Monitoring reduced impact logging (RIL) activities in sustainably managed forest areas in the Amazon is a costly and complex, yet crucial endeavor. One viable monitoring option is the use of airborne ...laser scanning (LiDAR), which enables estimating forest structure parameters over large areas in a reduced timeframe with high accuracy. In this study, we propose and assess the applicability of five monitoring indicators for RIL based on Light Detection and Ranging (LiDAR) data acquisition in areas under forest concession. Five Annual Production Units (APUs) were investigated within the Forest Management Unit (FMU) III of the Jamari National Forest, located in the Southwest of the Brazilian Amazon. These sites were surveyed by LiDAR in 2014 and 2015 (one year after the exploration). Digital Terrain Models (DTMs), Surface Models (DSMs), and Canopy Height Models (CHMs) were generated for each APU. The proposed indicators were: i. Detection and identification of crown removal in dominant and co-dominant trees above 30 m; ii. Gap detection in the forest canopy; iii. Impacts of Reduced Impact Logging on the Understory; iv. Changes in the vertical canopy profile; and v. Affected areas within Permanent Preservation Areas (PPAs) and restricted areas. There was a 3.95% reduction in the occurrence of taller canopies after RIL, and a higher occurrence of small gaps (λ > 1), with λ values (2.34) being higher in the area with the oldest logging history (APU 1). Gini coefficient values in all APUs were below 0.5, indicating a low intensity of disturbances in the forest canopy. The shape (γ) and scale (β) parameters of the understory and canopy were not significantly correlated with variables related to selective logging. Restricted areas were considered for the allocation of roads, trails, log landings, and places with slopes equal to or >15%, and the indices of areas affected by RIL in PPAs and restricted areas were <2%. The proposed indicators using LiDAR data show great potential for monitoring managed areas in the Amazon and can be utilized by concession companies and government oversight.
•Lambda (λ) values >1 across all areas indicated that gaps of up to 150 m2 were predominant.•Gini coefficient < 0.5 across all APUs, indicating low disturbance in the forest canopy.•The most notable impacts of Reduced Impact Logging (RIL) were attributed to the opening of skid trails.•Permanent Preservation Areas and Restrictive Areas remained unaffected by RIL activities.•LiDAR -derived indicators were found to be suitable for monitoring low-intensity logging in tropical forests.
The expansion and changes in land use and land cover in the Southwest Amazon are mainly related to the activities of logging without management rules, agriculture and cattle production, which ...resulted in the conversion of natural forests, especially along water courses. This study aimed to verify the diametric distribution of forestry species with higher importance value index in the riparian forest of the Acre River (Acre, Brazil). The forestry inventory was performed at eight municipalities crossed by the Acre River, using two stage sample units (conglomerates) and applying stratified random sampling techniques at the river bank. Twenty-seven primary plots were installed, within which another four secondary plots were implanted. It was fitted Weibull’s probability density functions with 2 and 3 parameters to species diametric distribution, provided by the maximum likelihood method. Graphic analysis verified that 86% of the species analyzed presented a distribution trend with positive asymmetry. The distribution of the Weibull function with two parameters presented better the best estimative of the frequency of species by diameter class of the natural forest evaluated. Considering the heterogeneity of the species, further studies to verify whether the distribution behavior follows the same trend is recommended.
A expansão e as mudanças no uso e cobertura da terra na parte sul da Amazônia ocidental estão vinculadas principalmente às atividades do extrativismo madeireiro sem regras de manejo e à produção ...agropecuária, que resultaram na conversão de florestas nativas, especialmente ao longo de cursos d’água. Esse estudo teve como objetivo verificar a distribuição diamétrica de espécies florestais com maior índice de valor de importância da mata ciliar do Rio Acre, AC. O inventário florestal foi realizado em oito municípios cortados pelo Rio Acre, utilizando unidades amostrais com dois estágios (conglomerados) e técnicas de amostragem aleatória estratificada pela faixa marginal do Rio Acre. Foram instaladas 27 parcelas primárias, dentro das quais foram distribuídas quatro parcelas secundárias. Para estudo da classificação diamétrica, foram avaliadas as funções de densidade probabilística de Weibull 2 e 3 parâmetros pelo método da máxima verossimilhança. Pela análise gráfica, verificou-se que 86% das espécies analisadas apresentaram tendência de distribuição com assimetria positiva. A distribuição da função Weibull com dois parâmetros estimou melhor a frequência de espécies por classe de diâmetros. Diante da heterogeneidade das espécies, recomendam-se novas pesquisas para verificar se o comportamento da distribuição segue a mesma tendência.
Boron (B) is a micronutrient that plays a role in the growth and development of plants. In beetroot (Beta vulgaris L.), B allows increased yield and accumulation of dry mass. This work aimed to ...evaluate the agronomic performance of beetroot fertigated with B in the municipality of Mossoró, RN. To this end, two field experiments were conducted in Mossoró, RN, Brazil, designed in complete randomized blocks. Five doses of B (0, 1.0, 2.0, 3.0, and 4.0 kg ha
−1
of B) were tested, with four replications. The treatments did not influence the plants' height, the number of leaves per plant, or the postharvest quality characteristics of the tuberous root. The maximum total and commercial yield of tuberous roots was 22.22 and 21.29 t ha
−1
, respectively, fertilizing with 4.0 kg ha
−1
of B. This dose also promoted the highest accumulation of B in the plant. Using doses above those evaluated can promote greater yield of tuberous beetroot. Therefore, further studies are necessary to determine the recommended dose of B for beets grown in semi-arid regions.
In regions with high temperatures, carrot cultivation is impracticable, as high temperatures tend to reduce yield and quality of the product. However, with the advent of summer cultivars, carrot ...cultivation in these regions has become viable. The aim of this work was to evaluate the performance of ten carrot cultivars in different planting seasons. The experiments were carried out at the Rafael Fernandes Experimental Farm of the Federal Rural Semiarid University (UFERSA). The experiments were carried out in May, June, July and August of 2017. The experimental design was a randomized block with ten treatments and four repetitions. The characteristics that were evaluated were the root classification (long, average and short roots); commercial, non-commercial and total yield; dry plant weight and root fresh weight. Both the planting season and the cultivar played important roles in agronomic performance throughout the experimental period. In May and June, the highest average yields and plant growth were obtained (43 and 45 t ha-1 yield, respectively). Hybrid cultivars showed better performance than open-pollinated cultivars in terms of yield. The Brasília, BRS Planalto, and Kuronan varieties showed poor performance in all the evaluated characteristics.
The chemical composition of carrot roots is variable and influenced by genetic factors and cultivation conditions, such as crop system, soil type and physical properties, planting time, rainfall, and ...temperature during the growing season (Seljåsen et al., 2013), as well as phytosanitary aspects, fertilization, and planting density. ...understanding the environmental conditions in different regions and climates where a crop is grown is crucial when choosing a cultivar. Additional research is needed due to the difficulties of carrot production in warm and lower elevation regions, starting with the selection of cultivars with genetic potential for quality root production under high temperatures. ...it is assumed that the planting date influences the postharvest quality of carrot roots due to climatic and environmental variations, such as precipitation, temperature, and cloudiness. Results are presented in Table 2. Since the experiments were carried out in adjacent areas, only a composite sample was taken from the experimental area for analysis.
Fertilization plays an important role on carrot’s yield, root quality, storage, plant growth and on the environment. It was aimed to evaluate the plant growth and macronutrients accumulation of ...carrot cultivars as a function of two planting dates, under high temperatures in the Brazilian semi-arid. The experiments were carried out in randomized blocks design, with ten treatments and four repetitions. Treatments consisted of ten carrot cultivars sowed in two Planting dates. The characteristics that were evaluated were: plant growth (plant height, number of leaves, plant dry matter accumulation, mean fresh mass of the root) and macronutrient accumulation (N, P, K, Ca and Mg) in plant, leaves and root. Plant’s mean height ranged from 42.53 cm (Melinda) to 49.25 cm (Nativa); the highest plant dry matter was obtained by BRS Planalto (12.36 g) and Kuronan (12.18 g); the mean number of leaves was the lowest in Melinda and Nativa: 8.64 and 7.64 leaves plant-1. The root’s fresh weight had a significant decrease among the planting dates for the Brasília, Francine and Suprema cultivars. The nutrient accumulation varied accordingly to the planting date and cultivar.
ABSTRACT The objective of this study was to evaluate the efficiency of the use of phosphorus by maize cultivars for the production of green ears. Two experiments were carried out, one in the rainy ...season (March to June) and the other in the dry period (August to December), both at the Rafael Fernandes Experimental Farm, in the community of Alagoinha, belonging to the Universidade Federal Rural do Semiárido, in the municipality of Mossoró, RN, Brazil. The treatments consisted of a combination of three levels of phosphorus (low, medium and high) and eight corn cultivars (Dona Josélia, Carrapateira, Pontinha, Cruzeta, Potiguar, BRS 2022, Status and AG 1051). A randomized block design was used in a 3 × 8 factorial scheme, with four repetitions. The evaluated characteristics were: number and total mass of green ears, number and mass of tradable, stuffed and depleted green ears, agronomic and physiological efficiency of production of recovery and use of phosphorus. The cultivars showed better productive performance when fertilized with phosphorus. The cultivars Cruzeta, Potiguar, BRS 2022, Status, AG 1051 and Carrapateira were the most efficient in the use of phosphorus to produce green maize.
RESUMO Objetivou-se avaliar a eficiência da utilização de fósforo por cultivares de milho para produção de espigas verdes. Foram conduzidos dois experimentos, um no período chuvoso (março a junho) e outro no período seco (agosto a dezembro), ambos na Fazenda Experimental Rafael Fernandes, na comunidade de Alagoinha, pertencente à Universidade Federal Rural do Semiárido, no município de Mossoró, RN. Os tratamentos foram constituídos pela combinação de três níveis de fósforo (baixo, médio e alto) e oito cultivares de milho (Dona Josélia, Carrapateira, Pontinha, Cruzeta, Potiguar, BRS 2022, Status e AG 1051). Foi utilizado o delineamento experimental em blocos ao acaso, em esquema fatorial 3 × 8, com quatro repetições. As características avaliadas foram: número e massa total de espigas verde, número e massa de espigas verdes comercializáveis (empalhadas e despalhadas), eficiências agronômica, fisiológica, de produção de espigas, de recuperação e de utilização do fósforo. As cultivares apresentaram melhor desempenho produtivo quando adubadas com fósforo. As cultivares Cruzeta, Potiguar, BRS 2022, Status, AG 1051 e Carrapateira foram as mais eficientes na utilização do fósforo para a produção de milho verde.
The aim of this study was to evaluate the effect on intake, apparent digestibility, and ruminal constituents of sheep in response to the addition of increasing levels of babassu mesocarp flour (BMF) ...to the diet. Twenty crossbred sheep (29.17±2.23 kg) were used in a randomized complete block design. Lambs were confined for 21 days, with 16 days for diet adaptation and 5 days for data collection, in which they were fed an isonitrogenous diet (16.5±0.2 CP, DM basis) containing 70% of concentrate and 30% (DM basis) of Tifton 85 hay. Increasing levels of BMF were 0, 10, 20, and 30% (DM basis). There was a quadratic effect (P<0.05) on the DM intake, nutrients intake, and digestibility of CP and NFC. The digestibility of DM, OM, TC, and NDF decreased linearly, while EE digestibility increased linearly with increasing levels of BMF. The high NDF content presented in the chemical composition of the babassu mesocarp flour ranked the same as fibrous food, which can limit the inclusion in the diet of high production animals. So, babassu mesocarp flour is an alternative for energy source in lambs feed and can be added at levels up to 10%.
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