The need for a canopy perspective to understand the importance of phenotypic plasticity for promoting species coexistence and light-use complementarity in forest ecosystems
The need for a canopy perspective to understand the importance of phenotypic plasticity for promoting species coexistence and light-use complementarity in forest ecosystems
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DOI：
10.1007/s11284-012-1025-6
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发表时间：
2013-03-01
影响因子：
2
通讯作者：
Nabeshima, Eri
中科院分区：
文献类型：
--
作者：
Ishii, Hiroaki;Azuma, Wakana;Nabeshima, Eri
由于树木的体积比其他生物大得多，树木决定了森林生态系统的结构和能量特性。从草地到森林，叶面积指数决定了光合作用所截获的光能数量，在世界各种陆地生态系统中，叶面积指数随着树冠高度的增加而增加。在垂直发育良好的森林中，生态位分化沿着垂直梯度的光可用性可能会促进物种共存。此外，共存树种之间光合特性的空间和时间差异（功能多样性）可能促进光能的互补利用，从而提高多树种森林的生物量和生产力。树木的进化保持了高度的表型可塑性，因为森林生态系统中资源的空间/时间分布是高度异质性的，树木通过个体发育增加了近1,000倍，从而改变了自己的环境。高表型可塑性可能使树种共存，通过在资源丰富的环境中的分歧，以及通过在资源有限的环境中的收敛。我们建议，个人水平的表型可塑性的广度，在条件等离子体水平（叶和芽），是一个重要的因素，促进物种共存和资源利用的互补性在森林生态系统中。光合作用相关性状的可塑性与林分生产力之间的联系的跨生物群系比较将为森林生态系统物种组合与生产力之间的关系提供功能性解释。
Because of their overwhelming size over other organisms, trees define the structural and energetic properties of forest ecosystems. From grasslands to forests, leaf area index, which determines the amount of light energy intercepted for photosynthesis, increases with increasing canopy height across the various terrestrial ecosystems of the world. In vertically well-developed forests, niche differentiation along the vertical gradient of light availability may promote species coexistence. In addition, spatial and temporal differentiation of photosynthetic traits among the coexisting tree species (functional diversity) may promote complementary use of light energy, resulting in higher biomass and productivity in multi-species forests. Trees have evolved retaining high phenotypic plasticity because the spatial/temporal distribution of resources in forest ecosystems is highly heterogeneous and trees modify their own environment as they increase nearly 1,000 times in size through ontogeny. High phenotypic plasticity may enable coexistence of tree species through divergence in resource-rich environments, as well as through convergence in resource-limited environments. We propose that the breadth of individual-level phenotypic plasticity, expressed at the metamer level (leaves and shoots), is an important factor that promotes species coexistence and resource-use complementarity in forest ecosystems. A cross-biome comparison of the link between plasticity of photosynthesis-related traits and stand productivity will provide a functional explanation for the relationship between species assemblages and productivity of forest ecosystems.