Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season?
Abstract Background Plants have been hypothesized to maintain strong control over xylem tension by closing stomata and to operate at a water potential above or near the critical potential at which cavitation commences. An alternative hypothesis holds that cavitation temporarily relieves water stress...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2018-12-01
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| Series: | Forest Ecosystems |
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| Online Access: | http://link.springer.com/article/10.1186/s40663-018-0158-7 |
| _version_ | 1797966587233304576 |
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| author | Dayong Fan Shouren Zhang Hui Yan Qian Wu Xinwu Xu Xiangping Wang |
| author_facet | Dayong Fan Shouren Zhang Hui Yan Qian Wu Xinwu Xu Xiangping Wang |
| author_sort | Dayong Fan |
| collection | DOAJ |
| description | Abstract Background Plants have been hypothesized to maintain strong control over xylem tension by closing stomata and to operate at a water potential above or near the critical potential at which cavitation commences. An alternative hypothesis holds that cavitation temporarily relieves water stress and stomatal closure is insufficient to prevent short term “run-away” cavitation. Methods The objectives of this study were to investigate the leaf conductivity loss at noon (Loss) of 13 woody species differing in leaf phenology at two sites on karst topography in the wet season in southwestern China; the hydraulic architecture of woody species has rarely been reported previously. Loss was predicted from minimum field leaf water potentials (Ψ min) and laboratory-generated vulnerability curves. We also measured the maximum quantum efficiency of photosystem II using chlorophyll a fluorescence (F v /F m) and other associated leaf traits. Results Loss in the field varied substantially, from 1.39% in evergreen Itea chinensis to 90.07% in deciduous Sapium sebiferum. However, the Loss did not significantly decrease the efficiency of photosystem II. The water potential at which a 50% loss in leaf conductivity occurred (Ψ 50) was not correlated to Ψ min. The co-occurring evergreen and deciduous species differed significantly in some stem hydraulic and associated leaf traits. Deciduous species had higher hydraulic conductance, photosynthetic rate, stomatal conductance, lower cavitation-resistance and minimum water potential than co-occurring evergreen species. Conclusions There was no sign that karst woody species in southwestern China could control xylem tension above the threshold to avoid substantial xylem cavitation in the wet season. There was no association between Loss and F v /F m among the studied species. This “isohydric” regulation behaviour, as well as abundant rainfall in the wet season, may explain why large variations of Loss existed across karst woody species in southwestern China. |
| first_indexed | 2024-04-11T02:17:46Z |
| format | Article |
| id | doaj.art-eb2007902d944235ac08aaf82f367528 |
| institution | Directory Open Access Journal |
| issn | 2197-5620 |
| language | English |
| last_indexed | 2024-04-11T02:17:46Z |
| publishDate | 2018-12-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Forest Ecosystems |
| spelling | doaj.art-eb2007902d944235ac08aaf82f3675282023-01-03T00:52:05ZengKeAi Communications Co., Ltd.Forest Ecosystems2197-56202018-12-015111110.1186/s40663-018-0158-7Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season?Dayong Fan0Shouren Zhang1Hui Yan2Qian Wu3Xinwu Xu4Xiangping Wang5College of Forestry, Beijing Forestry UniversityState Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesState Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesState Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesState Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of SciencesCollege of Forestry, Beijing Forestry UniversityAbstract Background Plants have been hypothesized to maintain strong control over xylem tension by closing stomata and to operate at a water potential above or near the critical potential at which cavitation commences. An alternative hypothesis holds that cavitation temporarily relieves water stress and stomatal closure is insufficient to prevent short term “run-away” cavitation. Methods The objectives of this study were to investigate the leaf conductivity loss at noon (Loss) of 13 woody species differing in leaf phenology at two sites on karst topography in the wet season in southwestern China; the hydraulic architecture of woody species has rarely been reported previously. Loss was predicted from minimum field leaf water potentials (Ψ min) and laboratory-generated vulnerability curves. We also measured the maximum quantum efficiency of photosystem II using chlorophyll a fluorescence (F v /F m) and other associated leaf traits. Results Loss in the field varied substantially, from 1.39% in evergreen Itea chinensis to 90.07% in deciduous Sapium sebiferum. However, the Loss did not significantly decrease the efficiency of photosystem II. The water potential at which a 50% loss in leaf conductivity occurred (Ψ 50) was not correlated to Ψ min. The co-occurring evergreen and deciduous species differed significantly in some stem hydraulic and associated leaf traits. Deciduous species had higher hydraulic conductance, photosynthetic rate, stomatal conductance, lower cavitation-resistance and minimum water potential than co-occurring evergreen species. Conclusions There was no sign that karst woody species in southwestern China could control xylem tension above the threshold to avoid substantial xylem cavitation in the wet season. There was no association between Loss and F v /F m among the studied species. This “isohydric” regulation behaviour, as well as abundant rainfall in the wet season, may explain why large variations of Loss existed across karst woody species in southwestern China.http://link.springer.com/article/10.1186/s40663-018-0158-7Karst forestLeaf conductivity lossLeaf phenologyPhotochemistry efficiency of photosystem II |
| spellingShingle | Dayong Fan Shouren Zhang Hui Yan Qian Wu Xinwu Xu Xiangping Wang Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? Forest Ecosystems Karst forest Leaf conductivity loss Leaf phenology Photochemistry efficiency of photosystem II |
| title | Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? |
| title_full | Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? |
| title_fullStr | Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? |
| title_full_unstemmed | Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? |
| title_short | Do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season? |
| title_sort | do karst woody plants control xylem tension to avoid substantial xylem cavitation in the wet season |
| topic | Karst forest Leaf conductivity loss Leaf phenology Photochemistry efficiency of photosystem II |
| url | http://link.springer.com/article/10.1186/s40663-018-0158-7 |
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