Resumo Para explorar os atributos físicos e químicos do solo e espacializar o estoque de carbono orgânico do solo em um trecho de Floresta Atlântica (Estacional Semidecidual Submontanal, Espírito Santo, Brasil), este estudo avaliou quatro camadas de solo (0-5, 5-10, 10-20 e 20-40 cm), as inter-relações dos atributos físicos e químicos e a espacialização do estoque de carbono orgânico do solo aplicando a interpolação por “cokrigagem”. Foram coletadas 12 amostras em cada camada de solo, sendo determinados os teores de nutrientes, a densidade do solo, a textura e o teor de carbono orgânico, sendo também determinado o estoque de carbono. Os atributos do solo mais significativos na variação dos dados foram verificados pela ordenação por Análise de Componentes Principais (ACP) agrupando as parcelas semelhantes quanto às características físicas e químicas. Com base na autocorrelação espacial dos atributos do solo, os dados do modelo de elevação digital (altitude e declividade) para o local estudado foram combinados para explorar a relação de coordenadas entre os parâmetros do terreno e o estoque de carbono orgânico do solo. Foi verificado o aumento da fertilidade do solo paralelo ao aumento do teor de matéria orgânica, auxiliando no entendimento das diferenças e similaridades dos sítios identificados no campo. Observa-se diferença espacial no estoque de carbono orgânico do solo, sendo o maior verificado nas áreas de menor declividade e altitude.

Abstract This study aimed to explore the physical and chemical attributes of the soil and to spatialize the soil organic carbon stock in a stretch of Atlantic Forest by evaluating four soil layers and the interrelationships of physical and chemical attributes as well as the spatialization of soil organic carbon stock by applying cokriging interpolation. Thus, 12 soil samples were collected in a soil layer, and the nutrient content, soil density, texture, soil organic carbon content and the soil carbon stock were determined. A Principal Component Analysis (PCA) grouped the most similar plots in terms of physical and chemical characteristics. Based on the spatial autocorrelation of the soil attributes, the digital elevation model data (altitude and slope) for the studied site were combined to explore the coordinate relationship between the terrain parameters and the soil organic carbon stock. We verified an increase in the soil fertility parallel to the increase in the organic matter content in the soil, helping to understand the differences and similarities of the identified sites in the field. There is a spatial difference in the soil organic carbon stock, with the largest being observed in areas of lower slope and altitude. The physical and chemical attributes of the soil in the Atlantic Forest varied according to the sampled points, being strongly related to the relief. The spatial variability altered soil organic carbon stocks in the forest under study.

Resumo A dinâmica da serapilheira é um dos processos fundamentais para o crescimento e manutenção dos fragmentos florestais nativos, sendo considerada a principal via de ciclagem de nutrientes nas florestas. Portanto, estudos sobre a serapilheira acumulada e conteúdo de nutrientes subsidiam informações para uma melhor compreensão da dinâmica dos nutrientes. O objetivo do estudo foi avaliar o estoque de serapilheira e nutrientes em diferentes estações do ano e a taxa instantânea de decomposição em um fragmento de Floresta Atlântica ao longo de dois anos. A amostragem da serapilheira foi realizada em 12 parcelas permanentes com dimensões de 20 m x 50 m. Determinou-se a massa seca da serapilheira e o teor dos nutrientes. O acúmulo médio anual de serapilheira foi de 5.269 kg ha-1. Não houve diferença estatística na quantidade de serapilheira entre as estações do ano. Houve diferença estatística nos teores de N, P, K Ca e Mg entre as diferentes estações do ano. Os estoques de nutrientes foram de 123.3, 92.8, 13.2, 11.8, 9.6 e 3.0 kg ha-1 para Ca, N, Mg, S, K e P, respectivamente. O total de nutrientes na serapilheira acumulada foi de 253,7 kg ha-1 ano-1. O tempo de renovação da serapilheira foi de 281 dias. O tempo para a decomposição de 50% e 95% da mesma foi de 196 e 850 dias, respectivamente. A produção média de serapilheira, o estoque de nutrientes e a decomposição estão de acordo com outros estudos realizados, indicando que o fragmento de Floresta Atlântica sazonal semidecidual apresenta indicadores de ciclagem de nutrientes. Esses resultados encontrados mostram que o ecossistema se encontra sustentável sob ponto de vista da ciclagem e liberação dos nutrientes.

Abstract Litter dynamics is one of the fundamental processes for the growth and maintenance of native forest fragments, being considered the main pathway for nutrient cycling in forests. Therefore, studies on accumulated litter and nutrient content provide information for a better understanding of nutrient dynamics. The aim of the study was to evaluate leaf litter and nutrient stock in different seasons and the instantaneous rate of decomposition in an Atlantic Forest Fragment over two years. Litter sampling was carried out in 12 permanent plots with dimensions of 20 m x 50 m. Litter dry mass and nutrient concentration were determined. The average annual accumulation of litter was 5269 kg ha-1. There was no statistically significant difference in the amount of litter between seasons. There was a statistically significant difference in the contents of N, P, K Ca and Mg between the different seasons. Nutrient stocks were 123.3, 92.8, 13.2, 11.8, 9.6, 3.0 kg ha-1 year-1 for Ca, N, Mg, S, K and P respectively. The total of nutrients in the accumulated litter was 253.7 kg ha-1 year-1. The litter renewal time was 281 days. The times required for 50% and 95% litter decomposition were 196 and 850 days. The average litter stocks, nutrients and decomposition are in line with other studies, indicating that the Atlantic Forest fragment seasonal semi-deciduous presents indicators of nutrient cycling. These results show that the ecosystem is sustainable from the point of view of cycling and nutrient release.

Resumo A dinâmica de serapilheira é um dos processos fundamentais para o crescimento e manutenção de fragmentos florestais nativos, sendo considerada a principal via da ciclagem de nutrientes em florestas. Dessa forma, estudos sobre produção de serapilheira e conteúdo de nutrientes fornecem subsídios que proporcionam um melhor entendimento da dinâmica dos nutrientes. O objetivo do estudo foi identificar a sazonalidade e as condições meteorológicas que influenciam na quantifidade e no retorno de nutrientes através da serapilheira em um fragmento de Floresta Atlântica. A amostragem de serapilheira foi realizada mensalmente em 12 parcelas permanentes. Cada parcela continha 5 coletores distribuídos sistematicamente. A serapilheira foi classificada, quantificada a massa seca e nutrientes nas frações folhas e galhos + miscelânea. Foi constatado comportamento sazonal com as maiores deposições na estação do inverno. A produção média anual foi de 6,78 Mg ha-1, sendo 64,9% composta por folhas. A entrada média de nutrientes anual foi de 135.1, 115.7, 39.7, 23.5, 17.6 e 4.6 kg ha-1 para Ca, N, K, Mg, S e P respectivamente. A variável meteorológica precipitação apresentou influencia no padrão de deposição. O aumento na eficiência do uso de nutrientes no segundo ano em comparação com o primeiro indica que as plantas estrategicamente podem estar retranslocando quantidades relativas de seus nutrientes sob condições de estresse hídrico.

Abstract Litter dynamics is one of the fundamental processes for the growth and maintenance of native forest fragments, being considered the main pathway for nutrient cycling in forests. Studies on litter production and nutrient content therefore provide insights that provide a better understanding of nutrient dynamics. This study identifies the seasonality and meteorological conditions that influence the quantity and return of nutrients through litter in an Atlantic Forest fragment. Litter sampling was carried out monthly in 12 permanent plots. Each plot contained 5 littertraps distributed systematically. The litter was classified, and the dry mass and nutrients in the leaves and branches and miscellaneous fractions was quantified. Seasonal behavior was observed, with the highest depositions in the winter season. The average annual production was 6.78 Mg ha-1, with 64.9% being composed of leaves. The mean annual nutrient intake was 135.1, 115.7, 39.7, 23.5, 17.6 and 4.6 kg ha-1 for Ca, N, K, Mg, S and P, respectively. The meteorological variable precipitation influenced the deposition pattern. The increase in nutrient-use efficiency in the second year compared to the first indicates that plants strategically may be re-translocating relative amounts of their nutrients under water stress conditions.

ABSTRACT Background: Background: Eucalypt harvest residues are critical to nutrient balances and forest soil productivity mainly in areas with consecutive forest rotations. However, nutrient release and their relations over decomposition are still poorly understood in tropical sites. We aimed to understand how nutrients are released from leaves, branches, and bark (as harvest residues), and how nutrient concentrations could be limiting the decomposition of each fraction. We measured mass loss and nutrient release of Eucalyptus urophylla x Eucalyptus grandis harvest residues for 365 days in Southeast Brazil. Results: Results: Leaves fraction showed a faster decomposition rate than branches and bark, but nutrient accumulation was observed for all harvest residues, especially bark and branches at later stages of the decomposition. Decomposition of all harvest residues seemed to be P-limited with a stronger limitation occurring for leaf litter decomposers. The decomposition of more lignified residues such as bark and branches was less influenced by climatic variables than leaf decomposition. Conclusion: Conclusion: Eucalypt harvest residues had a great contribution to soil fertility, and retaining them in the soil systems will enhance soil fertility in the short (leaves) and long-term (branches and bark) and can partially supply the nutrients for the next rotation.

ABSTRACT Background: The objective of this study was the genetic characterization of remaining populations of the species Paratecoma peroba occurring in fragments of the Atlantic Forest, by estimating parameters of diversity and genetic structure. The study was carried out in two forest fragments, the Atlantic Forest Environmental Education Pole (area 1) and the Pacotuba National Forest (area 2), where 93 adult trees were identified. Results: Ten Inter Simple Sequence Repeats (ISSR) primers were used in genotyping, obtaining 112 amplified bands with 87.5% polymorphism. The genetic diversity estimated for the populations from the Nei (H*) and Shannon (I*) indices was higher for area 1. For the joint data, moderate genetic diversity was observed, referring to the average values of 0.26 and 0.40, obtained for the H* and I* indices, respectively. Molecular variance analysis resulted in moderate differentiation between populations (Φ ST = 0.143), while gene flow analysis (N m = 6.69) revealed the occurrence of similar alleles between them. However, the predominance of a single genetic group in area 2, revealed from Bayesian approach, indicates that its genetic structure, possibly generated by the current scenario of fragmentation of the Atlantic Forest and the distancing of populations, affecting the contemporary gene flow. Conclusion: Despite the moderate genetic diversity of the species for the area 2 population, actions toward inclusion of seedlings obtained from seeds from neighboring fragments, including area 1, and the increase in the connectivity of forest fragments through ecological corridors, could assist in augmenting its genetic variation.

Abstract The aim of the study was to investigate Pseudobombax aff. petropolitanum (PP) contribution on annual fine litterfall, carbon content, and nutrient concentration, compared to other woody species (OS) on a neotropical inselberg in Espírito Santo state, Brazil. Annual fine litterfall was systematic monthly collected (November 2011-October 2012) by means of 15 littertraps (0.25 m2) placed in five transects, oven-dried (65 °C, 72 h), weighed, and C content and nutrients concentration (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Zn) were estimated. PP performed lower litterfall, C content, and nutrient concentration excepting higher K concentration, compared to OS. The results suggested that PP performed higher nutrient conservation, which indicated its potential in restoring degraded areas observed in the inselberg.

Abstract The objective of this study was to analyse the initial medium-term growth of a P. reticulata settlement under different phosphorus doses. The experiment was carried out in an area of Atlantic Forest, Sooretama, Northern Espírito Santo State, Brazil. Five doses of P per each tree (0 g, 27 g, 47 g, 67 g and 87 g) were tested in a randomized block design with three replicates and 18 plants per plot. At 3 months, 9 months and 15 months, height and diameter were measured at the soil level. At 36 months height, diameter at breast height, survival, basal area, and nutritional evaluation of the trees were measured. A logistic model was also used to model the growth in height of individual trees and a logistic model considering fixed effects and mixed form (fixed and random effects), in order to verify if the inclusion of the random effect (tree) would result in gains in terms of accuracy in the estimation of the future height of P. reticulata trees. The species presents potential for use in reforestation programs under edaphoclimatic conditions tested and under similar conditions. The species was not very demanding in P, and the addition of this nutrient promotes negative effects on its growth in the short and medium term. Regarding the model of growth in height, the logistic model adjusted in the mixed form showed to be superior to the traditional adjustment.

Resumen El objetivo de este estudio fue analizar el crecimiento inicial a mediano plazo de un asentamiento de P. reticulata bajo diferentes dosis de fósforo. El experimento se llevó a cabo en un área del Bosque Atlántico, Sooretama, norte del estado de Espírito Santo, Brasil. Se probaron cinco dosis de P por árbol (0 g, 27 g, 47 g, 67 g y 87 g) en un diseño de bloques al azar con tres repeticiones y 18 plantas por parcela. A los 3 meses, 9 meses y 15 meses se midió la altura y el diámetro a nivel del suelo. A los 36 meses de la siembra, se midió el diámetro a la altura del pecho, la supervivencia y el área basal y se hizo una evaluación nutricional de los árboles. También se utilizó un modelo logístico para modelar el crecimiento en altura de árboles individuales y el modelo logístico considerando efectos fijos y forma mixta (efectos fijos y aleatorios) para verificar si la inclusión del efecto aleatorio (árbol) resultaría en ganancias en términos de precisión en la estimación de la altura futura de los árboles de P. reticulata. La especie presenta potencial para su uso en programas de reforestación en condiciones edafoclimáticas probadas y en condiciones similares. La especie no fue muy exigente en fósforo y la adición de este nutriente promovió efectos negativos en su crecimiento a corto y mediano plazo. Con respecto al modelo de crecimiento en altura, el modelo logístico ajustado en forma mixta mostró ser superior al ajuste tradicional.

ABSTRACT: The evaluation of diversity and genetic structure allows us to verify with precision the effect of evolutionary and anthropic processes on species. The objective of this research was to evaluate the divergence and the genetic structure of two natural populations of Dalbergia nigra, using molecular markers Inter Simple Sequence Repeats (ISSR). Leaf samples were collected from two populations, located in the National Forest of Pacotuba and the Private Natural Heritage Reserve of Cafundó. Eight ISSR primers were used, which resulted in 97 bands, with 68.04% of polymorphism. Based on the joint data, the values of 0.33 for the Nei index (H*) and 0.50 for the Shannon index (I*) indicated moderate to high genetic diversity, being influenced by the presence of genetically dissimilar individuals in the National Forest of Pacotuba. Most of the genetic divergence was intrapopulational (85.96%), with moderate differentiation between populations (ΦST = 0.1404). The estimated historical gene flow between the fragments was low (Nm = 3.21) when compared with results from other tree species, and the genetic structuring analysis separated the populations into two groups, corresponding to the two populations evaluated. The results indicate a small genetic share among populations, however, populations are becoming structured. The satisfactory levels of genetic diversity benefit the use of the trees as matrixes for programs of restoration and recovery of degraded areas, connectivity of landscapes, and sustainable use of forest resources.

ABSTRACT The usual propagation method for Dalbergia nigra is via seedings; however, the seasonal supply has a variable quantity of seeds which limits the continuous production of seedlings. Therefore, the objective of this study was to establish a vegetative propagation protocol via mini-cuttings technique for D. nigra from juvenile shoots obtained from seedlings. The experimental design was completely randomized in a 2 x 2 x 4 factorial scheme, with two geographical origins: two controlled release fertilizer doses (4.0 and 8.0 g.dm-³) and four indole-3-butyric acid (IBA) concentrations (0; 2,000; 4,000; and 6,000 mg.Kg-1), with four replications. The mini-cuttings were removed from the tubes after 60 days of propagation in the greenhouse, and the substrate was completely removed by washing in running water to observe the roots. The survival percentage, rooting, rooting speed and variables related to mini-cuttings vigor (largest root length (RL, cm.plant-1), number of roots (NR), surface area (SA, mm2), root volume (RV, mm³) and root dry mass (RDM, g.plant-1) were measured. The results indicated that D. nigra has an aptitude for vegetative propagation by mini-cuttings with survival values and rooting greater than 70%. Geographical origins present a different set of responses for survival, rooting and vigor of mini-cuttings. Stock plant nutrition influences mini-cuttings root growth. IBA concentrations did not promote an effect on the mini-cuttings rooting percentage; however, exogenous auxin at the dose of 6,000 mg.Kg-1 provided mini-cuttings with greater vigor in their radical system. Nonetheless, further research is suggested to define the feasibility of using this regulator in the vegetative propagation of this species.

ABSTRACT Paratecoma peroba is a native forest species of great economic and ecological interest, currently at risk of extinction. In addition to the difficulty of finding adult individuals of this species, plant production is limited, so the use of mini-cuttings can facilitate the spread of P. peroba. Thus, the objective of this study was to analyse the effect of different doses of controlled release fertilizer (CRF) on rooting, growth, photosynthetic metabolism and nutritional balance of P. peroba clones propagated by mini-cuttings. Five doses of CRF (0, 2, 4, 6 and 8 kg.m-3) were tested, arranged in a completely randomized design with 12 repetitions and each repetition consisted of eight clones. Evaluations were carried out in the three stages of clones production: 1) Survival at 60 days in a greenhouse, 2) Rooting at 105 days in a shade house; and 3) Evaluation Productivity index, morphological variables, physiological metabolism, and nutritional through macronutrient contents, diagnosis and recommendation integrated system (DRIS) indices and the average nutritional balance index of clones at 120 days in the area of hardening. There was no influence of CRF on survival and rooting of mini-cuttings. The CRF favoured a higher productivity index, vegetative growth and physiological activity of the clones. The 6 kg.m-3 dose was sufficient to obtain nutritionally balanced clones.

ABSTRACT The Atlantic Forest is a biome that has suffered anthropic actions, such as the extraction of hardwood, which can lead to the extinction of endemic species of great economic and ecological value, such as Dalbergia nigra. In this perspective, large-scale multiplication studies are necessary to contribute to the conservation of this species. The objective of this work was to establish a protocol for the in vitro production of axenic seedlings of D. nigra. Four experiments were performed: I. Immersion times in NaOCl. II. Disinfecting agents in seed germination of D. nigra. III. NaOCl toxicity in seeds of the model species Lactuca sativa L. IV. Culture media and glutamine in the germination and initial growth of D. nigra. All experiments were arranged in a completely randomized design. For a better disinfestation and less harmful effects to the seedlings, it is recommended that the seeds be treated with 70% alcohol (1 min) and NaOCl (14 min). NaOCl has a high phytotoxic, cytotoxic, and genotoxic effect, and its mechanism of action in the L. sativa cell cycle is clastogenic and aneugenic, suggesting the formation of abnormal seedlings in D. nigra. The WPM medium and its supplementation with glutamine (0.75 mg.L-1) are recommended.

RESUMO A mecanização na implantação florestal exige elevada demanda por energia, tempo e altos custos operacionais e de produção. Assim, estudos relacionados à influência de variáveis sobre a eficiência dessas atividades são fundamentais, para reduzir custos e otimizar as operações. Objetivou-se, com este estudo avaliar o desempenho operacional e de custos das operações mecanizadas de implantação florestal em áreas de plantio de Eucalyptus sp. Os dados foram coletados em plantios de eucalipto localizados na região norte do estado do Espírito Santo, Brasil. A análise do desempenho operacional determinou a distribuição dos tempos operacionais, disponibilidade mecânica, grau de utilização, eficiência operacional e produtividade das máquinas. A análise de custos estimou os custos operacionais nas atividades de implantação florestal. As operações de plantio florestal foram: afastamento de resíduos, subsolagem, coveamento com adubação, plantio, capina química e adubação de cobertura. De acordo com os resultados, o plantio (39,20%) e o afastamento dos resíduos (15,99%) representaram os maiores tempos do ciclo operacional, os menores tempos produtivos (51,48% e 53,64%) e, por fim, os maiores tempos em manutenção (32,95% e 29%). A capina química e subsolagem, apresentaram os menores tempos em manutenção (4,64% e 3,47%). A adubação de cobertura foi a operação que apresentou maior produtividade (2,99 ha he-1) e o afastamento de resíduos a menor (0,97 ha he-1). Os maiores custos por hora efetiva (13,57 R$ he-1) e menores custos de produção (81,59 R$ ha-1) ocorreram no plantio. A subsolagem apresentou maior custo de produção (112,80 R$ ha-1). O menor custo operacional foi obtido na operação de adubação. Os custos operacionais tiveram como maiores pesos o custo de mão-de-obra, de combustível e de manutenção e reparos.

ABSTRACT Mechanization in forestry implantation demands high energy, time, and high operational and production costs. Thus, studies related to the influence of variables on the efficiency of these activities are essential to reduce costs and optimize operations. The objective of this study was to evaluate the operational and cost performance of mechanized forest implantation operations in Eucalyptus sp. Data were collected from eucalyptus plantations located in the northern region of the state of Espírito Santo, Brazil. The analysis of operational performance determined the distribution of operating times, mechanical availability, degree of utilization, operational efficiency, and productivity of the machines. The cost analysis estimated the operating costs in forestry implantation activities. The forest planting operations were: waste removal, subsoiling, digging with fertilization, planting, chemical weeding, and covering fertilization. According to the results, planting (39.20%) and waste removal (15.99%) represented the longest operating cycle times, the shortest production times (51.48% and 53.64%), and finally the longest maintenance times (32.95% and 29%). Chemical weeding and subsoiling showed the lowest maintenance times (4.64% and 3.47%). The cover fertilization was the operation that presented the highest productivity (2.99 ha he-1), and the removal of residues had the lowest (0.97 ha he-1). The highest costs per effective hour (R$13.57 he-1) and lowest production costs (R$81.59 ha-1) occurred at planting. Subsoiling had the highest production cost (R$112.80 ha-1). The lowest operating cost was obtained in the fertilizing operation. Operating costs had the greatest weight in labor, fuel, and maintenance and repairs.

ABSTRACT Melanoxylon brauna is a tree species native to the Atlantic Forest of high ecological and economic value. The objective of this study was to evaluate the growth and nutritional status of seedlings of two Melanoxylon brauna cultivars grown in substrate with different controlled-release fertilizer doses (CRF). The experiment was arranged in a randomized block 4 × 2 factorial design, with four CRF doses (0, 2, 4, and 8 kg m-3) and two seed origins (Viçosa-MG and Linhares-ES), with four replicates and 126 seedlings per plot. At 60, 90, and 120 days after emergence, seedlings were collected to measure variables related to emergence, growth, and nutrition. The greatest growth and best nutritional status were found for seedlings originated from seeds collected in Linhares at CRF dose of 8 kg m-3. On the other hand, seedlings originated from seeds collected in Viçosa showed low emergence and high plant mortality.

ABSTRACT The objective of the present study was to evaluate the influence of spacing, species richness, and sampling time on accumulated litter in forest restoration areas in the state of Espírito Santo, Brazil. The experiment was conducted under a randomized complete block design, in a subdivided plot scheme. Six treatments were evaluated, consisting of a combination of spacing levels and species richness. Accumulated litter samples were weighed and chemically analyzed to obtain nutrient concentrations. The variables analyzed in the restoration process, in general, did not influence litter biomass and nutrient concentrations. The time elapsed between restoration implantation and data sampling for the present study may have been insufficient for the occurrence of differences in variables evaluated. Despite the small amount of accumulated litter, it is of great importance for soil physical protection and fertility improvement, generating conditions for the stabilization of new forest species in the restoration area.

ABSTRACT The objective of this work was to understand the relationship between decomposition of leaf litter and climatic elements and determine the mineralization of nutrients in the decomposition process in a fragment of Semideciduous Submontane Forest, located in southern state of of Espírito Santo. Overall, 84 litterbags were deposited in 12 permanent plots, collecting one litterbag per plot for 30, 60, 90, 150, 210, 270 and 360 days after the beginning of the experiment. The leaf material remaining in the litterbag was oven-dried and weighed, with later analysis of nutritional compounds. The leaf litter decomposition rate was 1.42, 75.95% of decomposing litter at the end of the evaluation period. Mineralization occurred in the following order: K, Corg., Mg, S, P, N and Ca. There was a positive correlation of average and minimum air temperature, as well as accumulated precipitation and leaf litter decomposition .