Functional composition rather than species richness determines root characteristics of experimental grasslands grown at different light and nutrient availability
Functional composition rather than species richness determines root characteristics of experimental grasslands grown at different light and nutrient availability
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DOI：
10.1007/s11104-016-2853-x
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发表时间：
2016-03
期刊：
影响因子：
4.9
通讯作者：
Alrun Siebenkäs;C. Roscher
中科院分区：
文献类型：
--
作者：
Alrun Siebenkäs;C. Roscher
背景和目的许多生物多样性实验的结果已经证实了多样性对地上植物生产力的积极影响。然而，植物多样性与地下植物群落特征之间的关系及其在变化的环境条件下的一致性却知之甚少。方法在田间试验中，在交叉光照和施肥水平下，种植了由4个多年生温带草地物种组成的两个独立的池，每个池分别代表两个功能群(草、杂草)和两个生长状态(高、小)的两种和四种混交种。结果物种丰富度的增加和施肥量的增加不影响地下部分的特征。遮荫降低了立根生物量，影响了根系形态特征。不同功能组成的群落在不同的资源利用率下，根系生物量和根长密度在深度剖面和根系形态性状上的垂直分布是不同的，遮荫与施肥结合时，差异部分增大。结论植物物种丰富度与资源利用率无关，不会增加根系垂直分离度，但当不同根型和根系形态性状的物种混合在一起时，地下资源的互补利用潜力增加。
Background and aimsResults from many biodiversity experiments have established evidence for positive effects of diversity on aboveground plant productivity. However, less is known about the relationships between plant diversity and belowground plant community characteristics and their consistency at altered environmental conditions.MethodsMonocultures, two- and four-species mixtures of two independent pools of four perennial temperate grassland species, each representing two functional groups (grasses, forbs) and two growth statures (tall, small), were grown in a field experiment at crossed levels of light and fertilization. Standing root biomass and root morphological traits were studied in the second year of treatment applications.ResultsIncreased species richness or fertilization did not influence belowground characteristics. Shading decreased standing root biomass and affected root morphological characteristics. The vertical distribution of standing root biomass and root length density over the depth profile and root morphological traits differed in communities of varying functional composition irrespective of resource availability, and differences were partly increased when shading was combined with fertilization.ConclusionsIndependent of resource availability, plant species richness does not increase vertical root segregation, but the potential for complementary use of belowground resources increases when species with different rooting patterns and root morphological traits are combined in mixtures.