Navegando por Autor "COSTA, Rafael Ferreira da"

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Acesso aberto (Open Access)
Fluxos de CO2 do solo na Floresta Nacional de Caxiuanã, Pará, durante o experimento ESECAFLOR/LBA
(2013-03) SILVA JUNIOR, João de Athaydes; COSTA, Antonio Carlos Lôla da; AZEVEDO, Pedro Vieira de; COSTA, Rafael Ferreira da; METCALFE, Daniel B.; GONÇALVES, Paulo Henrique Lopes; BRAGA, Alan Pantoja; MALHI, Yadvinder Singh; ARAGÃO, Luiz Eduardo Oliveira e Cruz de; MEIR, Patrick
The ESECAFLOR/LBA experiment was carried out at the Caxiuanã National Forest, Pará State, and this article intends to investigate the effect of hydrological stress on the total soil respiration. Two adjacent 1 hectare plots were defined in January 2002. One plot remained in its natural conditions and was used as a control (A), while in the exclusion plot (B) plastic cover panels were installed in order to drain about 70% of the total rainfall to outside of the plot. Accumulated monthly rainfall was recorded from 2005 January to December. During 2005 the rainfall over the ECFPn was 2,211.6 mm, or 9.96% above the mean of 2,011.2 mm. The average soil moisture was 15.6±9.2 and 9.5±3.4% in the plots A and B, respectively. The average soil temperature was 25.6±0.4 and 25.7±0.5 ºC, for the A and B plots, respectively. The average soil CO2 flux was 3.46±0.44 and 3.21±0.84 μmolCO2 m-2s-1 in the A and B plots, respectively. With the exclusion of part of rain in plot B, it had a reduction of 7.23% in the soil CO2 flux (0.25 μmolCO2 m-2s-1), 39.1% in the soil humidity (6.1p.p.), and an increase of 0.39% in the soil temperature (0.1ºC). The soil moisture in parcel B was lesser than in the parcel A, due to the exclusion system of rain. However at the beginning of the year, site B undergone some changes causing the measuring values to be about the same on both areas.
Acesso aberto (Open Access)
Modelagem da interceptação na Floresta Nacional de Caxiuanã, no Leste da Amazônia
(2008-09) OLIVEIRA, Leidiane Leão de; COSTA, Rafael Ferreira da; COSTA, Antonio Carlos Lôla da; SOUSA, Francisco de Assis Salviano de; BRAGA, Alan Pantoja
The present work was carried out in the Ferreira Penna Scientific Station, at the Caxiuanã National Forest in Melgaço, Pará, Brazil (01º 42’ 30” S; 51º 31’ 45” W; 60 m of altitude) in the Eastern Amazonia. It is an upland forest area with closed vegetation, 35 m average canopy high, some emergent trees with 50 m high and species density between 450 and 550 plants per hectare. The objective was to compare the estimations of rainfall interception using two numerical models, for the period from March to December of 2004. The measured rainfall interception was 248 mm corresponding to 21.5% of total precipitation (1,153.4 mm) above canopy. The rainfall interception was simulated, by Rutter´s and Gash´s models, at good level of accuracy. The Gash model overestimated the interception by 17.3% (42.8 mm), while the Rutter model overestimated by only 0.5% (1.1 mm) of the observed interception.
Acesso aberto (Open Access)
Precipitação efetiva e interceptação em Caxiuanã, na Amazônia Oriental
(Instituto Nacional de Pesquisas da Amazônia, 2008-12) OLIVEIRA, Leidiane Leão de; COSTA, Rafael Ferreira da; SOUSA, Francisco de Assis Salviano de; COSTA, Antonio Carlos Lôla da; BRAGA, Alan Pantoja
The present work was carried out at the Ferreira Penna Scientific Station, in the Caxiuanã National Forest, Melgaço, Pará, Brazil (01º 42" 30"S; 51º 31" 45"W; 60 m a.s.l.). The studied region is an upland forest with closed vegetation and a mean canopy height of 35 m although some trees can be 50 m high. The species density is between 450 and 550 plants per hectare. The aim was to quantify the net precipitation, throughfall, stemflow and rain interception by vegetation, from March to December of 2004. For the throughfall measurements 25 rain gauges were randomly distributed in an one hectare area subdivided in one hundred parcels of 10 x 10 m, while the stemflow was measured on seven trees with a stem diameter at breast height representative of the area. The results showed values of net precipitation of 905.4 mm, throughfall of 885.4 mm, stemflow 20 mm and rain interception of 248 mm,corresponding respectively to 78.5%, 76.8%, 1.7% e 21.5% of the total precipitation above the canopy which was 1,153.4 mm for the study period.
Acesso aberto (Open Access)
Transpiração em espécie de grande porte na Floresta Nacional de Caxiuanã, Pará
(2007-04) COSTA, Rafael Ferreira da; SILVA, Vicente de Paulo Rodrigues da; RUIVO, Maria de Lourdes Pinheiro; MEIR, Patrick; COSTA, Antonio Carlos Lôla da; MALHI, Yadvinder Singh; BRAGA, Alan Pantoja; GONÇALVES, Paulo Henrique Lopes; SILVA JUNIOR, João de Athaydes
During the “Long-term of impact drought on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment” (ESECAFLOR), this study was carried out, which is a subproject of Large Scale Biosphere Atmosphere Experiment in Amazônia (LBA), located in the Ferreira Penna Scientific Station (FPSS) in the Caxiuanã National Forest (CNF) in Pará State (1o 42’ 30’’ S; 51o 31’45’’ W; 62 m altitude). The region has a well-preserved forest, with canopy of 35 m. The predominate tree species in the landscape are Eschweilera coriacea (White Matá-matá), Voucapoua americana (Acapu) and Protium pallidum (White Pitch). Sap flow measurements were made in the wet season (03-16 December 2000 and 12-25 January 2003), to evidence the effect of long term induced drought, aiming to determinate the transpiration of Eschweilera coriacea. The ESECAFLOR site consists of two different areas with 1 ha each. Plot A (control) and Plot B (rainfall exclusion). The Trunk Heat Balance (THB)method was applied to sap flow measurements, by Sap Flow Meter P4.1 system. Between analysed periods, the mean transpiration of E. Coriacea increased 56% in the tree A237 (control plot) and decreased 68% in B381 (drought plot)
Acesso aberto (Open Access)
Variabilidade espacial do conforto térmico e a segregação social do espaço urbano na cidade de Belém, PA
(2013-12) SILVA JUNIOR, João de Athaydes; COSTA, Antonio Carlos Lôla da; PEZZUTI, Juarez Carlos Brito; COSTA, Rafael Ferreira da
This work contributes to the study of urban climate in Belém, PA, during the lesser rainy season, along with an analysis of social segregation issues on urban space. A campaign for collecting meteorological data during the lesser rainy season on the region was made. The data were used to calculate the thermal comfort index inside the neighborhoods and compare them with the characteristic social types in each neighborhood. The results indicated that the West and Central areas of the city were less comfortable, because they are more urbanized and have less vegetation than other areas, while the East and West areas were more comfortable, with more vegetated areas and predominance of low buildings. The analysis indicated that there is not a well-defined pattern between the neighborhoods social types and theirs thermal comfort conditions, because the surface characteristics are more significant to the local microclimate changes.
Acesso aberto (Open Access)
Variabilidade sazonal da condutância estomática em um ecossistema de manguezal amazônico e suas relações com variáveis meteorológicas
(2011-06) RODRIGUES, Hernani José Brazão; COSTA, Rafael Ferreira da; RIBEIRO, João Batista Miranda; SOUZA FILHO, José Danilo da Costa; RUIVO, Maria de Lourdes Pinheiro; SILVA JUNIOR, João de Athaydes
This work investigated the variations of stomatal conductance (gs) in the rainy and dry seasons and its dependence relations with meteorological variables measured in an Amazonian mangrove ecosystem. Data were originated from the ECOBIOMA project, part of the Large Scale Biosphere-Atmosphere Experiment in Amazon (LBA). Stomatal conductance followed the tendency of the radiation balance variation, reaching maximum values during the day and minimum values at night. The conductance showed greater fluctuations in the rainy season, with mean value of gs = 0.015 m s-1, however smaller in magnitude than in the dry season. During the dry season, the mean value was gs = 0.027 m s-1, with lower range, varying between 0.010 and 0.042 m s-1. The meteorological variables used for establishing the dependence relations with the daily variability of stomatal conductance were the following; specific moisture deficit (δq), vapor pressure deficit (PVD), net radiation (Rn) and wind velocity (Vv). The PVD showed the best correlation with gs, with R2 = 0.99 for both periods. In spite of the importance of Vv in the gaseous changes between the vegetation and the atmosphere, it presented the smallest influence in the mean variation of the gs, with R2 = 0,44 for the rainy and R2 =0,51 for the dry period.