Litter decomposition and arthropod composition under different ultraviolet levels following prescribed burn in a subtropical pastureland
Reduction in faunal diversity is suggested to reduce litter decomposition, whereas increases in ultraviolet (UV) radiation may directly enhance or indirectly retard litter decomposition. Here we examined the effect of soil arthropods and UV radiation on litter decomposition in burned and unburned plots during a 469-day field experiment in a subtropical pastureland of Puerto Rico. Prescribed burn reduced soil arthropod diversity and increased UV radiation during the initial period of 240 days following the burn, and consequently reduced plant litter decomposition. The density of predators was lower in the burned than in control treatment. UV radiation reduced total arthropod density and diversity by retarding the recolonization of soil arthropods in the burned plots with reduced abundance of predators after 344 days post-burn incubation. Prescribed burn slowed down plant litter decomposition through direct reduction in arthropod diversity immediately after fire and through increase in UV radiation that retards the recolonization of arthropods in later stages after the prescribed burn in the subtropical pastureland.