Spillovers from protected areas such as national parks and wildlife reserves can play a significant role in boosting biodiversity beyond their boundaries with potential benefits to people through ecosystem services such as climate mitigation, water retention and erosion control.
Published in Nature the study by Professor Graeme Cumming, from The University of Western Australia's Oceans Institute and School of Earth and Oceans, looked in depth at vegetation spillovers – the projected difference in plant composition made by protected areas to land adjacent to their boundaries – across Australia.
The results showed that 71 per cent (2,189) of 3,063 of the measured protected areas provided vegetation spillovers within 5km of the boundary, with this proportion declining predictably at greater distances.
In Western Australia, some of the protected areas with the largest spillover effects at 5km included Monadnocks Conservation Park, Lane Poole Reserve and Beelu National Park.
“Spillovers from protected areas multiply the benefits of area-based conservation by increasing the range of places endangered and beneficial or useful species can live and grow,” Professor Cumming said.
“This knowledge can help make informed decisions to tackle ongoing biodiversity loss and ecosystem degradation.”
Plant growth on protected area boundaries is influenced by local variation in the environment such as differences in rainfall and topography, as well as by broader geographical gradients.
After correcting for these influences, the study also found that the size of the vegetation spillover effect was influenced by management inside the protected area.
The analysis further suggested that vegetation spillovers could be predicted at broad scales based on easily measured environmental variables, location and management type.
“Biodiversity conservation efforts and value assessments often focus on what is inside protected areas, but greater attention to spillovers is likely to show that protected areas are more valuable to society than most estimates suggest,” Professor Cumming said.
“This research could help state and commonwealth governments to design policy to deliberately facilitate the spread of biodiversity and its benefits from protected areas.”