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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Frontiers Media S.A.
2022-09-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2022.974745/full |
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| author | Xue Dai Xue Dai Xue Dai Zhongbo Yu Zhongbo Yu Zhongbo Yu Ashley M. Matheny Wei Zhou Wei Zhou Wei Zhou Jun Xia |
| author_facet | Xue Dai Xue Dai Xue Dai Zhongbo Yu Zhongbo Yu Zhongbo Yu Ashley M. Matheny Wei Zhou Wei Zhou Wei Zhou Jun Xia |
| author_sort | Xue Dai |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-12-10T12:58:06Z |
| format | Article |
| id | doaj.art-302b769d00444563b98408222226b776 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-10T12:58:06Z |
| publishDate | 2022-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-302b769d00444563b98408222226b7762022-12-22T01:48:01ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2022-09-011310.3389/fpls.2022.974745974745Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateauXue Dai0Xue Dai1Xue Dai2Zhongbo Yu3Zhongbo Yu4Zhongbo Yu5Ashley M. Matheny6Wei Zhou7Wei Zhou8Wei Zhou9Jun Xia10State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, ChinaJoint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing, ChinaCollege of Hydrology and Water Resources, Hohai University, Nanjing, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, ChinaJoint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing, ChinaCollege of Hydrology and Water Resources, Hohai University, Nanjing, ChinaDepartment of Geological Sciences, University of Texas at Austin, Austin, TX, United StatesState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, ChinaJoint International Research Laboratory of Global Change and Water Cycle, Hohai University, Nanjing, ChinaCollege of Hydrology and Water Resources, Hohai University, Nanjing, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, ChinaPlant 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.https://www.frontiersin.org/articles/10.3389/fpls.2022.974745/fullvegetation coverclimate changeevapotranspirationTibetan Plateaudecoupling |
| spellingShingle | Xue Dai Xue Dai Xue Dai Zhongbo Yu Zhongbo Yu Zhongbo Yu Ashley M. Matheny Wei Zhou Wei Zhou Wei Zhou Jun Xia Increasing evapotranspiration decouples the positive correlation between vegetation cover and warming in the Tibetan plateau Frontiers in Plant Science vegetation cover climate change evapotranspiration Tibetan Plateau decoupling |
| 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 | vegetation cover climate change evapotranspiration Tibetan Plateau decoupling |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2022.974745/full |
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