Plant diversity and habitat structure affect tree growth, herbivory and natural enemies in shelterbelts

Abstract

Abstract Shelterbelts have become a refuge and source of food for wildlife because of habitat loss in farmlands. However, effects of shelterbelt attributes such as plant diversity and habitat structure on different trophic levels within shelterbelts are unclear. Effects of shelterbelt woody plant diversity and habitat structure (lower vegetation strata, logs, litter and rocks) were measured on the growth and herbivory of Eucalyptus blakelyi saplings that were caged from birds, caged from birds and arthropods and un-caged. Arthropod diversity of E. blakelyi saplings and shelterbelts was evaluated. Height and stem diameter of saplings in all treatments was positively correlated with plant diversity. Habitat structure was negatively correlated with numbers of leaves on E. blakelyi saplings and positively correlated with herbivory, which was greater in saplings caged from birds. The overall abundance of arthropods inhabiting shelterbelts correlated positively with plant diversity, but negatively with habitat structure. Araneae and Formicidae were the most common taxa on E. blakelyi saplings and were more numerous on saplings caged from birds, suggesting an important role of these vertebrates as predators of shelterbelt arthropods.