Restoring Rivers in the Twenty-First Century: Science Challenges in a Management Context

摘要: Abstract Legal mandates force consideration of at least some level river restoration in many developed nations (e.g., Clean Water and Endangered Species Act the United States, or Framework Directive European Union), but a lack specifics legislation compels decision-makers to ask three persistent management questions: (1) How much do we need? (2) best achieve cost-effective restoration? (3) know have restored enough? Moreover, broader context is permeated with tremendous inertia continue development rivers for societal economic gain, continual application small fragmented actions, skepticism that can succeed face climate change steady population growth. It this identify key science challenges twenty-first century. We suggest fundamental shift toward restoring watershed processes (process-based restoration) needed if scientists are begin developing tools provide relevant policy answers. The basic conceptual framework process-based requires understand how habitat formed changes, changes alter biota, human actions both habitats landscape create habitats. Restoration must then directly address caused degradation, thereby addressing root causes biological impacts. Understanding will allow better advancing restoration, including eco-system models predict what kinds needed, an expanded suite techniques large ecosystems, comprehensive suites metrics monitoring health.