As Earth's climate rapidly changes, species range shifts are considered key to species persistence. However, some range-shifting species will alter community structure and ecosystem processes. By adapting existing invasion risk assessment frameworks, we can identify characteristics shared with high-impact introductions and thus predict potential impacts. There are fundamental differences between introduced and range-shifting species, primarily shared evolutionary histories between range shifters and their new community. Nevertheless, impacts can occur via analogous mechanisms, such as wide dispersal, community disturbance and low biotic resistance. As ranges shift in response to climate change, we have an opportunity to develop plans to facilitate advantageous movements and limit those that are problematic.

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Existing projections of climate change impacts focus primarily on direct abiotic impacts on individuals and populations. However, these models often ignore species interactions, which are vital for determining community composition and structure. To evaluate both direct and indirect effects of climate change on species distributions, we applied the Menge–Sutherland model, which describes the relative role of predation and environmental stress in regulating community structure. Using a space‐for‐time approach, we tested the predictions that (1) predators are more strongly impacted by increasing environmental stress than prey (as described in the Menge–Sutherland model) and (2) incorporating indirect (predator) effects increases our ability to predict impacts of increased temperature on prey distributions. We surveyed vertical distributions of predators (sea stars) and a foundational prey species (mussels) at 20 intertidal sites spanning a thermal gradient along the West Coast of the United States. Using generalized linear models and structural equation models, we found that as temperature increased, the upper limits of foundational prey species decreased (a direct effect), while prey lower limits also shifted downward, due to an indirect effect of temperature on predator distributions. Under future climate change, mussel ranges may undergo vertical shifts toward subtidal habitats, allowing for localized persistence of mussels and associated species. Our model comparisons indicate that this framework—incorporating both direct and indirect environmental stress effects within a classic community regulation model—can improve prediction of responses to warming. Community regulation models could be expanded to inform management and conservation efforts during unprecedented climate and ecological change.

Globally, species are undergoing range shifts in response to climate change. However, the potential impacts of climate-driven range shifts are not well understood. In southern California, the predatory whelk Mexacanthina lugubris has undergone a northward range shift of more than 100 km in the past four decades. We traced the history of the whelk’s range shift and assessed potential effects using an integrated approach, consisting of field surveys, as well as feeding and thermotolerance experiments. We found that at sites where Mexacanthina and native species co-occurred, native whelks distributions peaked lower in the intertidal. In laboratory experiments, we found that the presence of Mexacanthina led to reduced growth in native whelks (Acanthinucella spirata). Additionally, the range-shifting whelk was able to tolerate higher temperatures than common native species (A. spirata and Nucella emarginata), suggesting further impacts as a result of climate warming. Many species are likely to undergo range shifts as a coping mechanism for changing climatic conditions. However, communities are unlikely to shift as a whole due to species-specific responses. By studying the impacts of range-shifting species, like Mexacanthina, we can better understand how climate change will alter existing community structure and composition.