Transpiration sensitivity of urban trees in a semi-arid climate is constrained by xylem vulnerability to cavitation
Transpiration sensitivity of urban trees in a semi-arid climate is constrained by xylem vulnerability to cavitation
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DOI：
10.1093/treephys/tps015
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发表时间：
2012-04-01
期刊：
影响因子：
4
通讯作者：
Pataki, Diane E.
中科院分区：
文献类型：
--
作者：
Litvak, Elizaveta;McCarthy, Heather R.;Pataki, Diane E.
建立植物水力特性与蒸腾作用对环境因子（如大气蒸汽压亏缺（D））的响应之间的定量联系，对于提高我们理解植物水分关系的能力至关重要。我们研究了气孔响应D灌溉树木在城市景观的洛杉矶，加州。我们发现了一个很强的线性关系的敏感性树级蒸腾估计从液流（m（T），树蒸腾和ln D之间的关系的斜率）和蒸腾在D = 1千帕（E-Tref），这是类似于以前的调查气孔行为在自然环境中。此外，m（T）与分支的空化脆弱性显著相关（P-50）。虽然m（T）在环孔树种和散孔树种之间似乎没有差异，但m（T）和P-50之间的关系在木材解剖学上是不同的。因此，我们的研究证实了系统的差异，在水的关系，在环与扩散多孔的物种，但这些差异似乎是更强烈的气孔敏感性D和脆弱性空化，而不是气孔敏感性本身之间的关系。
Establishing quantitative links between plant hydraulic properties and the response of transpiration to environmental factors such as atmospheric vapor pressure deficit (D) is essential for improving our ability to understand plant water relations across a wide range of species and environmental conditions. We studied stomatal responses to D in irrigated trees in the urban landscape of Los Angeles, California. We found a strong linear relationship between the sensitivity of tree-level transpiration estimated from sap flux (m(T); slope of the relationship between tree transpiration and ln D) and transpiration at D = 1 kPa (E-Tref) that was similar to previous surveys of stomatal behavior in natural environments. In addition, m(T) was significantly related to vulnerability to cavitation of branches (P-50). While m(T) did not appear to differ between ring- and diffuse-porous species, the relationship between m(T) and P-50 was distinct by wood anatomy. Therefore, our study confirms systematic differences in water relations in ring- versus diffuse-porous species, but these differences appear to be more strongly related to the relationship between stomatal sensitivity to D and vulnerability to cavitation rather than to stomatal sensitivity per se.