Quasi-steady uptake and bacterial community assembly in a mathematical model of soil-phosphorus mobility

TL;DR

This paper presents a mathematical model of soil phosphorus uptake involving plants and bacteria, revealing equilibrium states, oscillatory dynamics, and community reassembly influenced by fertilization, emphasizing the importance of time-series data.

Contribution

It introduces a novel mathematical framework for soil-phosphorus dynamics that captures community assembly and nutrient uptake behavior under different conditions.

Findings

Multiple equilibrium states identified, including coexistence and monopolization.

Dynamics controlled by chemical adsorption to bacterial death ratio, leading to oscillations or steady states.

Fertilization can induce community reassembly without affecting nutrient content.

Abstract

We mathematically model the uptake of phosphorus by a soil community consisting of a plant and two bacterial groups: copiotrophs and oligotrophs. Four equilibrium states emerge, one for each of the species monopolising the resource and dominating the community and one with coexistence of all species. We show that the dynamics are controlled by the ratio of chemical adsorption to bacterial death permitting either oscillatory states or quasi-steady uptake. We show how a steady state can emerge which has soil and plant nutrient content unresponsive to increased fertilization. However, the additional fertilization supports the copiotrophs leading to community reassembly. Our results demonstrate the importance of time-series measurements in nutrient uptake experiments.