Leaf size and angle vary widely across species: what consequences for light interception?
Leaf size and angle vary widely across species: what consequences for light interception?
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DOI：
10.1046/j.1469-8137.2003.00765.x
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发表时间：
2003-06-01
期刊：
影响因子：
9.4
通讯作者：
Westoby, M
中科院分区：
文献类型：
--
作者：
Falster, DS;Westoby, M
不同物种的建筑结构差异很大。更陡的叶片角度和增加的自遮阳被认为可以通过减少总光拦截来减少潜在的碳增益。另一种假设是，更陡的叶片角度通过强调从低角度拦截光线来提高全天的碳增益。在这里，我们将结构特性（叶片角度和叶片大小）的变化与发生在澳大利亚森林两个地点的38个多年生物种的叶片展示、光捕获和模拟碳增益的跨物种模式联系起来。通过将3d数字化与建筑模型YPLANT相结合，可以进行建筑比较。叶片角度较浅的物种有较大的日光截获和潜在的较大的碳增益。自遮阳，而不是叶片角度，解释了物种之间在光捕获和潜在碳增益方面的大部分差异。物种平均叶片大小是自遮阳的最重要决定因素。我们的研究结果提供了第一个跨物种的证据，证明更陡的叶片角度可以减少白天暴露在过量光线下的时间，而不仅仅是最大化碳的增加。
Architecture can vary widely across species. Both steeper leaf angles and increased self-shading are thought to reduce potential carbon gain by decreasing total light interception. An alternative hypothesis is that steeper leaf angles have evolved to improve day-long carbon gain by emphasising light interception from low angles.Here we relate variation in architectural properties (leaf angle and leaf size) to cross-species patterns of leaf display, light capture and simulated carbon gain in branching-units of 38 perennial species occurring at two sites in Australian forest. Architectural comparison was made possible by combining 3D-digitising with the architecture model YPLANT.Species with shallow angled leaves had greater daily light interception and potentially greater carbon gain. Self-shading, rather than leaf angle, explained most variance between species in light capture and potential carbon gain. Species average leaf size was the most important determinant of self-shading.Our results provide the first cross-species evidence that steeper leaf angles function to reduce exposure to excess light levels during the middle of the day, more than to maximise carbon gain.