Earthworms and microannelids as proxies of the macro- and the mesofauna will be quantitatively sampled at sites along selected climosequences and analysed with respect to abundance, species composition, vertical distribution and functional traits of species. The resulting patterns of soil fauna will be compared with the formation of humus horizons in the sampled profiles aiming to discriminate among biologically different humus forms. The overall aim is to model the effect of climate (altitude vs. exposure) on the diversity of soil biota and the dynamics of humus forming processes. Moreover, a special focus will be given on humus forms strongly influenced by woody material (lignoforms). A description method of the horizons (here called xylons) forming these lignoforms will be developed. Thus, numerous characteristics of these xylons will be investigated (specific components, coloration, macromorphological aspects, among others). The most relevant characteristics for a new taxonomy of these specific horizons will then be determined by statistical analyses, leading to a more accurate classification of lignoforms and providing a better understanding of their diversity and dynamics. New knowledge about relationships between soil/vegetation level (macro-scale), ligno-humus forms level (meso-scale, main crossroads of the ecosystem) and microbiological activity level (micro-scale) under different climatic conditions will be provided by crossing the results of WP1 with other WPs