LITTER DECOMPOSITION AND NUTRIENT RELEASE IN A SUBTROPICAL FOREST OF ARGENTINA

Abstract

The aims of this study were to determine the litter decomposition rate, the release dynamic and return to the soil of the N, P and K nutrients coming
from four native species, namely, espina corona (Gleditsia amorphoides), guayaibf
(Patagonula americana), mora (Chlorophora tinctoria) and urunday (Astronium balansae) in a subtropical forest of Argentina, during one year. Litter decomposition and nutrient release were fitted either to a double exponential model and/or to a simple exponential model in order to find the best fit. Espina corona produced the greatest amount of litter, had the greatest initial amounts of N, P and K and decomposed rapidly. These traits indicated that espina corona played a major role in nutrient cycling in the subtropical moist forest of the Estricta Natural Reservation. Following espina corona, and in decreasing order, mora released more nutrients, and guayaibf and urunday gave considerably smaller nutrient concentrations. Differences in litter decomposition or release rates of nutrients to the soil from different leaf litter types reflect the complexity of the decomposition and release processes. This was confirmed by the fact that both litter decomposition and nutrient release followed different mathematical models according to the species. It is important to note that the species diversity allows a natural ecosystem to maintain its fertility and nutrient balances.