Land use change fundamentally rewires how climate shapes belowground biodiversity
spun authors
summary
Tropical agriculture erases unique mycorrhizal fungal communities and alters climate-driven diversity patterns, revealing uncultivated soils as critical reservoirs of belowground biodiversity.
We surveyed paired cultivated (maize or potato) and adjacent uncultivated soils across a ~1700 m elevational gradient in the Ecuadorian Andes, spanning large ranges in temperature and precipitation. Using DNA metabarcoding, we quantified AM fungal richness and community composition and modelled how these patterns respond to land use, climate, and soil chemistry.
Agricultural conversion caused a major loss of AM fungal diversity, with cultivated soils supporting ~80% fewer taxa than nearby uncultivated vegetation. Uncultivated soils also contained three times more unique fungal taxa, highlighting their importance as reservoirs of belowground biodiversity. Importantly, the effects of land use were climate dependent: in uncultivated soils, AM fungal richness increased with temperature and declined with precipitation, whereas cultivated soils showed the opposite trends. Models that included interactions between land use and climate explained substantially more variation in fungal richness than models with land use or climate alone.
Land use change also strongly altered fungal community composition. Differences between cultivated and uncultivated soils were driven primarily by species replacement (turnover) rather than simple nested loss of taxa, especially at warmer and wetter sites. This indicates that agriculture reshapes fungal communities by favoring different species, not just fewer species.
Overall, the study demonstrates that land use change fundamentally reshapes climate–biodiversity relationships for tropical soil fungi. The results emphasize that conserving belowground biodiversity—and the ecosystem services it supports—requires accounting for both climate gradients and land management, particularly in biodiversity-rich tropical mountain regions.
