Ecological analysis of intraspecific variability of eastern white pine (Pinus strobus) under climate change by combining provenance and demographic data

Context: Many forest tree species are composed of a gradient of populations adapted to different environmental segments, especially to temperature gradients. Therefore, populations are likely to respond differently to climate change compared to the entire species. Objectives: Using Pinus strobus as an example, we model geographic patterns of growth potential and habitat suitability to understand how intraspecific genetic variation affects its response under climate change, and facilitate management. Methods: We model populations’ growth potential based on data from provenance tests and delineate three intraspecific regions: cold, middle, and warm. We predict climatic habitat suitability by modelling relative abundance for each of the intraspecific regions for current and future climates. Finally, we combine habitat suitability with growth potential and explore how combinations of these two can be used to match genotypes and climate. Results: Suitable combinations of habitat quality and growth potential shift from the US to Canada in the future, especially under the RCP 8.5 scenario, although the Northeast states retain desirable combinations of both. The main contributors to the future abundance and productivity are populations from the middle region, followed by those from the warm region. Future suitable habitats for populations in the cold region show the most decline, supporting the need for more management of these populations. Conclusions: By delineating homogeneous population groups into three intraspecific regions, and considering both habitat suitability and growth potential, our analysis evaluates potential future changes for eastern white pine, including assisted migration, to facilitate better management of this commercially and ecologically important species.