Below‐ground complementarity effects in a grassland biodiversity experiment are related to deep‐rooting species

作者：Natalie J. Oram, Janneke Ravenek, Kathryn E. Barry, Alexandra Weigelt, Hongmei Chen, Arthur Geßler, Annette Gockele, Hans de Kroon, Jan Willem van der Paauw, Michael Scherer‐Lorenzen, Annemiek E. Smit‐Tiekstra, Jasper van Ruijven, Liesje Mommer · 发表于：Journal of Ecology · 年份：2017 · DOI：10.1111/1365-2745.12877 · 被引用次数：128 · 研究领域：Ecology and Vegetation Dynamics Studies、Soil Carbon and Nitrogen Dynamics、Plant and animal studies

Abstract Below‐ground resource partitioning is often proposed as the underlying mechanism for the positive relationship between plant species richness and productivity. For example, if species have different root distributions, a mixture of plant species may be able to use the available resources more completely than the individual species in a monoculture. However, there is little experimental evidence for differentiation in vertical root distributions among species and its contribution to biodiversity effects. We determined species‐specific root standing biomass over depth using molecular techniques (real‐time qPCR ) in a large grassland biodiversity experiment (one to eight plant species mixtures), in 2 years. Species‐specific root biomass data were used to disentangle the effects of positive interactions between species (complementarity effects) and effects due to dominance of productive species (selection effects) on root biomass in mixtures. In a next step, these biodiversity effects were linked to the diversity of rooting depths and the averaged rooting depth of the community. Root biomass increased with species richness. This was mainly due to positive interactions (the complementarity effect), which increased with species richness below‐ground. In contrast, the selection effect decreased with species richness. Although there was considerable variation in vertical root distribution between species in monocultures, the diversity of rooting strategies did not explain th...