Quantifying landscape change as a consequence of plantation forestry expansion: a case study of the Koala Zone in south-west Victoria

Abstract

ABSTRACT As the global trend of habitat fragmentation and plantation establishment continues to rise, the amount of habitat that can be provided by plantations for native forest-dwelling fauna becomes increasingly pertinent. Potential benefits of plantation establishment for fauna are often dependent on the vegetation they replace, as converting native forest or natural non-forest ecosystems to plantation forest is detrimental to biodiversity. However, establishing plantation forests on previously cleared land may increase landscape heterogeneity by providing movement corridors and complementary forest habitat. Here, we present a case study of the expansion of plantation forestry in south-west Victoria, Australia, and discuss implications for koalas and other forest-dwelling fauna. Using the Hansen Global Forest Change v1.4 (2000–2016) dataset and Google Earth Engine, we quantified the amount of recent landscape change (forest cover gain and loss) attributed to plantations in south-west Victoria from 2000 to 2016 and determined the area of plantations established adjacent to native forest. We observed high levels of landscape change during the study period, with harvested plantations accounting for 70.5% (81 490 ha) of all forest lost and established plantations accounting for 75.4% (98 388 ha) of all forest gained. Of those plantations established, 34% (13 056 ha) occurred within 1 km of native forest, while only 2.8% (690 ha) occurred within 100 m of native forest. Our analysis highlights the importance of planting and harvesting regimes that consider overall landscape configuration as well as the spatial arrangement of plantations adjacent to native forest. Such considerations may increase plantation value to wildlife and overall biodiversity by enabling higher levels of functional connectivity, limiting habitat isolation and facilitating the movement of wildlife within and beyond plantation forests.