Global change and headwater streams - from land use to thermal regimes

Because water flows downhill, streams reflect actions in their watersheds. My research group uses both experimental and epidemiological approaches to identify stressors such as land use, thermal regimes, and chemicals that trigger ecological thresholds causing aquatic biota to fundamentally change composition to alternative states. Aquatic communities can show dramatic responses to even small amounts of land use change, with some taxa disappearing from watersheds entirely. Within the context of global change, up to 50% of aquatic biodiversity may be lost from some watersheds. Threshold values for a given stressor can differ between adjacent physiographic regions, but once degradation occurs our research suggests that ecological condition may be difficult, if not impossible, to restore.

• Announcement (pdf)