Carbon stock of the herbaceous layer under diferente plant cover in fragments of Caatinga

Abstract

Climate change and the extensive areas of dry tropical forests (DTF) used in the production of pasture determine the need to investigate alternative managements that would make it possible to increase carbon stock. As such, the aim of this research was to estimate the carbon stock in the herbaceous layer of two fragments of seasonally dry tropical forest: i) a fragment of dry tropical forest under 40 years of regeneration and ii) forest submitted to the thinning of trees with a diameter ,10 cm. The research was carried out over nine years (2010-2018) in two micro basins inserted in a fragment of DTF in the district of Iguatu, Ceará. Herbaceous material was collected continuously every month in each micro basin, with 10 replications, giving a total of 2,160 samples (2 micro basins x 10 replications x 12 months x 9 years). The material was dried in an oven at 60 °C; the biomass content was then determined and later converted to carbon content. The carbon stock varied according to the rainfall in the region. The area under thinning recorded greater carbon stock for 80% of the months over the study period compared to the area under regeneration. It was found that the thinning management afforded the greatest amounts of carbon stock during both the rainy and the dry seasons, differing statistically from the area under regeneration (α=0.05), and is one alternative for increasing the carbon stock of the herbaceous layer.