Aims

Soil resources distribute heterogeneously in natural ecosystems, which is known as soil heterogeneity. Responses of plant roots to soil heterogeneity are important for their adaptation to the changes of environments. However, few observations of root systems in soil are recorded, and there is a lack of comprehensive theory for roots responses to soil heterogeneity.

Methods

Soil heterogeneity including configurational heterogeneity and qualitative heterogeneity is developed in three dimensions via extending a stochastic spatially explicit lattice-based habitat model in two dimensions. Root dynamics of plants growing in such soil heterogeneity in three dimensions are simulated. In these simulations, three parameters (i.e. ratio of root distributed in resource-rich patches, mean root length and root number of plants) are measured.

Results

Comparing with the previous two dimensional model of heterogeneous pattern formation, this three-dimensional model is time-saving and more efficiency. The spatial pattern of habitats, as well as the adaptability of plants to soil heterogeneity, determines how plants place their roots into resource-rich and resource-poor patches. The plasticity of root architecture plays an important role in the root response to soil heterogeneity. Specifically, plants with the ability to respond to resources would adopt a large number of roots with short root length as the ratio of resource-rich patches is relatively small, while they would adopt a small number of roots with long root length as the ratio of resource-rich patches is relatively large.

Conclusions

Such realistic three-dimensional model allows us to better explore the effects of soil heterogeneity on plant root dynamics. Applying this model in root dynamics improves our understanding of root distribution in spatial habitat and of the formation mechanism of root morphology.

中文翻译：

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用三维模型模拟植物个体根系分布

宗旨

土壤资源在自然生态系统中分布不均，称为土壤异质性。植物根系对土壤异质性的响应对其适应环境变化具有重要意义。然而，对土壤中根系的观察记录很少，并且缺乏根系对土壤异质性响应的综合理论。

方法

土壤异质性包括构型异质性和定性异质性，通过在二维空间扩展基于随机空间显性格的栖息地模型，在三个维度上发展。从三个维度模拟了在这种土壤异质性中生长的植物的根系动态。在这些模拟中，测量了三个参数（即分布在资源丰富斑块中的根的比率、平均根长度和植物的根数）。

结果

与之前的异质图案形成二维模型相比，这种三维模型更省时、更高效。栖息地的空间格局，以及植物对土壤异质性的适应性，决定了植物如何将其根部置于资源丰富和资源贫乏的斑块中。根系结构的可塑性在根系对土壤异质性的响应中起着重要作用。具体而言，具有资源响应能力的植物，由于资源丰富的斑块比例相对较小，会采用大量根长较短的根，而由于资源丰富斑块的比例较小，它们会采用少量根长较长的根作为资源丰富的补丁比较大。

结论

这种逼真的三维模型使我们能够更好地探索土壤异质性对植物根系动态的影响。将该模型应用于根系动力学，提高了我们对空间生境中根系分布和根系形态形成机制的理解。