Optimization of leaf morphology in relation to leaf water status: A theory
Optimization of leaf morphology in relation to leaf water status: A theory
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DOI：
10.1002/ece3.6004
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发表时间：
2020-01-22
影响因子：
2.6
通讯作者：
Martin, Yvonne E.
中科院分区：
文献类型：
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作者：
Ding, Junyan;Johnson, Edward A.;Martin, Yvonne E.
叶面积、最大碳同化率、脉序等叶经济性状与水分有效性相关。此外，在潮湿地区，叶子通常又宽又大，而在干旱/半干旱以及炎热和寒冷地区，叶子通常又窄又窄。我们使用最优化理论来解释这些模式。我们已经创建了一个约束优化叶片模型，将叶片形状与叶脉结构联系起来，并将其集成到耦合的蒸腾作用和碳同化过程中。该模型最大限度地提高净叶碳增益（NPPleaf）超过木质部水势的损失。叶性状之间的模型关系与经验观察到的模式是一致的。作为叶片形状-脉序关系的结果，我们的模型进一步预测，阔叶树具有总体较高的NPPleaf相比，窄叶。此外，在相同的限制条件下，阔叶植物的气孔阻力低于窄叶植物。在叶面积相同的情况下，阔叶树平均而言具有较大的导管和较低的总叶木质部阻力，因此在水分运输方面更有效，但对空化的抗性较低。该模型将叶片的脉序结构与叶片形状联系起来，并以水势为约束条件，通过叶片水力设计的安全-效率权衡，对叶片性状协方差的一般规律提供了物理解释。
The leaf economic traits such as leaf area, maximum carbon assimilation rate, and venation are all correlated and related to water availability. Furthermore, leaves are often broad and large in humid areas and narrower in arid/semiarid and hot and cold areas. We use optimization theory to explain these patterns. We have created a constrained optimization leaf model linking leaf shape to vein structure that is integrated into coupled transpiration and carbon assimilation processes. The model maximizes net leaf carbon gain (NPPleaf) over the loss of xylem water potential. Modeled relations between leaf traits are consistent with empirically observed patterns. As the results of the leaf shape-venation relation, our model further predicts that a broadleaf has overall higher NPPleaf compared to a narrowleaf. In addition, a broadleaf has a lower stomatal resistance compared to a narrowleaf under the same level of constraint. With the same leaf area, a broadleaf will have, on average, larger conduits and lower total leaf xylem resistance and thus be more efficient in water transportation but less resistant to cavitation. By linking venation structure to leaf shape and using water potential as the constraint, our model provides a physical explanation for the general pattern of the covariance of leaf traits through the safety-efficiency trade-off of leaf hydraulic design.