PRODUCTIVE FOREST RECOVERY IN LEGAL RESERVE AREA: A CASE STUDY IN EASTERN AMAZON

This study aimed to evaluate a model for Legal Reserve (LR) recovery based on a mixed timber production system (planting + natural regeneration) in the eastern Amazon, state of Pará. For data collection, seven plots of 50 m x 20 m were established, and all individuals with DBH (diameter at breast height) ≥ 5 cm were inventoried. Species diversity, horizontal structure, and commercial wood production were assessed at 13 years of age. A total of 103 species were found, distributed among 69 genera and 33 families. The population density was 1,425 individuals per hectare, and dominance corresponded to 19.45 m².ha-1. The total wood volume was 121.4 m³.ha-1, with 63.3 m³.ha-1 coming from the planted species (S. parahyba var. amazonicum) and 58.1 m³.ha-1 from natural regeneration. Among the regenerating species, Cecropia distachya showed the highest values for the evaluated parameters. The adopted model showed potential for use in LR environmental recovery, reconciling this action with revenue generation through silvicultural interventions that can be applied to the stand, aiming for wood production. To achieve this, adjustments to the regulations governing the forest management of recovering areas are necessary

Estimation of the commercial height of trees with laser meter: a viable alternative for forest management in the Brazilian Amazon

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 present limitations to this type of forest, promoting low precision measurements with high variation errors. Laser meter device appears as a viable alternative, since 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 from any distance from the tree. However, there are no studies evaluating the precision of this device. Due to importance and difficulties evidenced, 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 residues and calculations of bias statistics, mean absolute deviation, standard deviation of differences and coefficient of determination (R2). 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 tendencies (bias) and had low mean error, showing values close to "0". The standard deviation of differences indicated low dispersion of errors. There was no tendency to underestimate or overestimate the commercial heights of trees. Laser meter presents precision for estimating the commercial height of trees in tropical forest in the Brazilian Amazon

Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby pode ser utilizada em enriquecimento de clareiras de exploração florestal na Amazônia

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

Agriculture and forest: A sustainable strategy in the Brazilian Amazon

Abstract 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 228x10 3 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

Sustentabilidade da produção madeireira de Goupia glabra Aubl. (cupiúba) na Amazônia brasileira.

The sustainability of the production of timber in natural forests is a subject matter of great discussion. The concern to have perpetuity in the forest production, mainly of species of value in the market, is a challenge for the management of natural forests. This research was developed with the objective of analyzing the dynamics of growth in six experimental areas of forest management monitored in the Brazilian Amazon and discuss the ability of the species to recover in 35 years, in order to subsidize strategies for sustainable forest management. To compose this study, we used data from a continuous forest inventory of six experimental areas of the Network of Monitoring of the Dynamics of Forest in the Amazon. – Redeflor, monitored by Embrapa Amazônia Oriental and Embrapa Amazônia Ocidental, located in three states of the Brazilian Amazon: State of Pará (n = 4), State of Amapá (n = 1) and State of Amazonas (n = 2). In the study, the parameters were analyzed: density of trees (arv.ha-1), basal area (m².ha-1), mortality (arv.ha-1 and %.year-1), recruitment (arv.ha-1 and %.year-1) and periodic annual increment in diameter (IPAd). With the parameters of dynamics analyzed, obtained the rate of recovery of the trees (%.arv) with DBH ≥ 20 cm capable of reaching the minimum diameter allowed by the current law (DBH ≥ 50 cm), in 35 years. The trees of G. glabra with DBH ≥ 20 cm presented a natural density distinct between the areas, with variation of 0,8 to 5,5 arv.ha-1, occupying a basal area of 0,343 to 1,814 m².ha-1. The dynamics of mortality and recruitment, after 31 years of monitoring, evidenced that the species did not recover the density and dominance after the harvest. The IPAd, between monitored sites, varied of 0,19±0,27 to 0,93±0,55 cm.ano-1, in which the smaller diameter trees (DBH 20-49,9 cm) presented the rates highest of growth. The recovery of the stock of trees with DBH ≥ 50 cm was on average 28%, although was observed a high variation among the managed areas. The estimate of a tree with a diameter of 20 cm to reach the cutting diameter (DBH ≥ 50 cm) needs approximately 83 years. The verification of the non-recovery of the original stock of trees of G. glabra, in 35 years, requires a different management of the pattern, with a longer interval between harvests, considering the dynamics of growth of the species in the managed area.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorA sustentabilidade da produção de madeira de florestas naturais é um assunto de grande debate. A preocupação em ter disponível continuamente os recursos naturais, principalmente, madeiras de espécies de valor no mercado, tornou-se um desafio para o manejo. Esta pesquisa foi desenvolvida com o objetivo de analisar a dinâmica de crescimento em seis áreas experimentais de manejo florestal monitoradas na Amazônia brasileira e discutir sobre a capacidade de recuperação da espécie, em 35 anos, de maneira a subsidiar estratégias para um manejo florestal sustentável da espécie. Para compor este estudo, foram utilizados dados de inventário florestal contínuo, de seis áreas experimentais, da Rede de Monitoramento da Dinâmica de Florestas na Amazônia – Redeflor, monitoradas pela Embrapa Amazônia Oriental e Embrapa Amazônia Ocidental, localizadas em três estados da Amazônia brasileira: Pará (n = 4), Amapá (n = 1) e Amazonas (n = 2). No estudo, foram analisados os seguintes parâmetros: densidade de árvores (arv.ha-1), área basal (m².ha-1), mortalidade (arv.ha-1 e %.ano-1), recrutamento (arv.ha-1 e %.ano-1) e incremento periódico anual em diâmetro (IPAd). A partir dos parâmetros de dinâmica analisados foi obtida a taxa de recuperação das árvores (%.arv) com DAP ≥ 20 cm capazes de alcançar o diâmetro permitido pela norma de manejo (DAP ≥ 50 cm), em 35 anos. As árvores de G. glabra com DAP ≥ 20 cm apresentaram densidade natural distinta entre as áreas, com variação de 0,8 a 5,5 arv.ha-1, ocupando uma área basal de 0,343 a 1,814 m².ha-1. A dinâmica de mortalidade e recrutamento, mesmo após 31 anos de monitoramento, evidenciou que a espécie não recuperou a densidade e dominância após à colheita. O IPAd, entre os sítios monitorados, variou de 0,19±0,27 a 0,93±0,55 cm.ano-1, na qual as árvores de menor diâmetro (DAP 20-49,9 cm) apresentaram as maiores taxas crescimento. A recuperação do estoque de árvores com DAP ≥ 50 cm foi em média 28%, embora constatada uma alta variação entre as áreas manejadas. A estimativa de uma árvore com diâmetro de 20 cm para atingir o diâmetro de corte (DAP ≥ 50 cm) necessita de aproximadamente 83 anos. A constatação da não recuperação do estoque original de árvores de G. glabra, em 35 anos, requer um manejo diferenciado do modelo vigente, com maior intervalo de tempo entre colheitas, considerando a dinâmica de crescimento da espécie na área manejada

Silvicultural Management System Applied to Logged Forests in the Brazilian Amazon: A Case Study of Adaptation of Techniques to Increase the Yield and Diversity of Species Forestry

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

Growth and Yield of Schizolobium parahyba var. amazonicum According to Soil Management in Agroforestry Systems: A Case Study in the Brazilian Amazon

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