Simple measures to capture the robustness and the plasticity of soil microbial communities

TL;DR

This paper introduces simple measures to quantify the robustness and plasticity of soil microbial communities, revealing their resilience in population balance and adaptability in species composition.

Contribution

It proposes novel, straightforward metrics based on population distribution and rank order to distinguish robustness from plasticity in soil microbes.

Findings

Microbial communities maintain population balance despite nutrient perturbations.

Species composition shows high adaptability during recovery.

Soil microbes are robust in population structure but flexible in species makeup.

Abstract

Soil microbial communities are known to be robust against perturbations such as nutrition inputs, which appears as an obstacle for the soil improvement. On the other hand, its adaptable aspect has been also reported. Here we propose simple measures for these seemingly contradicting features of soil microbial communities, robustness and plasticity, based on the distribution of the populations. The first measure is the similarity in the population balance, i.e. the shape of the distribution function, which is found to show resilience against the nutrition inputs. The other is the similarity in the composition of the species measured by the rank order of the population, which shows an adaptable response during the population balance is recovering. These results clearly show that the soil microbial system is robust (or, homeostatic) in its population balance, while the composition of the species is rather plastic and adaptable.