Gases do efeito estufa e dinâmica do carbono sob fitofisionomias do cerrado no Parque Nacional das Nascentes do Rio Parnaíba - PNNRP

Abstract

In recent years, a number of studies have shown that global warming and climate change are one of the most relevant and deserving of special attention among the environmental problems in order to find ways to reduce greenhouse gas emissions. Greenhouse effect and consequently minimize the intensification of the phenomenon. This process of intensification of the greenhouse effect is evidenced, mainly by the increase in the atmospheric concentrations of its three main gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), increased rapidly over the years. Although the effect of these gases is together, CO2 presents the largest relative contribution, since it is present in the atmosphere in higher concentrations and can be emitted from several sources, both natural and anthropogenic. In this context, the study aimed to quantify the emission of greenhouse gases under different phytophysiognomies of the Cerrado biome in the Parnaíba River National Park, as well as to verify the chemical and physical quality attributes of the soil and the behavior of the carbon dynamics. For this evaluation, two 1 ha plots under two Cerrado phytophysiognomies were delineated in the Parnaíba Rio Nascentes National Park, which were subdivided into five subplots equivalent to 0.2 ha. In the two phytophysiognomies soil samples were collected at depths of 0.00 - 0.05 m and 0.05 - 0.10 m, in order to evaluate the chemical and physical attributes of the soil, as well as to measure the emission rate of the greenhouse gases in the different phytophysiognomies through the Monitor Multigases - MX6 iBrid ™. In relation to soil quality, the study found that they are relatively acidic, with low natural fertility, relevant soil densities, and contribute with a significant content of organic carbon and total nitrogen, and good water retention capacity In the soil, mainly for Cerradão phytophysiognomy. As for the carbon dynamics in the soil, it was found that it is available at considerable levels in these areas and relatively stocked, indicating the quality of these soils. The cerrado areas studied presented a significant carbon sink, but also acts as emitting source, since the emission values of CO2, CH4 and N2O were significant and varied as regards the distribution of emissions in the phytophysiognomic samples. Thus, it is noteworthy that the PNNR presented significant emissions regarding greenhouse gases, although it is due to natural relationships between the soil-plant-atmosphere system in its phytophysiognomies.