Core Projekt 9 - Monitoring of aboveground arthropod diversity with main emphasis on xylobionts

点击翻译按钮获取中文摘要

Arthropods are highly diverse and essentially involved in numerous biological processes. Tree crowns provide habitats for a large part of this diversity, but are still a vastly uncharted territory. The major aim of this project is to quantitatively and qualitatively assess the influence of forest management on the diversity and functional roles of canopy arthropods. For this we 1) perform a thorough recording of the diversity of canopy arthropods. Based on data of several years we analyse the structure, dynamics and guild composition of tree specific arthropod communities in forests under different management regimes. 2) We experimentally accumulate dead wood – a rare key resource in managed forests – in individual trees and on the ground and analyse the effects on the populations of xylobionts and their interaction with other guilds (e.g. predator-prey relationships), 3) we investigate (also experimentally and in cooperation with other projects) the importance of xylobiontic arthropods for coarse woody debris decomposition. The repeated monitoring of canopy arthropod diversity by means of insecticidal knock down allows an estimation of stability and resilience of species-rich communities. Our project provides important data for other projects, allowing relating canopy diversity with that of other habitats and communities with the aim to achieve a more comprehensive modelling of forest ecosystem processes. Our previous work has shown that increasing land-use intensity in grasslands leads to changes in pollinator composition (more dipterans, fewer bees) and also affects plants where land use winners (e.g. fly-pollinated Heracleum sphondylium and Ranunculus acris) and losers can be distinguished. We currently investigate whether this translates into lower pollination of selected losers (e.g. bee-pollinated Lotus or Campanula), and higher pollination of winners. Such processes will accelerate the success and decline of plant populations in intensively used grasslands. Long-term monitoring of these processes is applied for here.