A functional trait-based approach to understand community assembly and diversity-productivity relationships over 7 years in experimental grasslands
A functional trait-based approach to understand community assembly and diversity-productivity relationships over 7 years in experimental grasslands
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DOI：
10.1016/j.ppees.2013.02.004
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发表时间：
2013-01-01
影响因子：
3.6
通讯作者：
Schulze, Ernst-Detlef
中科院分区：
文献类型：
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作者：
Roscher, Christiane;Schumacher, Jens;Schulze, Ernst-Detlef
几项多年生物多样性实验表明，物种丰富度与生产力之间存在正相关关系，这种关系随着时间的推移而加强，但控制生产力的机制尚未得到很好的理解。我们使用实验草地（耶拿实验）的混合物含有不同数量的物种（4，8，16和60）和植物功能组（1-4;草，豆科植物，小草本植物，高草本植物），探索模式的变化，功能性状组成以及气候变量作为预测因子的社区生物量生产跨越几年（2003年至2009年）。在这段时间内，高社区平均性状值从与快速增长相关的性状值占主导地位的性状值，这表明保护与生长相关的资源和成功的繁殖。几个生产力相关的性状的手段，社区之间的趋同增加表明，环境过滤和排斥竞争力较弱的物种在社区组装过程中发挥了作用。一个普遍的趋势，增加功能性状的多样性和社区之间的趋同建议生态位分化，通过限制相似性在较长的时间内，类似的机制在社区播种不同的多样性。群落生物量的生产主要解释了几个关键的平均性状（高生长，大种子质量和叶片氮浓度），并在较小程度上由功能多样性的氮素获取策略，功能丰富的多个特征和功能均匀度在光获取特性。物种丰富度的增加，一个非常富有成效的豆科植物（Onobrychis viciifolia）和气候变量的存在解释了一个额外的比例在社区生物量的变化。在一般情况下，随着时间的推移，社区的生物量生产下降，但社区具有较高的功能丰富度在多个特征具有较高的生产力在几年内。我们的研究结果表明，人工维持物种组成的社区内的组装过程最大限度地提高功能多样性，通过生态位分化和排除较弱的竞争对手，从而保持其高生产力的潜力。(C)2013 Elsevier GmbH. All rights reserved.
Several multi-year biodiversity experiments have shown positive species richness-productivity relationships which strengthen over time, but the mechanisms which control productivity are not well understood. We used experimental grasslands (Jena Experiment) with mixtures containing different numbers of species (4, 8, 16 and 60) and plant functional groups (1-4; grasses, legumes, small herbs, tall herbs) to explore patterns of variation in functional trait composition as well as climatic variables as predictors for community biomass production across several years (from 2003 to 2009). Over this time span, high community mean trait values shifted from the dominance of trait values associated with fast growth to trait values suggesting a conservation of growth-related resources and successful reproduction. Increasing between-community convergence in means of several productivity-related traits indicated that environmental filtering and exclusion of competitively weaker species played a role during community assembly. A general trend for increasing functional trait diversity within and convergence among communities suggested niche differentiation through limiting similarity in the longer term and that similar mechanisms operated in communities sown with different diversity. Community biomass production was primarily explained by a few key mean traits (tall growth, large seed mass and leaf nitrogen concentration) and to a smaller extent by functional diversity in nitrogen acquisition strategies, functional richness in multiple traits and functional evenness in light-acquisition traits. Increasing species richness, presence of an exceptionally productive legume species (Onobrychis viciifolia) and climatic variables explained an additional proportion of variation in community biomass. In general, community biomass production decreased through time, but communities with higher functional richness in multiple traits had high productivities over several years. Our results suggest that assembly processes within communities with an artificially maintained species composition maximize functional diversity through niche differentiation and exclusion of weaker competitors, thereby maintaining their potential for high productivity. (C) 2013 Elsevier GmbH. All rights reserved.