Assisted Migration is Plausible for a Boreal Tree Species under Climate Change: A Quantitative and Population Genetics Study of Trembling Aspen (Populus tremuloides Michx.) in Western Canada

Authors

Chen Ding, Texas A&M Forest ServiceFollow
Jean S. Brouard, Isabella Point Forestry Ltd.

Document Type

Article

Journal/Book Title/Conference

Ecology and Evolution

Volume

12

Issue

10

Publisher

John Wiley & Sons Ltd.

First Page

1

Last Page

20

Publication Date

10-5-2022

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Abstract

A novel method was tested for improving tree breeding strategies that integrate quantitative and population genetics based on range-wide reciprocal transplant experiments. Five reciprocal common garden tests of Populus tremuloides were investigated including 6450 trees across western Canada focusing on adaptation traits and growth. Both genetic parameters and home-site transplant models were evaluated. We found a genetic trade-off between growth and early spring leaf flush and late fall senescence. Coefficients of phenotypic variation (CVp) of cell lysis (CL), a measure of freezing injury, shrank from 0.28 to 0.10 during acclimation in the fall, and the CVp slope versus the freezing temperature was significantly different from zero (R² = 0.33, p = .02). There was more between-population genetic variation in fall phenology than in spring leaf phenology. We suggest that P. tremuloides demonstrated a discrepancy between the ecological optimum and the physiological optimum minimum winter temperature. The sub-optimal growing condition of P. tremuloides is potentially caused by the warmer ecological optimum than the physiological optimum. Assisted migration and breeding of fast growers to reforest cooler plantation sites can improve productivity. Transferring the study populations to less than 4°C of extreme minimum temperature appears safe for reforestation aligning with the historical recolonization direction of the species. This is equivalent to a 5–10° latitudinal northward movement. Fall frost hardiness is an effective criterion for family selection in the range tested in this study.

Comments

Article published by John Wiley & Sons Ltd. in Ecology and Evolution.

Recommended Citation

Ding, C., and J. S. Brouard. 2022. Assisted migration is plausible for a boreal tree species under climate change: A quantitative and population genetics study of trembling aspen (Populus tremuloides Michx.) in western Canada. Ecology and Evolution 12:e9384.