Association between geomorphic attributes of watersheds, water temperature, and salmon spawn timing in Alaskan streams

摘要: Abstract Intraspecific variation in the seasonal reproductive timing of Pacific salmon (Oncorhynchus sp.) has important implications for resilience and organisms freshwater terrestrial communities that depend on resources. Stream temperature well known associations with spawn but how stream watershed geomorphology relates to is less understood. We used multivariate statistics applied five environmental variables compare conditions across 36 watersheds Wood River basin southwest Alaska. found first two axes a principal components analysis (PCA) explained 76% summer among streams 45% sockeye salmon. The average habitat characteristics characterized three groups were significantly distinct from one another. Sites supporting early spawning populations tend have steeper smaller watersheds, while late occur draining large, lower gradient lakes drainage network. Finally, we show little spatial correlation landscape, thereby producing fine-scale mosaic river basin. These results demonstrate hydrology interact produce heterogeneous thermal template natural selection influence basins.