The Role of Biodiversity on the Evaporation of Forests
The Role of Biodiversity on the Evaporation of Forests
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DOI：
10.1007/3-540-26599-6_7
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
D. Baldocchi
中科院分区：
文献类型：
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作者：
D. Baldocchi
在参观植物园或穿过混合物种森林时，人们得到的印象是树木的形式和功能非常多样化。被子植物树的叶子可以是薄的或肉质的，有光泽的，暗的或多毛的。它们可以大也可以小。它们的形状可以是简单的或复合的，线性的或浅裂的，心形的，三角形的，卵形的或椭圆形的，在许多变化的例子中。在茎上，叶子可以成簇排列，成轮排列或从单独的离生叶柄伸出。在水分的调节和运输方面，被子植物的木质部可能在叶片的一侧或两侧有气孔，也可能具有环状多孔木质部（如栎或榆）或弥漫性多孔木质部（如桦或槭）。相比之下，裸子植物要么有针（如松属），要么有鳞（如杜松属）。它们的植物成分可以排列在枝条中，如云杉（Picea spp.），也可以由束状花序上的针群组成，如松树（Pinus spp.）。从这些简单的观察中，人们可以推测生物多样性可能会影响树木的蒸腾速率和它们的年度水分收支。但真的是这样吗？由于物种之间对光能、水和营养物质的相互作用和竞争（如Allen等人，2002年）、进化（Beerling等人，2001年）以及提出问题的空间和时间尺度（Waide等人，1999年），这个简单问题的答案是复杂的。遗传多样性与生物地球化学强迫相结合，产生了生理和形态特征不同的植物物种（Mooney 2001）。一组特定的植物特征有助于在树种之间进行蒸腾排序，因为这些元素影响叶片和植物的能量平衡。例如，通过竞争和进化获得的生物多样性是造成叶片大小、厚度、形状和反射特性等形态差异的原因。这些特征很重要，因为它们影响叶片的空气动力阻力和辐射平衡。生理因素的物种依赖差异通过改变水的需求和供应来影响蒸腾作用。考试-
On visiting an arboretum or walking through a mixed-species forest, an impression one receives is that there is much diversity in the form and function of trees. The leaves of angiosperm trees can be thin or fleshy, shiny, dull, or hairy. They can be large or small. Their shape can be simple or compound, linear or lobed, cordate, deltate, ovate, or elliptical, among many examples of variation. On a stem, the leaves can be grouped in clumps, arranged in whorls or extend from individual isolated petioles. As for the regulation and transport of water, angiosperms may possess stomata on one or both sides of a leaf and have either ring porous (eg, Quercus or Ulmus spp.) or diffuse porous (eg, Betula or Acer spp.) xylem. Gymnosperms, by contrast, have either needles (eg, Pinus spp.) or scales (Junipers spp.). Their phytoelements can be arranged in shoots, as with spruce (Picea spp.), be comprised of groups of needles on fascicles, as with pine (Pinus spp.). From these simple observations, one may surmise that biodiversity could affect rates of transpiration of trees and their annual water budget. But does it? The answer to this simple question is complicated due to interactions and competition among species for light energy, water and nutrients (eg, Allen et al. 2002), evolution (Beerling et al. 2001), and to the space and time scale at which it is asked (Waide et al. 1999). Genetic diversity, combined with biogeochemical forcings, produce plant species that differ in physiological and morphological features (Mooney 2001). A specific set of plant features contributes to a ranking of transpiration among tree species because such elements affect the energy balance of leaves and plants. For example, biodiversity, achieved through competition and evolution, is responsible for morphological differences in leaf size, thickness, shape, and reflective properties. These features are important because they affect the aerodynamic resistance and radiative balance of leaves. Species-dependent differences in physiological factors affect transpiration by altering the demand for and supply of water. For exam-