Bis 02/2019 bei Tierökologie I
Dispersal distances and food webs of tree hollow arthropods (LWF Project L56)
left to right: Tree hollow in a beech, Ischnomera sanguinicollis, Crepidophorus mutilatus
The aim of my PhD thesis is to find a compromise between forestry use and preservation of biodiversity. One possible way to preserve the biodiversity in a managed forest, without having considerable economic losses is to protect trees with tree hollows.
Tree hollows develop from decaying processes in the living tree, which do not kill the tree. Characteristic for tree hollows is a layer of loose sediment called mulm with increased nitrogen and mineral contents. It consists of decomposed wood and metabolites of wood degrading bacteria, fungi and insects.
Tree hollows are often very old and build a permanent and complex habitat for a multitude of rare xylobiont insect species. Thus tree hollows are an important key structure in the forest ecosystem and contribute to the increase and consolidate biodiversity. To make an informed recommendation for forest management strategies I investigate the dispersal distances of certain insect species using microsatellite analysis. It is important to obtain knowledge about the dispersal of tree hollow species, because dispersal is necessary for gene flow and the colonization of new habitats. It also affects population dynamics and the risk of a local extinction of insect populations.
Insect communities in tree hollows correspond to big food webs and consist of different types of animal-animal and animal-plant interactions in respect to the use of their trophic resources or interaction types. Thus I will investigate food-webs in tree hollows with stable isotope analysis for a better understanding of the tree hollow habitat.
My studies will provide data to calculate the minimal density and the spatial distribution of trees with tree hollows needed in a managed forest to provide stable insect populations.
PD Dr. Elisabeth Obermaier, Ökologisch Botanischer Garten,
Prof. Dr. Heike Feldhaar, Tierökologie I Abteilung Popultionsökologie der Tiere, Universität Bayreuth
Bayerische Landesanstalt für Wald- und Forstwirtschaft
BayCEER, Uni Bayreuth: Labor für Isotopen-Biogeochemie:
Prof. Dr. Gerhard Gebauer
Bayerische Landesanstalt für Wald und Forstwirtschaft:
Dr. Heinz Bussler
Herr Ulrich Mergner