Estimativa da produção anual de serapilheira dos bosques de mangue no Furo Grande, Bragança-Pará

Abstract

It is well known that environmental conditions of a determined place can influence the productivity of mangroves. So, the present study estimated the total and components litter production in Furo Grande, Bragança-PA. This study comprised four annual cycles (July/2000 to August/2004) at three sites. Seven traps were placed at each site along a 140 m transect, with 20 m intervals. Each trap had a useful area of 1 m2, with 1 mm2 mesh, suspended above the spring tide level. Accumulated material in the traps was collected on a monthly basis, sorted manually into leaves, flowers, fruits, stipules, twigs, and miscellaneous and then oven-dried to constant weight at 70ºC. The mean production of four years was 9.85 t.ha-1.year-1 at site 1, 6.41 t.ha-1. year -1 at site 2, and 5.99 t.ha-1. year -1 at site 3, with significant difference between sites 1 and 3 (H=7.53; df=2; p<0.05). Overall, the results showed that leaf was the most productive component, and together with flower, had peak in the dry season, which seems to favor energy saving to invest in reproduction, whereas fruit peak in the wet season, providing propagule dispersion and hence the renewal and maintenance of these forests.