Can Assisted Tree Migration Today Sustain Forest Ecosystem Goods and Services for the Future?
Forest Ecology and Management
Forest managers are exploring options to proactively facilitate forest adaptation to climate change (resistance or resilience) or to introduce species (transition) that are better suited to future climates. Forest managers must have confidence that implementing an assisted migration (AM) transition strategy will maintain a more reliable stream of goods and services than strategies emphasizing resistance or resilience. The outcome of transition strategies can be evaluated with forest landscape models having direct links to climate and atmospheric drivers. We used the LANDIS-II forest landscape model to conduct a simulation experiment in northern Wisconsin (USA) with climate scenarios and AM strategies as treatment factors, and metrics of ecosystem goods and services as response variables. We found that major forest functional types were maintained under some climate change with AM strategies that selected species having similar silvics and site adaptations as existing species but sourced from different climate regions. We also found that AM alone was increasingly unable to maintain ecosystem goods and services (e.g., productivity, wildlife food) with increasing severity of climate change. For instance, total woody biomass, total harvested biomass, and species and age class richness were largely determined by the climate scenario and not AM strategy. Our results suggest that modest changes in climate are likely to enhance species diversity and increase biomass production through longer growing seasons and CO2 fertilization, but that under extreme climate change even the most aggressive AM strategies fail to mitigate the deleterious effects of moisture stress and increased respiration on overall productivity. Where AM strategies were successful, there were subtle and unintended changes in the extent of available landscape goods and services. Additional research is needed to further refine AM strategies to conserve a complete range of goods and services under changing climate.
Gustafson, E. J., Kern, C. C., & Kabrick, J. M. (2023). Can assisted tree migration today sustain forest ecosystem goods and services for the future?. Forest Ecology and Management, 529, 120723.