Diurnal variation in mesophyll conductance and its influence on modelled water-use efficiency in a mature boreal Pinus sylvestris stand.

ABSTRACT: Mesophyll conductance (g_m) is a critical variable for the use of stable carbon isotopes to infer photosynthetic water-use efficiency (WUE). Although g_m is similar in magnitude to stomatal conductance (g_s), it has been measured less often, especially under field conditions and at high temporal resolution. We mounted an isotopic CO₂ analyser on a field photosynthetic gas exchange system to make continuous online measurements of gas exchange and photosynthetic ¹³C discrimination (Δ¹³C) on mature Pinus sylvestris trees. This allowed the calculation of g_m, g_s, net photosynthesis (A_net), and WUE. These measurements highlighted the asynchronous diurnal behaviour of g_m and g_s. W

SUBMITTER: Stangl ZR 

PROVIDER: S-EPMC6612512 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature