The role of demographic compensation in stabilising marginal tree populations in North America

Ecol Lett. 2022 Jul;25(7):1676-1689. doi: 10.1111/ele.14028. Epub 2022 May 22.

Abstract

Demographic compensation-the opposing responses of vital rates along environmental gradients-potentially delays anticipated species' range contraction under climate change, but no consensus exists on its actual contribution. We calculated population growth rate (λ) and demographic compensation across the distributional ranges of 81 North American tree species and examined their responses to simulated warming and tree competition. We found that 43% of species showed stable population size at both northern and southern edges. Demographic compensation was detected in 25 species, yet 15 of them still showed a potential retraction from southern edges, indicating that compensation alone cannot maintain range stability. Simulated climatic warming caused larger decreases in λ for most species and weakened the effectiveness of demographic compensation in stabilising ranges. These findings suggest that climate stress may surpass the limited capacity of demographic compensation and pose a threat to the viability of North American tree populations.

Keywords: demoraphic compensation; integral projection model; plant demography; population growth rate; range limit; vital rate.

Publication types

  • Letter

MeSH terms

  • Climate Change*
  • North America
  • Population Dynamics
  • Population Growth
  • Trees*