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Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau

Plant growth generally responds positively to an increase in ambient temperature. Hence, most Earth system models project a continuous increase in vegetation cover in the future due to elevated temperatures. Over the last 40 years, a considerable warming trend has affected the alpine ecosystem acros...

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Autores principales: Dai, Xue, Yu, Zhongbo, Matheny, Ashley M., Zhou, Wei, Xia, Jun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9537816/
https://www.ncbi.nlm.nih.gov/pubmed/36212321
http://dx.doi.org/10.3389/fpls.2022.974745
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author Dai, Xue
Yu, Zhongbo
Matheny, Ashley M.
Zhou, Wei
Xia, Jun
author_facet Dai, Xue
Yu, Zhongbo
Matheny, Ashley M.
Zhou, Wei
Xia, Jun
author_sort Dai, Xue
collection PubMed
description Plant growth generally responds positively to an increase in ambient temperature. Hence, most Earth system models project a continuous increase in vegetation cover in the future due to elevated temperatures. Over the last 40 years, a considerable warming trend has affected the alpine ecosystem across the Tibetan Plateau. However, we found vegetation growth in the moderately vegetated areas of the plateau were negatively related to the warming temperatures, thus resulting in a significant degradation of the vegetative cover (LAI: slope = −0.0026 per year, p < 0.05). The underlying mechanisms that caused the decoupling of the relationship between vegetation growth and warming in the region were elaborated with the analysis of water and energy variables in the ecosystem. Results indicate that high temperatures stimulated evapotranspiration and increased the water consumption of the ecosystem (with an influence coefficient of 0.34) in these degrading areas, significantly reducing water availability (with an influence coefficient of −0.68) and limiting vegetation growth. Moreover, the negative warming effect on vegetation was only observed in the moderately vegetated areas, as evapotranspiration there predominantly occupied a larger proportion of available water (compared to the wet and highly vegetated areas) and resulted in a greater increase in total water consumption in a warmer condition (compared to dry areas with lower levels of vegetation cover). These findings highlight the risk of vegetation degradation in semi-arid areas, with the degree of vulnerability depending on the level of vegetation cover. Furthermore, results demonstrate the central role of evapotranspiration in regulating water stress intensity on vegetation under elevated temperatures.
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spelling pubmed-95378162022-10-08 Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau Dai, Xue Yu, Zhongbo Matheny, Ashley M. Zhou, Wei Xia, Jun Front Plant Sci Plant Science Plant growth generally responds positively to an increase in ambient temperature. Hence, most Earth system models project a continuous increase in vegetation cover in the future due to elevated temperatures. Over the last 40 years, a considerable warming trend has affected the alpine ecosystem across the Tibetan Plateau. However, we found vegetation growth in the moderately vegetated areas of the plateau were negatively related to the warming temperatures, thus resulting in a significant degradation of the vegetative cover (LAI: slope = −0.0026 per year, p < 0.05). The underlying mechanisms that caused the decoupling of the relationship between vegetation growth and warming in the region were elaborated with the analysis of water and energy variables in the ecosystem. Results indicate that high temperatures stimulated evapotranspiration and increased the water consumption of the ecosystem (with an influence coefficient of 0.34) in these degrading areas, significantly reducing water availability (with an influence coefficient of −0.68) and limiting vegetation growth. Moreover, the negative warming effect on vegetation was only observed in the moderately vegetated areas, as evapotranspiration there predominantly occupied a larger proportion of available water (compared to the wet and highly vegetated areas) and resulted in a greater increase in total water consumption in a warmer condition (compared to dry areas with lower levels of vegetation cover). These findings highlight the risk of vegetation degradation in semi-arid areas, with the degree of vulnerability depending on the level of vegetation cover. Furthermore, results demonstrate the central role of evapotranspiration in regulating water stress intensity on vegetation under elevated temperatures. Frontiers Media S.A. 2022-09-23 /pmc/articles/PMC9537816/ /pubmed/36212321 http://dx.doi.org/10.3389/fpls.2022.974745 Text en Copyright © 2022 Dai, Yu, Matheny, Zhou and Xia. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Dai, Xue
Yu, Zhongbo
Matheny, Ashley M.
Zhou, Wei
Xia, Jun
Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title_full Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title_fullStr Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title_full_unstemmed Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title_short Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau
title_sort increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the tibetan plateau
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9537816/
https://www.ncbi.nlm.nih.gov/pubmed/36212321
http://dx.doi.org/10.3389/fpls.2022.974745
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