Revisitando a flora de Macaé de Cima, Rio de Janeiro, Brasil: o gênero Psidium (Myrtaceae)

Resumo As espécies de Psidium de Macaé de Cima, Rio de Janeiro, Brasil foram revisitadas após pouco mais de 20 anos da publicação do estudo de Myrtaceae para este trecho de Floresta Atlântica, a qual atualmente se constitui em uma Área de Proteção Ambiental. A identificação das espécies foi realizada com base em análise de coleções depositadas em herbário e observação dos indivíduos a campo. Os resultados incluem o tratamento taxonômico, chave de identificação, comentários e registro fotográfico das espécies. O número de espécies de Psidium na área de estudo foi ampliado de três para seis espécies, uma das quais P. ovale representando uma nova ocorrência para o estado do Rio de Janeiro. Os resultados revelaram a necessidade de estudos continuados de flora, especialmente em áreas de alta diversidade, e a sua importância para conservação das espécies e gestão de áreas protegidas

Flora of Espírito Santo: Psidium (Myrtaceae)

Abstract This study presents a floristic-taxonomic treatment of Psidium in the state of Espírito Santo, and is a result of fieldwork combined with analyses of herbarium specimens. Fourteen species of the genus were recognized in Espírito Santo state (P. brownianum, P. cattleianum, P. cauliflorum, P. guajava, P. guineense, P. longipetiolatum, P. myrtoides, P. oblongatum, P. oligospermum, P. ovale, P. rhombeum, P. rufum P. sartorianum, and Psidium sp.), accounting for about 34% of the species richness estimated for the genus in the Atlantic Rainforest biome. The species occur predominantly in lowland forests up to 700 meters above sea level. These areas are highly threatened due to urbanization of coastal areas and agricultural expansion in the state Espírito Santo. Therefore, the conservation of Psidium species in this state requires the creation of more lowland protected areas

Breve histórico e classificação da vegetação capixaba

Resumo O estado do Espírito Santo apresenta grande variedade de ecossistemas num território relativamente pequeno. A exuberância de suas florestas vem despertando o interesse de muitos naturalistas e viajantes desde o século XIX, os quais deixaram registros valiosos dos primeiros anos da ocupação das "Areas Prohibidas" a leste de Minas Gerais. O cultivo do café, um dos alicerces econômicos do estado, deu início à perda dessas florestas. Tais perdas alavancaram o movimento conservacionista e a pesquisa científica no estado. A biogeografia, riqueza de espécies e de processos ecológicos nos fragmentos que restaram no Espírito Santo ainda revelam surpresas. Dentro do domínio da Floresta Atlântica, o estado abriga diferentes tipos de vegetação: Floresta Ombrófila Densa, Floresta Ombrófila Aberta, Floresta Estacional Semidecidual, Savanas, Formações Pioneiras e Refúgios Ecológicos. A descrição e classificação da vegetação do Espírito Santo ainda está inacabada tendo em vista as incertezas levantadas por alguns estudos. Também não existe um mapa da vegetação que contemple adequadamente a diversificada vegetação. A despeito de tais limitações, apresentamos descrições sucintas sobre os tipos de vegetação que vêm sendo reconhecidos na literatura moderna

Flora of Espírito Santo: Psidium (Myrtaceae)

<div><p>Abstract This study presents a floristic-taxonomic treatment of Psidium in the state of Espírito Santo, and is a result of fieldwork combined with analyses of herbarium specimens. Fourteen species of the genus were recognized in Espírito Santo state (P. brownianum, P. cattleianum, P. cauliflorum, P. guajava, P. guineense, P. longipetiolatum, P. myrtoides, P. oblongatum, P. oligospermum, P. ovale, P. rhombeum, P. rufum P. sartorianum, and Psidium sp.), accounting for about 34% of the species richness estimated for the genus in the Atlantic Rainforest biome. The species occur predominantly in lowland forests up to 700 meters above sea level. These areas are highly threatened due to urbanization of coastal areas and agricultural expansion in the state Espírito Santo. Therefore, the conservation of Psidium species in this state requires the creation of more lowland protected areas.</p></div

The role of terrestrial bromeliads in determining the spatial organization of plant life forms in a tropical coastal forest

ABSTRACT The interplay between plant-plant interactions and light heterogeneity in the understory of tropical forests has rarely been examined. We aimed to identify the relative importance of the understory light environment and terrestrial bromeliads in explaining the abundance and spatial organization of different plant life forms along a coastal forest gradient from seashore inland in southeastern Brazil. We estimated the abundance of various life forms (herbs, woody plants, bromeliads, climbers, and palms) and the degree of light availability using hemispherical photographs in 165 plots (1 m2) within a 1.75 ha site. We used ordination methods, partial redundancy analysis (pRDA), spatial filtering using Moran’s eigenvector mapping, and Moran’s I splines. Forest cover was highly heterogeneous, but did not explain variation in abundance of life forms. Spatially, bromeliads were negatively associated with woody saplings, herbs and climbing plants at scales between 5-20 m, while the distance to seashore was found to be unrelated to these patterns. Our findings revealed that terrestrial bromeliads play an important role in the spatial organization of various life forms near the forest floor. Overall, the presence of terrestrial bromeliads and the plant area index better explained the understory vegetation than forest cover and distance to seashore

Phytochemical screening and phytocytotoxic effects of the tropical Myrcia vittoriana (Myrtaceae)

Abstract We investigated whether essential oil and aqueous and ethanolic extracts from M. vittoriana leaves have phytotoxic effects on the germination and initial development, and cytogenotoxic effects on the cell cycle, of model plants. The essential oil and extracts of M. vittoriana were characterized and used as treatments in phytotoxicity and cytotoxicity tests. The results indicated a reduction in germinative parameters and plant growth, with the higher concentrations of extracts and essential oil having the most evident effects. The cell cycle was also affected with a reduction of the mitotic index and the presence of chromosomal and nuclear alterations. All treatments showed clastogenic and aneugenic modes of action. The results can be associated with the synergistic effects of metabolites found in the extracts and essential oil, mainly the presence of the sesquiterpene germacrene D in the essential oil and of catechins, saponins, and tannins in the extracts. These substances inhibit plant germination and growth, confirming the phytotoxic effects of M. vittoriana in plant models, which should now be tested under field conditions