Species-specific stomatal response of trees to drought - a link to vegetation dynamics?
Species-specific stomatal response of trees to drought - a link to vegetation dynamics?
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DOI：
10.1111/j.1654-1103.2009.05701.x
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发表时间：
2009-06
影响因子：
2.8
通讯作者：
R. Zweifel;A. Rigling;M. Dobbertin
中科院分区：
文献类型：
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作者：
R. Zweifel;A. Rigling;M. Dobbertin
问：气孔调节是否特定于气候和树种，它是否揭示了物种对干旱的特定反应？这与植被动态有联系吗？地点：瑞士内高山干燥河谷。方法：用测得的树枝液流速率与潜在蒸腾速率之比(改进的彭曼-蒙特斯单叶法)连续估算樟子松、毛栎林、杜松林和云杉的气孔开度(θE)，每10分钟一次。结果：θE因气候和物种而异，表现出明显不同的干旱反应：在干旱条件下，气孔松比邻近树种更接近，但当天气相对潮湿和凉爽时，θE比其他树种高。在干旱胁迫下，栎类植物的气孔较开放，但在潮湿条件下，其θE较低。杜松耐旱性最强，而云杉气孔在夏季几乎完全关闭。结论：四个树种在θE方面的不同小气候偏好强烈表明，气候变化正在改变树木的生理表现，从而改变物种的特定竞争力。在所调查的地点，云杉和松树目前生活在它们承受不断上升的温度和干旱强度的生理极限，而栎属和杜松表现明显更好。这至少部分符合区域植被动态：在过去的30年里，松树的数量急剧下降，而栎树的数量却显著增加。我们的结论是，θE提供了一个物种应对当前和预测的气候的能力的指示。
Question: Is stomatal regulation specific for climate and tree species, and does it reveal species-specific responses to drought? Is there a link to vegetation dynamics? Location: Dry inner alpine valley, Switzerland Methods: Stomatal aperture (θE) of Pinus sylvestris, Quercus pubescens, Juniperus communis and Picea abies were continuously estimated by the ratio of measured branch sap flow rates to potential transpiration rates (adapted Penman-Monteith single leaf approach) at 10-min intervals over four seasons. Results: θE proved to be specific for climate and species and revealed distinctly different drought responses: Pinus stomata close disproportionately more than neighbouring species under dry conditions, but has a higher θE than the other species when weather was relatively wet and cool. Quercus keeps stomata more open under drought stress but has a lower θE under humid conditions. Juniperus was most drought-tolerant, whereas Picea stomata close almost completely during summer. Conclusions: The distinct microclimatic preferences of the four tree species in terms of θE strongly suggest that climate (change) is altering tree physiological performances and thus species-specific competitiveness. Picea and Pinus currently live at the physiological limit of their ability to withstand increasing temperature and drought intensities at the sites investigated, whereas Quercus and Juniperus perform distinctly better. This corresponds, at least partially, with regional vegetation dynamics: Pinus has strongly declined, whereas Quercus has significantly increased in abundance in the past 30 years. We conclude that θE provides an indication of a species' ability to cope with current and predicted climate.