Deep vicariance and frequent transoceanic dispersal shape the evolutionary history of a globally distributed fern family.

PREMISE: The historical biogeography of ferns is typically expected to be dominated by long-distance dispersal due to their minuscule spores. However, few studies have inferred the historical biogeography of a large and widely distributed group of ferns to test this hypothesis. Our aims were to determine the extent to which long-distance dispersal vs. vicariance have shaped the history of the fern family Blechnaceae, to explore ecological correlates of dispersal and diversification, and to determine whether these patterns differ between the northern and southern hemispheres. METHODS: We used sequence data for three chloroplast loci to infer a time-calibrated phylogeny for 154 of 265 species of Blechnaceae, including representatives of all genera in the family. This tree was used to conduct ancestral range reconstruction and stochastic character mapping, estimate diversification rates, and identify ecological correlates of diversification. RESULTS: Blechnaceae originated in Eurasia and began diversifying in the late Cretaceous. A lineage comprising most extant diversity diversified principally in the austral Pacific region around the Paleocene-Eocene Thermal Maximum. Land connections that existed near the poles during periods of warm climates likely facilitated migration of several lineages, with subsequent climate-mediated vicariance shaping current distributions. Long-distance dispersal is frequent and asymmetrical, with New Zealand/Pacific Islands, Australia, and tropical America being major source areas. CONCLUSIONS: Ancient vicariance and extensive long-distance dispersal have shaped the history of Blechnaceae in both the northern and southern hemispheres. The exceptional diversity in austral regions appears to reflect rapid speciation in these areas; mechanisms underlying this evolutionary success remain uncertain.

Composição, diversidade e distribuição geográfica de plantas vasculares de uma Floresta Ombrófila Densa Atlântica do Sudeste do Brasil / Composition, diversity and geographical distribution of vascular plants of an Atlantic Rain Forest, Southeastern Brazil

Na floresta Ombrófila Densa do Parque Estadual de Carlos Botelho - PECB (ca. 37.000 ha) foi avaliada a composição, riqueza e distribuição geográfica das espécies vasculares nativas. A análise de 1143 espécies pertencentes a 140 famílias (sensu APG III) confirmaram o padrão encontrado para outras florestas do Leste do Brasil, com altas riquezas de Myrtaceae (85 espécies), Orchidaceae (81), Fabaceae (57), Asteraceae, Melastomataceae (54), Lauraceae (53), Rubiaceae (51), Bromeliaceae (43), Piperaceae (30) e Solanaceae (25), além de pteridófitas (123). Os gêneros mais ricos do Parque foram: Eugenia (34), Ocotea (26), Leandra, Myrcia, Vriesea (18), Piper (16), Solanum (15), Miconia (14), Mollinedia (13) e Peperomia (12). Houve grande variação na riqueza e composição de espécies entre hábitos, bem como no número de famílias representadas nos hábitos considerados (apenas Rubiaceae teve espécies em todos os hábitos, exceto parasitas). As árvores obtiveram a maior contribuição na riqueza total (39,1%), valor que representou mais de 20% das espécies de árvores citadas para toda a Floresta Atlântica do Sudeste do Brasil. Em seguida, foram os epífitos (22,4%), ervas (18,4%), arbustos (10,1%), lianas (9,1%) e parasitas (0,9%). De maneira geral, a riqueza e a composição por hábitos foram bastante similares ao encontrado nas demais florestas neotropicais (e.g. alta contribuição de pteridófitas ente os epífitos), apesar de alguns dos hábitos permanecerem subamostrados no PECB (principalmente ervas, lianas e epífitos). A ocorrência de espécies endêmicas da Floresta Atlântica foi elevada (65%), com predominância de espécies de ocorrência no Sul da Floresta Atlântica (43%). Espécies pantropicais foram raras (2%), sendo mais comuns entre as pteridófitas e entre as herbáceas. Myrtaceae e Melastomataceae foram as famílias com maior número e proporção de espécies endêmicas.

In the Montane and Submontane Rain Forest of the Carlos Botelho State Park - PECB (ca. 37,000 ha) the composition, richness and geographical distribution of native, vascular forest species was evaluated. The analysis of 1143 species of 140 families supported the pattern found for other forests of Eastern Brazil, showing high species richness of Myrtaceae (85 species), Orchidaceae (81), Fabaceae (57), Asteraceae, Melastomataceae (54), Lauraceae (53), Rubiaceae (51), Bromeliaceae (43), Piperaceae (30) and Solanaceae (25), besides ferns (123). The most species-rich genera were Eugenia (34), Ocotea (26), Leandra, Myrcia, Vriesea (18), Piper, Solanum (16), Miconia (14), Mollinedia (13), and Peperomia (12). The richness and composition varied greatly among life forms, as well as the number of families represented in each one of them (only Rubiaceae had species in all life forms, except parasites). Trees had the largest contribution of total richness (39.1%), a value that represented more than 20% of the species listed for the whole Atlantic Forest of Southeastern Brazil. Trees were followed by epiphytes (22.4%), herbs (18.4%), shrubs (10.1%), lianas (9.1%), and parasites (0.9%). The overall richness and composition of life forms was quite close to other neotropical forests (e.g. high contribution of ferns among epiphytes), although some life forms remain undersampled in the PECB (mainly herbs, lianas and epiphytes). The occurrence of species endemic to the Atlantic Forest was pronounced (65%), with a predominance of species restricted to the Southern Atlantic Forest (43%). Pantropical species were rare (2%), being more common among ferns. Myrtaceae and Melastomataceae were the families with greater number and proportion of endemic species.

Flora vascular do Parque Estadual Carlos Botelho, São Paulo, Brasil / Vascular flora of the Carlos Botelho State Park, São Paulo, Brazil

Localizado na Serra de Paranapiacaba, sul do Estado de São Paulo, o Parque Estadual Carlos Botelho (PECB) abriga mais de 37.000 ha de Floresta Atlântica em um dos remanescentes mais importantes e extensos deste Bioma no Brasil. No Parque, predomina a Floresta Ombrófila Densa Montana e Submontana. Com o objetivo de organizar as informações florísticas disponíveis e direcionar futuros levantamentos, este estudo apresenta a lista de espécies vasculares nativas das florestas do PECB. Além de coletas pessoais dos autores, foram compilados mais de 3.900 registros citados desde 1967. Provindos de diferentes fontes de informação, estes registros foram checados para verificar a presença de sinonímias botânicas e novas combinações. Foi listado um total de 1.143 espécies vasculares pertencentes a 140 famílias e 528 gêneros (outras 63 espécies não foram incluídas por serem exóticas ou de ocorrência/identificação duvidosa). Houve grande riqueza de Myrtaceae, Orchidaceae, Fabaceae, Asteraceae, Melastomataceae, Lauraceae, Rubiaceae e Bromeliaceae. Apesar da alta riqueza de espécies, a riqueza de ervas, epífitos e lianas está certamente subestimada no Parque, de modo que futuros levantamentos certamente incluirão várias espécies na lista apresentada aqui. Adicionalmente, foram encontradas mais de 60 espécies com algum grau de ameaça de extinção, principalmente entre as famílias Myrtaceae, Lauraceae e Gesneriaceae. Assim, os resultados encontrados colocam o PECB entre as unidades de conservação com maior riqueza de espécies no Estado de São Paulo, com grande importância nacional para a conservação de espécies de plantas.

Located in the Serra de Paranapiacaba, South of São Paulo State, the Carlos Botelho State Park (PECB) shelters more than 37,000 ha of Atlantic Forest in one of the most important and large remnants of this Biome in Brazil. In the Park the Montane and Submontane rain forests are the predominant types of forests. Aiming to organize the available floristic information and to orient future surveys, this study presents the list of native vascular species of the PECB forests. Besides authors´ personal collections, more than 3,900 records since 1967 were compiled. Coming from different sources of information, these records were checked for the presence of botanical synonyms and new combinations. A total of 1,143 species belonging to 528 genera and 140 families were listed (other 63 species were not included because they were non-native or of doubtful occurrence/determination). There was a great richness of Myrtaceae, Orchidaceae, Fabaceae, Asteraceae, Melastomataceae, Lauraceae, Rubiaceae and Bromeliaceae. Although high species richness was found, the richness of herbs, lianas and epiphytes are certainly underestimated and future surveys will add many species to the list presented here. In addition, more than 60 endangered species were found, mainly among the Myrtaceae, Lauraceae and Gesneriaceae families. Therefore, these results put the PECB among the most species-rich conservation units of São Paulo state with great relevance to national conservancy of plant diversity.