Soil heterogeneity increases plant diversity after twenty years of manipulation during grassland restoration

The ‘environmental heterogeneity hypothesis’ predicts that variability in resources promotes species coexistence, but few experiments support this hypothesis in plant communities. A previous 15-y test of this hypothesis in a prairie restoration experiment demonstrated a weak effect of manipulated soil resource heterogeneity on plant diversity. This response was attributed to a transient increase in richness following a post-restoration supplemental propagule addition, occasionally higher diversity under nutrient enrichment, and reduced cover of a dominant species in a subset of soil treatments. Here, we report community dynamics under continuous propagule addition in the same experiment, corresponding to 16-20 y of restoration, in response to altered availability and heterogeneity of soil resources. We also quantified traits of newly added species to determine if heterogeneity increases the amount and variety of niches available for new species to exploit. The heterogeneous treatment co...

生境异质性假说（environmental heterogeneity hypothesis）认为资源的异质性可促进物种共存，但鲜有实验能在植物群落中验证该假说。此前一项在草原恢复实验中开展的为期15年的该假说验证研究显示，人为调控的土壤资源异质性对植物多样性的影响微弱。该微弱影响被归因于以下三方面：恢复后补充繁殖体添加所引发的物种丰富度短暂上升、养分富集条件下偶尔出现的更高植物多样性，以及部分土壤处理组中优势物种盖度的降低。本研究依托同一实验平台，报告了对应16至20年恢复时长的持续繁殖体添加条件下的群落动态，以探究土壤资源可用性与异质性改变所带来的影响。本研究同时对新增物种的性状进行了量化分析，以明确异质性是否能够提升可供新物种利用的生态位数量与多样性类型。异质性处理组的……