Macro- and micronutrient effects on decomposition of leaf litter from two tropical tree species: Inferences from a short-term laboratory incubation

While a large number of studies have investigated the effects of macronutrients such as nitrogen (N) or phosphorus (P) on litter decomposition, recent studies suggest that micronutrients including zinc (Zn) may also limit decomposition rates. Our goal was to compare the effects of nutrient addition on decomposition of two leaf litter types from tropical dry forest trees in a short-term laboratory microcosm experiment. Single nutrients (N, P, Zn, potassium, magnesium, and nickel) were applied to leaf litter in solution at low or high concentrations (to mimic in situ availability or to alleviate nutrient limitation, respectively), and decomposition was assessed as final mass remaining and carbon dioxide mineralization. Both mass remaining and CO₂ mineralization were affected by nutrient identity and concentration, and these effects varied by species. In general, P and Zn addition increased decomposition, Mg and N inhibited it, and K and Ni had no significant effects. Future studies should consider the interactions between decomposition processes, decomposer communities, and a wider range of macro- and micronutrients.