Prediction of temperate broadleaf tree species mortality in arid limestone habitats with stomatal safety margins
Prediction of temperate broadleaf tree species mortality in arid limestone habitats with stomatal safety margins
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具有气孔安全裕度的干旱石灰岩生境中温带阔叶树种死亡率的预测
DOI：
10.1093/treephys/tpz045
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发表时间：
2019-08-01
期刊：
影响因子：
4
通讯作者：
Liu, Shirong
中科院分区：
文献类型：
--
作者：
Chen, Zhicheng;Li, Shan;Liu, Shirong
越来越多的证据表明，在气候变化相关的严重干旱期间，树木死亡率普遍增加;然而，在自然环境中，用多物种群落进行的预测树木死亡率和探索相关机制的原位长期干旱实验相当有限。在我国北方干旱的石灰岩生境中，选择20个抗旱阔叶树种进行了为期7年的造林试验。测定了所有树种的气孔和木质部水力性状。研究发现，气孔关闭点与树种的木质部栓塞抗性和木质部最低水势密切相关，但与树种的存活率无关。水力破坏的维管系统似乎是树木死亡的主要原因，气孔安全裕度是一个更好的预测树木死亡率比传统上认为的木质部栓塞阻力和水力安全裕度。建议将气孔安全裕度作为干旱区树木死亡率预测和造林树种选择的指标。
A growing body of evidence highlights the occurrence of increased widespread tree mortality during climate change-associated severe droughts; however, in situ long-term drought experiments with multispecies communities for the prediction of tree mortality and exploration of related mechanisms are rather limited in natural environments. We conducted a 7-year afforestation trial with 20 drought-resistant broadleaf tree species in an arid limestone habitat in northern China, where the species displayed a broad range of survival rates. The stomatal and xylem hydraulic traits of all the species were measured. We found that species' stomatal closure points were strongly related to their xylem embolism resistance and xylem minimum water potential but not to their survival rates. Hydraulic failure of the vascular system appeared to be the main cause of tree mortality, and the stomatal safety margin was a better predictor of tree mortality than the traditionally considered xylem embolism resistance and hydraulic safety margin. We recommend the stomatal safety margin as the indicator for predicting drought-induced tree mortality and for selecting tree species in future forest restorations in arid regions.