Knowledge of how community structure changes across environmental gradients has generated a wealth of insight into the environmental and ecological processes structuring communities and ecosystems. Environmental gradients occur at multiple spatial scales and the structure of communities reflect the interaction of responses to gradients at various scales. We leverage large scale surveys conducted by the PISCO consortium across the rocky subtidal-intertidal environmental gradient over a 750 km latitudinal gradient to determine how coherent geographic patterns of community structure are between these ecosystems.
Clear biogeographic patterns were revealed for both systems with biological regions aligning with major geographic, geomorphological and oceanographic features. Intertidal and subtidal biogeography were very strongly correlated; spatial patterns of community composition were similar between these adjacent ecosystems. For these two ecosystems it is possible to model and predict the community patterns of one system based on patterns of community structure of the other. We discuss both the ecological (e.g., the significance of coherent patterns of adjacent ecosystems) and applied (e.g., ability to infer community structure of a more difficult ecosystem to sample from one that is less challenging to sample) implications of these results.