Assisted migration within species range ignores biotic interactions and lacks evidence

Abstract

AbstractIn the context of climate change, many plant species may have problems adapting or dispersing rapidly enough to keep pace with changing environmental conditions. Given these potential problems, some experts argue against using local plant ecotypes for ecosystem restoration. Instead, they propose to use foreign ecotypes that are adapted to the predicted climate in an approach called assisted migration within species range or predictive provenancing. I argue that such actions may cause a mismatch in biotic interactions and have negative effects on other organisms. As such, assisted migration should only be considered in cases when the local ecotypes would fail to ensure ecosystem services. In fact, there is little experimental evidence on the assisted migration approach so far, and what little there is does not seem to support its use. Even in altered climates, local ecotypes mostly performed equally well or better than foreign ones selected for their adaptations to these climates. The reason is that even if adaptation to climate plays a role, this factor may be overridden by other drivers of local adaptation, such as soil or biotic interactions. Despite assisted migration being a popular concept that is repeatedly commended in scientific literature and propagated among practitioners, it should not be considered a universal tool to improve restoration outcomes during climate change. Given the lack of hard experimental data, I call for large‐scale multispecies experimental studies that will provide the necessary evidence to derive general guidelines and recommendations for management of ecosystems during climate change.