Relative effects of habitat amount and patch size on ground-dwelling arthropod communities in small forest remnants
Habitat fragmentation is deemed as one of the major threats for biodiversity conservation, especially in forest ecosystems. In human dominated landscapes forests occur mostly as small patches, which play an underlying role in maintaining biodiversity at different spatial scales. Consequently, understanding the main drivers of biodiversity in small remnants is particularly relevant for sustainable landscape management. The main aim of this research was to compare the relative contributions of two different predictors, habitat patch size and habitat amount in the surrounding landscape, in describing patterns of ground-dwelling arthropod richness and composition within small forest patches. Between June and September 2010, 9734 arthropods (centipedes, ground-dwelling beetles and spiders) were collected in forest fragments (n=22, size range: 0.05 - 14.7 ha), continuous forest, and in the surrounding open habitats in the central Apennine mountains in central Italy. All individuals were identified at species, or at least generic, level. Species richness-area relationships were analyzed using GLM (generalized linear models) while pattern in species composition by dbRDA (Distance based redundancy analysis). Our results indicate that in small forest remnants (< 1 ha) forest species richness and composition is better described by the total forest habitat amount around a patch. Furthermore, the negative effect of a small patch size on species richness and compositional differences between large and small forest patches can be buffered by high forest habitat amount in surrounding landscape. Conservation of forest species in small remnants results to be particularly influenced by how the surrounding landscape is managed, as consequence even small patches can be valuable for biodiversity conservation.
See more of: Ten Minute Paper (TMP) Oral
