Fitness of multidimensional phenotypes in dynamic adaptive landscapes

• Integrating fitness into community ecology will improve trait-based predictions.
• Dynamic adaptive landscapes link phenotypes to fitness across environments.
• Fitness is a function of multidimensional phenotype–environment interactions.
• Intraspecific trait covariation constrains environmental niche breadth.

Phenotypic traits influence species distributions, but ecology lacks established links between multidimensional phenotypes and fitness for predicting species responses to environmental change. The common focus on single traits rather than multiple trait combinations limits our understanding of their adaptive value, and intraspecific trait covariation has been neglected in ecology despite its importance in evolutionary theory and its likely impact on species distributions. Here, we extend the adaptive landscape framework to ecological sorting of multidimensional phenotypes across environments and discuss how two analytical approaches can be used to quantify fitness as a function of the interaction between the phenotype and the environment. We encourage ecologists to consider how phenotypic integration will constrain species responses to environmental change.