PAIRED STREAM–AIR TEMPERATURE MEASUREMENTS REVEAL FINE‐SCALE THERMAL HETEROGENEITY WITHIN HEADWATER BROOK TROUT STREAM NETWORKS

摘要: Previous studies of climate change impacts on stream fish distributions commonly project the potential patterns habitat loss and fragmentation due to elevated temperatures at a broad spatial scale (e.g. across regions or an entire species range). However, these may overlook heterogeneity in vulnerability within local networks. We examined fine-scale temperature two headwater brook trout Salvelinus fontinalis networks (7.7 4.4 km) Connecticut, USA, by placing combined total 36 pairs air loggers that were approximately 300 m apart from each other. Data collected hourly March October 2010. The summer 2010 was hot (the second hottest record) had well below average precipitation, but comparable with those previous 2 years because streamflow dominated groundwater during base-flow conditions. Nonlinear regression models revealed variation networks, particularly warmest hours day (i.e. late afternoon evening) summer. Thermal variability primarily observed between segments, versus segment confluence confluence). Several cold tributaries identified which much less responsive temperature. Our findings suggested regional would not fully capture thermal misrepresent resilience Groundwater appeared play major role creating variation, characterizing this is needed for assessing accurately. Copyright © 2013 John Wiley & Sons, Ltd.