Estoque de serrapilheira como indicador de qualidade em três ambientes ciliares de floresta tropical úmida na mata atlântica

Abstract

The suppression of the world's forests for commercial use has caused an unprecedented loss of biodiversity and ecosystem services that nature provides to mankind. However, the restoration of these ecosystems to recover lost services is increasing, and an evaluation of the effectiveness of these processes by environmental quality bioindicators are necessary, such as the litterstock quantification. This study aimed at quantifying litter stock in three rainforest riparian areas as a way of subsidizing the improvement of ecosystem recovery strategies. The work was carried out at the São José Agroindustrial mill, located in Igarassu, Pernambuco, Brazil, with a total area of 246 km2. Three riparian forest were selected: one restored, one in advanced secondary succession and one conserved mature forest, and in each one 5 plots of 10 x 10 m were allocated on both sides of the river. The stock of litter deposited on the forests floor was collected using a 0.5 m x 0.5 m template. After collecting the material, samples were submitted to oven drying at 60º C for 72 hours. Then, each sample was selected and weighed by fractions (leaves, branches, reproductive parts and miscellaneous). The three areas differed in litter stock, presenting 8.7 t/ha (+- 1.39) for the Mature Area, 7.0 t/ha (+- 1.03) for the Advanced Succession Area and 5.0 t/ha (+- 1.69) for the Restored Area, with values similar to those found in other tropical forests. A predominant leaf fraction represented 72% of the litter in the Mature Area, 60% in the Advanced Succession Area and 55% in the Restored Area, probably because it is the largest source of soil nutrients. We conclude that the Restored Forest is in good process of returning of the ecosystem services, becoming necessary the maintenance and monitoring of the area allowing it to move towards a mature forest stage.