Landscape legacies: Koala habitat change in Noosa Shire, South-east Queensland
L.M. Seabrook1, C. A. McAlpine1, S. R. Phinn1, J. Callaghan2, and D. Mitchell2
1School of Geography, Planning and Architecture and The Ecology Centre, The University of Queensland, Brisbane, Queensland 4072
2The Australian Koala Foundation G.P.O. Box 2659, Brisbane 4001
Present day Australian landscapes are legacies of our colonial history, while future landscapes will be legacies of ecological processes and human impacts occurring today. This paper investigates the legacies of European settlement of Noosa Shire, South-east Queensland, with particular emphasis on the economic and political drivers and the resultant loss and fragmentation of Koala Phascolarctos cinereus habitat. Patterns of habitat loss between 1860 and 1970 were quantified at a coarse level from historical and land tenure records, while changes over the past 30 years were mapped at a finer spatial resolution from aerial photography and satellite imagery. Periods of high economic growth and to lesser extents depression are linked to increased vegetation clearing. Fifty per cent of P. cinereus habitat has been lost since 1860, with habitat class 2A (30-<50 per cent of preferred habitat trees) and 2C (10-<30 per cent of preferred habitat trees) suffering the highest proportion of loss. The period of greatest habitat loss was between 1890 and 1910, linked to the development of the dairy industry in the western half of Noosa Shire. A second significant phase of loss occurred since 1970, linked to the planting of exotic pine plantations, urbanisation and rural subdivision, with 35 per cent of remaining habitat being cleared, mainly in the southern part of the Shire. The cumulative loss of habitat has been accompanied by increasing levels of habitat fragmentation indicated by reduced patch size and increased patch linearity. Further analysis of the temporal aspects of habitat change is required in order to test the hypothesis that there is a relaxation period between the timing of habitat loss and current pattern of habitat occupancy of P. cinereus populations.