Influence of temperature and leaf-to-air vapor pressure deficit on net photosynthesis and stomatal conductance in red spruce (Picea rubens).

摘要

The roles of temperature (T) and leaf-to-air vapour pressure deficit (VPD) in regulating net photosynthesis (Anet) and stomatal conductance (Gs) of red spruce (Picea rubens) were investigated in a field study in the Penobscot Experimental Forest, Bradley and Eddington, Maine, and in a controlled environment experiment. Both Anet and Gs exhibited a relatively flat response to temperatures between 16 and 32deg C. Temperatures between 32 and 36deg C markedly decreased both Anet and Gs. Vapour pressure deficits above 2 kPa had significant effects on both Anet and Gs. The influence of VPD on Anet and Gs fit a linear response model and did not interact significantly with T effects.