Planting forest saplings is the most usual method for restoring areas degraded by mining. Therefore, the objective of this study was to evaluate the survival growth of planted forest species and spontaneous regeneration in post-bauxite mining areas. For this purpose, we sampled plots in recovery areas with ages ranging from five to nine years, in which the establishment, recruitment, mean annual increase in diameter and total height of the species were evaluated. The species were further classified for conservation status and origin. Of the 156 species found, 18 presented less than 25% of survival and were therefore not recommended for use in the areas, while another 22 planted species showed more than 55% survival, indicating that they can be used. Five species were registered with some threat level, another nine species were registered as exotic to Brazil and four to the Amazon. In general, 35 species were classified as suitable for planting, with an acceptable mortality rate and satisfactory growth. Thus, it was possible to select those most suitable for planting the post mining area through an evaluation of the survival rate and growth of the species.
The usage of spatial tools might be helpful in the optimization of decision-making regarding soil management, with technologies that assist in the interpretation of information related to soil fertility. Therefore, the present study evaluated the spatial variability of chemical attributes of the soil under an agroforestry system compared to a native forest in the municipality of Tomé-açu, Eastern Amazon, Brazil. Soil samples were performed at 36 points arranged in a 55 x 55 m grid. The soils were prepared and submitted to analysis in order to determine pH in H2O, exchangeable calcium, magnesium, potassium and aluminium, available phosphorus, potential acidity, organic matter, bases saturation and aluminium saturation. For each soil attribute, the spherical, gaussian and exponential models were adjusted. After the semivariograms fitting, data interpolation for assessment of spatial variability of the variables was performed through ordinary kriging. The spherical and gaussian models were the most efficient models in estimation of soil attributes spatial variability, in most cases. Most of variables presented a regular spatial variability in their respective kriging maps, with some exceptions. In general, the kriging maps can be used, and we can take them as logistical maps for management and intervention practices in order to improve the soil fertility in the study areas. The results principal components indicate the need for integrated management of soil chemical attributes, with localized application of acidity correctors, fertilizers and other types of incomes, using the spatial variability of these fertility variables.
O estudo tem como objetivo analisar a produção de açaí na região norte do Brasil nos anos de 2011 a 2017. Para isso foi realizado um levantamento de dados secundários do sistema de produção da extração vegetal de açaí nos estados da região norte do Brasil. A produção média de açaí os estados do Pará, Amazonas e Acre apresentaram maior produção de açaí no período de 2011 a 2017, respectivamente. Enquanto que os estados do Amapá, Rondônia, Roraima e Tocantins apresentaram menor produção, respectivamente. No período de estudo o estado do Pará foi o maior produtor de açaí região norte do Brasil. É necessário manter o equilíbrio entre produção açaí para a geração de emprego e renda ao mesmo tempo manter a biodiversidade, através do seu manejo adequado.
At a moment when the importance of planted forests in the Amazon region is increasing, hypsometric models become highly relevant tools as they allow monitoring of and planning for tree plantations in a way that is practical and economic for the producer. Thus, the objective of the current study was to select and adjust a model of hypsometric relationships for a clonal plantation of Tectona grandis Linn F., submitted to selective thinning, located in Capitão Poço municipality, Pará state, Brazil. Data were collected from permanent plots in five-year-old stands using the fixed area method and systematic process. The best adjusted model was selected with an adjusted determination coefficient (R²aj.%), residual standard deviation of the percentage estimate (Syx%), recalculated residual standard error (Syxr%), diagnosis of distribution of residuals as a percentage and the Percent Average Deviation (PAD%). Hyperbolic models 2 and 3 had the highest determination coefficients (83.42 and 83.40%) and lowest PAD (-0.006 and -0.154%). The polynomial (1) and hyperbolic models (2 and 3) showed the smallest errors in related to the estimates. Model 2 (hyperbolic) was found to generate the best estimate of total T. grandis clonal plantation height. Use of this hypsometric model will allow a significant reduction of costs and time in forest inventory studies.
O Brasil é um dos principais produtores de madeira reflorestada do mundo, ocupando a nona posição no ranking de áreas de povoamentos florestais. O plantio de floresta pode ser uma alternativa significativa para fortalecer o agronegócio sustentável na Amazônia, ao mesmo tempo que possibilitaria a redução da pressão sobre os recursos naturais da região. O objetivo desta pesquisa é analisar a conjuntura do mercado de floresta plantada no estado do Pará, como forma de compreender sua participação relativa no contexto nacional, caracterizando as principais espécies cultivadas, os municípios produtores, as empresas com atuação e expertise no ramo e ressaltar os desafios e oportunidades no setor. Os dados utilizados foram obtidos junto ao Instituto Brasileiro de Geografia e Estatística (IBGE), referente ao período entre 2013 a 2019. As variáveis analisadas foram produção em metros cúbicos (m³), valor da produção em reais (R$), área colhida em hectares (ha), preço em reais por metros cúbicos (R$.m-³). Verificou-se que o estado do Pará participa com 1,9% da produção nacional, ocupando a 11ª posição no ranking brasileiro de produção. O crescimento da produção paraense expande-se a partir do ano de 2015, principalmente a partir do cultivo do eucalipto. O uso de técnicas no manejo florestal de precisão, modernos projetos de plantio no estado, contribuem para uma maior produção de madeira plantada. Os povoamentos florestais são alternativas renováveis de grande potencial econômico, sobretudo para ocupar áreas já alteradas. Contudo, é notável que ainda exista poucos estudos relacionados ao plantio comercial de outras espécies adaptadas a realidade regional.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.