Abstract Acrocarpus fraxinifolius stands out due to its uses in the timber industry and rapid growth. However, information is scarce regarding its fertilization. We aim to understand how soil preparation and phosphorus doses affect A. fraxinifolius initial development. The experimental design used was a randomized block design in a 2 x 5 factorial scheme, consisting of two types of soil tillage (minimum and conventional) and five doses of phosphorus (P) (0, 50, 100, 150, and 200 g of simple superphosphate) with four replications, and plots formed by two plants. The measurement occurs at 30 and 210 days after planting, assessing the height and diameter at the stem height. Initially, the minimum tillage provided had a higher average height and diameter. However, conventional tillage, acidity correction, and fertilization with 108 g of simple superphosphate per plant resulted in Acrocarpus fraxinifolius plants with better growth at 210 days after planting.

Abstract We present the first records of insect visitors and pollinators of Bertholletia excelsa (Lecythidaceae) in a 25 years plantation outside the Amazon biome, flowering and producing Brazil nuts. We installed a platform to observe and photograph the insects. The collected insects were stored, mounted, and identified by specialists. Six species were observed, three of them classified as potential pollinators (Centris lutea, Eulaema nigrita, Eulaema cingulata). The species E. nigrita and E. cingulata were already reported as a pollinators of Brazil nut in Amazon. This is the first record of C. lutea as potential pollinators for B. excelsa.

Abstract Basic information about growth rate and response to silvicultural treatments on potential native species are bottlenecks for the wide use of these species for forest production. In this context, the objective of this work was to evaluate the silvicultural performance of four native species as a function of pruning intensity. The experimental design was completely randomized with ten replications and one plant per plot, in a 4 x 4 factorial scheme, four forest species, and four pruning intensities. At 30 and 42 months, height (H) and diameter at breast height (DBH) were evaluated, then the current annual increment (CAI) was calculated, as well as the mean annual increment (MAI) at 42 months. Guazuma ulmifolia showed higher growth in height and DBH compared to other species at both ages. The pruning resulted in a reduction of MAI in 0.15 cm. year-1 in DBH for every 25% of pruning intensity.

Resumo O uso de polímeros hidrorretentores surge como uma alternativa para disponibilizar água de forma adequada na fase de implantação de povoamentos florestais, além de reter nutrientes necessários para o estabelecimento e desenvolvimento destes. No presente trabalho, objetivou-se avaliar o efeito do polímero hidrorretentor e a influência de diferentes doses de fertilização mineral no crescimento, teor e acúmulo de nutrientes do híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis, na fase de implantação. O experimento foi realizado em delineamento de blocos casualizados completos, em esquema fatorial 2 x 5, sendo duas doses do polímero (0 e 1 g planta-1) e cinco combinações de fertilização mineral (N0P0K0, N0P1K0, N1P0K1, N1P1K1 e N2P2K2, correspondendo à dose de N (N0 = 0, N1 = 62 e N2 = 124 g do fertilizante por planta), P (P0 = 0, P1 = 75 e P2 = 150 g do fertilizante por planta) e K (K0 = 0, K1 = 62 e K2 = 124 g do fertilizante planta)), em três repetições com cinco plantas por parcela. As avaliações foram realizadas aos 30, 60, 120 e 150 dias pós-plantio, quando foram mensurados a altura total e o diâmetro do colo, além da análise química nutricional, aos 150 dias. A partir dos dados obtidos, observou-se que não houve interação entre o efeito do polímero e doses de fertilização mineral. Para o diâmetro do colo, o uso do polímero proporcionou maior crescimento às mudas somente nos 30 primeiros dias de avaliação, e para altura houve maior crescimento nas avaliações aos 30, 60 e 120 dias de plantio. Os tratamentos contendo fósforo (18% de P2O5) obtiveram maior incremento em diâmetro em relação aos demais nos primeiros 60 dias pós-plantio. Nas outras avaliações, a maior dose de fertilizante (N2P2K2) foi responsável pelo maior crescimento em diâmetro e altura. A maior dose de fertilização mineral promoveu maior acúmulo de NPK na parte aérea das plantas (caule, ramos e folhas). Portanto, o polímero proporcionou maior crescimento às mudas na fase inicial de desenvolvimento, e o fósforo se mostrou essencial para o crescimento em diâmetro e altura na fase de implantação do híbrido utilizado.

Abstract The use of water retaining polymer appears as an alternative to provide adequate water the phase of implantation the forest stands, further retaining nutrients necessary for the establishment and development of these. The objective of this study was to evaluate the effect of the water retaining polymer and influence of the different forms of mineral fertilization at growth, content and nutrient accumulation of a clonal hybrid of Eucalyptus urophylla x Eucalyptus grandis in the implantation phase. The experiment was carried out in a randomized complete block design at 2 x 5 factorial scheme, with two polymer doses (0 and 1 g plant-1) and five mineral fertilization combinations (N0P0K0, N0P1K0, N1P0K1, N1P1K1 e N2P2K2, corresponding to the dose of N (N0 = 0, N1 = 62 e N2 = 124 g of fertilizer per plant), P (P0 = 0, P1 = 75 e P2 = 150 g of fertilizer per plant) e K (K0 = 0, K1 = 62 e K2 = 124 g of fertilizer per plant)) in three replications with five plants per plot. The valuates were performed at 30, 60, 120 and 150 days post-planting, when total height and root collar diameter were measured, as well as nutritional chemical analysis, at 150 days. From the obtained data, observed that there was no interaction between the effect of the polymer and doses of mineral fertilization. For the root collar diameter use of the polymer only provided bigger growth seedlings at 30 days the evaluate, and for the height, there was greater growth in the valuates in the 30, 60 and 120 days of planting. The phosphorus treatments were obtained a bigger increment to the diameter in relation for the others 60 days after planting. These the other evaluations of higher fertilizer dosage (N2P2K2) was responsible for the greater growth in diameter and height. The higher dosage of mineral fertilization promoted greater accumulation at NPK in the aerial part of the plants (stem, branches e leaves). Therefore, the polymer gave a higher growth seedling in the initial phase development, and the phosphorus was shown to be essential for the growth in diameter and height in the phase of implantation of the hybrid used.

O objetivo deste trabalho foi avaliar o impacto da substituição de pastagens por reflorestamento com eucalipto e mata secundária sobre a dinâmica da matéria orgânica e emissão de N2O, em áreas da Mata Atlântica. As áreas avaliadas localizam-se no Município de Cruzeiro, SP, e têm histórico comum de uso da terra, tendo sido inicialmente ocupadas por pastagem. Desde 1973, uma parte desta área foi reservada para regeneração natural, outra foi ocupada com plantio de eucalipto e outra permaneceu como pastagem. Para quantificar o estoque de C e nitrogênio do solo e a abundância isotópica de 13C na matéria orgânica do solo (MOS), foram coletadas amostras de solo até 1 m de profundidade, com uso de três repetições. A emissão de N2O foi avaliada com câmaras estáticas pelo período de um ano. Não foram observadas diferenças significativas nos estoques de C e N do solo nas áreas de mata e eucalipto, em relação à pastagem. A mata apresenta maior influência sobre a composição da MOS. Na mata de eucalipto ocorrem as maiores perdas anuais de N, pela emissão de N2O.

The objective of this work was to evaluate the impact on soil organic matter dynamics and N2O emission of the substitution of pasture areas by eucaliptus reforestation and secondary forest. The evaluated areas are localized in Cruzeiro municipality, São Paulo state, Brazil. The areas presented common soil usage history, and were used, at first, as pasture. Since 1973, part of the area was reserved for regeneration of the secondary forest, another part was planted with eucalyptus, and the remaining was kept as pasture. To quantify the stocks of C, N and in soil and the 13C isotopic abundance in soil organic matter (SOM), samples from these areas were collected until 1-m depth, using three replicates. The emission of N2O was evaluated with static chambers for one year. The three areas did not show significant differences on C and N stocks of the secondary forest and eucalyptus areas, in comparison to the pasture one. Secondary forest and eucalyptus has greater carbon contribution to SOM. Secondary forest and eucalyptus have highest annual losses of N, as N2O.