The response of arboreal marsupials to landscape context over time: a large-scale fragmentation study revisited
Species extinction from habitat fragmentation and loss is a major concern world-wide. Given the temporal variability inherent in many ecosystems, long-term studies are important to understand how species respond to landscape change. We revisited a large-scale, natural experiment, 10 years after initial surveys to investigate the response of arboreal marsupials to anthropogenic landscape change over time.
The Tumut Fragmentation Study in south-eastern Australia encompasses 50,000 ha of contiguous Eucalyptus forests and eucalypt forest remnants surrounded by an exotic pine (Pinus radiata) plantation.
This study followed an established, statistically rigorous, replicated design that matched remnant eucalypt sites within the plantation to control sites within contiguous eucalypt forests. We recorded the presence and abundance of arboreal marsupials by spotlighting along transects. We used a range of generalized linear models to investigate interactions among independent and dependent variables and test hypotheses established at the outset of the study.
All of the species observed in eucalypt remnants in 1996 were present in 2007. However, the presence and abundance of some species had changed significantly between periods. Remnant size, isolation, the disturbance history of the pine matrix adjoining remnants, time since pine establishment, and/or the age of the pines were significant factors in explaining the presence and abundance of some species. We identify mechanistic processes that may be responsible for the differing response patterns of the four most common arboreal marsupial species.
Most native forest remnants continued to provide habitat for several arboreal marsupial species over the past decade. These results add considerable weight to recommendations calling for the preservation of native forests remnants during and after plantation establishment. The condition and management of the matrix can significantly affect wildlife populations in modified landscapes, and this should be given more consideration in conservation planning. Small changes to plantation design and management could have large positive impacts on indigenous wildlife populations around the world.