Changes in biomass allocation buffer low CO₂ effects on tree growth during the last glaciation.

ABSTRACT: Isotopic measurements on junipers growing in southern California during the last glacial, when the ambient atmospheric [CO₂] (c_a) was ~180 ppm, show the leaf-internal [CO₂] (c_i) was approaching the modern CO₂ compensation point for C₃ plants. Despite this, stem growth rates were similar to today. Using a coupled light-use efficiency and tree growth model, we show that it is possible to maintain a stable c_i/c_a ratio because both vapour pressure deficit and temperature were decreased under glacial conditions at La Brea, and these have compensating effects on the c_i/c_a ratio. Reduced photorespiration at lower temperatures would partly mitigate the effect of low c_i on gross

SUBMITTER: Li G 

PROVIDER: S-EPMC5324044 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature