24 research outputs found
Evidence needed to manage freshwater ecosystems in a changing climate: Turning adaptation principles into practice
It is widely accepted that climate change poses severe threats to freshwater ecosystems. Here we examine
the scientific basis for adaptively managing vulnerable habitats and species. Our views are shaped by a
literature survey of adaptation in practice, and by expert opinion. We assert that adaptation planning is
constrained by uncertainty about evolving climatic and non-climatic pressures, by difficulties in predicting
species- and ecosystem-level responses to these forces, and by the plasticity of management goals. This
implies that adaptation measures will have greatest acceptance when they deliver multiple benefits,
including, but not limited to, the amelioration of climate impacts. We suggest that many principles for
biodiversity management under climate change are intuitively correct but hard to apply in practice. This
view is tested using two commonly assumed doctrines: “increase shading of vulnerable reaches through tree
planting” (to reduce water temperatures); and “set hands off flows” (to halt potentially harmful abstractions
during low flow episodes). We show that the value of riparian trees for shading, water cooling and other
functions is partially understood, but extension of this knowledge to water temperature management is so
far lacking. Likewise, there is a long history of environmental flow assessment for allocating water to
competing uses, but more research is needed into the effectiveness of ecological objectives based on target
flows. We therefore advocate more multi-disciplinary field and model experimentation to test the costeffectiveness
and efficacy of adaptation measures applied at different scales. In particular, there is a need for
a major collaborative programme to: examine natural adaptation to climatic variation in freshwater species;
identify where existing environmental practice may be insufficient; review the fitness of monitoring
networks to detect change; translate existing knowledge into guidance; and implement best practice within
existing regulatory frameworks