Soil heterogeneity affects ramet placement of Hydrocotyle vulgaris
Soil heterogeneity affects ramet placement of Hydrocotyle vulgaris
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土壤异质性影响水生植物的分株布局
DOI：
10.1093/jpe/rtu003
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发表时间：
2015-02-01
影响因子：
2.7
通讯作者：
Yu, Fei-Hai
中科院分区：
文献类型：
--
作者：
Dong, Bi-Cheng;Wang, Jiu-Zhong;Yu, Fei-Hai
目的土壤异质性在自然生境中很常见。它可能引发觅食反应（在营养丰富的斑块中放置更多的株和/或根，而不是在营养贫乏的斑块中），并进一步影响植物的生长。然而，土壤异质性对竞争相互作用的影响很少得到测试。方法通过温室试验，研究土壤异质性对匍匐茎草本植物水子叶种内竞争的影响。在同质环境和不同斑块大小（大斑块和小斑块）的异质环境下分别种植1株（无竞争）和9株（有竞争）的寻常花。在非均质处理下，土壤由相同数量的富营养土和贫营养土按棋盘状排列组成；在均质处理下，土壤由相同数量的富营养土和贫营养土均匀混合组成。结果表明：相对于种内竞争，在大斑块处理下，寻常草对土壤异质性表现出觅食响应，富营养化斑块的生物量、株数、地上质量和根系质量显著高于贫营养化斑块。在小斑块处理中，当存在种内竞争时，观察到觅食反应，但当没有竞争时，没有观察到反应。然而，我们发现土壤异质性对草的总体生长和竞争强度都没有显著影响。我们的研究结果表明，对土壤异质性的觅食反应不一定是适应性的，种内竞争可能不受土壤异质性的影响。
AimsSoil heterogeneity is common in natural habitats. It may trigger foraging responses (placing more ramets and/or roots in nutrient-rich patches than in nutrient-poor patches) and further affect the growth of plants. However, the impact of soil heterogeneity on competitive interactions has been little tested.MethodsWe conducted a greenhouse experiment to investigate the effects of soil heterogeneity on intraspecific competition with a stoloniferous herb Hydrocotyle vulgaris. We grew one (without competition) or nine ramets (with competition) of H. vulgaris under a homogeneous environment and two heterogeneous environments differing in patch size (large or small patches). In the heterogeneous treatment, the soil consisted of the same number of nutrient-rich and nutrient-poor patches arranged in a chessboard manner, and in the homogeneous treatment, the soil was an even mixture of the same amount of the nutrient-rich and the nutrientpoor soil.Important FindingsIrrespective of intraspecific competition, H. vulgaris showed foraging responses to soil heterogeneity in the large patch treatment, e.g. it produced significantly more biomass, ramets, aboveground mass and root mass in the nutrient-rich patches than in the nutrientpoor patches. In the small patch treatment, foraging responses were observed when intraspecific competition was present, but responses were not observed when there was no competition. However, we find a significant effect of soil heterogeneity on neither overall growth nor competitive intensity of H. vulgaris. Our results suggest that foraging responses to soil heterogeneity may not necessarily be adaptive and intraspecific competition may not be influenced by soil heterogeneity.