Blue, green and in-between: objectives and approaches for evaluating wetland flow regimes based on vegetation outcomes

Evaluating wetland vegetation responses to flow regimes is challenging because of the inherently complex, variable and dynamic nature of wetland vegetation in space and time. We propose four principles to guide the development of management objectives and evaluation approaches to support adaptive management of wetland vegetation in flow-managed systems. First, we assert a need for more explicit, direct and defensible alignment of management objectives, targets and indicators to reflect broader ecological, sociocultural and economic values, and the underlying ecosystem functions that support them. Second, we propose a framework for indicator selection across multiple spatiotemporal scales and levels of ecological organisation, from individuals to landscape mosaics (vegscapes). Third, we emphasise the need to evaluate vegetation condition and responses to environmental flows in relation to a more nuanced understanding of temporal flow dynamics. Finally, we discuss the importance of considering the effects of non-flow variables that can modify vegetation responses to environmental flows. We highlight key knowledge needs required to support the implementation of these principles, particularly the urgency of improving our understanding of ecological, sociocultural and economic values of wetland vegetation and the attributes and functions that support these values.