Variação espaço-temporal do estoque e sequestro de carbono na biomassa lenhosa ao longo de um gradiente hidroedáfico em florestas alagáveis de igapó no Parque Nacional do Jaú, Amazônia Central.

Abstract

Floodplain forests provide a relevant function in flood regulation and the global carbon (C) cycle. An accurate conclusion about seasonal inundation effect and soil conditions in the biomass rates and C-storage is still scanty. Basin-wide variations in forest biomass, age trees, growth increasing and stem turn over rates are closely related to edaphic as well as climatic conditions. However, informations based on flooding gradients that can probably control the forest productivity remain to be accurately determined. Therefore, the present study was undertaken to correlate carbon sequestration and stocking rates in the woody biomass from igapós forests from black water along to hydroedaphical gradient. The study was performed at Jaú National Park in igapó forest region. The sampled species had achieved DBH>10 cm criterion among six monitoring plots, were included at forest inventory spread along hydroedaphical gradient on distinct topographical conditions (high, moderate and low flooded forest) in a total area of 6 ha. It was estimated stand-age, wood biomass productivity combining tree-ring data, hydroedaphical factors and allometric equations based on diameter, height and wood density. The present study showed Jaú igapó ecosystem presented an evident relation among environmental variables and tree growing. Age-diameter and age-biomass modeling, both relations, indicated significant correlations. Low flooded gradient level presented expressive results. Although the highest occurence of older trees individuals in the low-flooded forest, this topographical level accumulates more coarse biomass over their lifetime than trees in the topographies that undergo a longest duration flooding. The flooding gradient was shown to have a close correlation with forest productivity.