Warming overcomes dispersal-limitation to promote non-native expansion in Lake Baikal

Non-native species and climate change pose serious threats to global biodiversity. However, the roles of climate, dispersal, and competition are difficult to disentangle in heterogeneous landscapes. We combine empirical data and theory to examine how these forces influence the spread of non-native species in Lake Baikal. We analyze the potential for Daphnia longispina to establish in Lake Baikal, potentially threatening an endemic, cryophillic copepod Epischurella baikalensis. We collected field samples to establish current community composition and compared them to model predictions informed by flow rates, present-day temperatures, and temperature projections. Our data and model agree that expansion is currently limited by dispersal. However, projected increases in temperature reverse this effect, allowing D. longispina to establish in Lake Baikal's main basin. A strong negative impact emerges from the interaction between cli-mate change and dispersal, outweighing their independent effects. Climate, dispersal, and competition have complex, interactive effects on expansion with important implications for global biodiversity.(c) 2022 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.

Automated summary

Climate change and non-native species pose significant threats to biodiversity in Lake Baikal. Based on empirical data and theoretical analysis, this study reveals that the current limitation on the spread of non-native species is primarily attributed to dispersal. However, projected temperature increases are expected to overcome this limitation and allow non-native species to establish in Lake Baikal, leading to negative impacts on endemic species.