Data for 'topographic controls on stomatal and mesophyll limitations to photosynthesis in two sub-alpine conifers'

Leaf stomatal and mesophyll conductances limit photosynthesis and influence water use efficiency. Few studies have quantified the relative limitations imposed by these CO2 diffusion pathways on photosynthesis in mature conifer trees under natural conditions. Here we report observations on stomatal and mesophyll conductance changes during seasonal drying across contrasting topographic positions in two Rocky Mountain conifers. We predicted that topographic controls on soil water availability and energy balance would determine limitation to photosynthesis by mesophyll conductance across conifer species with contrasting patterns of stomatal and hydraulic traits.