Abstract The objective of this study was to evaluate and financially compare the forest management system in alternates bands (MAB) and the selective management system (SS). The study was carried out at the MAGELA Project, located in the municipality of Codó, state of Maranhão, Brazil. The data was collected in six permanent plots of 50 x 200 m, located in the Annual Production Units (APU) nº 01 and 02. In the financial analysis, the net present value was used for infinite horizon (NPV), land expected value (LEV), equivalent annual value (EAV), benefit/cost ratio (BCR), internal rate of return (IRR), average production cost (APC) and an annual discount rate of 9.0%. The MAB system was more financially viable for annual discount rates below 9.9%. However, at annual discount rates equal to or greater than 12%, the SS system was economically viable.

Resumen El objetivo de este estudio fue evaluar y comparar financieramente el sistema de manejo forestal en bandas alternas (MAB) y el sistema de manejo selectivo (SS). El estudio se realizó en el Proyecto MAGELA, ubicado en el municipio de Codó, estado de Maranhão, Brasil. Recolectamos los datos en seis parcelas permanentes de 50 x 200 m, ubicadas en las Unidades de Producción Anual (APU) nº 01 y 02. En el análisis financiero, usamos el valor presente neto para horizonte infinito (VPN ), valor esperado del terreno ( LEV), valor anual equivalente (EAV), relación beneficio / costo (BCR), tasa interna de retorno (TIR), costo promedio de producción (APC) y una tasa de descuento anual del 9.0%. El sistema MAB era más viable financieramente para tipos de descuento anuales inferiores al 9,9%. Sin embargo, a tasas de descuento anuales iguales o superiores al 12%, el sistema de SS era económicamente viable.

ABSTRACT: Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

SUMMARY: Mini-cutting is the most common commercially used clonal propagation method in Brazil. However, several environmental interferences can impact this process, hindering the production of propagules. Mini-tunnel have been used to overcome these difficulties, allowing for an increase in the productivity of mini-stumps and the rooting of mini-cuttings. This study aimed to evaluate the effect of mini-tunnel models on the mini-stump productivity of two hybrid eucalyptus clones over two seasons. The study was conducted in the seedling nursery of a forestry company located in Alto Vale do Jequitinhonha, Minas Gerais, Brazil. Three models of the mini-tunnel were used: mini-tunnel 35 cm, 55 cm, 55 cm tubular, and without cover (control) over two seasons (cold and hot). The total and effective productivity of mini-cuttings were evaluated and the levels of chlorophyll A and B, total chlorophyll, height, leaf area, and dry matter of the mini-cuttings were determined. Together, season and use of the mini-tunnel influenced the productivity of the mini-cuttings of both clones. Use of the mini-tunnel resulted in high productivity, especially in the cold period. Mini-cuttings produced during the hot season showed greater growth, dry matter, and leaf area than those collected during the cold season. The use of mini-tunnels is an effective method to increase the productivity of clonal eucalyptus mini-gardens, as shown here by its overall positive influence on mini-cuttings of both genotypes.

RESUMEN: El miniestaca es el método de propagación clonal más utilizado comercialmente en Brasil. Sin embargo, este proceso sufre varias interferencias ambientales que pueden dificultar la producción de propágulos. Los mini túneles se han utilizado para superar estas dificultades, permitiendo también un aumento de la productividad de las minicepas y el enraizamiento de las miniestacas. Este estudio tuvo como objetivo evaluar el efecto de los modelos de mini túneles sobre la productividad de minicepas de dos clones híbridos de eucalipto, en dos temporadas. El estudio se realizó en el vivero de plántulas de una empresa forestal ubicada en Alto Vale do Jequitinhonha, Minas Gerais, Brasil. Se utilizaron tres modelos de mini túneles: mini túnel de 35 cm, 55 cm, tubular de 55 cm y sin cobertura (control), en dos temporadas (frío y calor). Se evaluó la productividad total y efectiva de miniestacas y se determinaron los niveles de clorofila A y B, clorofila total, altura, área foliar y masa seca de las miniestacas. La temporada y el uso del mini túnel, en conjunto, influyeron en la productividad de las miniestacas de ambos clones. El uso del mini túnel resultó en una alta productividad, especialmente en el período frío. Las miniestacas producidos en la estación cálida mostraron mayor crecimiento, materia seca y área foliar, que los recolectados en la estación fría. El uso del mini túnel es un método eficaz para aumentar la productividad de los minihuertos clonales de eucalipto, como lo demuestra aquí su influencia positiva general sobre las miniestacas de ambos genotipos.

RESUMO: O objetivo do trabalho foi determinar o padrão espacial e a associação espacial de grupos de árvores comerciais da Amazônia.Realizou-se um censo florestal em uma área de 2.000 ha localizada na Floresta Nacional do Tapajós (FNT), Pará. No censo coletou-se a circunferência à altura do peito (CAP), igualou superior a 158 cm e as coordenadas cartesianas das árvores comerciais. Para determinar o padrão espacial foi utilizada a função K de Ripley assumindo um raio de 5 m, variando a uma distância máxima de 1.500 m. Para a função K univariada foram realizadas 500 simulações Monte Carlo e para a função bivariada foram realizadas 500 simulações toroidais, ambas com 99,8% de probabilidade. Os grupos de árvores comerciais que possuíram padrão espacial agregado em no mínimo 50% da distância de análise foram Astronium lecointei, Bagassa guianensis, Couratari guianensis, Manilkara huberi, Mezilaurus itauba, Vochysia maxima. Grupos de árvores comerciais, segundo critério de comercialização para árvores tropicais no Brasil, seguem um padrão espacial aleatório e agregado e possuem associações espaciais de independência espacial.

ABSTRACT: This study was conducted to establish the pattern and the spatial associations of the Amazon commercial tree groups. In a region extending across 2,000 ha in the Tapajós National Forest (FNT), Pará, a forest census was conducted. The census included commercial trees of perimeter at breast height (PBH), equal to or greater than 158 cm and the Cartesian coordinates of their bearings. Using Ripley’s K function, the spatial pattern was discerned, with 5 m radius being assumed, and maximum distances varying up to 1,500 m. Then, with 99.8% probability for both, 500 Monte Carlo simulations were performed for the univariate K function, and 500 toroidal simulations were done for the bivariate function.The commercial tree groups, which revealed an aggregated spatial pattern in a minimum of approximately 50% of the analysis distance were namely, Astronium lecointei, Bagassa guianensis, Couratari guianensis, Manilkara huberi, Mezilaurus itauba, and Vochysia maxima. In Brazil, the commercial tree groups, based on the commercialization criteria for tropical trees show random and aggregated spatial patterns with associations of spatial independence.

SUMMARY: This study aimed at evaluating the performance of different models based on Artificial neural networks (ANN) to estimate the total height of eucalyptus trees (Eucalyptus spp.), reducing the number of measurements in the field. Forty-eight ANN were tested, different from each other by the number of trees used as training sample, number of trees used to calculate the dominant height and use of variables (a) categorical, (b) categorical and continuous and (c) continuous, except for the diameter at 1.30 meters above the ground (DBH), used in all combinations. Estimates of height obtained by ANN were compared with values observed and estimates obtained by a hypsometric model. The ANN that showed the best results were used for the height estimation in forest inventory data for further application in the Schumacher and Hall volumetric model. The proposed models were efficient to estimate the total height of eucalyptus trees and allowed the expressive reduction of the number of trees to be measured in forest inventory. The best model found is composed of five trees as training sample, one as test sample and one as validation sample; dominant height coming from the height of the tallest tree in the plot; categorical variable Clone and continuous variables DBH, DBH dominant and basal area of the plot.

RESUMEN: El objetivo fue evaluar el desempeño de diferentes modelos basados en Redes Neuronales Artificiales (RNA) en la estimación de la altura total de los eucaliptos, reduciendo el número de mediciones en el campo. Se analizaron 48 RNA, diferentes entre sí por el número de árboles utilizados como muestra de entrenamiento; número de árboles utilizados para calcular la altura dominante; y el uso de (a) variables categóricas, (b) categóricas y continuas y (c) continuas, con la excepción del diámetro a 1,30 m del suelo (DAP), utilizadas en todas las combinaciones. Las estimaciones de altura obtenidas por RNA han sido comparadas con los valores observados y con las estimaciones obtenidas por un modelo hipsométrico. Las RNA que presentaron los mejores rendimientos se utilizaron para estimar la altura en los datos del inventario forestal, para el cálculo posterior del volumen de cada árbol. Los modelos propuestos demostraron ser eficientes para estimar la altura total de los eucaliptos y permitieron la reducción expresiva de la cantidad de árboles que se medirán en el inventario forestal. El mejor modelo encontrado se compone de cinco árboles como muestra de entrenamiento, uno como muestra de prueba y uno como muestra de validación; altura dominante desde la altura del árbol más alto en la parcela; variable categórica clon; y variables continuas DAP, DAP dominante y área basal de la parcela.

SUMMARY: The method, which uses the arithmetic mean and standard deviation (M1) of total heights (Ht), is often used in the stratification of uneven-aged forests and assumes that the Ht must follow a normal standard curve considering a standard deviation of the mean. In cases where this assumption is rejected, alternative methods are used, such as the fundamentals in multivariate analysis (M2) and Lorey’s mean height (M3). The objective was to evaluate the method M1 considering its assumption and comparing it with methods M2 and M3. The data were collected in 308 contiguous plots of 100 m², installed in an Alluvial Ombrophylous Forest. The assumption of the method M1 was analyzed adjusting a Normal Probabilistic Density Function, evaluated by the K-S test. The methods were evaluated using discriminant analyses, structural analyses and three-dimensional vertical profiles. It was verified that the assumption was not met. The discriminant analyses showed that the classification was 100 % correct in methods M1 and M3. The 13 most important species, in descending order, were the same in all three methods. However, from the 13th, the differences were more remarkable in the method M1. Firstly, it is recommended to use the method M3, as it is more practical and provides results that are equal to those obtained using the method M2. However, if the objective is to obtain a higher level of detail, the option is the method M2 since it allows obtaining up to five strata with 100 % correct classification.

RESUMEN: El método que usa la media aritmética y la desviación estándar de las alturas totales - Hts (M1) se usa a menudo en la estratificación de bosques con edades desiguales y supone que Hts debe seguir una curva estándar normal, considerando una desviación estándar de la media. En los casos en que se rechaza este supuesto, se utilizan métodos alternativos, como los fundamentos del análisis multivariado (M2) y la altura promedio de Lorey (M3). El objetivo de este estudio fue evaluar el método M1 considerando su suposición y comparándolo con los métodos M2 y M3. Los datos fueron recolectados en 308 parcelas contiguas de 100 m². Hts se obtuvieron en base a una varilla medida. La suposición del método M1 se analizó ajustando una función de densidad probabilística normal, evaluada mediante la prueba K-S. Los métodos se evaluaron mediante análisis discriminante, análisis estructural y perfiles verticales tridimensionales. Se encontró que la suposición no se cumplió. Los análisis discriminantes mostraron que la clasificación era 100 % correcta en los métodos M1 y M3. Las 13 especies más importantes, en orden decreciente, fueron las mismas en los tres métodos. Sin embargo, a partir del día 13, las diferencias fueron más notables en el método M1. Primero, se recomienda el uso del método M3, ya que es más práctico y proporciona los mismos resultados que los obtenidos por el método M2. Sin embargo, si el objetivo es obtener un mayor nivel de detalle, la opción es el método M2, ya que permite obtener hasta cinco estratos con una clasificación 100 % correcta.

ABSTRACT Determination of leaf nutrient concentrations is traditionally performed by carrying out destructive procedures, requiring laboratory chemical analysis, specialized equipment, and skilled labor. However, technological advances in recent years have now made it possible to analyze leaf nutrient concentrations using non-destructive methods such as leaf reflectance. This study evaluates the relationship between leaf reflectance and nutrient concentration in order to develop and apply nutrient indices by proximal sensing data in plantations of Eucalyptus. Two experiments were carried out for the development, application and validation of nutrient indices in Eucalyptus stands in the municipalities of Lassance and Três Marias, Minas Gerais state, Brazil. Study I was undertaken in Eucalyptus stands with 25 months old and, three clones. Leaves from the lower crown were visually classified into five color patterns using the Munsell chart for plant tissues. Study II was carried out in commercial stands of a hybrid of Eucalyptus urophylla ST Blake, whith 9, 12, 15 and 25 months old. Analysis revealed strong relationships between leaf nutrients and leaf reflectance in the visible and near infrared regions (400 - 900 nm) of the light spectrum. Correlation analysis between leaf reflectance and nutrients can be useful in an exploratory analysis of leaf nutrient concentration. Some nutrient indices developed (NI, PI, SI and CuI) provided satisfactory estimates of leaf nutrient concentration in Eucalyptus stands. The nutrient indices developed in this study may be a useful alternative to laboratory chemical analysis.

ABSTRACT The objective of this work was to evaluate the effects of fertilization, spatial arrangement and age on the biomass production in eucalyptus. The experiment was set up in a randomized block design with four replicates. Overall, 15 fertilizations adopted by forest companies in plots were evaluated, and two arrangements, 3.0 x 3.0 m and 6.0 x 1.5 m, were tested in subplots. Diameter at 1.30 m and total height were measured at 12, 24, 36, 48 and 60 months after planting to estimate trunk biomass. Dependence between commercial fertilization and arrangement were observed for trunk biomass. The biomass production rate in treatments where higher amounts of nutrients were applied decreased from the second year. The 3.0 x 3.0 m arrangement proved to be the most attractive option at 60 months using treatment with 2000 kg of agrosilicon, 400 kg of reactive phosphate, 130 kg of 04:26:16 + 0.5% Cu + 0.5% Zn and 150 kg of KCl + 1% B.

ABSTRACT The objective of this study was to analyze the adaptive cluster sampling (ACS), simple random sampling (SRS) and systematic sampling (SS) processes to obtain the number of ha-1 trees of Carapa guianensis Aubl. in the Amazon. The data were obtained through 100% inventory and sampling simulations, considering a DBH ≥ 25 cm, a sampling intensity of 4%, a maximum error of 10% and plots of 0.09, 0.16 and 0.25 ha. The last two sizes were only used to analyze their effect on the ACS estimators. The processes were evaluated for accuracy, precision (E%) and confidence interval (CI), while the mean ha-1 of the processes were compared with that of the 100% inventory by the Z test. The ACS process showed no significant difference between its average ha-1 trees and the 100% inventory, and it was also the most accurate and the only one whose CI was true. However, it presented a final sample intensity 3.6 times greater than the simple and systematic random samplings, in addition to E% above 10%, which makes it unacceptable, legally, and economically unfeasible. The other processes had densities significantly higher than the 100% inventory, with sample intensities lower than ACS and E% lower than 10%, making them legally viable. The use of larger plots in the ACS implies larger clusters and a greater tendency to underestimate the number of trees, resulting in larger sample errors and less accuracy.

ABSTRACT Rupestrian complexes of the Serra do Espinhaço are recognized for their high degree of biodiversity and endemism. However, environmental impacts, particularly from mining, have degraded these environments. The purpose of this study was to describe the herbaceous-subshrub communities that occur in quartzitic (QRC) and ferruginous (FRC) rupestrian complexes in different seasons of the year, with regard to floristic similarity and phytosociological structure. Additionally, the study aimed to identify native species with potential use for the restoration of similar degraded areas. Vegetation was sampled from plots located in the municipality of Conceição do Mato Dentro, state of Minas Gerais. Five contiguous strata of 10 × 50 m were demarcated in each environment, in which 12 plots of 2 × 1 m (2 m²) were randomly distributed, for a total of 60 plots (sample units) in each physiognomy. The studied communities exhibited few similarities and lower floristic diversity than other rupestrian complexes. Detrended correspondence analysis distinguished the communities of FRC from those of QRC. The species with the highest value of importance in FRC were Bulbostylis fimbriata and Centrosema brasilianum, while in QRC Echinolaena inflexa had the highest values, thus, making them eligible for restoration programs in similar environments.

RESUMO Este estudo tem como objetivo realizar análises econômica e de risco de investimento em plantios de eucalipto situados em Minas Gerais, considerando a influência do custo do seguro de florestas, evidenciando o seu impacto no projeto. Os custos de implantação e condução são oriundos de plantios de eucalipto localizados no Vale do Jequitinhonha, Minas Gerais. O custo do seguro de florestas foi obtido por meio de uma simulação de cotação junto à uma seguradora. Para a avaliação econômica utilizou-se o Valor Presente Líquido (VPL), a Taxa Interna de Retorno (TIR) e o Benefício Periódico Equivalente (BPE). Procedeu-se a análise de sensibilidade de risco pelo método de Monte Carlo. A análise econômica realizada foi considerada viável por todos os indicadores utilizados em todas as três situações trabalhadas. Mas, pela análise de risco de investimento, tem-se a probabilidade de 11,5% de chances do valor de VPL estar abaixo de zero na situação 1, 18,5% na situação 2 e 25% na situação 3. O custo do seguro de florestas aumenta a probabilidade de valor negativo para os indicadores econômicos, pois ele aumenta o custo do projeto, porém ele foi input o que menos influenciou no valor final do VPL. A subvenção do governo reduz a probabilidade do risco de investimento, uma vez que diminui o custo do seguro de florestas.

ABSTRACT The objective of this study is to carry out economic and risk assessment of eucalyptus plantations located in Minas Gerais, considering the influence of the cost of forest insurance, evidencing its impact on the project. The costs of implementation and driving come from eucalyptus plantations located in the Jequitinhonha Valley, Minas Gerais. The cost of forest insurance was obtained through a simulation of a quote from an insurer. For the economic evaluation, the Net Present Value (NPV), the Internal Rate of Return (IRR) and the Equivalent Periodic Benefit (EPB) were used. The risk sensitivity analysis was performed by the Monte Carlo method. The economic analysis was considered viable by all indicators used in all three situations. However, by the analysis of investment risk, we have a probability of 11.5% chance of NPV being below zero in situation 1, 18.5% in situation 2 and 25% in situation 3. The cost of Forest insurance increases the likelihood of negative value for economic indicators, as it increases the cost of the project, but it was input that less influenced the final value of the NPV. The government grant reduces the likelihood of investment risk as it lowers the cost of forest insurance.

RESUMO Complexos rupestres apresentam uma grande diversidade de padrões fenológicos como resposta à alta biodiversidade deste ecossistema e sua variação ambiental. Espécies dioicas apresentam distinção entre os sexos quanto às exigências nutricionais para crescimento e reprodução, compreendendo fatores determinantes na variação da fenologia reprodutiva e vegetativa, principalmente em ambientes restritivos. O estudo objetivou compreender a fenologia reprodutiva e vegetativa da espécie dioica Baccharis platypoda, associando as estratégias fenológicas ao sistema sexual e às variações sazonais do ambiente. O estudo foi realizado em três áreas de campo rupestre, onde foi observada a fenologia de trinta plantas, entre setembro/2010 e setembro/2011. Foram aplicados o método de intensidade de Fournier, correlação de Spearman e análise circular. As fenofases reprodutivas tiveram início no mês de fevereiro com encerramento entre setembro e outubro, enquanto que as fenofases vegetativas apresentaram variações de intensidade ao longo desse período. As fenofases vegetativas de ambos os sexos apresentaram baixo padrão sazonal, enquanto que as fenofases reprodutivas apresentaram forte sazonalidade. A espécie B. platypoda apresentou pequenas variações nas estratégias fenológicas de indivíduos masculinos e femininos, principalmente na duração das fenofases reprodutivas e no crescimento vegetativo para alocação de recursos. A fenologia reprodutiva da espécie esteve associada a algumas variáveis ambientais, principalmente para as fenofases de frutificação, enquanto que a fenologia vegetativa, de modo geral, esteve mais associada à fenologia reprodutiva das espécies.

ABSTRACT Rupestrian grasslands present great diversity of phenological patterns in response to the high biodiversity of this ecosystem and its environmental variation. Dioecious species show distinction between the genders in relation to the nutritional requirements for growth and reproduction, comprehending determining factors, especially in restrictive environments. The purpose of the study was to comprehend the reproductive and vegetative phenology of the dioecious species Baccharis playtypoda, joining the phenological strategies with the sexual system and the environment seasonal variations. The study was performed in three areas of rupestrian grassland, where the phenology of thirty plants from September/2010 through September/2011 was observed. The Fournier intensity method, Spearman’s correlation and circular analysis were used. The reproductive phenophases began in February and ended between September and October, while the vegetative phenophases presented intensity variation during that period. The vegetative phenophases of both genders has shown low seasonal standard, while the reproductive phenophases has presented strong seasonality. The species B. platypoda has presented little variations in the phenological strategies of male and female individuals, mainly during the reproductive phenophases and in the vegetative growth for the allocation of resources. The species’ reproductive phenology had been associated to some environmental variables, mainly for the fructification phenophases, while the vegetative phenology, in general, had been most associated to the reproductive phenology of the species.

Resumo: O objetivo deste trabalho foi avaliar a influência da espessura, sombreamento e origem do topsoil na restauração ambiental de uma área de pastagem degradada. O experimento foi realizado em delineamento em blocos casualizados, em esquema fatorial (3 x 2 x 2) + 2. Os tratamentos foram compostos pela combinação das origens do topsoil (estágio inicial ou médio de regeneração), espessuras do topsoil (10, 20 ou 30 cm de camada superficial de solo) e ausência ou presença de sombrite de 70%; com duas testemunhas adicionais (T1 e T2). Foi realizada a caracterização físico-química do topsoil, assim como o levantamento florístico e a cobertura do solo. Houve boa correlação entre a densidade do solo e a porosidade total. A cobertura vegetal desenvolvida apresentou um total de 2.932 indivíduos de hábitos herbáceo, arbustivos e subarbustivos, identificadas 33 espécies em 11 famílias e 1 morfoespécie. Já o levantamento florístico do estrato arbóreo registrou 235 indivíduos pertencentes a 21 espécies e 14 famílias e 2 espécies sem identificação. O topsoil de 20 cm de espessura é o que apresenta melhor índice de regeneração natural, onde o sombreamento exerceu uma influência positiva sobre a umidade e a regeneração natural do banco de sementes. O topsoil proveniente de floresta de estágio médio é o mais adequado para restauração de áreas de pastagem degradadas.

Abstract: The objective of this work was to evaluate the influence of topsoil thickness, shading and origin when performing environmental restoration in a degraded pasture area. The experiment was conducted in a randomized block design with a factorial (3 x 2 x 2) + 2 layout. Treatments consisted of combinations of topsoil origins (forest at early or middle regeneration stages), topsoil thicknesses (10, 20, or 30-cm superficial soil layer), and presence or absence of 70% shading; with two additional control treatments. Surveys on topsoil physical-chemical attributes and flora and soil coverage were conducted. Good correlation was observed between bulk density and total porosity. Vegetation comprised a total of 2,932 individuals of herbaceous, shrub and subshrub plants; 33 species in 11 families and 1 morphospecies were identified. A floristic survey of the tree stratum revealed 235 individuals belonging to 21 species and 14 families, as well as 2 unidentified species. The best natural regeneration index is observed in the 20-cm topsoil layer, where shading exerts a positive influence on the humidity and natural regeneration of the seed bank. Topsoil from middle-stage forest is the most suitable for restoration of degraded pasture areas.

ABSTRACT Nitrogen (N) has commonly been applied in Eucalyptus stands in Brazil and it has a direct relation with biomass production and chlorophyll content. Foliar N concentrations are used to diagnose soil and plant fertility levels and to develop N fertilizer application rates. Normally, foliar N is obtained using destructive methods, but indirect analyses using Vegetation Indexes (VIs) may be possible. The aim of this work was to evaluate VIs to estimate foliar N concentration in three Eucalyptus clones. Lower crown leaves of three clonal Eucalyptus plantations (25 months old) were classified into five color patterns using the Munsell Plant Tissue Color Chart. For each color, N concentration was determined by the Kjeldahl method and foliar reflectance was measured using a CI-710 Miniature Leaf Spectrometer. Foliar reflectance data were used to obtain the VIs and the VIs were used to estimate N concentrations. In the visible region, the relationship between N concentration and reflectance percentage was negative. The highest correlations between VIs and N concentrations were obtained by the Inflection Point Position (IPP, r = 0.97), Normalized Difference Red-Edge (reNDVI, r = 0.97) and Modified Red-Edge Normalized Difference Vegetation Index (mNDI, r = 0.97). Vegetation indexes on the red edge region provided the most accurate estimates of foliar N concentration. The reNDVI index provided the best N concentration estimates in leaves of different colors of Eucalyptus urophylla × grandis and Eucalyptus urophylla × urophylla (R2 = 0.97 and RMSE = 0.91 g kg−1).

RESUMO: As translocações de populações raras são consideradas como o último recurso para conservação de espécies, cuja destruição do habitat é iminente. O objetivo deste trabalho foi avaliar o efeito de duas classes de altura e três intensidades de redução foliar no crescimento, incremento periódico, sobrevivência e inserção de folhas em mudas de Aspidosperma cylindrocarpon (peroba) obtidas via resgate de plântulas em um remanescente de Floresta Estacional Semidecídua. Foram resgatados 240 indivíduos, os quais foram divididos em duas classes de altura (Classe I-5 a 15cm e Classe II-20 a 35cm), submetidos a três intensidades de redução foliar (0%, 50% e 100%) e em seguida, transportados para casa de sombra com 50% de redução de luminosidade. As medições de altura, diâmetro e emissão de novas folhas foram realizadas em oito tempos (0, 15, 60, 75, 90, 105, 120 e 135 dias), e a sobrevivência aos 135 dias. A taxa média de sobrevivência foi de 82,9%, sendo 77,5% para a classe de 5-15cm e 88,3% para classe de 20-35cm. O maior crescimento das mudas ocorreu para a redução de 0%, para ambas as classes. A inserção de folhas foi maior nas reduções de 100%, observando-se diminuição ao longo do tempo. Portanto, é aconselhável resgatar mudas de peroba nas duas classes de altura, sem necessidade de redução foliar.

ABSTRACT: Translocation of rare populations is regarded as the last resort for the conservation of species whose habitat destruction is imminent. The objective of the present study was to evaluate the effect of two height classes and three leaf reduction intensities on growth and increases in height, stem diameter, survival, and new leaf production in seedlings of Aspidosperma cylindrocarpon (peroba) obtained via rescue seedlings in a remnant of tropical semi deciduous forest. We recovered 240 individuals that were divided into two height classes (Class I-5 to 15cm and Class II-20 to 35cm) and subjected to three leaf reduction intensities (0%, 50%, and 100%), which were then transported to a shade house with 50% light reduction. Measurements of height, stem diameter, and new leaf production were collected 8 times at 0, 15, 60, 75, 90, 105, 120, and 135 days, and survival rate was measured at day 135. The average survival rate was 82.9%; 77.5% for one Class I (5-15cm) and 88.3% for Class II (20-35cm). Higher seedling growth was observed for the 0% leaf reduction treatment in both height classes. The leaves insertion were greater in the 100% cuts, with a decrease observed over time. It is advisable to restore A. cylindrocarpon seedlings in two height classes owing to the high survival rate, leaf appearance, and growth reported in the present study. The no-leaf reduction treatment (0%) is the most viable alternative for the production of A. cylindrocarpon seedlings, via rescue seedlings.