Influence of four major plant traits on average height, leaf-area cover, net primary productivity, and biomass density in single-species forests: a theoretical investigation
Influence of four major plant traits on average height, leaf-area cover, net primary productivity, and biomass density in single-species forests: a theoretical investigation
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DOI：
10.1111/j.1365-2745.2010.01735.x
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发表时间：
2011-01-01
影响因子：
5.5
通讯作者：
Westoby, Mark
中科院分区：
文献类型：
--
作者：
Falster, Daniel S.;Brannstrom, Ake;Westoby, Mark
P>1。已知许多植物性状会影响个体性能的各个方面，包括碳吸收率、组织更新率、死亡率和繁殖力。这些特征必然会影响植被的新兴特性，因为叶面积覆盖、平均高度、初级生产力和生物量密度等数量是由个体的集体行为产生的。然而，尽管植物功能类型的植被模型广泛使用，并且每种功能类型都是由一系列性状定义的，但人们对个体性状对这些新兴特性的影响知之甚少。2．我们研究了四个关键性状（叶子经济策略、成熟高度、木材密度和种子大小）对四个新兴植被特性（叶面积平均高度、叶面积指数、净初级生产力和生物量密度）的影响。我们采用特征、大小和斑块结构的植被动态模型，允许从个体水平的生长过程和概率干扰扩展到景观水平的预测。根据已知的经验模式设计和校准了包含相关权衡的生理生长模型。由此产生的植被模型自然地表现出植被动态中常见的一系列现象。 3．我们对单一物种林地进行了建模，在其已知的经验范围内改变每个特征。种子大小对植被特性的影响很小，主要是因为我们的集合种群不受种子限制。其余性状均对植被特性有较大影响，尤其是对生物量密度的影响。叶片经济策略影响最低光照需求，从而影响总叶面积和断面积。成熟时的木材密度和高度主要通过改变个体茎质量来影响植被。这些性状的影响在生产力和平均扰动间隔不同的林分中得以维持，有时甚至被放大。4．综合：自然性状变异会导致植被的突现特性发生巨大差异，其程度接近因场地生产力和干扰频率的变化而产生的差异。因此，我们的结果强调需要下一代植被模型，该模型将功能特征及其对植被斑块和大小结构的影响结合起来。
P>1. Numerous plant traits are known to influence aspects of individual performance, including rates of carbon uptake, tissue turnover, mortality and fecundity. These traits are bound to influence emergent properties of vegetation because quantities such as leaf-area cover, average height, primary productivity and density of standing biomass result from the collective behaviour of individuals. Yet, little is known about the influence of individual traits on these emergent properties, despite the widespread use in current vegetation models of plant functional types, each of which is defined by a constellation of traits.2. We examine the influence of four key traits (leaf economic strategy, height at maturation, wood density, and seed size) on four emergent vegetation properties (average height of leaf area, leaf-area index, net primary productivity and biomass density). We employ a trait-, size- and patch-structured model of vegetation dynamics that allows scaling up from individual-level growth processes and probabilistic disturbances to landscape-level predictions. A physiological growth model incorporating relevant trade-offs was designed and calibrated based on known empirical patterns. The resulting vegetation model naturally exhibits a range of phenomena commonly observed in vegetation dynamics.3. We modelled single-species stands, varying each trait over its known empirical range. Seed size had only a small effect on vegetation properties, primarily because our metapopulations were not seed-limited. The remaining traits all had larger effects on vegetation properties, especially on biomass density. Leaf economic strategy influenced minimum light requirement, and thus total leaf area and basal area. Wood density and height at maturation influenced vegetation mainly by modifying individual stem mass. These effects of traits were maintained, and sometimes amplified, across stands differing in productivity and mean disturbance interval.4. Synthesis: Natural trait variation can cause large differences in emergent properties of vegetation, the magnitudes of which approach those arising through changes to site productivity and disturbance frequency. Our results therefore underscore the need for next-generation vegetation models that incorporate functional traits together with their effects on the patch and size structure of vegetation.