January 2023

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Alternatives to estimate biomass and carbon in Atlantic Forest fragment in Northeast Brazil

Adriano Castelo dos Santos, Maria Betânia Galvão dos Santos Freire, Ane Cristine Fortes da Silva, Lucca Silveira Mousinho Mossio, Luiz Carlos Marangon, Fernando José Freire, Rosival Barros de Andrade Lima, Luciedi de Cássia Leôncio Tostes, João da Luz Freitas, Giovana Elvira de Melo, César Henrique Alves Borges

ABSTRACT: Biomass quantification in the Atlantic Forest is difficult due to a scarcity of destructive tree sampling data for this biome.Many studies have used general pantropical models to quantify their biomass stocks. However, doubts still need to be raised about the ability of these models to accurately estimate the biomass of trees in the Atlantic Forest biome. Thus, the objective of this work was to evaluate and test the performance of allometric equations with different input variables to estimate biomass and accumulated carbon in dominant species in an Atlantic Forest fragment in northeastern Brazil. A recent study in the area, with 1,324 inventoried trees, was used to obtain the phytosociological and dendrometric data needed to analyze forest biomass. We selected five pantropical allometric equations with good reproducibility for humid tropical forests and a local equation (Atlantic Forest) to calculate above-ground biomass (AGB). The input variables used were tree diameter at breast height (DBH), tree height (H), wood density (p), and bioclimatic variables (E) (water stress and rainfall). The findings support the conclusion that there is a significant difference between the six equations tested to estimate biomass and carbon in the forest fragment.Therefore, if H, DBH, and density data are available after the forest inventory of the area, the pantropical equation can be used to quantify the AGB. Otherwise, the local equation is a viable alternative. These results can help elaborate environmental projects targeting the carbon market and enabling the forest for REDD+ projects.

[ FULL TEXT PDF 1-8 ] DOI: 10.22587/ajbas.2023.17.1.1

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An Examination of Audio-Visual Simple Reaction Times in Selected Court Games

Md. Nasim Reza, Md. Hamidur Rahman, Muhammad Shahidul Islam, Arup Gayen

ABSTRACT: This research examined the audio-visual simple reaction times in the hands and legs of basketball, handball, and volleyball players. A total of thirty-six (N=36) male athletes randomly participated in this study, among them (n=12) basketball players, (n=12) handball players, and (n=12) volleyball players. The players’ average ages were 22.33±1.15; 22.00±1.41; 21.75±1.22, and they competed at the university level in their respective sports. The timer for Audio-Visual Reaction was used to measure the auditory and visual simple reaction times of the hands and legs in milliseconds. The mean, standard deviation, independent t-test, and one-way ANOVA were used, and the level of significance was set at p<0.05. The F-value of auditory reaction time was 0.21 (> 0.05) in basketball, handball, and volleyball players' strong hand, 0.05 (> 0.05) in weak hand, 1.02 (> 0.05) in strong leg, and 2.23 (> 0.05) in weak leg. Whereas, the strong hand had a visual reaction time of 1.37 (> 0.05), the weak hand had a reaction time of 0.51 (> 0.05), the strong leg had a reaction time of 2.31 (> 0.05), and the weak leg had a reaction time of 0.65 (> 0.05). According to the statistical examination, no significant difference was obtained in auditory and visual reaction times among basketball, handball, and volleyball players with their strong and weak hands and strong and weak legs. Since there was no significant difference in the ANOVA analysis, the reaction times of the limbs (auditory and visual) were compared between each of the two games. The weak leg auditory reaction time was significantly different between basketball and handball players in an independent t-test (t (22) = 2.17, sig. = 0.041 at p 0.05). This study concluded that the auditory and visual simple reaction ability of hands and legs was closer for the three different court games, and a difference was obtained between basketball and handball players concerning weak leg auditory reaction time.

[ FULL TEXT PDF 9-14 ] DOI: 10.22587/ajbas.2023.17.1.2

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Modelling of a water filtration pilot by a chemical tracer using the Modflow "Finite Differences"

Eric Foto, Oscar Allahdin, Nicole Poumaye, Olga Biteman

ABSTRACT: For the supply of drinking water to the population, we have set up a surface water treatment system: horizontal sand filtration. This process is based on the principle of bank filtration; it is a natural rustic treatment, based on slow biological filtration, which does not require any reagent. The objective of this work is to propose a tool to describe the groundwater flow on a complete water filtration system with the MODFLOW model in order to follow the evolution of the hydrodynamic parameters on the one hand and to determine the transit time of the water in the pilot. The calibration with a chemical tracer, fluorescein, allowing to optimise the defined parameters (hydraulic conductivities, recharge) of the aquifer in order to obtain calculated loads as close as possible to those measured in given observation points, and the reading and saving of the imposed hydraulic loads were carried out with the "results extractor" module. The variation of the slope of the 2nd compartment from 5% to 20% significantly reduces the transit time of the tracer from 6.3 h to 5.2 h in the device. It was also found that the transit time increased as the sand grain size decreased, but this did not indicate a malfunction of the device. The results obtained showed that it is possible to perform a hydrodynamic modelling of the system in order to reproduce the experiments performed on the physical device. The steady-state modelling shows that the curves calculated at each piezometer are close to the experimental curves, except for the variation in sand grain size (piezometer 3), probably due to the preferred path. The differences in concentration between the calculated and experimental values at piezometers 3 and 4 are due to a dilution and/or adsorption effect by the fine sand. The calibration of the model allows an appropriate sizing according to each problem.

[ FULL TEXT PDF 15-23 ] DOI: 10.22587/ajbas.2023.17.1.3

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