Landscape transformation : impact on butterflies and beetles in south-eastern Australia
Creators: name: Sweaney, Nicole
Publisher: name: The Australian National University
Year: 2014
Subjects: subject: Butterflies Ecology Australia New South Wales
subject: Butterflies Effect of habitat modification on
subject: Beetles Ecology Australia New South Wales
subject: Beetles Effect of habitat modification on
subject: Agricultural landscape management Australia New South Wales
subject: Landscape protection Australia New South Wales

description: Agricultural pastures are one of the most common land-cover types in fragmented terrestrial landscapes. While they may act as a 'matrix' (i.e. unable to support sustainable populations) for some species, for others they can have high conservation potential. In many parts of the world, agricultural pastures are being replaced by tree plantations, which will influence the distribution of patch-associated species and those that occur more broadly across the landscape. Understanding how species respond to landscape transformation is critical to the successful conservation of biodiversity. My thesis introduction further explores possible consequences of landscape transformation and the ecological and management context of my research (Chapter 1). I then present my systematic review, which assesses how the matrix has so far been considered in fragmentation studies on butterflies (Chapter 2). I found it was significantly more likely for studies not to include the matrix in their experimental design. This result was concerning as 80% of the papers which did consider the matrix reported that it had a negative impact on butterflies. My review highlights the need for future research to ensure the matrix is included appropriately in the experimental design of studies in fragmented landscapes. I then present empirical research on butterflies (Chapter 3) and ground-active beetles (Chapter 4) in a landscape of native Eucalyptus woodland patches surrounded by agricultural pastures and pine plantations in the southwest slopes of New South Wales, Australia. My results suggest that farmland offers resources to both taxa. Conversely, in areas where farmland has been transformed to plantation, I found significantly fewer beetles and a complete absence of butterflies. This research indicates that land-cover change could have serious implications for the successful dispersal of animals, and may lead to population isolation and/or biotic homogenisation. I further explore mechanisms driving the distribution of butterflies in this landscape by investigating movement of Heteronympha merope (common brown butterfly) at edges of eucalypt woodland, agricultural pasture and pine plantation (Chapter 5). I found individuals were less likely to approach pine edges compared to edges of farmland or eucalypt. They also were unlikely to cross pine edges, and in cases where they did cross, they always returned to the area they were released from. If released within pine, individuals actively departed. These results further support the suggestion that dense pine plantations may interrupt successful disperal for species in patchy landscapes. My thesis demonstrates the effects of landscape transformation on patch-associated species and others that occur more widely across the landscape. The lack of biodiversity supported by plantations is particularly concerning for conservation considering demands for plantation wood will result in plantation expansion in many areas worldwide. This thesis concludes by providing recommendations for improving the conservation value of plantations (Chapter 6), including; adopting earlier thinning schedules and preserving corridors of native trees or understorey vegetation. Implementing my recommendations will likely improve matrix use and patch connectivity for invertebrates and other taxa. Future research should concentrate on evaluating the effectiveness of my management recommendations for various taxa and systems (Chapter 6).