Stomata Are Driving the Direction of CO 2 -Induced Water-Use Efficiency Gain in Selected Tropical Trees in Fiji.

Autor: Soh WK; National Botanic Gardens (OPW), Glasnevin, D09 VY63 Dublin, Ireland., Yiotis C; Department of Biological Applications and Technology, University of Ioannina, 45110 Ioannina, Greece., Murray M; Department of Botany, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, D02 PN40 Dublin, Ireland., Pene S; School of Geography, Earth Science and Environment, University of the South Pacific, Laucala Campus, Suva 679, Fiji., Naikatini A; Forest Research Division, Colo-i-Suva Station, Ministry of Forestry, Suva 679, Fiji., Dornschneider-Elkink JA; School of Politics and International Relations, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland., White JD; Department of Biology, Baylor University, Waco, TX 76798, USA., Tuiwawa M; South Pacific Regional Herbarium, University of the South Pacific, Laucala Campus, Suva 679, Fiji., McElwain JC; Department of Botany, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2, D02 PN40 Dublin, Ireland.
Jazyk: angličtina
Zdroj: Biology [Biology (Basel)] 2024 Sep 19; Vol. 13 (9). Date of Electronic Publication: 2024 Sep 19.
DOI: 10.3390/biology13090733
Abstrakt: Understanding plant physiological response to a rising atmospheric CO 2 concentration ( c a ) is key in predicting Earth system plant-climate feedbacks; however, the effects of long-term rising c a on plant gas-exchange characteristics in the tropics are largely unknown. Studying this long-term trend using herbarium records is challenging due to specimen trait variation. We assessed the impact of a c a rise of ~95 ppm (1927-2015) on the intrinsic water-use efficiency (iWUE) and maximum stomatal conductance ( g smax ) of five tropical tree species in Fiji using the isotopic composition and stomatal traits of herbarium leaves. Empirical results were compared with simulated values using models that uniquely incorporated the variation in the empirical g smax responses and species-specific parameterisation. The magnitude of the empirical iWUE and g smax response was species-specific, ranging from strong to negligible. Stomatal density was more influential than the pore size in determining the g smax response to c a . While our simulation results indicated that photosynthesis is the main factor contributing to the iWUE gain, stomata were driving the iWUE trend across the tree species. Generally, a stronger increase in the iWUE was accompanied by a stronger decline in stomatal response. This study demonstrates that the incorporation of variation in the g smax in simulations is necessary for assessing an individual species' iWUE response to changing c a .
Databáze: MEDLINE
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