PubMed · 2026-04-29
A decade-long drought study found that soil microbes keep breaking down dead plant material at normal rates even under prolonged dry conditions. Whether the litter comes from grasses or shrubs matters more for decomposition speed than drought stress itself.
Grass litter decomposed faster than shrub litter because it was richer in carbohydrates, driving higher microbial enzyme activity and more decomposition genes detected via DNA sequencing.
A decade of reduced rainfall did not increase the lignin (tough woody compound) fraction in either grass or shrub litter, meaning drought did not make plant material significantly harder for microbes to break down.
Microbial communities shifted from fungi-dominated to bacteria-dominated over the 18 months, reflecting a recycling of dead microbial biomass — a succession pattern that held regardless of drought treatment.
