Epsilon Archive for Student Projects

Abstract

Insects contribute to many important ecosystem functions, such as pollination, decomposition and pest control. Their diversity has recently decreased globally, which may be due to several factors, such as large-scale intensive forestry. The aim of this study is to examine how insect species composition in the polypore Fomes fomentarius has changed today compared to 1992-95, with a particular focus on the beetle Rhopalodontus perforatus. The study also examines how different environmental microhabitat variables affect the number of insect species in F. fomentarius. The method involved collecting polypores of F. fomentarius from birch trees in Nyvallen and Vattholma near Uppsala in Sweden. Insects living in the polypore were then hatched in laboratory, thereafter collected and identified to species or family level. Statistical methods such as Chi2, Fischer and Spearman’s correlation coefficient were used to determine changes in species composition and the impact of environmental microhabitat variables. The results showed that there has been some change in species composition, with an increase in the proportional abundance of R. perforatus. Based on the environmental variables, fruiting body area (calculated as depth times width) showed the strongest positive correlation with number of insect species.