Simulating root distribution of plant individual with a three-dimensional model

Abstract

Abstract 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.