Abstract
Forest composition is critical for its functioning. While global
environmental changes have modified forest composition, it remains
unclear how temporal shifts in functional composition differ across
regions and biomes. Using extensive spatial and long-term forest
inventory data (17,107 plots monitored 1951–2016) across Canada, we
found that functional composition shifted toward fast-growing deciduous
broadleaved trees and higher drought tolerance over time; notably, this
functional shift was more rapid in colder regions (boreal biome).
Further, the functional composition of colder plots shifted toward
drought tolerance more rapidly with rising CO2 than warmer plots
(temperate biome), suggesting the vulnerability of boreal forests
against global environmental changes. Future ecosystem management
practices should consider spatial differences in functional responses to
global environmental change, with attention to boreal forests
experiencing higher rates of warming and compositional changes.