Transient Instability and Patterns of Reactivity in Diffusive-Chemotaxis Soil Carbon Dynamics

by Fasma Diele, Andrew L. Krause, Deborah Lacitignola, Carmela Marangi, Angela Monti, and Edgardo Villar-Sepúlveda

Microbes in the soil play a key role in the carbon cycle by breaking down organic matter and influencing whether carbon is stored or released into the atmosphere. This study uses a simplified mathematical model to explore how microbes respond to chemical signals, a behavior known as chemotaxis, which can lead them to cluster in specific areas. These clusters may form "hotspots" of carbon activity. We show that traditional theories don't fully explain how these hotspots emerge, especially in two-dimensional models where temporary growth and nonlinear effects are important. Understanding these dynamics can improve predictions of carbon storage and emissions, helping guide climate strategies and sustainable soil management.

Microbial chemotaxis drives clustering around organic carbon, creating hotspots of activity. Stability analysis reveals regions of transient and asymptotic instability as chemotactic sensitivity increases, while simulations show spatial patterns and bifurcation curves linking heterogeneity to chemosensitivity.