ACÚMULO DE SERAPILHEIRA EM PLANTIOS PUROS E EM FRAGMENTO DE MATA ATLÂNTICA NA FLORESTA NACIONAL DE NÍSIA FLORESTA-RN

Abstract

The present work aimed to estimate the litterfall rate accumulation in stands of Parkia pendula Benth., Caesalpinia ferrea var. ferrea Mart. ex Tul., Caesalpinia echinatta Lam., Mimosa caesalpiniifolia Benth. and in the native forest in Nísia Floresta National Forest, in the Municipality of Nísia Floresta-RN. The biomass was collected with a metallic frame accomplished in 10 points of each stand in dry and rainy season of 2003. The material was separated in leaves, branches and miscellany fractions, washed, dried at 65ºC for 48 hours and after weighted. Larger biomass accumulation was observed in the Parkia pendula stand with 15.49 Mg.ha-1 and the smallest in Caesalpinia echinatta with 9.52 Mg.ha-1. It was verified in all the stands more leaf biomass production with high amount for Caesalpinia ferrea and Mimosa caesalpiniifolia, accumulating 10.38 and 10.25 Mg.ha-1, respectively. The branches+bark production was larger in the Parkia pendula plot with 4.95 Mg.ha-1 and in the native forest with 3.19 Mg.ha-1. The litterfall accumulation in the pure plantations was larger in the dry period, reaching 33% more than in the rainy season. The cluster analysis classified the forest typologies in two blocks, being the first formed by Caesalpinia ferrea, Mimosa caesalpiniifolia and Parkia pendula, and the second by Caesalpinia echinatta and native forest, with the leaf fraction being the main discriminatory variable.