Resource complementation and the response of an insect herbivore to habitat area and fragmentation |
| |
Authors: | Kyle J Haynes Tim Diekötter Thomas O Crist |
| |
Institution: | (1) Department of Zoology, Miami University, Oxford, OH 45056, USA;(2) IFZ—Department of Animal Ecology, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany |
| |
Abstract: | Few studies have disentangled the effects of the area and fragmentation of a focal habitat type on species that use multiple
habitat types within a landscape. We experimentally investigated the effects of habitat area, habitat fragmentation, and matrix
composition on the movement and distribution of Melanoplus femurrubrum. Adults of this grasshopper feed preferentially on grasses, but oviposit almost exclusively in soil dominated by forbs. We
compared population densities among plots that were made to vary in the area and fragmentation of clover habitat and composition
of the matrix (grass or bare ground) within which clover habitat was embedded. In addition, a mark-recapture survey was conducted
to examine effects of habitat area, fragmentation, and matrix composition on loss of individuals from a plot’s clover habitat
and movement between clover subplots within plots. Overall densities of adult M. femurrubrum (averaged over clover and matrix) were 2.2× higher in plots where the matrix was composed of grass as compared to bare ground,
and 1.8× higher in plots with 64 compared to 16 m2 of clover habitat. Overall densities of nymphs were also positively influenced by greater clover area, but were unaffected
by matrix composition. Within focal clover habitat embedded in grass matrix, adult densities were 2.1× higher in small clover
subplots than large clover subplots. We conclude that the grass matrix had a positive effect on adult densities, but not nymph
densities, because grass and forb-dominated habitats likely provide complementary resources only for adults. The aggregation
of adults on small clover subplots within grass matrix was mainly attributed to a greater rate of emigration loss per unit
area. In addition, this study emphasizes that a species’ response to changes in the area of a focal habitat type can depend
significantly on the availability of complementary resources in the surrounding landscape.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. |
| |
Keywords: | Agroecosystem Habitat loss Landscape matrix |
本文献已被 PubMed SpringerLink 等数据库收录! |
|