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This study evaluated the anatomical and chemical components of the bark of Protium tenuifolium, a tree species from the Brazilian Amazon, to provide information supporting its value in various industries as a source of polyphenols and natural antioxidants. The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na2SO3). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem and rhytidome. The average chemical composition was 15.9% extractives, 35.3% total lignin, 1.9% suberin, 15.4% ash and 31.5% polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1%, and that in the treatment with water and Na2SO3 was 8.1%. The ethanol-water extract had a high phenolic content (112.6 mg GAE g-1 extract). The bark extract showed strong antioxidant activity, reaching 83.5% inhibition of DPPH free radicals, which was higher than the value of 75.0% for the commercial antioxidant BHT at the same concentration. These results demonstrate that Protium tenuifolium is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics. The extraction of these compounds adds substantial value to the bark of this Amazonian species.

The existence of degraded forests is common in the Eastern Amazon. The maintenance of these forests standing and the recovery of their productivity play an important role in the conservation of biodiversity, storage and carbon sequestration. However, the management techniques currently employed are designed for natural forests in the first harvest cycle or lightly explored and do not apply adequately to forests that have gone through several harvest cycles. Therefore, adaptations and the establishment of new management criteria that take into account other characteristics of these types of forests are necessary to ensure their sustainability. The objective of this study was to propose a silvicultural management system that has the potential to recover and perpetuate the productivity of an intensively logged tropical forest. A forest census was carried out on 535.6 ha for trees with dbh ≥ 25 cm. With these data, the following two treatments were designed: (1) criteria: the BDq method was applied from B = 9.8 m2 ha−1, D = 100 cm and q = 2. The criteria for standing wood commercialization were, in this order, first, Health, second, Tree Stem, third, Tree Density and fourth, dbh ≥ 105 cm. (2) Control: the planning was in accordance with Brazilian regulations. For the cost–benefit and sensitivity analysis, the Net Present Value (NPV) was used and a projection of ±20% was made in the commercial price of standing wood. In the criteria treatment, a higher number of trees and species destined for the commercialization of standing wood was verified in relation to the control treatment, showing a greater diversity of species. In the criteria treatment, NPV was positive and superior to the control treatment in all scenarios. The proposed silvicultural management system with an object of an explored and enriched forest, with criteria for harvesting trees with a minimum cut diameter of 25 cm, proved to be viable to generate economic returns and with conservationist potential for the continuous supply of forest products and maintaining biodiversity.

Studies on applying of soil management practices in the management of paricá and the effects on growth and yield are essential to auxiliary its cultivation and would allow us to inform management and conservation decisions to reconciliate biodiversity, wellbeing, and sustainable production. This case study aimed to evaluate the growth and yield of paricá at different soil management practices, including consortium with an agricultural production, in the Brazilian Amazon. Paricá was implanted, consorted with soybean in the first year, and maize in the second, in a 5 × 2 m spacing. The treatments T1 = subsoiling, basal dressing, top-dressing, inoculation of microorganisms and consortium with soybean/maize were applied. In T2, T3, T4, and T5, we applied the same practices of T1, except subsoiling (T2), basal dressing (T3), top-dressing (T4) and inoculation of microorganisms (T5). T6 was the control, which used none of these practices, including the consortium with soybean/maize. The results indicate that the highest rate of plant survival occurred in T2, while T3 and T4 promoted greater intraspecific competition, compromising the growth in dbh and the yield (m3 ha−1) of plants in future ages. Growth in dbh and th and the yield of plants in the soybean/maize consortium period was higher in T2 and T6. In future ages, the dbh and yield of plants demonstrated higher growth trends in T6, T1, and T5. Agroforestry practices of soil management influence the growth and yield of paricá plants. However, there is a tendency for greater growth and yield for paricá plants cultivated in the absence of agroforestry practices for soil management proposed in this case study. When opting for AFS (paricá intercropped with soybean and maize), it is recommended for paricá a subsoiling, fertilization, and inoculation of microorganisms.

Avaliou-se a sobrevivência e o crescimento de mudas de Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby (paricá) plantadas aleatoriamente em três tamanhos de clareiras causadas pela exploração florestal de impacto reduzido, na Fazenda Rio Capim, no município de Paragominas, Pará. As medições foram realizadas em cinco ocasiões (2005, 2006, 2008, 2010 e 2011). As clareiras foram classificadas em pequenas (200-400 m²), médias (401-600 m²) e grandes (> 600 m²). Com base na sobrevivência e no crescimento de mudas, nos seis primeiros anos após o plantio, sugere-se Schizolobium parahyba var amazonicum para plantios em clareiras, com áreas a partir de 200 m2 , causadas por exploração florestal de impacto reduzido.

This article addresses a case study on the application of criteria for harvesting, aiming at restoration and profitability in a degraded tropical forest in the Amazon. The objective is to provide technical and economic information to promote a truly sustainable silvicultural management system in forests with this profile and turn them into a desirable financial asset for conservation and social development. In the forest census, 85.907 trees ha&minus, 1 (100.8566 m3 ha&minus, 1) were inventoried with diameter at breast height (dbh) &ge, 25 cm, belonging to 106 commercial species. When applying the harvest criteria, 19.923 trees ha&minus, 1 (29.99 m3 ha&minus, 1), referring to 53 species, were destined for harvest. Some trees were selected by more than one criterion, totalizing 17.985 trees ha&minus, 1 by density, 1.831 trees ha&minus, 1 by compromised health, 0.212 trees ha&minus, 1 by maximum dbh, 18.933 trees ha&minus, 1 by minimum dbh, 1.385 trees ha&minus, 1 by tree stem (quality 3), and 0.080 trees ha&minus, 1 by species conservation. In all scenarios, the application of criteria for harvesting proved to be profitable with excellent cost&ndash, benefit ratios. The selection of trees with a minimum cutting diameter of 25 cm in shorter cycles tends to allow the promotion of new commercial species. The set of actions presented has the potential to favor the maintenance of biodiversity and expansion of low-density populations, health and the potential increment of the forest productivity. In addition, it is more feasible for the supply of forest products in a shorter time than provided for in Brazilian regulations, however, they must respect the specificities of the species and also of the site.

Commercial height of the tree is a key variable for estimating the wood stock in tropical forests managed for timber production purposes. Most available measurement devices suffer limitations in this type of forest, promoting low precision measurements with high variation errors. The laser meter device appears as a viable alternative, as in addition to using trigonometric principles, it is not necessary that the device is close to the eyes of the meter to carry out the measurement. The device can be used to measure commercial height of trees on flat or sloping terrain, at different distances from the tree. However, there are no studies evaluating the precision of this device. The objective of this study was to determine the precision of the laser meter method for estimating the commercial height of trees, as compared to the actual measurement in a tropical forest in the Brazilian Amazon. Measurements were made on 300 trees with commercial height between 7 and 14 m. Actual commercial heights were measured with graduated ruler. Applied tests were paired t test, graphical analysis of residuals and calculations of bias statistics, mean absolute deviation, standard deviation of differences, and coefficient of determination (R 2). Paired t test indicated that the mean of the heights measured by the laser meter is statistically equal to that of the graduated ruler. Measurements with laser meter did not show bias and had mean error of 0.0745. The standard deviation of the differences indicated dispersion of errors of 0.97, equal to that shown in the graduated rule. Laser meter presents an alternative method for estimating the commercial height of trees in tropical forest in the Brazilian Amazon. There was no tendency to underestimate or overestimate the commercial heights of trees. Use of the laser meter is potentially of use for measuring the commercial height of trees in tropical forests., A new method and device to measure commercial height of trees in natural forests is proposed. The method has, besides practicality, good precision, and low cost, a great differential: The technician does not need to use the device close to the eyes. The technician observes the laser beam in the tree trunk and remains in the same position to realize the three measures necessary to obtain the commercial height. The device can be used to measure commercial height of trees on flat or sloping terrain from any distance from the tree.

A distribuição diamétrica assume particular importância na caracterização da estrutura populacional de uma floresta. Este estudo avaliou a distribuição diamétrica da população da espécie ZiziphuscinnamomumTriana&Planch em uma área de manejo florestal (535,6 ha) no município de Dom Eliseu-PA.Foram utilizados dados provenientes de inventário florestal contínuo (IFC), com área amostral de 7,5 ha, realizados em 2009, 2012 e 2014. Z. cinnamomumapresentou maior número de indivíduos na classe de diâmetro de 10 cm, o que qualifica a espécie como regenerante na área. Made available in DSpace on 2020-10-06T09:13:06Z (GMT). No. of bitstreams: 1 Ziziphus-Sabrina14192-36781-1-PB.pdf: 621956 bytes, checksum: 87c47049594d978dbb9d932eefd0a2f3 (MD5) Previous issue date: 2020

Este trabalho trata de uma experiência inovadora em relação a critérios para colheita de árvores em floresta natural degradada na Amazônia. A pesquisa foi desenvolvida em 535,6 ha de floresta na Fazenda Shet, em Dom Eliseu - PA, usando a base de dados do censo florestal referente a árvores com DAP ≥ 25 cm. Os critérios para colheita das árvores consideraram, prioritariamente, os seguintes elementos: grau de sanidade, qualidade do fuste (2 e 3), diâmetro máximo a permanecer na floresta (DAP < 100 cm), árvores de menor diâmetro (25 ≥ DAP ≤ 55 cm), espécies com maior densidade de árvores por unidade de área, distribuição diamétrica, segundo o coeficiente de Liocourt, manutenção das espécies intensamente exploradas no passado e com população de árvores ≤ 0,15 arv.ha-1. Foram inventariadas 46.012 árvores, pertencentes a 106 espécies, e planejadas para colheita 23,19% (10.671 árvores), aos 12 anos após a exploração anterior. Baseando-se no planejamento da colheita e seguindo os critérios, a previsão de colheita em relação à população total inventariada teve como resultado: 2,16% árvores pelo critério de sanidade; 15,45% pela forma de fuste; 0,26% pelo diâmetro máximo; 93,93% pelo menor diâmetro; 57,50% pela densidade arbórea; e 5,04% pela manutenção das espécies. A colheita foi realizada em 98,79% das árvores com sanidade comprometida; 22,20% com fuste 2 e 3; 97,39% com diâmetro máximo; 95,02% com menor diâmetro; e 90,30% com maior densidade arbórea. Foram mantidas 98,14% das espécies Astronium lecointei, Cordia goeldiana, Copaifera sp., Hymenaea courbaril, Hymenolobium petraeum, Handroanthus serratifolius e Manilkara elata, intensivamente exploradas no passado, e 98,70% de outras 53 espécies com menor abundância (≤ 0,15 arv.ha-1). O planejamento da exploração seguindo os critérios de colheita propostos possibilitou a extração de árvores em ciclos de 10 a 12 anos, sendo um tempo menor que o previsto pela legislação. A manutenção da diversidade de espécies arbóreas e a conservação da floresta em pé, previstas com esses critérios técnicos, podem ser alternativas para o manejo florestal ecológica e economicamente viável. Made available in DSpace on 2020-10-06T09:11:41Z (GMT). No. of bitstreams: 1 25856-214461-4-PB.pdf: 1513555 bytes, checksum: 119ca5814dcdab4981636aa7e6ba2a63 (MD5) Previous issue date: 2020

Avaliou-se o desempenho de mudas de Cedrela odorata L. (cedro), plantadas em clareiras causadas pela exploração florestal de impacto reduzido, no município de Paragominas, no Estado do Pará. Analisou-se a sobrevivência e o crescimento das mudas para estudar a possibilidade de utilizá-las em enriquecimento de clareiras, na Amazônia brasileira. Em 200 ha foram selecionadas 400 clareiras, divididas em três classes de tamanho: pequenas (200?400 m²), médias (401?600 m²) e grandes (> 600 m²). Em 236 dessas 400 clareiras foram plantadas 470 mudas de cedro, em 2005, quando também foi realizada a primeira avaliação da sobrevivência e do crescimento das mudas. Outras avaliações foram realizadas em 2006, 2008 e 2010. Constataram-se, após os cinco anos de monitoramento, altas taxas de sobrevivência, em torno de 81,8%, e de crescimento com média de 70,0 cm em altura e 0,23 cm em diâmetro. Portanto, pode-se inferir que Cedrela odorata se adapta a ambientes de clareiras e poderá ser indicada para plantios de enriquecimento de florestas após a colheita da madeira. Há a necessidade de continuar o monitoramento. Made available in DSpace on 2018-10-03T01:02:40Z (GMT). No. of bitstreams: 1 333611665041PB.pdf: 367441 bytes, checksum: dba5c6c5a5e283df359335af2d34f944 (MD5) Previous issue date: 2018-10-02

Large-scale agriculture is increasing in anthropogenically modified areas in the Amazon Basin. Crops such as soybean, maize, oil palm, and others are being introduced to supply the world demand for food and energy. However, the current challenge is to enhance the sustainability of these areas by increasing efficiency of production chains and to improve environmental services. The Amazon Basin has experienced a paradigm shift away from the traditional slash-and-burn agricultural practices, which offers decision makers the opportunity to make innovative interventions to enhance the productivity in previously degraded areas by using trees to ecological advantage. This study describes a successful experiment integrating the production of soybean and paricá (Glycine max L. and Schizolobium amazonicum) based on previous research that indicated potential topoclimatic zones for planting paricá in the Brazilian state of Pará. This paper shows that a no-tillage system reduces the effects of drought compared to conventional tillage still used by many farmers in the region. The integrated system was implemented during the 2014/2015 season in 234.6 ha in the high-potential zone in the municipality of Ulianópolis, Pará. Both soybean and paricá were planted simultaneously. Paricá was planted in 5 m x 2 m inter-tree spacing totaling 228x103 trees per hectare and soybean, in 4 m x 100 m spacing, distributed in nine rows with a 0.45 m inter-row distance, occupying 80% of the area. The harvested soybean production was 3.4 t ha-1, higher than other soybean monocultures in eastern Pará. Paricá benefited from soybean fertilization in the first year: It exhibited rapid development in height (3.26 m) and average diameter (3.85 cm). Trees and crop rotation over the following years is six years for forest species and one year for each crop. Our results confirm there are alternatives to the current production systems able to diminish negative impacts resulting from monoculture. In addition, the system provided environmental services such as reduced soil erosion and increased carbon stock by soil cover with no-tillage soybean cultivation. The soybean cover contributes to increased paricá thermal regulation and lower forestry costs. We concluded that innovative interventions are important to show local farmers that it is possible to adapt an agroforest system to large-scale production, thus changing the Amazon.