2 resultados para Eucalipto, cultivo, aspectos ambientais, Brasil

em Repositorio Institucional da UFLA (RIUFLA)


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Nature Protection Areas (NPA) are important in the modern world, although still created with no well-defined criteria, overall in state and municipal spheres. In addition, there are no consistent information on the existence or factors that influence the creation and distribution of these areas. The present work had the objectives of identifying the Nature Protection Areas in Minas Gerais, Brazil, considering the municipalities and their mesoregions; perform a space-temporal analysis of the NPAs in Minas Gerais; relate the existence of NPAs with the Municipal Human Development Index (MHDI) and the municipal Gini Index (GI); relate the existence of NPA with the space-temporal and population density of each municipality; relate the Gross Domestic Product (GDP) with the presence of NPAs; relate the existence of NPAs with the occurrence of preservation areas in municipalities within the Atlantic Forest Biome; and verify the influence of the Ecological Sales and Services Tax (Ecological ICMS) institute over the creation of municipal NPAs in Minas Gerais. To reach these objectives, we researched databases, governmental websites, contacted managers and sent questionnaires to the 853 municipalities of Minas Gerais. After tabulating the data, statistical tests were applied to verify possible correlations. The results showed that the state has 9.26% of its territory protected, with the predominance of units of Sustainable Use, especially Environmental Protection Areas, which constitute 69.9% of this area. Only 1.96% of the territory are protected by Integral Protection (IP). We found no correlation between MHDI and the presence of NPAs. However, we verified that municipalities with IP units present higher GI when compared to the others, suggesting that the presence of this conservation unit (CU) model may be associated to social inequality. The results also showed a higher concentration CU in regions that use little of its natural resources as main economic basis and in municipalities with higher GDP. We also registered a positive correlation between the size of the municipalities, of the mesoregions, preserved area of the Atlantic Forest and population density. The Ecological ICMS did not contribute for a better IP in the state and, currently, does not represent an incentive to the creation of CU in Minas Gerais, even in the case of Environmental Protection Areas. This work registered a high degree of vulnerability if the protection system in this state, based on low restriction conservation units.

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Forestry has grown in a continuous and accelerated manner in Brazil, constituting a strategic activity for the generation of employment, income and tributes, favoring social and economic development of Brazilian agribusiness. The objectives of this study were: (1) evaluate the contents of K, Ca and Mg in the reserve compartments, non-interchangeable, interchangeable, available and the speed of its release, its correlations and its effects over productivity (annual average increment – AAI) of eucalyptus plantations, in forest sites cultivated in soils of the state of Rio Grande do Sul; (2) evaluate the initial growth, nutrition and physiological aspects of eucalyptus plants, cultivated with and without the addition of mineral sources of potassium (K), calcium (Ca) and magnesium (MG), in soils obtained from forest sites in the state of Rio Grande do Sul. In the first study, contents of K, Ca and Mg were evaluated in sulfuric digestion extract, boiling nitric acid, ammonium chloride, Mehlich-1 (only K), potassium chloride (Ca and Mg), as well as the release speed of these nutrients in the soil. In the second study, growth variables, nutritional aspects, photosynthetic rate (A) and transpiration rate of the plants (E) grown in distinct soils were evaluated under controlled conditions. The contents of K, Ca and Mg varied between compartments and depths in the studied soil classes, with the highest proportions found in the reserve compartment, indicating the importance of this compartment for the supplement of these nutrients at average and long terms. The great majority of K, Ca and Mg compartments presented significant correlations between each other, showing the dependence between them and the importance of evaluating the contents of these nutrients in the different compartments to adapt the nutritional management of the plants to each soil class, and to obtain continuous productions, minimizing the negative effects to the environment. Plants cultivated in soils that present larger reserves, availability and K, Ca and Mg release kinetics, presented similar height (H), stem diameter (SD) and shoot dry mass (SDM), with or without fertilization with K, Ca and Mg. The plants presented higher leaf content and accumulation of K in all soils fertilized with K, Ca and Mg.