Mesofauna as drivers and passengers of decomposition in tropical forests

Background/Question/Methods

As dead plant material accumulates on the floor of tropical forests, a bevy of creatures are sustained by this substrate as it is broken apart by the environment and its inhabitants. The structure of the detrital food web - from microbe to microfauna to mesofauna to macroscopic eukaryotes – is steadily becoming elucidated. The functional roles of the great diversity of animals in the litter environment are enigmatic, and even less understood are the causes and consequences of the structures of detrital communities. Among the many animals in the litter, ants reign from the top of the food web, though little is known about exactly what ants do inside leaf litter on a day-to-day basis. I present a set of observational and manipulative studies to understand how mesofauna – especially ants – respond to litter decomposition, and how they may influence decomposition processes.

Results/Conclusions

Mesofaunal arthropod density and richness track decomposition rates, however other properties of the detrital environment prevail in importance. The biomass of ants, independent of taxon, is a driver of the rate of litter decomposition. Many of the processes involving decomposition and litter food webs are context specific, varying with a multitude of biotic and abiotic constraints. As litter mesofauna are as sensitive to abiotic conditions as the processes that drive decomposition, additional work in other localities and other lineages is required to untangle cause, correlation and consequence.