Temperature, emergence phenology and consumption drive seasonal shifts in fish growth and production across riverscapes.

Changes in biophysical conditions through time generate spatial and temporal variability in habitat quality across landscapes. For river ecosystems, researchers are increasingly able to characterize spatial and temporal patterns in habitat conditions, referred to as shifting habitat mosaics, yet rarely demonstrate how this translates into corresponding biological processes such as organism growth and production. We assessed spatial patterns and processes determining seasonal changes in juvenile Chinook Salmon Oncorhynchus tshawytscha size, growth and production over 30-40 km in two NE Oregon subbasins.

Can stream and riparian restoration offset climate change impacts to salmon populations?

Understanding how stream temperature responds to restoration of riparian vegetation and channel morphology in context of future climate change is critical for prioritizing restoration actions and recovering imperiled salmon populations. We used a deterministic water temperature model to investigate potential thermal benefits of riparian reforestation and channel narrowing to Chinook Salmon populations in the Upper Grande Ronde River and Catherine Creek basins in Northeast Oregon, USA. A legacy of intensive land use practices in these basins has significantly reduced streamside vegetation and increased channel width across most of the stream network, resulting in water temperatures that far exceed the optimal range for salmon growth and survival.