Seasonal litterfall and nutrients in an Atlantic Forest fragmente

Sazonalidade da deposição de serapilheira e nutrientes em um fragmento de Floresta Atlântica

Abstract

Litter dynamics is one of the fundamental processes for the growth and maintenance of native forest fragments, being considered the main pathway for nutrient cycling in forests. Studies on litter production and nutrient content therefore provide insights that provide a better understanding of nutrient dynamics. This study identifies the seasonality and meteorological conditions that influence the quantity and return of nutrients through litter in an Atlantic Forest fragment. Litter sampling was carried out monthly in 12 permanent plots. Each plot contained 5 littertraps distributed systematically. The litter was classified, and the dry mass and nutrients in the leaves and branches and miscellaneous fractions was quantified. Seasonal behavior was observed, with the highest depositions in the winter season. The average annual production was 6.78 Mg ha^-1, with 64.9% being composed of leaves. The mean annual nutrient intake was 135.1, 115.7, 39.7, 23.5, 17.6 and 4.6 kg ha^-1 for Ca, N, K, Mg, S and P, respectively. The meteorological variable precipitation influenced the deposition pattern. The increase in nutrient-use efficiency in the second year compared to the first indicates that plants strategically may be re-translocating relative amounts of their nutrients under water stress conditions.

Keywords:
ecosystem functions; nutrient cycling; secondary succession