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: Despite the importance of Plathymenia reticulata for forestry and ecological purposes, a protocol for the vegetative propagation of the species remains unclear mainly due to the low adventitious rooting of the propagules of the species. In this sense, this work aimed to evaluate the rooting of mini-cuttings of juvenile materials of P. reticulata and our hypothesis: (1) maintaining propagules under mist chamber for different periods affects the rooting process; (2) the mini-stump management system due to the restriction of the root system affects the production of mini-cuttings and the quality of clonal seedlings. Results: It was not necessary for more than 30 days in a mist chamber to induce rooting. The highest percentage of rooting was obtained 50 days after staking. Mini-gardens set up in suspended seed bed and tubes (280 cm3) had the average mini-cuttings productivity of 4.32 and 2.06, respectively, over 270 days of exploration (monthly collections). At 120 days after staking, there was no difference in the survival and in the final quality of clonal seedlings produced. However, clonal seedlings from mini-garden in tubes had higher height, leaf area, and number of first-order roots. Regardless of the mini-garden management, the clonal seedling production index was 50%. Conclusion: We can conclude that P. reticulata seedling production via mini-cutting technique is possible.

Resumo O trabalho teve como objetivo avaliar o uso do lodo de esgoto tratado (LET) associado a substrato à base de casca de pinus (SC1) ou à base de fibra de coco (SC2), em diferentes proporções, como substrato para produção de mudas de vinhático. O experimento foi conduzido em casa de vegetação, localizada na unidade de apoio a pesquisa da Universidade Estadual do Norte Fluminense, de junho a novembro de 2016. Utilizaram-se 20, 40, 60, 80% de LET associados ao SC1 ou ao SC2, 100% de LET e o tratamento com SC1 com adubação convencional (controle). O lodo de esgoto foi higienizado com adição de cal a 15% do peso seco. Os resultados revelam que as menores proporções de LET no substrato resultaram em mudas com melhor crescimento em altura, diâmetro do coleto, área foliar, massa seca da parte aérea e do sistema radicular, comprimento e volume radicular. A nodulação foi negativamente influenciada nas mudas produzidas em proporções acima de 20% de LET. A agregação do torrão ao substrato não foi influenciada pela adição de LET, entretanto, houve aumento da curvatura do torrão nas mudas produzidas em maiores quantidades de LET. O conteúdo da parte aérea de N, P e K foi menor nas mudas produzidas em substrato com LET. Para produção de mudas de vinhático, sugere-se a proporção de 20% de lodo de esgoto associado ao SC1 ou SC2, não havendo prejuízos em relação às mudas produzidas em substrato comercial adubado, utilizado comercialmente.

Abstract The aim of this work was to evaluate the treated sewage sludge (LET) associated with commercial substrate based on pinus bark (SC1) or based on coconut fiber (SC2), in different proportions, as substrate for the production of vinhático seedlings. The study was led in a greenhouse, located in the research support unit of the State University of North Fluminense. The treatments considered as substrates were 20, 40, 60, 80% of LET associated with SC1 or SC2, 100% of LET and the treatment with SC1 with conventional fertilization (control). The sewage sludge was sanitized with addition of lime to 15% of dry weight. The results showed that the lower LET proportions in the substrate resulted in seedlings with better growth in height, stem diameter, leaf area, dry mass of shoot and root system, root length and volume. The nodulation was negatively influenced in the seedlings produced in proportions above 20% LET. The aggregation of the clod was not influenced by the addition of LET, however, there was increase of the curvature of the clod in the seedlings produced in larger amounts of LET. The shoot content of N, P and K was lower in the seedlings with LET. For the production of vinatic seedlings, 20% of sewage sludge associated with SC1 or SC2, is suggested, with no losses in relation to the seedlings produced in commercial substrate that received fertilization, used commercially.

ABSTRACT The aim of our study was to evaluate the dendrometric characteristics of Atlantic Forest trees of 21 years of deployment in the mountain region of Rio de Janeiro, Brazil and their influence on topsoil fertility. We evaluated the survival rates, total heights, and diameters at 1.30 m of all trees in the stand. The characterized soil chemical attributes were pH, P, K, Ca, Mg, Al, and organic matter at 0-0.1 m depth. The averages were compared by Student’s test (p<0.05). While Myroxylon peruiferum and Amburana cearensis had lower survival rates than the other species, Plathymenia reticulata had a larger diameter. All tree species showed diameter growth, though it was larger for Dalbergia nigra, Plathymenia reticulata, Schizolobium parahyba, Esenbeckia leiocarpa, and Lecythis Pisonis. All stands showed medium organic matter content, from 3.3 to 4.1%, and low P. The soils under the Dalbergia nigra and Plathymenia reticulata stands are the most acidic and with low Ca, Mg, and K levels. Our study demonstrated differences in growth patterns and that the species influenced the soil chemical characteristics differently.

ABSTRACT Khaya ivorensis stands out because of the quality of the wood and high economic value. Its propagation has been carried out by seeds, an obstacle in the production in large scale seedlings, since the seeds present high value and they result in heterogenous stands. The vegetative propagation is an alternative to overcome these problems. The aim of this work was to verify the feasibility of mini-cutting for african mahogany, evaluating the pro- ductivity of the mini-stumps, the rooting of mini-cuttings using different concentrations of IBA and the clonal seedlings quality. The mini-stumps were produced from seeds in tubes, pruned at 8 cm, at 60 days. At 100 days after apical pruning, the fi rst sprouts col- lection was performed, and the mini-cuttings were submitted to concentrations of IBA (0; 2,000; 4,000 and 6,000 mg.L-1) for rooting evaluation. The seedlings were transplanted to clonal mini-garden, in which four collections of mini-cuttings were performed. Clonal seedlings quality was evaluated at 120 days after staking. The species showed tolerance to apical pruning and successive collections of mini-cuttings, with 96.4% survival and more than 92% of the mini-stumps producing mini-cuttings. It was observed 100% survival and rooting of mini-cuttings. There was no effect of the IBA on the rooting percent- age of the mini-cuttings, however, the higher concentration of IBA increase the thinner root production. The fi nal clonal seedling quality has similar growth for all treatments.