Weak tradeoff between xylem hydraulic efficiency and safety: climatic seasonality matters
Weak tradeoff between xylem hydraulic efficiency and safety: climatic seasonality matters
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木质部水力效率和安全性之间的弱权衡：气候季节性很重要
DOI：
10.1111/nph.16940
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发表时间：
2020-10-15
期刊：
影响因子：
9.4
通讯作者：
Yin, Deyi
中科院分区：
文献类型：
--
作者：
Liu, Hui;Ye, Qing;Yin, Deyi
一个经典的理论提出，植物木质部不能既高效的水运输和抗栓塞，因此，水力效率安全权衡应该存在。然而，权衡是弱的，许多物种表现出低效率和低安全性，落在预期的权衡空间之外。目前还不清楚在什么样的气候条件下，这些物种可以保持竞争力的健身。我们汇编了来自全球178个站点的499种木本植物的682个观测结果的水力效率和安全特性，并测量了每个观测结果在建议的权衡空间内的位置。对于被子植物和裸子植物，从高气候季节性，特别是降水季节性的网站的观测，往往有更高的水力安全和效率比低的季节性网站的观测。具体而言，高蒸汽压赤字，高太阳辐射，以及雨季降水量少是驱动因素。强烈的气候季节性和干旱在干旱和潮湿的季节似乎是生态过滤器，选择与共同优化的安全和效率的物种，而相反的环境条件可能允许低效率和安全的植物的存在。
A classic theory proposes that plant xylem cannot be both highly efficient in water transport and resistant to embolism, and therefore a hydraulic efficiency-safety trade-off should exist. However, the trade-off is weak, and many species exhibit both low efficiency and low safety, falling outside of the expected trade-off space. It remains unclear under what climatic conditions these species could maintain competitive fitness. We compiled hydraulic efficiency and safety traits for 682 observations of 499 woody species from 178 sites world-wide and measured the position of each observation within the proposed trade-off space. For both angiosperms and gymnosperms, observations from sites with high climatic seasonality, especially precipitation seasonality, tended to have higher hydraulic safety and efficiency than observations from sites with low seasonality. Specifically, high vapour pressure deficit, high solar radiation, and low precipitation during the wet season were driving factors. Strong climatic seasonality and drought in both dry and wet seasons appear to be ecological filters that select for species with co-optimized safety and efficiency, whereas the opposite environmental conditions may allow the existence of plants with low efficiency and safety.