Importância das bromélias epífitas na ciclagem de nutrientes da Floresta Atlântica

Abstract

Epiphytic material can be considered an important source of nutrients for forests found on poor soils. This work was done in a tract of a primary Atlantic Forest with located in the Pico do Papagaio, Ilha Grande, RJ, Brazil. Over a year, the total litter and that produced by epiphytic bromeliads were collected by different ways (16 of 0.25m2 for total litter and 10 of 25m2 for that of bromeliads). Complete aliquots of matter collected were used to determine the composition of N, P, K, Na, Ca and Mg with atomic absorption spectrophotometer. During one year, litter production of bromeliads was of 327.8kg/ha, which represented 3.1% of total litter produced in the same period (10,690.9kg/ha). The contribution of bromeliad litter presented a very irregular spatial distribution in relation to the total litter. With relation to the flux of nutrients, the biggest roles were played by Na (4.4kg/ha/yr); K (7.6kg/ha/yr); and Mg (7.0kg/ha/yr), that corresponded to 27.5, 18.7 and 13.9% respectively of the contribution from litter in general. This participation occurred in function of the relatively elevated concentration of these nutrients in bromeliad litter.