Resilience of soil to biological invasion: analysis of spread on networks
MetadataShow full item record
A network model for soil pore volume is presented and applied to the analysis of biological invasion of microorganisms. The pore geometry of two soils with a relatively high or low bulk density were quantified with the use of X-ray tomography and networks were constructed to present the pore space by channels connecting intersecting points. This network was subsequently quantified by the measurement of biologically relevant parameters, such as the distribution of lengths of the links between two nodes, the coordination number of the nodes, and the distribution of the sizes of the links between two nodes. Spread of microorganisms was subsequently considered as a function of these characteristics and embedded into a simple epidemiological model for spread that can be mapped onto percolation theory. We found that the networks display critical behaviour for biological invasions with a greater resilience to invasion for the more densely packed soil. We also found that inherent heterogeneity of soil systems further contributes to resilience to invasion.