Vertical gradients in photosynthetic physiology diverge at the latitudinal range extremes of white spruce.

ABSTRACT: Light availability drives vertical canopy gradients in photosynthetic functioning and carbon (C) balance, yet patterns of variability in these gradients remain unclear. We measured light availability, photosynthetic CO₂  and light response curves, foliar C, nitrogen (N) and pigment concentrations, and the photochemical reflectance index (PRI) on upper and lower canopy needles of white spruce trees (Picea glauca) at the species' northern and southern range extremes. We combined our photosynthetic data with previously published respiratory data to compare and contrast canopy C balance between latitudinal extremes. We found steep canopy gradients in irradiance, photosynthesis and leaf traits at the southern range limit, but a lack of variation across canopy positions at the norther

SUBMITTER: Schmiege SC 

PROVIDER: S-EPMC10092832 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature