Deadwood Decay in central European FORests

Deadwood is an important and large carbon pool in unmanaged forests and will become more important in managed forests, as changes in forest management and/or more frequent disturbances will likely lead to higher deadwood amount in Central European forests. The trajectories of deadwood dynamics can be currently not accurately assessed due to lack of a conceptual understanding and data on deadwood carbon stocks, carbon fluxes, importance of fungi for deadwood decay and the habitat value of deadwood. DD FOR will introduce a conceptual understanding of deadwood dynamics during its observable lifetime from deadwood creation to fragmentation and incorporation into the soil. Hypothesizing that temperature is the main driver of deadwood decay and that warming is stronger at higher elevation, the results of DD FOR will help quantify the impacts of global warming on the carbon cycle. We will also test, whether deadwood decay is faster under moderate moisture conditions and how management can modulate decay rates, through debarking, deadwood alignment and/or microsites. Based on field experiments, we will develop temporal models on deadwood change over time, that can be combined with forest inventory data and/or forest growth models, to ensure uptake of project results. Our field sites will span temperature and precipitation gradients of Central Europe (~3-8 °C average annual temperature, ~700-1700 mm annual precipitation sum) and complement European research initiatives on deadwood research (e.g. BELongDead, BIOCOMP), by expanding the current observation network into cool and wet mountain forests. For important tree species in Central Europe (e.g. Picea abies, Pinus sylvestris, Fagus sylvatica, Quercus sp.) we will establish chronosequences of deadwood samples, building on pilot studies by the applicant and existing research infrastructure. For selected deadwood pieces we will conduct monitoring of saproxylic insects using emergence and flight interception traps and quantify the fungal communities using wood samples, fruiting body inventories and state-of-the-art analytical methods, including meta bar-coding. This will establish decay rate benchmarks for fungal species, depending on climate and their host species.