Aims

The positive effects of spatial heterogeneity in soil nutrients on plant performance have been well documented, but whether such effects depend on the presence of soil biota or the substrate type in which the heterogeneity is manipulated remains largely unknown.

Methods

In a greenhouse experiment, we grew the rhizomatous clonal grass Leymus chinensis in three different substrates (i.e., field soil, potting soil, and mixtures of ceramsite and quartz) that were subjected to two different soil nutrient treatments (i.e., a homogeneous treatment and a heterogeneous treatment consisting of low- and high-nutrient soil patches) and inoculated with either live or sterilized soil biota.

Results

In the presence of the live soil biota, L. chinensis produced more biomass in the homogeneous than in the heterogeneous treatment, independent of the substrate type. With the sterilized soil biota, however, L. chinensis produced more biomass in the heterogeneous than in the homogeneous treatment. In the heterogeneous treatment consisting of the field soil and the potting soil, L. chinensis produced more biomass in the high-nutrient patches than in the low-nutrient patches. In contrast, it produced more biomass in the low-nutrient patches than in the high-nutrient patches in the heterogeneous treatment consisting of the field soil and the mixture of quartz and ceramsite.

Conclusions

Both soil biota and soil substrates can influence the responses of clonal plants to soil nutrient heterogeneity. Our results highlight the vital importance of including soil biota and soil physical properties in studies designed to examine the effects of soil nutrient heterogeneity on plant performance, population dynamics, species coexistence and ecosystem functioning.

中文翻译：

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土壤生物区系和土壤基质影响根瘤菌克隆草羊草对养分异质性的响应

目的

土壤养分中空间异质性对植物生长的积极影响已得到充分证明，但是这种影响是否取决于土壤生物区系的存在或操纵异质性的基质类型仍然未知。

方法

在温室实验中，我们在三种不同的基质（即田间土壤，盆栽土壤以及陶粒和石英的混合物）上种植了根茎无性系羊草（Leymus chinensis），并对其进行了两种不同的土壤养分处理（即均质处理和土壤处理）。异种处理，包括低养分和高养分的土壤斑块，并接种活的或无菌的土壤生物区系。

结果

在实况土壤生物的存在，羊草产生在均质更多的生物量比在多相处理，独立衬底的类型。然而，对于无菌土壤生物区系而言，中华绒螯蟹在异质性土壤中产生的生物量要高于均质处理。在由田间土壤和盆栽土壤组成的异质处理中，中华绒螯蟹在高养分斑块中产生的生物量要多于低养分斑块中的生物量。相反，在由田间土壤以及石英和陶粒的混合物组成的异质处理中，低养分斑块产生的生物量高于高养分斑块。

结论

土壤生物区系和土壤基质都可以影响克隆植物对土壤养分异质性的响应。我们的研究结果突出表明，在旨在检查土壤养分异质性对植物性能，种群动态，物种共存和生态系统功能的影响的研究中，将土壤生物区系和土壤物理特性纳入研究至关重要。