Decline in diversity of tropical soil fauna under experimental warming

Climate change is exacerbating a global decline in biodiversity. Numerous
observational studies link rising temperatures to declining biological
abundance, richness, and diversity in terrestrial ecosystems, yet few
studies have considered the highly diverse and functionally significant
communities of tropical forest soil and leaf litter fauna. Here, we report
major declines in the order-level richness and diversity of soil and leaf
litter fauna following three years of experimental whole-profile soil
warming in a tropical forest. This decline was greatest during the dry
season, suggesting that warming effects could be exacerbated by drought.
Contrary to findings from higher latitudes, total faunal abundance
increased under warming, with major shifts in community composition. These
responses were driven by increased dominance of a relatively small number
of thermophilic taxa, and of oribatid mites in particular. Our study
provides direct experimental evidence that warming causes diversity
declines and compositional shifts for tropical forest soil and leaf litter
fauna, a result with potential consequences for soil carbon cycling and
which highlights the vulnerability of tropical biodiversity to climate
change.