The importance of mesofauna and decomposition environment on leaf decomposition in three forests in southeastern Brazil

• Published in: Plant ecology 2012-08, Vol.213 (8), p.1303-1313
• Main Authors: Castanho, Camila T., Lorenzo, Leda, de Oliveira, Alexandre A.
• Format: Article
• Language: English
• Subjects: Abiotic factors; Acceleration; Analysis; Applied Ecology; Biodiversity; Biogeochemistry; Biomedical and Life Sciences; Community & Population Ecology; Deciduous forests; Decomposition; Dry forests; Ecology; Ecosystem components; Experimental design; Forest litter; Forest soils; Forests; Leaves; Life Sciences; Litter; Plant Ecology; Soil ecology; Soil fauna; Soil microorganisms; Soil water; Terrestial Ecology; Terrestrial ecosystems; Thermal decomposition; Tropical forests
• ISSN: 1385-0237; 1573-5052
• DOI: 10.1007/s11258-012-0089-2

We examined the effects of soil mesofauna and the litter decomposition environment (above and belowground) on leaf decomposition rates in three forest types in southeastern Brazil. To estimate decomposition experimentally, we used litterbags with a standard substrate in a full-factorial experimental design. We used model selection to compare three decomposition models and also to infer the importance of forest type, decomposition environment, mesofauna, and their interactions on the decomposition process. Rather than the frequently used simple and double-exponential models, the best model to describe our dataset was the exponential deceleration model, which assumed a single organic compartment with an exponential decrease of the decomposition rate. Decomposition was higher in the wet than in the seasonal forest, and the differences between forest types were stronger aboveground. Regarding litter decomposition environment, decomposition was predominantly higher below than aboveground, but the magnitude of this effect was higher in the seasonal than in wet forests. Mesofauna exclusion treatments had slower decomposition, except aboveground into the Semi-deciduous Forest, where the mesofauna presence did not affect decomposition. Furthermore, the effect of mesofauna was stronger in the wet forests and belowground. Overall, our results suggest that, in a regional scale, both decomposers activity and the positive effect of soil mesofauna in decomposition are constrained by abiotic factors, such as moisture conditions.