Palm seeds are known for displaying dormancy and a thick endocarp that delays germination and embryo growth; but water treatments may accelerate their germination process. Additionally, ex-situ conservation can cause seed viability loss over time. Data on seed dormancy and storage have been neglected for many native palm species in Brazil. We investigated the effect of water treatments and one-year storage on the germination of Copernicia alba Morong, a palm tree from the Brazilian Pantanal wetland. To address our aim, fresh and stored pyrenes were immersed in water (at room temperature for 24, 48, and 72h) and in hot water (~75°C for 5- and 10-min). Fresh pyrenes germinated up to 84% in control, reaching 100% after water immersion for 48 and 72h. In contrast, one-year storage reduced germination by almost 50%, but water immersion slightly increased the germination of stored pyrenes. On the contrary, hot water decreased germination for both fresh and stored pyrenes. Seeds of C. alba may be classified as orthodox seed storage behavior. Taken all together, water treatments at room temperature improved the germination of the pyrenes. In contrast, long-term seed storage and hot-water treatments may jeopardize germination.

As sementes de palmeiras geralmente apresentam dormência e um endocarpo espesso que retarda a germinação e o crescimento do embrião, contudo, tratamentos com água podem acelerar o processo de germinação das suas sementes. Além disso, a conservação de sementes ex-situ pode causar perda de viabilidade das sementes ao longo do tempo. Dados sobre dormência e armazenamento de sementes têm sido negligenciados para muitas espécies de palmeiras nativas no Brasil. Nós investigamos o efeito da imersão em água e armazenamento de um ano sobre a germinação de sementes de Copernicia alba Morong, uma palmeira do Pantanal brasileiro. Para testar nosso objetivo, pirênios recém-colhidos e armazenados foram imersos em água a temperatura ambiente por 24, 48 e 72h e água quente (~75°C por 5 e 10 min). Pirênios recém coletados germinaram 84% no controle, atingindo 100% após imersão em água por 48 e 72h. Em contraste, o armazenamento de um ano reduziu germinação em ~50%; contudo, a imersão em água promoveu a germinação dos pirênios armazenadas. Por outro lado, a água quente diminuiu a germinação dos pirênios frescos e os armazenados. Sementes de C. alba podem ser classificados em ortodoxas. Em geral, nbsp;a imersão em água à temperatura ambiente aumentou a germinação dos pirênios. Entretanto, armazenamento for longa duração e tratamentos com água quente podem prejudicar a germinação.

RESUMO As sementes de palmeiras geralmente apresentam dormência e um endocarpo espesso que retarda a germinação e o crescimento do embrião, contudo, tratamentos com água podem acelerar o processo de germinação das suas sementes. Além disso, a conservação ex-situ de sementes pode causar perda de viabilidade das sementes de Arecacea especies ao longo do tempo. Dados sobre dormência e armazenamento de sementes têm sido negligenciados para muitas espécies de palmeiras nativas no Brasil. Por conta disso, nós investigamos o efeito da imersão em água e armazenamento de um ano sobre a germinação de sementes de Copernicia alba Morong, uma palmeira do Pantanal brasileiro. Pirênios recém-colhidos e armazenados foram imersos em água a temperatura ambiente por 24, 48 e 72h e água quente (~75°C por 5 e 10 min). Pirênios recém coletados germinaram 84% no controle, atingindo 100% após imersão em água por 48 e 72h. O armazenamento de um ano reduziu a germinação em ~50%, todavia, a imersão em água promoveu a germinação dos pirênios armazenadas. A água quente diminuiu a germinação dos pirênios frescos e os armazenados. De acordo com os resultados, sementes de C. alba podem ser classificadas em ortodoxas. Em geral, a imersão em água à temperatura ambiente aumentou a germinação dos pirênios. Entretanto, armazenamento for longa duração e tratamentos com água quente podem prejudicar a germinação.

ABSTRACT Palm seeds are known for displaying dormancy and a thick endocarp that delays germination and embryo growth, but water treatments may accelerate their germination process. Additionally, ex-situ conservation of arecaceae species may cause loss of seed viability over time. Data on seed dormancy and storage have been neglected for many native palm species in Brazil. Therefore, we investigated the effect of water treatments and one-year storage on the germination of Copernicia alba Morong, a palm tree from the Brazilian Pantanal wetland. Fresh and stored pyrenes were immersed in water (at room temperature for 24, 48, and 72h) and in hot water (~75°C for 5 and 10-min). Fresh pyrenes germinated up to 84% in control, reaching 100% after water immersion for 48 and 72h. One-year storage reduced germination by almost 50%, but water immersion slightly increased the germination of stored pyrenes. Hot water decreased germination for both fresh and stored pyrenes. Seeds of C. alba may be classified as orthodox seed storage behavior. Taken all together, water treatments at room temperature improved the germination of the pyrenes. In contrast, long-term seed storage and hot-water treatments may jeopardize germination.

ABSTRACT We analyzed the phenological responses of shrub-tree species of lowland deciduous (LDF) and submontane deciduous (SFD) forests in the Pantanal, and assessed their relationships with climatic factors at the community level and with strategies for seed dispersal. Vegetative and reproductive phenophases of 50 tree-shrub species were monitored monthly (12 months), and their relationship with climatic variables was tested using multiple linear regression. Time of leaf budding differed between areas for autochoric species and between autochoric and anemochoric species at LDF. Leaf fall in communities and functional groups was seasonal and highly synchronous during the dry season (95 % of species). Leaf budding peaked at the end of the dry season with > 80 % synchrony. In general, the species presented low synchrony or asynchrony for flowering phenophases, while fruiting phenophases were weakly seasonal but differed between functional groups. Temperature and precipitation were the regulating factors of vegetative phenophases in LDF, while daylength regulated them in SDF. Abiotic factors only influenced flowering phenophases at the dispersion group level. Only ripe fruits were related to reduced daylength. The phenophases of the deciduous forests of the Pantanal seem to be regulated not only by climatic factors but also by strong endogenous control.

Resumo: As cangas são afloramentos ferruginosos que ocorrem ao sopé do Maciço do Urucum, na Borda Oeste do Pantanal, Corumbá-MS. No Brasil, o conhecimento sobre a florística e ecologia das comunidades vegetais associadas a essas formações ainda é incipiente. Esses habitats estão entre os mais ameaçados e menos estudados do Brasil, devido à sua associação a depósitos de minério de ferro de alta qualidade. Nós apresentamos um cheklist da flora desses ambientes, resultante de diversos esforços de coleta de diferentes autores em 10 áreas do Maciço. Foram registradas 302 espécies distribuídas em 53 famílias botânicas e 175 gêneros. Poaceae (43 espécies), Fabaceae (41), Euphorbiaceae (22), Cyperaceae (19), Malvaceae (19), Convolvulaceae (15), Malpighiaceae (13) e Apocynaceae (11) representaram 60,6% da riqueza específica. Nossos dados adicionam 59 novas ocorrências de espécies de angiospermas para a flora de cangas do Maciço do Urucum. Das espécies apresentadas, 27 ainda não possuíam registro de ocorrência para o Mato Grosso do Sul e três espécies não haviam sido ainda registradas para o Brasil. A alta diversidade e a presença de espécies endêmicas, raras, ameaçadas e/ou ainda não catalogadas para a região do Maciço do Urucum reforça a necessidade de unidades de conservação locais que possam garantir a preservação dessas espécies, uma vez que as áreas de proteção ambiental existentes na região são insuficientes para garantir a manutenção de populações típicas desse habitat.

Abstract: "Cangas" are ironstone outcrops occurring at the foot of the Urucum Plateau, on the western edge of Pantanal, Corumbá-MS. In Brazil, the knowledge about flora and ecology of the plant communities associated with these formations is still incipient. These habitats are among the most threatened and less studied in Brazil because of their association with high quality iron ore deposits. We present a cheklist of the flora from these formations, resulting from different authors' collecting efforts in 10 areas of the Plateau. A total of 302 species have been recorded; they were distributed in 53 botanical families and 175 genera. Poaceae (43 species), Fabaceae (41), Euphorbiaceae (22), Cyperaceae (19), Malvaceae (19), Convolvulaceae (15), Malpighiaceae (13) and Apocynaceae (11) accounted for 60.6% of the species richness. Our data add 59 new occurrences of species of angiosperms to the ironstone outcrops flora in the Urucum Plateau. Among these, 27 species had no occurrence record for Mato Grosso do Sul and three species had not yet been recorded for Brazil. The high diversity and presence of endemic, rare, endangered and/or not yet cataloged species for the Urucum Plateau region, reinforces the need for local conservation units that can guarantee the preservation of these species, since the existing environmental protection areas are insufficient to guarantee the maintenance of typical species from this habitat in the region.

The perturbation of Neotropical forests generates large disturbances in biological communities. The species that suffer least from the resulting habitat fragmentation are the pioneers, because they possess greater ability to inhabit disturbed environments. Therefore, it is expected that species diversity will be greater in areas subjected to intermediate disturbance, such as the opening of gaps, because a large number of pioneer species will develop and coexist with species of more advanced successional stages. This study aimed to compare two forest remnants that differed in size and disturbance intensity, in order to determine the effects of disturbances on species diversity and the size ratios of individual trees. This was accomplished with comparative analyses of diversity, richness and diameter ratios obtained for 10 plots at two semideciduous forest sites. We recorded a total of 85 species, of which 70 were in the private nature reserve Fazenda Santa Maria, 58 were in Iguaçu National Park, and 43 were at both sites. Diversity was greater in the more disturbed remaining forest, because this area showed higher species richness, which is in accordance with some premises of the intermediate disturbance theory. There was also an increase in the number of pioneer individuals, and the less disturbed area showed individuals with larger diameters, which is likely attributable to the removal of large individuals from the more disturbed area during the anthropogenic process of forest modification.

This study describes the influence of edaphic factors on the floristic composition of an area of cerradão (woodland savanna) in the city of Campo Grande, located in the Brazilian central-west. In 10 plots (5 × 20 m each), we evaluated all trees with a diameter at breast height > 4.77 cm. Soil samples were analyzed for each plot in order to determine edaphic variables correlated with species composition. We sampled 1180 individuals of 61 species. The evenness index was 0.74, which indicates uneven distribution of species, which was explained by a high abundance of Qualea parviflora, Curatella americana, Qualea grandiflora, Terminalia argentea and Astronium fraxinifolium. We registered more trees in the smallest diameter class and in the middle layer of the vertical structure. The soil was dystrophic with a clay texture, which explains the higher abundance of species related to dystrophic cerradão. However, we also found some trees typical of mesotrophic cerradão and deciduous forests, which could be attributable to the presence of patches of fertile soil within the dystrophic cerradão or could indicate that those mesotrophic species are tolerant of lower levels of soil nutrients.

É apresentado um levantamento das espécies da família Orchidaceae encontradas no Morro Santa Cruz, Municípios de Corumbá e Ladário, Mato Grosso do Sul, Brasil. Foram realizadas coletas semanais, de janeiro a outubro de 1999, em diferentes altitudes, nas partes do morro ainda com vegetação preservada. As exsicatas foram incorporadas ao herbário COR, com duplicatas enviadas aos herbários CPAP e SP. Foram coletadas 21 espécies, pertencentes a 19 gêneros, sete terrícolas - Aspidogyne longicornu, Cyrtopodium virescens, Epistephium sclerophyllum, Habenaria juruenensis, Habenaria polycarpa, Oeceoclades maculata e Sarcoglottis curvisepala, uma hemiepífita - Vanilla palmarum, e as demais holoepífitas - Acianthera pubescens, Alatiglossum macropetalum, Campylocentrum hasslerianum, Cattleya nobilior, Encyclia conchaechila, Epidendrum coronatum, Epidendrum densiflorum, Isochilus linearis, Lophiaris morenoi, Octomeria warmingii, Polystachya concreta, Sophronitis cernua, e Xylobium foveatum. São apresentados uma chave para identificação das espécies, descrições, lista de material examinado e comentários pertinentes, bem como ilustrações de dez espécies estudadas.

A survey of the orchids found at the "Santa Cruz" Hills, Municipalities of Corumbá and Ladário, Mato Grosso do Sul State, Brazil was carried out. Collections were achieved weekly from January to October, 1999, trying to cover different altitudes in that parts of the hills with vegetation still preserved. The herbarium materials were housed at herbarium COR with duplicates at CPAP, and SP. Twenty one orchid species belonging to 19 genera were found. Seven are terrestrial - Aspidogyne longicornu, Cyrtopodium virescens, Epistephium sclerophyllum, Habenaria juruenensis, Habenaria polycarpa, Oeceoclades maculata, and Sarcoglottis curvisepala -, one hemiepiphytic - Vanilla palmarum -,and the remaining are holoepiphytic - Acianthera pubescens, Alatiglossum macropetalum, Campylocentrum hasslerianum, Cattleya nobilior, Encyclia conchaechila, Epidendrum coronatum, Epidendrum densiflorum, Isochilus linearis, Lophiarismorenoi, Octomeria warmingii, Polystachya concreta, Sophronitis cernua, and Xylobium foveatum. Identification key, descriptions of examined materials and illustrations were provided.

Foi realizado um estudo numa mata ripária (rio Paraguai, Brasil) para verificar a mortalidade da vegetação após uma cheia excepcional, em 1995. Indivíduos com diâmetro a altura do peito > 5cm foram marcados em 108 parcelas (10×10m) em 1994 e reamostrados em 1996. A taxa de mortalidade total foi de 4,1%. A mortalidade aumentou nas faixas topográficas mais altas, ao nível de comunidade, indicando que lugares onde as inundações são mais raras são mais afetados pelas grandes cheias.

A study was conducted in a riparian forest (Rio Paraguai, Brazil) to verify the vegetation mortality after an exceptional flooding in 1995. Individuals with diameter at breast height > 5 cm were sampled in 108 (10×10m) plots in 1994, and re-sampled in 1996. The total mortality rate was 4.1% per year. The mortality increased with the increasing of topographic positions, at community level, suggesting that places where the flooding is less frequent are more affected by extreme floods.