International audienceno abstrac

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.Amazonia | floristics | rain forests | seed plants | species diversity

Resumo No final da década de 1960, pesquisadores do Museu Paraense Emílio Goeldi (MPEG) iniciaram as coletas botânicas na Serra dos Carajás, resultando em um expressivo acervo e interessantes descobertas sobre a flora local, marcada por endemismos e pressão por atividades mineradoras. Em 2014, foi estabelecido o projeto "Flora das cangas da Serra dos Carajás" através da cooperação entre o MPEG e o Instituto Tecnológico Vale de Desenvolvimento Sustentável (ITVDS), visando especialmente a elaboração da flora das cangas da FLONA Carajás. Um acervo de cerca de quinze mil exsicatas, depositadas principalmente nos herbários MG e BHCB além de HCJS, INPA, IAN, NY e RB constitui a base para o desenvolvimento da flora. Até o momento, a flora inclui 151 famílias de angiospermas, gimnospermas, licófitas e samambaias e briófitas (musgos e hepáticas). Neste trabalho apresentamos um breve histórico dos estudos botânicos na região, caracterização da área de estudo, e procedimentos metodológicos adotados no desenvolvimento do projeto. Também, constitui a introdução para o volume 1 da Flora das cangas de Carajás composto por 55 famílias, sendo quatro de briófitas, duas de licófitas, oito de samambaias, uma de gimnospermas e 40 de angiospermas, incluindo 139 gêneros e 248 espécies.

Resumo Nas cangas da Floresta Nacional (FLONA) de Carajás e no Parque Nacional dos Campos Ferruginosos (PNCF) foram registradas 856 espécies, distribuídas em 116 famílias de fanerógamas. As famílias mais ricas foram Poaceae (86), Fabaceae (65) e Rubiaceae (46). O hábito herbáceo foi o melhor representado. Dois gêneros, 24 espécies e uma subespécie são apontadas como endêmicas das cangas da área de estudos. Na FLONA de Carajás, a Serra Norte, com maior amostragem, possui 659 espécies de fanerógamas e na Serra Sul foram registradas 545 espécies. Aproximadamente 60% das espécies documentadas na área de estudos, incluindo espécies endêmicas, não possuem registro para o PNCF. Através da lista taxonômica aqui apresentada, foi possível demonstrar considerável distinção entre as cangas da Serra dos Carajás e as do Quadrilátero Ferrífero, em Minas Gerais, apontando também pouca correspondência dessas duas listas com a canga de Corumbá, no Mato Grosso do Sul. A riqueza e singularidade da flora da região, que inclui diversas espécies endêmicas, associada à ameaça a que estão submetidos estes ambientes por atividades de mineração, apontam para a necessidade de um planejamento para conservação das espécies da flora das cangas de Carajás.

Ecological restoration is essential in rehabilitating degraded areas and safeguarding biodiversity, ecosystem services and human welfare. Using functional traits to plan restoration strategies has been suggested as they are the main ecological attributes that underlie ecosystem processes and services. However, few studies have translated ecological theory into actual restoration practices that can be easily used by different stakeholders. In this article, we applied a multiple-trait approach to select plant species for the restoration of degraded lands inside the Brazilian Amazon Forests. We selected 10 traits encompassing ease of management, geographical distribution and interactions with animals and other ecosystem services and scored these traits using 118 native species. Then, we ranked all species according to the total number of traits that they exhibited to obtain a list of 53 highly ranked species. In addition, we employed non-metric multidimensional scaling (NMDS) to assess the variation in these traits across the entire group of species. Based on the results, we selected a subset of species that maximizes functional diversity (high variability). We performed a sparse linear discriminant analysis (SLDA) to highlight a minimum set of traits to effectively discriminate botanical families. The final list of species and their traits highlight the importance of preserving not only the historical reference of a focused ecosystem but also its functional diversity to restore the interaction with local fauna, enrich the food chain and guarantee ecosystem services for local communities.

Carajasia is described as a new genus of Rubiaceae. It is so far known only from the mountain summits of Serra dos Carajás (Pará, Brazil), where it is part of a shrubby vegetation surrounded by tropical rainforest. The new genus belongs to the tribe Spermacoceae and is positioned within it to the Spermacoce clade. Carajasia is unique within the clade in having a very particular combination of characters: flowering branches with two axillary flowers per node, homostylous flowers, corollas with a fringe of moniliform hairs, pubescent styles with distinct stigma lobes, bilobed nectariferous discs covered by triangular papillae, pollen with a double reticulum and fruits with a peculiar type of dehiscence. A detailed description of Carajasia is presented, including observations of the fruit and pollen, along with distribution maps and images of the plant in its habitat. A dichotomous key to distinguish Carajasia from other genera with deeply divided stigmas is provided. A molecular phylogenetic study was carried out using ITS and ETS sequences to determine the phylogenetic position of the new genus within the Spermacoce clade. The results of the combined analyses demonstrated that Carajasia is sister to Galianthe with moderate to high support. Both genera form a weakly supported clade with Schwendenera. This clade is sister to the other genera of the Spermacoce clade studied in this work. Galianthe and Schwendenera share with Carajasia pollen with a double reticulum, but they are clearly differentiated by suffruticose habit, heterostylous flowers and the pattern of fruit dehiscence. To clarify the phylogenetic position of Carajasia, some morphological characters are discussed based on the molecular results: division of the stigma, pollen types and floral syndrome.

No abstract

In the Cerrado Biome of Brazil, African grasses constitute a serious problem, occurring in virtually all protected areas. Molasses grass (Melinis minutiflora P. Beauv.) accumulates more biomass than do most other species of the herbaceous stratum vegetation native to the Cerrado. In this study, our aim was to determine the impact of M. minutiflora on native vegetation, as well as (using simulations of fire traits) on the characteristics of fires, in invaded areas of the Serra do Rola-Moça State Park (Parque Estadual da Serra do Rola-Moça, PESRM), a protected area where fires are frequent, in the state of Minas Gerais, Brazil. Our main results are that M. minutiflora considerably increases the amount of biomass, becoming the main combustible plant in the campo-cerrado (grassy-woody savanna) fires in the PESRM; that the native monocot biomass is inversely correlated with the M. minutiflora biomass, suggesting suppression of the native herbaceous stratum; that eudicots are diminished by M. minutiflora, both in number of individuals and number of species; and that fires are more severe in M. minutiflora-invaded areas.