Dr. Paolo Cherubini (WSL, Switzerland) and Prof. Markus Egli (University of Zurich, Switzerland) have the lead of work package 3 (WP3). 

Although the persistence or decay rates of coarse woody debris (CWD) over time and as function of climate is a basic information which is instrumental for understanding the cycle of carbon and nutrients, only very scarce data about this relationship are available. Consequently, the main aim of WP3 is to study the decay mechanisms of CWD (rate, dependence of climate) and its incorporation into the humus of the soil. The main research questions are the following: 

• How does climate affect coarse woody decay at alpine sites:

• how do chemical properties of alpine coniferous trees vary as a function of decay?  

• how are biochemical characteristics influenced by the thermal regime?

• What time scales are involved in the CWD decay of Picea abies and how do they vary with climate? 

• How quickly is CWD (Picea abies) integrated into soil organic matter fractions? In which way are the decay products of CWD stabilised?

We focus only on natural forest ecosystems of subalpine sites along an altitudinal gradient (climosequence) by using a biogeochemical (C, N, lignin, cellulose, δ13C, δ15N, nutrients), dendrochronological (tree ring width sequences of deadwood to derive the time since death; cross-dating with a master chronology) and dating (14C; for highly decomposed tree material that cannot be dated using dendrochronology) approach. In addition, experimental manipulations by using soil-mesocosm where highly labelled (δ13C) plant material (Picea abies) and wood blocks are placed and used to characterise and quantify the related decomposition processes and its integration into soil organic matter (chemical and physical) fractions

WP3 - Team 

WP3 - Participating students