Climate change drives increased directional movement of landscape ecotones

Context Ecotones are boundary zones formed where overlap between neighboring ecosystems creates an intermediate ecosystem with unique ecological characteristics. Dynamic ecotones change position along a boundary over time and can be further categorized as either shifting, where the adjacent ecosystems alternatively drive movement of the ecotone but maintain the same relative location over time, or directional, where one system encroaches into the other and the ecotone moves laterally. Objectives The purpose of this work was to examine how climate change alters movement dynamics of both directional and shifting ecotones. Methods In three ecosystem case studies, we examine the effects of climate change on landscape-scale ecotone movement across the marine, terrestrial, and interfacing environments. Results Shifts in local and global climate drive changes in ecotone patterns, increasing directional ecotone movement at both shifting and directional ecotones. Specifically, unidirectional changes in climate patterns disrupt dynamic equilibria at shifting ecosystem boundaries, thereby facilitating unidirectional movement at the previously shifting boundaries. Climate changes additionally accelerate pre-existing directional migration of ecotones through changes to abiotic gradients. Conclusion Directional climate change increases directional movement in multiple types of ecotone. Future work should consider the rate and feedback mechanisms of ecotone movement and function at additional ecotones.

Automated summary

Climate change alters movement dynamics of both directional and shifting ecotones, with shifts in climate driving changes in ecotone patterns and increasing directional movement. Unidirectional changes disrupt dynamic equilibria at shifting boundaries, facilitating unidirectional movement, while climate changes accelerate pre-existing directional migration of ecotones through changes to abiotic gradients. Future work should consider the rate and feedback mechanisms of ecotone movement and function at additional ecotones.