The proliferation of woody plant species over grassland areas has been reported in different regions of the planet. This phenomenon has caused economic, social and environmental effects in the Brazilian Pantanal. Traditional knowledge based on scientific evidences technically supports the forms of management to control the process of colonization of woody plants in native grasslands, thus promoting the original ecological restoration of these ecosystems. Our study aimed to evaluate three management regimes with prescribed fire for controlling the invasion of Vochysia divergens Pohl. on grassland matrix areas in the Brazilian Pantanal. The results obtained showed that prescribed fire is an efficient tool in controlling V. divergens in the early stages of its establishment, and effectively contributes to ecological restoration processes in the savannah grasslands, aimed at controlling woody tree and shrub species invasions in the grasslands of the Brazilian Pantanal.

The resurgent navigation project known as the Hidrovia Paraguay-Paraná threatens the integrity of the Pantanal, the world's largest wetland, which is considered a biome of its own. Intensive barge navigation is intended to transport crops (soybean, sugar, corn) and cement, iron and manganese from areas of production in Brazil, Paraguay and Bolivia to the oceanic ports of the Plata River. This short communication assembles the information available on the potential impacts of the planned deepening of the natural channel of the Paraguay River in its ~700 km-long upper section. These river channel alterations would disconnect the river from its floodplain, shorten the inundation period, and shrink the wetland area, resulting in severe degradation of the globally outstanding biological and cultural diversity of the Pantanal. The river sediments are mostly sandy and would require perpetual dredging. The reaches needing the most intensive dredging are those of the highest ecological value, protected as a National Park, UNESCO World Heritage and Biosphere Reserves, and various Indigenous reserves and Ramsar sites. Climate change is projected to increase the occurrence of low water periods. Between 2019 and 2021, navigation was impossible even in the already-deepened reaches of the Paraguay River between Corumbá and Asuncion during long periods of the year. Thus, despite considerable financial and technical efforts, the success of the navigation project is doubtful, whereas enormous environmental, cultural, and social impacts can be anticipated. For these reasons, the Brazilian government had already turned down the project in 2000. We suggest alternative, less impactful modes of transport of commodities, e.g., via railway.

The objectives of this research were to verify the relationships between the dendrometric and edaphic variables with the yield of oleoresin from Copaifera spp., and to adjust equations to predict yield from a primary forest. Thirty Copaifera spp. trees were selected to extract oleoresins over 24 hours, using a 1.91 cm (¾ inch) auger. In addition, data were collected on tree size and the edaphic characteristics of the topsoil around of each tree. Principal components analysis was used to verify the relationships between variables and a regression analysis was used to verify variables that may be best to predict oleoresin yield. After the principal components analysis, the only variable related to the oleoresin yield was the stem height, which had the best adjusted coefficient of determination (0.84) and relative standard error (13.11%). We found the yield of oleoresin from Copaifera spp. in primary a forest had a significant and positive correlation with the stem height, whereas no significant correlations were found between yield, or any other dendrometric or topsoil variables studied.

Copaiba trees, of the genus Copaifera (Fabaceae), produce an oleoresin that has pharmacological applications. The yield from the trees is very variable, and factors affecting production are still unknown. We evaluated the yield of oleoresin from Copaifera spp. in the Cerrado-Amazonia ecotone, as well as its relationship with the growth and age of trees. We sampled 30 Copaifera trees by extracting oleoresin for 24 h with a metal borer. Increment cores were collected from 15 trees to determine their age by counting growth rings and to calculate the mean annual increment of the diameter at breast height. The cylinders were sanded and the number of growth rings was counting with a magnifying glass (10x). The ages of trees from which increment cores were not collected were estimated by simple regression analysis. The proportions of productive and non-productive trees were recorded. The best adjusted model for age estimation showed R(2)adjust. = 0.616 and Syx% = 4.42. The average productivity of oleoresin was 0.124 L per day, and 30% of the trees were productive. The proportion of productive trees increased with increasing diameter at breast height and age, but after a point, increasing diameter was associated with reduced productivity. The mean annual increment had an inverse relationship with diameter for the productivity of oleoresin. The results suggest that other factors could be triggering and controling the oleoresin production and not only the age.

Genetic diversity studies in natural forest species populations have consistently expanded in recent years. Considering that biodiversity is directly related to genetic variation among and within populations, its study has become essential to the knowledge of genetic patterns. The study assessed genetic diversity of a Mezilaurus itauba population, detecting similarity and dissimilarity evaluating distribution intensity of adult and juvenile trees in remnant rain forest fragments in southern Amazon, Brazil. Leaf and cambium samples were randomly collected from 36 reproductive individuals. Eleven RAPD (random-amplified polymorphic DNA) primers were tested for genetic similarity analyses. The obtained data demonstrated that the species presented 79.77% polymorphism among the loci observed, with genetic diversity occurring between juvenile and adult trees. The population studied presented genetic diversity, forming three well-distinguished groups.

Spatial analysis of forest tree distribution is a powerful tool to respond to basic ecological questions, and represent a useful support to strategies of genetic conservation and sustainable management practices of forest resources. Spatial analysis techniques combined with the use of Geographical Information Systems have been commonly applied to the study of stochastic processes in order to determine the existence of clusters to be related to microenviromental conditions and/or genetic factors. The present study focused on the distribution patterns of individuals of Mezilaurus itauba in a seasonal forest of the southern Amazon, with the aim of providing information about the spatial arrangement of these species at the juvenile and adult stages. Ripley's K function with radius of 10, 20 and 30 m was used to describe spatial distribution patterns. The hypothesis of complete spatial randomness (CSR) of individuals was tested by constructing confidence envelopes for the Ripley's K function through Monte Carlo simulations using a Poisson homogeneous process. The results obtained suggest a general random distribution of individuals, though a tendency to clustering at close distances was detected for individuals classified as adults (DBH > 50 cm). Contrastingly, a completely randomized spatial pattern was found for juveniles trees (DBH < 50 cm). Our results provide a useful baseline for the development of sustainable management plans and conservation of Mezilaurus itauba, as well as for other economically-exploited, native tree species in the southern Amazon forest.

O presente estudo objetivou avaliar a germinacao in vitro de embrioes zigoticos de Mauritia flexuosa em diferentes temperaturas. O material botânico foi coletado na localidade denominada Vale do Rio Paciencia, Parque nacional da Chapada dos Guimaraes, Mato Grosso, Brasil. A coleta dos frutos foi realizada diretamente das arvores selecionadas, totalizando 10 individuos distribuidos em transecto estabelecido ao longo das margens do Rio Paciencia. Os frutos acondicionados em sacos de papel foram transportados ao Laboratorio de Biotecnologia da Faculdade de Agronomia da Universidade Federal de Mato Grosso (BIOTEC), sendo mensurados e despolpados para a extracao das sementes e embrioes zigoticos. Utilizaram-se 60 embrioes dispostos em câmara de germinacao, com temperaturas de 20, 25, 30, 35 e 40°C e fotoperiodo de 16 h. Os dados foram analisados estatisticamente aplicando-se analise de regressao polinomial. Os resultados mostraram que a germinacao de embrioes in vitro viabilizou o estabelecimento do buriti, constatado pelos altos indices de germinacao. Embrioes germinaram mais lentamente quando submetidos a temperaturas amenas. As melhores taxas de germinacao ocorreram nas temperaturas de 30°C (75%) e 35°C (83,33%). A tecnica de cultivo in vitro de embrioes zigoticos de Mauritia flexuosa pode ser utilizada para a propagacao de mudas da especie buscando-se homogeneizar as taxas de germinacao. http://periodicoscientificos.ufmt.br/index.php/afor/article/view/1473

The study aimed to establish floral composition, diversity levels, category size, phytosociological structure, commercial use and ecological group of species present in the regeneration of open ombrophile forest in southern Amazon, Brazil. Data were collected at S?o Nicolau farm, in the municipality of Cotrigua?u, northwest of Mato Grosso state, coordinates 51°9'19.5"S and 58°14'53"W. One hundred plots of 10 × 10 m were allocated. All individuals between 29.9 and 59.9 cm had circumference at breast height (CAP) measure, with sub-plots of 5 × 5 m which were measured in all subjects between 1:50 m in height 29.9 cm CAP and sub-plots of 2 × 2 m for individuals between 0.30 to 1.5 m tall. The information obtained in the field were processed in excel spreadsheet. The results showed the occurrence of 610 individuals belonging to 82 species, 34 plant families, with a diversity index of Shannon & Weaver’s 2.77. The index of value of importance showed species Protium robustum, Maquira calophilla and Inga fagifolium with greater ecological importance in fitocenose. The higher values for Natural Regeneration were the species Protium robustum, Maquira calophilla and Inga fagifolium with 16.42, 8.03 and 7.76 respectively.