WIDESPREAD LAND COVER TRANSFORMATION AND THE MANAGEMENT IMPACTS FOR TROPICAL MEANDERING RIVER SYSTEMS

Tropical meandering rivers and their floodplains provide habitats to many of the planet’s critically endangered species, but they are now being threatened by recently intensified rates of deforestation driven by global demands for food and biofuels. This has been especially true for the Kinabatangan River of northern Borneo, where palm oil plantations have replaced the majority of natural forest during the past 30 years. Using the Kinabatangan as a natural laboratory, we report that tropical deforestation not only increases the rate by which meandering rivers migrate across their floodplains, but widespread forest clearing appears to affect the nature of river meandering itself. In the absence of trees protecting and stabilising riverbanks, river flows can more efficiently access and mobilise riverbank materials, the result being that agricultural practices become increasingly costly for cases of complete riverbank deforestation. Our results are based on an analysis of Landsat imagery spanning the duration of active deforestation, which then informed a numerical model that allowed us to assess the economic impacts of widespread land clearing. The findings should inform management practices to better support the sustainability and ecological functioning of tropical river floodplain habitats.