Gilson Fernandes da Silva

Quantificação do estoque de carbono e avaliação econômica de diferentes alternativas de manejo em um plantio de eucalipto

Este estudo teve por objetivos: quantificar o estoque de madeira para a producao de carvao e serraria em uma floresta de eucalipto; quantificar o estoque de carbono nos diferentes compartimentos da floresta; e avaliar economicamente alternativas de manejo, com vista a insercao de povoamentos florestais no mecanismo de desenvolvimento limpo e na venda de creditos de carbono. Para isso, realizou-se um inventario florestal em uma plantacao de Eucalyptus grandis, com 6 anos de idade, no Municipio de Vicosa, Minas Gerais. Apos as analises, verificou-se que: a) o fuste e o componente da arvore que mais contribui, em media, para o total de carbono da parte aerea (81,84%), seguido por casca (8,05%), galhos (7,74%) e folhas (2,57%); b) 47,7 toneladas de carbono por hectare estao estocadas na parte aerea das arvores; 14,71 nas raizes e 8,72 na manta orgânica, totalizando 71,13 toneladas de carbono por hectare; c) a producao de madeira somente para a venda de creditos de carbono, sem considerar o seu uso final, e economicamente viavel, segundo criterios quantitativos de avaliacao do projeto, se a tonelada de carbono for comercializada a precos maiores que US

Análise da influência de diferentes tamanhos e composições de amostras no ajuste de uma relação hipsométrica para Eucalyptus grandis

10,07; e d) a venda de creditos de carbono torna o empreendimento ainda mais atrativo economicamente, sobretudo porque a receita e auferida no inicio do projeto.

Projeção do estoque de carbono e análise da geração de créditos em povoamentos de eucalipto

The adjustment of hypsometric relations using data from forest inventory aiming at the estimation of individual tree volumes is a common task in Brazilian forestry companies. This study used a data set of 481 trees of Eucalyptus grandis from a forest inventory. Simulation was carried out varying sample sizes from 6 to 204 sample-trees. For each sample size it was run 10,000 simulations for each size samples selected randomly. This study aimed at evaluating the effect of sample size and structure on the precision of a previously chosen hypsometric model which had, as independent variables, the Diameter at Breast Height (DBH) and the tree age. It was also evaluated the effect of these covariates on the tree heights estimates. It was concluded that a sample with at least 27 trees could more precisely estimate tree height when compared to smaller samples. In addition, sample sizes containing more than 27 trees did not shown significant improving on the precision of the height estimates. For the hipysometric model, the variable DBH was more valuable to estimate the tree height than the covariate age. For the trees with larger DBH, the variable age showed to be more influent.

Avaliação de métodos de medição de altura em florestas naturais

The objectives of this study were to predict volumetric yield and carbon stock in the stems of eucalypt plantation trees, as well as to economically evaluate the inclusion of the Reduced Emission Certificates (RECs) in forest projects by quantitative criteria. Thus, data from Eucalyptus grandis stands, located in Guanhaes-Minas Gerais, were used. Based on the volume and carbon equations for the stems of individual trees and for 95 permanent plots, Clutter growth and production model (1983) were adjusted for volumetric production and carbon stock projection. After analysis, it was verified that: a) the growth and yield model proposed by Clutter (1983) provided technical cutting ages according to the productivity capacity of the stands, both for volumetric yield and carbon stock; b) the technical cutting ages (TCAs) were practically the same, considering the volumetric and carbon stocks; c) the economic rotations were greater than the technical cutting age in sites with low and average productivity (S = 20 and S = 26), regardless of the inclusion or not of the CERs in the analysis; d) the CERs contributed to the economic viability of the forest projects in low productivity sites, considering the budgets for the establishment of the projects; e) in the sensitivity analysis, the item wood price had the greatest influence on the economic viability of the projects. In contrast, the Reduced Emission Certificates (RECs) had little influence.

Equações hipsométricas, volumétricas e de taper para onze espécies nativas

The objective of this work was to compare methods of tree height measure in natural foress. Total heights measured by hypsometer Vertex were compared with those obtained by escalade of the trees. The method of visual estimate was also tested, with and without training, as a more practical alternative and of slower cost. The tested methods were evaluated for three height classes: 1 - (15-25 meters); 2 - (25-35 meters) and; 3 - (> 35 meters). At the end, it was concluded that the increase in the height of the trees reduced precision of the estimate for the appraised methods, being more evident in the visual estimate without training. The only statistical difference, at the level of 5% of probability for the test t, among the averages of heights for the appraised methods and the averages of the heights obtained by escalade, in the different classes, occurred in the visual estimate with training in the class 2. The statistics Average Deviation (DM), Average of the Absolute Differences (MD) and Standard Deviation of the Differences (DPD) indicated larger precision in the estimate of the height for the visual estimate with training, following Vertex and visual estimate without training.

Avaliação de um modelo de passo invariante na predição da estrutura de um povoamento de Eucalyptus sp.

The objective of this study was to adjust hypsometric, volumetric and taper equations for eleven native species planted in experimental plots, at Universidade Federal de Vicosa, Minas Gerais, Brazil. After analysis, it was verified that: a) the hipsometric model 2 best adjusted for nine species; b) the volumetric model 2 was best adjusted to the data of main stem volume with bark for six species, while the volumetric model was better adjusted for five species; c) Taper model 3 showed better performance, being selected to describe the profile stem of ten species.

DINÂMICA DO ESTOQUE DE CARBONO EM FUSTE DE ÁRVORES DE UMA FLORESTA ESTACIONAL SEMIDECIDUAL

This study was carried out to evaluate the step-invariant diametric distribution model, proposed by Guimaraes (1994), for the prediction of a Eucalyptus stand production, simulating the alterations in the horizontal and vertical structures with time. Data were taken from annual measurements, with measurement age between 25 and 89 months, of the first rotation of hybrid eucalyptus stands (Eucalyptus grandis x Eucalyptus urophylla), plant spacing of 3.0 x 2.0 m, located in the northeast region of State of Bahia. To perform prognoses percentiles were taken at 50 and 75% of the diametric distribution, and the heights corresponding to the diameters in these positions. The prediction model was proved to be feasible for efficient use, since there were similar tendencies between the forecasted and the observed volumes in the plots. Besides, its use in growth and production prediction of Eucalyptus sp. studies is recommended for its simplicity and result compatibility.

Estoque volumétrico, de biomassa e de carbono em uma floresta estacional semidecidual em viçosa, minas gerais

Objetivou-se, neste trabalho, avaliar a dinâmica do estoque de carbono no fuste das arvores de uma Floresta Estacional Semidecidual, por meio do monitoramento de 10 parcelas permanentes instaladas na Mata da Silvicultura, Vicosa, Minas Gerais. Foram identificados e medidos todos os individuos com DAP ≥ 5 cm, nos anos de 1994, 1997, 2000, 2004 e 2008. O estoque medio de carbono no fuste das arvores aumentou de 47,9 ton.ha-1, no ano de 1994, para 61,81 ton.ha-1, no ano de 2008, representando, para os 14 anos de monitoramento, um incremento periodico de 0,994 ton.ha-1.ano-1.

Comparação entre procedimentos de amostragem para espécies florestais raras e padrão de distribuição espacial agregado

-1 . As arvores vivas contribuiram em media com 82,8% deste total, seguido da serapilheira (5,1%); especies nao arboreas (4,2%); arvores mortas (3,5%); arvoretas (2,9%); mudas (1,5%). Do total de biomassa, 181,48 t ha -1 (79,8%) estavam acima do solo; 34,3 t ha -1 (15,1%) nas raizes e 11,62 t ha -1 (5,1%) na serapilheira.O estoque total de carbono foi de 108,98 ± 35,33 t ha -1 . As arvores vivas contribuiram com 82,6%; serapilheira 5,2%; especies nao arboreas 4,2%; arvores mortas 3,5%; arvoretas 3,0%; mudas 1,5%. Do estoque total de carbono, 86,93 t ha -1 (79,7%) estavam acima do solo; 16,41 t ha -1 (15,1%) nas raizes e 5,64 t ha -1 (5,2%) na serapilheira. ABSTRACT - The objective of this study was to estimate volume, biomass and carbon Stocks in trees (level 1), shrubs and seedlings (level 2) and litter (level 3), in a Semideciduos Seazonal Forest in Vicosa, Minas Gerais State, Brazil. Data of level 1 of approaching were obtained from 15 plots with 0.1 ha each. Fifteen plots of 25 m 2 and 6.25 m 2 were used in levels 2 and 3, respectively, located in level 1 plots. The total volume outside bark (stem + crown) was estimated in 281.51 ±105.80 m 3 ha -1 and 15.2% of this estimate corresponded to bark volume. The stem contributed with 80.30% of the total volume and the crown with 19.70%. The total biomass was estimated in 227.40 ± 77.81 t ha -1 . Of this total, 181.48 t ha -1 (79.7%) were aboveground; 34.3 t ha -1 (15.2%) in the roots and 11.62 t ha -1 (5.1%) in the litter. The alive trees contributed on average with 82.8% of the total biomass, followed by litter (5.1%); no arborous species (4.2%); dead trees (3.5%); shrubs (2.9%); seedlings (1.5%). The total carbon stock was estimated in 108.98 ± 35.33 t ha -1 . The percentile contribution was similar to found for biomass: alive trees 82.6%; litter 5.2%; no arborous species 4.2%; dead trees 3.5%; shrubs 3.0%; and seedlings 1.5%. Of the total carbon stock, 86.93 t ha -1 (79.7%) were aboveground; 16.41 t ha -1 (15.1%) in the roots and 5.64 t ha -1 (5.2%) in the litter.

Avaliação de modelos de afilamento segmentados na estimação da altura e volume comercial de fustes de Eucalyptus sp.

The objective of this work was to evaluate the procedure adaptive sampling procedure used in forest inventories for species with low population density and aggregated spatial distribution pattern, in relation to procedures normally used in forest inventories. Thus, a population was simulated in a 90 ha forest, subdivided into 100 units (N = 100) with areas of 9,000 m² each, presenting 44 individuals of a given species, and submitted to three sampling procedures: simple random sampling; systematic sampling and adaptive cluster sampling, with initial samples selected through simple random sampling and systematic sampling. After analyses, it was verified that the systematic sampling was the best procedure to estimate the total number of individuals of the studied species. Besides, it was observed the need of further investigation on the effect of the size and form of plots, the aggregation scale and size of the population, and their combinations, on the efficiency of the estimators of the adaptive cluster sampling.