Conclusions
Our study highlights, that effects of non-native trees on resident
insect abundance and diversity do not depend on the geographical
proximity of the area of origin, as often assumed especially by
practitioners in forestry, but predominately on the phylogenetic history
non-natives share with their resident, native counterparts. Our study
furthermore shows, that non-native tree species should be regarded
differentiated and that impacts of non-native trees on insect
communities in the introduced range differ according to their
relatedness to native congeners. While closely related non-native
congeners hosted a higher number of insect individuals and species, more
distantly related non-natives of the same genus inhabit significantly
less species and individuals. This highlights the necessity of account
for phylogenetic history as a global driver of the effects of non-native
tree species in future alien species and forest management. This study
was performed with four of the most important tree genera of the
temperate zone. Our results therefore can provide important input for
tree species selection and management in forestry and urban greening in
the future.