Effects of growth temperature on gas exchange of Chamaecyparis formosensis and C. obtusa var. formosana seedlings occupying different ecological niches
Journal
Trees - Structure and Function
Date Issued
2021
Author(s)
Abstract
Key message: The difference in gas exchange between C. formosensis and C. obtusa var. formosana reflects their ecological niches. Elevated growth temperature limited photosynthesis and acclimation of both species to a similar degree. Elevated temperature caused by global warming influences the growth and physiology of trees. Seedlings of Chamaecyparis formosensis and C. obtusa var. formosana were used in this study to understand the influence of high temperature on mountain cloud forest trees. Because seedlings of these two species are dominant in the different ecological niches, C. formosensis dominant in gap while C. obtusa var. formosana under canopy, they might have different gas exchange parameters and different sensitivity to high temperatures. In this study, gas exchange of seedlings of these two species grown in five temperature regimes, 15/13?°C, 20/15?°C, 25/20?°C, 30/25?°C, and 35/30?°C (11/13?h) was compared. In comparison between the two species, C. formosensis had higher?CO2 assimilation rate?(A) and?transpiration rate (E) than C. obtusa var. formosana. In both species, A and stomatal conductance (gs) were reduced by high growth temperature. The CO2 compensation point and relative stomatal limitation of A increased at high temperature but the carboxylation efficiency was not influenced by growth temperature. Therefore, the response of A to growth temperature was influenced more by stomatal conductance than by biochemistry. The optimum temperature for A (Topt) of both cypresses increased with growth temperature but no difference was found between two species. At high leaf temperature, seedlings grown at high temperatures did not have higher A than those grown at low temperatures. Accordingly, the difference in gas exchange between C. formosensis and C. obtusa var. formosana reflects their ecological niches. Elevated temperature limited photosynthesis and acclimation of both species to a similar degree. ? 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Subjects
Carbon dioxide; Carboxylation; Forestry; Gases; Global warming; Growth temperature; Photosynthesis; Value engineering; Carboxylation efficiencies; Compensation points; Elevated temperature; High growth temperatures; Optimum temperature; Stomatal conductance; Stomatal limitations; Temperature limiteds; Ecology
Type
journal article