Projecting the impact of climate change on bitou bush and boneseed distributions in Australia

Global climate change will have significant implications for the management of invasive species in Australia and throughout the world. Changes to temperature and precipitation regimes may influence the fecundity, recruitment and competitive ability of invasive species leading to expansions or contractions of species distributions. Using point localities derived from the Global Biodiversity Information Facility (GBIF), and NSW National Parks and Wildlife Service survey data we have modelled projections of the potential future bioclimatic ranges of the widespread weeds bitou bush (Chrysanthemoides monilifera subsp. rotundata (DC.) Norl.) and boneseed (Chrysanthemoides monilifera subsp. monilifera (L.) Norl.) within Australia. Uncertainty exists in estimates of future climate, due to differences in projections derived from alternate climate models. Also, the severity of climate change will depend on emissions scenarios that will be influenced by human population levels, socio-economic conditions and technological changes. To address some of the uncertainty surrounding future climate, we projected species distributions onto scenarios derived from two climate models (CSIRO MK2 and NCAR) and two emissions scenarios (A1f and B1) for the year 2030. Through investigating the potential for climate change to alter the distribution of bitou bush and boneseed, managers can make informed decisions when developing strategies with a long term perspective.