Eder Pereira Miguel

Determinants of the Brazilian Amazon deforestation

The Amazon rainforest is the world’s largest biome, containing almost 50% of the planet’s known biodiversity and is the biggest source of fresh water, which is approximately one-fifth of the global reserves. However, the sustainable use of this ecosystem is threatened by several factors, and deforestation is the main problem. This study addresses the deforestation of the Brazilian Amazon forest, in particular evaluate the determinants of the deforestation process, using for this purpose, time-series of several socioeconomic factors from 1990 to 2015. The methodology applied included statistical analyzes based on the application of multivariate discriminant analysis with the stepwise criteria. The results showed that in order of importance cattle, roads network, population, logging and crop areas were the determinant variables of the deforestation in the amazon. Key words: Cattle, population, deforestation, Brazilian Amazon.

INTERPOLADOR GEOESTATÍSTICO PARA ESTIMAR VOLUME NUM POVOAMENTO DE Eucalyptus urophylla, EM RIO VERDE/GOIÁS

Os metodos tradicionais de estatistica aplicados em inventarios florestais nao exploram suficientemente as relacoes existentes entre as unidades amostrais. O presente estudo buscou comparar as estimativas de um interpolador geoestatistico em relacao ao inventario florestal tradicional. A area de estudo envolveu um total de 116 hectares de Eucalyptus urophylla em Rio Verde/GO. Esta floresta, plantada em 2005, tem espacamento 2,8 m x 1,8 m. Para este estudo foram amostradas 23 parcelas de 400 m² cada. Para avaliacao do processo de interpolacao foram utilizadas de forma aleatoria 13 parcelas das 23 alocadas. As outras 10 parcelas foram utilizadas para validacao da interpolacao. Os resultados desta pesquisa indicam que nao houve diferenca significativa entre as estimativas feitas a partir da Krigagem Ordinaria e do inventario florestal tradicional. Assim sendo, o metodo se mostrou eficiente para estimar o volume no povoamento florestal em estudo, podendo contribuir com muita eficiencia na espacializacao dessa variavel.SUMMARY: Traditional Statistical methods applied to forest inventories have not sufficiently assessed relationships among sampling units. This study intended to compare the resulting estimates derived from a geostatistical interpolator and from a traditional forest inventory. The study area encompassed a total of 116 hectares of Eucalyptus urophylla, located in Rio Verde/ GO, Brazil. This is a 6.5 years old forest, planted in 2005, with spacing of 2.8 mx 1.8 m. In this study, we sampled 23 plots of 400 m² each. Also, we randomly allocated 13 of 23 plots to assess the interpolator method. The remaining 10 plots were used to validate the interpolation results and to compare with data derived from the forest inventory. This research results indicate that the difference between Ordinary Kriging and traditional inventory estimates was not significantly different. Therefore, the method was successfully applied to estimate the volume in forest land and can pontentially support volume estimation throughout an entire area of interest.