Root system size and precision in nutrient foraging: responses to spatial pattern of nutrient supply in six herbaceous species
Root system size and precision in nutrient foraging: responses to spatial pattern of nutrient supply in six herbaceous species
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DOI：
10.1111/j.1365-2745.2001.00618.x
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发表时间：
2001-12
影响因子：
5.5
通讯作者：
D. Wijesinghe;E. John;S. Beurskens;M. Hutchings
中科院分区：
文献类型：
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作者：
D. Wijesinghe;E. John;S. Beurskens;M. Hutchings
1通过实验验证了以下假设：在异质环境中：（i）植物根系的大小与其在营养丰富斑块中精确定位根系的能力呈负相关;（ii）根系较大的植物根系定位精度受营养斑块距离的影响较小;（iii）根系位置较精确的物种，其生物量的变异较大（敏感性）对养分供应异质性的反应;和（iv）当与菌根结合时，植物在根的位置上将不那么精确，并且将在地上结构或与适合度相关的属性上投入更多的生物量。2将6种草本植物（Arteriatherum elatius、Festuca ovina、Plantago lanceolata、Campanula rotundifolia、Papaver rhoeas和Sonchus oleraceus）的单株分别置于有或无菌根的盆栽中。相同数量的养分在离植物不同距离处均匀或不均匀地供应。在所有处理中，花盆接受相同数量的营养素。3树种根系生物量与精度呈显著负相关。几个物种，包括一些大的根系，表现出小，但非常显着的差异，在不同的治疗方法之间的精度。只有高精度物种罂粟和低精度物种风铃草表现出对不同异质性模式产生的生物量的敏感性。[4]将根放置在营养丰富的斑块中的精度受到与实验中使用的最小根的物种罂粟和较大根的物种之一车前草斑块的距离的影响。没有证据支持这样的假设，即小根物种的精度受营养斑块距离的影响大于大根物种。5菌根的存在并不影响任何物种的根放置精度。然而，分配到根的生物量显着较低，在蒿属，分配到生殖结构显着较高的风铃草，当菌根存在。6这项研究证实，在与根系大小有关的营养觅食精度方面，物种之间存在差异。它还表明，物种内的精确度随营养丰富斑块的位置而变化，并且物种在营养觅食中显示精确度的能力取决于其环境设置。
1 An experiment was carried out to test the hypotheses that in heterogeneous environments: (i) the size of species’ root systems will be negatively correlated with their ability to place roots precisely in nutrient‐rich patches; (ii) precision of root placement will be less affected by distance to nutrient patches in species with large root systems; (iii) species with greater precision in root placement will show greater variation in biomass (sensitivity) in response to heterogeneity in nutrient supply; and (iv) plants will be less precise in root placement, and will invest more biomass in above‐ground structures or in fitness‐related attributes, when in association with mycorrhizas. 2 Single plants of six herbaceous species (Arrhenatherum elatius, Festuca ovina, Plantago lanceolata, Campanula rotundifolia,Papaver rhoeas and Sonchus oleraceus) were grown in pots with mycorrhizas either present or absent. The same amount of nutrients was supplied either homogeneously or heterogeneously at different distances from the plants. Pots received the same quantity of nutrients in all treatments. 3 There was a significant negative correlation between species’ root system biomass and precision. Several species, including some with large root systems, showed small but highly significant differences in precision between the various treatments. Only the high‐precision species Papaver and the low‐precision species Campanula exhibited sensitivity in biomass produced in response to different patterns of heterogeneity. 4 The precision with which roots were placed in nutrient‐rich patches was affected by distance from patches in Papaver, the smallest‐rooted species used in the experiment, and in Plantago, one of the larger‐rooted species. There was no evidence to support the hypothesis that precision would be affected more by distance from nutrient patches in small‐rooted species than in large‐rooted species. 5 The presence of mycorrhizas did not affect precision of root placement in any species. However, allocation of biomass to roots was significantly lower in Arrhenatherum, and allocation to reproductive structures was significantly higher in Campanula, when mycorrhizas were present. 6 This study confirms that there are differences between species in precision of nutrient foraging that are related to root system size. It also shows that there is variation in precision within species in response to the location of nutrient‐rich patches, and that the ability of a species to display precision in nutrient foraging is dependent on its environmental setting.