Predicting trajectories of dryland wetland vegetation transformation under climate change: a case study of the northern Murray–Darling Basin, Australia

Abstract

Dryland wetland vegetation is, paradoxically, both highly sensitive and extremely resilient to environmental change. In the short-term, rapid responses of wetland biota and ecological processes to wetting and drying, which influence ecosystem structure and function, enable rapid reproduction which enhances long-term resilience. However, over longer periods, mechanisms such as seed dormancy and persistent seed and egg banks enable dryland wetland ecosystems to recover after major environmental perturbations such as mega-droughts or wildfire. Climate change is likely to have a significant effect on key drivers of ecological response in dryland wetlands, including hydrology and its interface with other climatic stimuli, e.g. temperature, as well as the frequency and intensity of extreme events. Like species, wetland ecosystems may respond to climate change in three main ways, namely, disappear, persist without significant adjustment, or transform. Here, we consider the conditions under which each of these responses may eventuate for dryland wetlands, by using wetland vegetation of the northern Murray–Darling Basin Australia, as a case study. We also explore what wetland transformation might entail in this region in terms of wetland ecological character and the key values this supports. Finally, we consider the implications for wetland policy and management at present and as trajectories of wetland change unfold.