Navegando por Autor "YARED, Jorge Alberto Gazel"

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Acesso aberto (Open Access)
Growth and survival of Sclerolobium paniculatum vogel and the relationship between rainfall and the increment in diameter at different planting spacings
(Universidade Federal do Pará, 2016-06) NARDUCCI, Tainah Silva; YARED, Jorge Alberto Gazel; BRIENZA JÚNIOR, Silvio
Sclerolobium paniculatum Vogel is a species that has good potential for reclamation of degraded soils. The aim of the investigation was to evaluate the growth and survival of the species and the influence of rainfall on growth in diameter as a function of different spacings (4 m x 2 m, 4 m x 3 m, and 4 m x 4 m). The results indicate that the temporal analysis (period from November 2007 to August 2013) detected significant differences (p ≤ 0.05) in height between the 4 m x 2 m and 4 m x 4 m spacings, while no significant difference in diameter was found between the 4 m x 2 m and 4 m x 3 m spacings. However, the statistical differences did not persist when the data was analyzed at seven and half years old. Regarding survival, a significant difference was observed only between the 4 m x 4 m spacing and the others, with superiority to the former. A strong correlation was found between rainfall and the increment in diameter of individuals in the broader spacings (R = 0.80 in the 4 m x 3 m spacing and R = 0.77 in the 4 m x 4 m spacing), while in the denser spacing the correlation was moderate (R = 0.56 in the 4 m x 2 m spacing). Since the spacings adopted did not influence tree growth by the end of the period, the choice will depend on other factors such as survival and costs of implementation and forestry management. Plantations in regions with larger rainfall amplitude may benefit the productivity of the species.
Acesso aberto (Open Access)
O valor econômico da extração manejada de madeira no baixo Amazonas, estado do Pará
(2012-06) SANTANA, Antônio Cordeiro de; SANTOS, Marcos Antônio Souza dos; SANTANA, Ádamo Lima de; YARED, Jorge Alberto Gazel
The objective of this study was to estimate the economic value and the trade margin of roundwood from managed areas. Besides generating a positive margin values, they are relatively higher In this chain than those generated in activities contributing to deforestation in the Amazon. Additionally, the unfolding mean rate of 37.3% was achieved (2.68 m3 of logs for each 1.0 m3 of sawn timber), which revealed a low technological level of companies. At the lower Amazon, the average economic value from the extraction and sale of standing timber in the local market was R$ 23.48/m3, with a minimum value of R$ 9.06/m3 for the species in category C4 (softwood) and a maximum of R$ 55.63/m3 for the species of category C1 (special wood). Thus, considering an extraction flow of 30 years and assuming the extraction of 25 m3/ha in management designs of forest areas from concession contracts in the state of Pará, it is generate an average economic value of R$ 587.00/ha or R$ 19.56/ha/year, which is relatively higher than the profit generated by the activities of extensive livestock (around R$ 180.00 per hectare or R$ 6.00/ha/year) and grain crops (approximately R$ 420.00 per hectare or R$ 14.00/ha/year), which are the main responsibles for deforestation in the Amazon. It also presents a higher profitability than the reforesting with Paricá, whose income is R$ 192.26/ha or R$ 7.12/ha/year. The marketing margin showed that society tends to appropriate of 14.30% of the economic value generated in the wood chain from the transition contracts.