Optimal stomatal conductance in relation to photosynthesis in climatically contrasting Eucalyptus species under drought
Optimal stomatal conductance in relation to photosynthesis in climatically contrasting Eucalyptus species under drought
复制标题
DOI：
10.1111/j.1365-3040.2012.02570.x
复制
发表时间：
2013-02-01
影响因子：
7.3
通讯作者：
Ellsworth, David S.
中科院分区：
文献类型：
--
作者：
Heroult, Arnaud;Lin, Yan-Shih;Ellsworth, David S.
气孔导度（gs）的模型是基于gs和CO2同化（Anet）之间的耦合，通常假设这种关系的斜率（g1）在物种之间是恒定的。然而，如果不同的植物物种适应了不同的水资源获取成本，那么物种之间的g1就会存在差异。我们假设，G1应适应不同的气候物种之间的差异，并测试了理论和植物水力学的联系，使用四种桉树从不同的气候起源在一个共同的花园。最佳气孔理论预测，亚湿润区物种的碳增益边际水成本较低，因此g1比湿润区物种低。在协议的理论，即G1与供水的组织碳成本，我们发现木材密度和G1之间的关系，桉树品种的气候起源的对比。有显着的减少，在干旱期间的参数g1在潮湿，但不亚湿润的物种，后者组保持g1在干旱。有很大的差异，气孔行为之间的相关树种在协议与最佳气孔理论，这些差异是一致的，在水的吸收和运输的碳收益的经济。
Models of stomatal conductance (gs) are based on coupling between gs and CO2 assimilation (Anet), and it is often assumed that the slope of this relationship (g1) is constant across species. However, if different plant species have adapted to different access costs of water, then there will be differences in g1 among species. We hypothesized that g1 should vary among species adapted to different climates, and tested the theory and its linkage to plant hydraulics using four Eucalyptus species from different climatic origins in a common garden. Optimal stomatal theory predicts that species from sub-humid zones have a lower marginal water cost of C gain, hence lower g1 than humid-zone species. In agreement with the theory that g1 is related to tissue carbon costs for water supply, we found a relationship between wood density and g1 across Eucalyptus species of contrasting climatic origins. There were significant reductions in the parameter g1 during drought in humid but not sub-humid species, with the latter group maintaining g1 in drought. There are strong differences in stomatal behaviour among related tree species in agreement with optimal stomatal theory, and these differences are consistent with the economics involved in water uptake and transport for carbon gain.