Abstract
Soil bacteria live in patchy and dynamic environments where cells in
adjacent microhabitats may realize vastly different generation times
ranging from hours to years within small soil volumes. This study links
bacterial population demographics with soil conditions to better
estimate mean bacterial cell ages by tracking individual lineages over
space and time using a mechanistic model of bacterial life in soil.
Results show heavy-tailed distributions of generation times that follow
a power law across all hydration conditions, implying no simple
definition of mean soil bacterial age where soil volumes may harbor
cells with very broad range of ages living side by side. The study
highlights ubiquitous conditions that support a “genetic reservoir” of
physiological traits for each bacterial species that may be preserved in
soil cold spots and reintroduced during episodic reunification events
(soil wetting).