Towards a species-level phylogeny for Neotropical Myrtaceae: Notes on topology and resources for future studies.

PREMISE: Increasingly complete phylogenies underpin studies in systematics, ecology, and evolution. Myrteae (Myrtaceae), with ~2700 species, is a key component of the exceptionally diverse Neotropical flora, but given its complicated taxonomy, automated assembling of molecular supermatrices from public databases often lead to unreliable topologies due to poor species identification. METHODS: Here, we build a taxonomically verified molecular supermatrix of Neotropical Myrteae by assembling 3909 published and 1004 unpublished sequences from two nuclear and seven plastid molecular markers. We infer a time-calibrated phylogenetic tree that covers 712 species of Myrteae (~28% of the total diversity in the clade) and evaluate geographic and taxonomic gaps in sampling. RESULTS: The tree inferred from the fully concatenated matrix mostly reflects the topology of the plastid data set and there is a moderate to strong incongruence between trees inferred from nuclear and plastid partitions. Large, species-rich genera are still the poorest sampled within the group. Eastern South America is the best-represented area in proportion to its species diversity, while Western Amazon, Mesoamerica, and the Caribbean are the least represented. CONCLUSIONS: We provide a time-calibrated tree that can be more reliably used to address finer-scale eco-evolutionary questions that involve this group in the Neotropics. Gaps to be filled by future studies include improving representation of taxa and areas that remain poorly sampled, investigating causes of conflict between nuclear and plastid partitions, and the role of hybridization and incomplete lineage sorting in relationships that are poorly supported.

Florística de trepadeiras em floresta semidecidual e em mata ciliar no vale do rio Araguari, MG / Floristic of climbing plants in semideciduous and riparian forests of the Araguari river, MG

Trepadeiras são importantes componentes de florestas tropicais e contribuem para a composição e riqueza de espécies, porém são poucas as pesquisas que enfocam esse hábito de vida. O objetivo deste trabalho foi determinar a composição florística de trepadeiras em um fragmento de floresta semidecidual e outro de mata ciliar em Uberlândia-MG e comparar essa composição com a de fragmentos de outras fisionomias semelhantes. O levantamento florístico foi realizado mensalmente durante os anos de 2006 e 2007 por meio de caminhadas aleatórias. As espécies coletadas foram categorizadas segundo o hábito trepador, modo de ascensão, síndrome de dispersão e frequência de ocorrência. Para determinar as similaridades florísticas foi utilizado o método UPGMA com o índice de Jaccard. Nos dois fragmentos foram amostradas 62 espécies, 41 gêneros e 20 famílias. Na floresta semidecidual e mata ciliar foram encontradas 39 e 33 espécies, respectivamente. As famílias mais ricas em espécies foram Malpighiaceae (9 spp.), Bignoniaceae (8 spp.) e Convolvulaceae (7 spp.) e os gêneros mais ricos foram Fridericia Mart. (5 spp.), Ipomoea L. (5 spp.) e Serjania Mill. (4 spp.). Foi registrado maior número de trepadeiras lenhosas do que não-lenhosas e houve predominância da estratégia de ascensão volúvel e da dispersão anemocórica tanto na floresta semidecidual como em mata ciliar. A similaridade florística entre os nove fragmentos analisados foi baixa, com uma composição de espécies bastante heterogênea, mesmo entre áreas mais próximas, indicando uma elevada diversidade ß de trepadeiras nas áreas estudadas.

Climbers are important components of tropical forests and contribute to their species composition and richness. However only few studies have focused on this specific growth habit. The aim of this study was to determine the floristic composition of climbers in a riparian and a semideciduous forests in Uberlândia-MG, and compare these floras with other forest areas. The floristic survey was conducted monthly during 2006 and 2007 using random walks. The species collected were categorized according to the climbing habit, climbing strategy, dispersal syndrome and frequency of occurrence. Jaccard's similarity index with UPGMA was used to determine the floristic similarities. In both sites the sampling totaled 62 species, in 41 genera and 20 families. In semideciduous and riparian forests we found 39 and 33 species, respectively. The richest families in species were Malpighiaceae (9 spp.), Bignoniaceae (8 spp.) and Convolvulaceae (7 spp.) and the richest genera were Fridericia Mart. (5 spp.), Ipomoea L. (5 spp.) and Serjania Mill. (4 spp.). It was recorded a higher number of woody climbing than vines. The predominant strategies were twining-climbing mechanism and wind dispersal in both semideciduos and riparian forests. The floristic similarity between nine fragments analyzed was low, with species composition very heterogeneous, even among the closest areas, indicating a high ß diversity of climbers in these areas.