Evaluation of deadwood characteristics, its dynamics, and feeding traces of saproxylic insects in the context of forest management and conservation. Dissertation
Deadwood is an important structural component of forest ecosystems. It contributes to ecosystem functioning by providing a microclimate favourable for many organisms and facilitating natural tree regeneration. The characteristics and dynamics of deadwood influence carbon fluxes and the habitat availability for many related species. Overall, about 25% of forest-dwelling species depend on deadwood, i.e. saproxylic species that are functionally important for ecosystem processes related to deadwood availability and dynamics. The volume of deadwood has often been used for assessing the conservation value of natural and managed forests. While in natural European temperate forests, volume of deadwood can be very high, it is severely reduced in silviculturally managed forests. Accordingly, in Europe many saproxylic species—particularly those that depend on specific characteristics such as large diameter logs of late decomposition stages or large amounts of deadwood—have greatly declined. For biodiversity conservation and ecosystem functioning related to deadwood, unmanaged natural forest reserves have become increasingly important in Europe by providing reference data for close-to-nature forestry. In addition, a better understanding of the relationship between deadwood characteristics and a variety of tree- and forest stand-related factors, macroclimatic conditions and silvicultural forest management is needed. This doctoral thesis therefore investigates how treeforest stand- and landscape-factors, forest management, and changing climate influence deadwood characteristics and dynamics in unmanaged and managed forests. It also aims to improve our knowledge of saproxylic insect’s habitat requirements and their responses to habitat changes. Keywords: Austria; Climate change; Coleoptera; Deadwood volume; Deadwood diversity; Decomposition; Forest management; National Forest Inventory; Natural forest reserves; Standing deadwood; Threshold; Volume loss
