Caracterização da variabilidade espacial do carbono em uma microbacia de floresta primária na Amazônia Central

Abstract

The Amazonian ecosystem is basic for the global climate, because of being considered the biggest carbon reservoir between the ecosystems. So, we understand the behavior of the carbon in the cycle biogeochemical in microbasin scale can contribute to studies in bigger scale and also strengthen mitigative measures for preservation of the Amazon region. The main objective of this study quantified and he understood the mechanisms of export of the carbon for the hydrological cycle. The study area was in the section 2 (two) of the microbasin of the narrow stream Asú, and the sampling period was between setember/2017 to setember/18. For this study two were approached questions: 1) Which the contribution / relation of the haste-infiltration for the carbon that is exported to atmosphere?; 2) In what proportion is the carbon released by river road for atmosphere in a microbasin scale?. To answer to these questions the study it was divided in two parts (chapters): I) Space variability of the carbon in full zone of a microbasin of primary forest in the central Amazon region. In this study the objective valued and he quantified the concentrations of dissolved organic carbon, inorganic carbon dissolved in the full zone and organic carbon dissolved in the haste, level of the groundwater and the parameters physicist chemists of pH and conductivity to the long topographical gradient (plateau, slope and sandbar) in ground dry land. II) Dynamic of the carbon in the transport river road in a microbasin of natural forest in the central Amazon region, with the objective to understand the mechanism of flow and storage of carbon that is exported river road in the microbasin scale, through the quantification of the flows of dissolved organic carbon, inorganic carbon dissolved in the narrow stream, the dissolved organic carbon of the haste and the flow of CO2. For getting this variable there was used the methodology of the floating camera and the equilibration, flow, respiratory tax (dissolved oxygen), and the parameters chemical-physically (pH and conductivity). The concentrations of dissolved inorganic carbon and the values of temperature and pH were used by them to calculate the partial pressure of CO2 of the water, when it was based on the balance equations thermodynamic. The results of the total haste of the area of study during the period of 1 a year was of 2,136 mm, and groundwater varied of 0,95 m (above the surface) and the least registered one was -1,23 m (below the surface). The middle concentrations of dissolved organic carbon (18,19 mg/L) and dissolved inorganic carbon (5,28 mg/L) in the underground water demonstrated significant differences (p <0,05) between the dry and rainy period. The concentrations of organic carbon dissolved in the water of the rain presented variations between the internal haste (plateau and sandbar) and total haste. And the results of the correlations of the organic carbon dissolved with rainfall and with level of the water in the full zone, demonstrated to have a straight influence in the carbon availability to the long topographical gradient, in other words the measure what there was variation rainfall, the level of the groundwater and the concentrations also were suffering variations. The study demonstrated that there is a straight relation between the concentrations of dissolved organic carbon and dissolved inorganic carbon obtained under the different compartments in the environments studied with the processes that include the hydrological cycle. The middle values of the concentrations of organic carbon dissolved in the haste it was of 4,60 ± 0,69 mg/L, and for the full zone the middle values of dissolved organic carbon and dissolved inorganic carbon were of 18,19 ± 11,66 mg/L and 5,28 ± 2,22 mg/L respectively, and this disparity of detour standard corresponds to the set of data of different depths and surrounding. 16 Regarding the flows of dissolved organic carbon and inorganic carbon dissolved in the narrow stream the obtained middle values were respectively of 2,20 ± 2,34 mg/s and 0,55 ± 0,53 mg/s, with tax of middle breathing of 0,52 ± 1,08 μM/hora, and the middle flow 0,25 ± 0,23 m/s, with the middle values of flow of CO2 of 9,85 ± 3,11 μmol CO2 m-2 s-1. Interim to the values, can quantify the carbon entry for the equivalent internal haste 5,07 mg/L and the extern haste of 3,66 mg/L, and with the exit for the narrow stream approximately of 3.101,04 T CO2 /hac/y. There is study presented important relations in the concentrations and transport / storage of carbon in the aquatic environment in different compartments (haste, ground, underground and superficial water) of a microbasin of primary forest.