Hydraulic properties and drought response of a tropical bamboo(Cephalostachyum pergracile)

Wanwalee Kongjarat ¹Lu Han ¹Amy Ny Aina Aritsara ²Shu-Bin Zhang ²Gao-Juan Zhao ²Yong-Jiang Zhang ³Phisamai Maenpuen ¹Ying-Mei Li ⁴Yi-Ke Zou ¹Ming-Yi Li ⁵Xue-Nan Li ⁶Lian-Bin Tao ⁷Ya-Jun Chen⁸

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作者信息

1. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;University of the Chinese Academy of Sciences,Beijing 100049,China
2. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;T-STAR Core Team,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China
3. School of Biology and Ecology,University of Maine,Orono,ME,USA;Climate Change Institute,University of Maine,Orono,ME 04469,USA
4. School of Biological and Chemical Science,Pu'er University,Xueyuan Road,Yunnan 665000,China
5. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;Institute of Ecology and Geobotany,School of Ecology and Environmental Sciences,Yunnan University,Kunming,Yunnan 650091,China
6. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;School of Ecology and Environment,Southwest Forestry University,Kunming,Yunnan 650224,China
7. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China
8. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;T-STAR Core Team,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yunnan 666303,China;Yuanjiang Savanna Ecosystem Research Station,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Yuanjiang,Yunnan 653300,China
折叠

Abstract

Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the under-lying mechanisms remain unclear.This study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem)estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing curves.Additionally,we investigated the seasonal water potentials,native embolism level(PLC)and xylem water source using stable isotope.We found that C.pergracile exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water loss.Interestingly,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS)to protect the stem from excessive xylem tension.During the dry season,approximately 49％of the water was absorbed from the upper 20-cm-deep soil layer.Consequently,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33％in the wet season to 12.87±4.09％in the dry season were observed.In summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in C.pergracile accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.

Key words

Climate change/Drought/Hydraulic safety/Hydraulic vulnerability segmentation/Stable isotope/Tree mortality

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基金项目

National Natural Science Foundation of China(32071735)

National Natural Science Foundation of China(32371576)

National Natural Science Foundation of China(32350410420)

National Natural Science Foundation of China(41861144016)

National Natural Science Foundation of China(31570406)

CAS'Light of West China'Program()

14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences(E3ZKFF1K)

14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences(E3ZKFF2B)

Yunnan Provincial Science and Technology Department(2018HB068)

Yunnan Revitalization Talents Support Plan(YNWR-QNBJ-2019177)

出版年

2024

植物多样性(英文)

中国科学院昆明植物研究所，中国植物学会

植物多样性(英文)

CSTPCDCSCD

影响因子：0.617

ISSN：2096-2703

参考文献量75

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