Dinâmica do efluxo de dióxido de carbono (CO2) do solo em duas áreas distintas na Amazônia

Abstract

Terrestrial ecosystems are important for understanding the exchange of CO2 between surface and atmosphere. Research has sought to understand the potential for carbon sequestration and emissions in different agroecosystems. Among them, the natural pastures that have significant participation in the carbon cycle food subsidy for meat production. As well as the production of palm oil responsible for the production of 30% of edible oil in the world and part of the production of biodiesel. In this study, two land cover uses (iLPF and oil palm monocultures) and CO2 efflux were evaluated. The closed dynamic chamber method associated with an infrared gas analyzer was used. This work presents monthly observations in monoculture of palm oil and in two iLPFs the first with African mahogany (Khaya ivorensis A. Chev.) And the second with teak (Tectona grandis L. f.). In the first case in the palm oil monoculture, leaf stacking was responsible for the higher CO2 efflux values within the measurement rings during the two observed periods (rainy and less rainy) compared to the two other observed points (palm base) and carrier). In the experiment carried out in the iLPF area, the dynamics of the CO2 efflux (EFCO2) differed between the three systems studied. The increase in EFCO2 During midday compared to mid-morning (eight hours) at all points studied. In the control area (capoeira) there was no great variation observed, being more stable. The highest EFCO2 values in the two iLPF systems (teak and mahogany) were found at the base of the trees for the mahogany system and in the trampled pasture for the teak system followed by the base of the trees. The low variation in CO2 soil efflux between morning and noon in capoeira may indicate that they resemble natural forests, with trees creating a soil microclimate that is suitable for the growth of soil microorganisms. Soil moisture correlated positively weakly at the base of the teak and in the transition area. In the case of soil temperature, no positive correlation was observed for the area in question, only moderately in the control area. In the analyzes, no positive correlations were found between EFCO2 and soil moisture at any of the points studied in the mahogany area. In turn, a weak relationship between Ts and area between trees was found. The smallest variations in soil temperature were found in poultry followed by iLPF mahogany in the shaded area (Base mahogany and among mahogany plants). The largest variations of Ts in the studied period (rainy) occurred in the area of iLPF with teak. Trees influence the CO2 dynamics when they are not distributed in forest areas.