Legume species differ in the responses of their functional traits to plant diversity
Legume species differ in the responses of their functional traits to plant diversity
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DOI：
10.1007/s00442-010-1735-9
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发表时间：
2011-02-01
期刊：
影响因子：
2.7
通讯作者：
Schulze, Ernst-Detlef
中科院分区：
文献类型：
--
作者：
Roscher, Christiane;Schmid, Bernhard;Schulze, Ernst-Detlef
植物可以通过功能性状的变化来应对环境影响，从而提高其相对于邻居的性能。我们假设性状调整也应该针对生物环境的影响而发生，特别是群落不同植物多样性的影响。我们以12种豆科植物为模型，在不同植物种类（1、2、4、8、16和60）和功能群（1-4）数量的实验草地上评估了它们在形态、生理、生活史和性能特征方面的变化。平均性状值及其对植物多样性的响应变化因豆科物种和性状而异。生长较高的红豆草 (Onobrychis viciifolia) 对植物多样性的增加几乎没有表现出性状变化，而身材较短的物种则以明显的适应性方式做出反应。节间更长的芽的形成、以叶质量为代价增加支持组织的生物量分配、减少分枝、更高的比叶面积和更低的叶δ C-13 值表明在更多样化的群落中增加了获取光的努力。尽管叶片氮浓度和地上部生物量：氮比不受植物多样性增加的影响，但大多数豆科植物的叶三角洲 N-15 值下降，并且 N-15 自然丰度方法的应用表明它们变得更加依赖共生 N-2 固定。随着群落多样性的增加，一些物种形成较少的花序并延迟开花。观察到的功能性状变化通常表明豆科植物优化光和养分捕获的策略，但它们在很大程度上取决于物种，并且仅部分归因于随着植物多样性的增加而增加的冠层高度和群落生物量。因此，分析单个植物物种及其对植物多样性增加群落中生长条件的调整对于更深入地了解生物多样性与生态系统功能关系背后的机制至关重要。
Plants can respond to environmental impacts by variation in functional traits, thereby increasing their performance relative to neighbors. We hypothesized that trait adjustment should also occur in response to influences of the biotic environment, in particular different plant diversity of the community. We used 12 legume species as a model and assessed their variation in morphological, physiological, life-history and performance traits in experimental grasslands of different plant species (1, 2, 4, 8, 16 and 60) and functional group (1-4) numbers. Mean trait values and their variation in response to plant diversity varied among legume species and from trait to trait. The tall-growing Onobrychis viciifolia showed little trait variation in response to increasing plant diversity, whereas the species with shorter statures responded in apparently adaptive ways. The formation of longer shoots with elongated internodes, increased biomass allocation to supporting tissue at the cost of leaf mass, reduced branching, higher specific leaf areas and lower foliar delta C-13 values indicated increasing efforts for light acquisition in more diverse communities. Although leaf nitrogen concentrations and shoot biomass:nitrogen ratios were not affected by increasing plant diversity, foliar delta N-15 values of most legumes decreased and the application of the N-15 natural abundance method suggested that they became more reliant on symbiotic N-2 fixation. Some species formed fewer inflorescences and delayed flowering with increasing community diversity. The observed variation in functional traits generally indicated strategies of legumes to optimize light and nutrient capturing, but they were largely species-dependent and only partly attributable to increasing canopy height and community biomass with increasing plant diversity. Thus, the analysis of individual plant species and their adjustment to growth conditions in communities of increasing plant diversity is essential to get a deeper insight into the mechanisms behind biodiversity-ecosystem functioning relationships.