Here, we develop a method to examine where and for which species shifting isotherms will outpace species dispersal using stream networks of the southern Appalachian Mountains (United States) and their highly speciose and endemic fish fauna as a model system.  Despite accessibility and thermal suitability, non-temperature habitat conditions in tributaries are unsuitable for some dispersing species, thus probably precluding establishment of persistent populations.  Our findings demonstrate a trade-off shaping the efficacy of thermal refugia that depends on species-specific habitat associations and reveal individual-level dispersal behaviour, body size and stream network geometry as general correlates of climate change vulnerability.
THERM