Climbing mechanisms and the diversification of neotropical climbing plants across time and space.

Climbers germinate on the ground but need external support to sustain their stems, which are maintained attached to supports through modified organs, that is, climbing mechanisms. Specialized climbing mechanisms have been linked to higher diversification rates. Also, different mechanisms may have different support diameter restrictions, which might influence climbers' spatial distribution. We test these assumptions by linking climbing mechanisms to the spatiotemporal diversification of neotropical climbers. A dataset of climbing mechanisms is presented for 9071 species. WCVP was used to standardize species names, map geographical distributions, and estimate diversification rates of lineages with different mechanisms. Twiners appear concentrated in the Dry Diagonal of South America and climbers with adhesive roots in the Chocó region and Central America. However, climbing mechanisms do not significantly influence the distribution of neotropical climbers. Also, we found no strong support for correlations between specialized climbing mechanisms and higher diversification rates. Climbing mechanisms do not strongly impact the spatiotemporal diversification of neotropical climbers on a macroevolutionary scale. We argue that the climbing habit is a synnovation, meaning the spatiotemporal diversification it promotes is due to the sum effect of all the habit's traits rather than isolated traits, such as climbing mechanisms.

Phylogenomic loci define the generic boundaries of Gochnatieae and improve resolution at the species level in Moquiniastrum (Compositae).

Understanding the evolution of the tribe Gochnatieae (Compositae) has been the subject of considerable effort in the past decade. This is due to the key position of this tribe in the phylogeny of the sunflower family and the corresponding implications for biogeographic and morphological evolution of Compositae. Previous studies have confirmed the monophyly of this tribe as well as most of the genera that belong to it. However, phylogenetic resolution of Gochnatieae at both the genus- and species-level has remained poor. A subset of new phylogenomic loci used in this study has proven effective and has improved phylogenetic resolution in this group. The results of this work demonstrate Gochnatieae is a well-supported clade comprised of nine genera (Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Moquiniastrum, Nahuatlea, Pentaphorus, Richterago, Tehuasca). One recently described genus, Vickia, was not included in this study; but its placement in Gochnatieae as a tenth genus in the tribe is well-justified. The monospecific Cyclolepis, which had been circumscribed within the tribe since its inception but was subsequently removed and designated as incertae sedis since 2014, is also shown to belong to Gochnatieae. We confirmed the monophyletic Moquiniastrum with two well-supported subclades. Ancestral area reconstruction analyses show that Gochnatieae originated in Eastern South America about 53 my. Apparently, except for Cyclolepis and Richterago, the ancestors of the other genera of Gochnatieae originated about 44 my from an area that now corresponds to the central Andes. The presence of the genera in the Chaco phytogeographic province, central Chile, and Mexico-United States-Caribbean is a result of dispersal from the central Andes. The ancestral distribution of Moquiniastrum corresponds to a large area comprising Eastern South America and the current central Andes, about 32 my. Ancestral character state reconstruction that included four characters indicates several states associated with complex plant reproductive biology such as gynodioecy, gynomonoecy, and polygamodioecy are derived in Gochnatieae as are heterogamous capitula (in Moquiniastrum and Richterago), dimorphic and subdimorphic corollas (in Cnicothamnus, Moquiniastrum, and Richterago), and the presence of marginal female corollas (in Moquiniastrum and Richterago). Within Moquiniastrum, two subclades (Densicephalum and Polymorphum) exhibit divergent patterns of trait evolution associated with these reproductive characters which suggests this genus can serve as a model to understand the sexual system evolution in plants.

Amazon plant diversity revealed by a taxonomically verified species list.

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.

Caffeoylquinic Acids: Separation Method, Antiradical Properties and Cytotoxicity.

Twelve chlorogenic acid derivatives and two flavones were isolated from Moquiniastrum floribundum (Asteraceae, other name: Gochnatia floribunda). Compounds were evaluated in relation to their cytotoxicity and antiradical properties. Cytotoxicity was not observed for compounds, however, chlorogenic acid derivatives showed antiradical activity and were more active than the Trolox standard. Quinic acid esterified with caffeoyl group at C-4 position showed higher antiradical activity compared to acylation at C-3 or C-5 positions. Additional caffeoyl groups esterified in quinic acid increase the antiradical activity observed for 4-caffeoylquinic acid. Excepted to 3,4-dicaffeoylquinic acid methyl ester, methyl ester derivatives show higher capacity of trapping radicals than their respective acids. Consequently, the presence of caffeoyl group at C-4 position of quinic acid is suggested as fundamental to obtain the highest antiradical activity.

Nahuatlea: a new genus of compositae (Gochnatieae) from North America.

In the course of a detailed molecular study of the tribe Gochnatieae (Compositae: Gochnatioideae) it became apparent that the genus Gochnatia (sensu Cabrera) was not monophyletic but composed of a number of morphologically, geographically, and molecularly distinct clades. All but one of these clades had previously been recognized at the generic or sectional level and therefore had a name that could be applied. However, one clade, whose members are from Mexico and adjacent parts of the United States, had never been recognized as a distinct taxon. The Mexican clade is the sister group of the Caribbean clade which seems to indicate a dispersal event from Southern South America to Mexico and from Mexico to the Caribbean. Here we provide the Mexican clade with a genus name, Nahuatlea, and make the necessary new combinations. The name is derived from Nahuatl, the major indigenous language that is spoken in the area where most of the collections were gathered. A genus description, key to species, images, and a short, species descriptions, are provided.

Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m-2 y-1, storage: 55, 113 and 38 g m-2, on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

Livros didáticos de Biologia do Ensino Médio: resultados do PNLEM/2007 / High school biology textbooks: results from PNLEM/2007

Em 2005, os livros didáticos de Biologia do ensino médio publicados no Brasil foram avaliados, como parte do Programa Nacional do Livro para o Ensino Médio (PNLEM). Neste artigo, relatamos resultados dessa avaliação. Os critérios e o processo de avaliação são apresentados de modo detalhado, bem como os principais problemas das obras não-recomendadas para compra pelo MEC e os principais aspectos positivos das obras recomendadas. Das 18 obras submetidas à avaliação, nove satisfizeram os critérios mínimos de qualidade para aprovação. Sete obras didáticas excluídas apresentaram problemas em todas as classes de critérios de avaliação. Todas as nove obras excluídas exibiram problemas relativos à correção e adequação conceituais, e à precisão da informação básica fornecida. As qualidades mais frequentes nas obras recomendadas diziam respeito à adequação metodológica e à construção do conhecimento. Não encontramos evidências claras de que a frequência de escolha pelos professores do ensino médio refletiu a qualidade dos itens avaliados, conforme estabelecida pela equipe que analisou as obras.

In 2005, Brazilian Biology high school textbooks were evaluated as part of the National Program for the High School Textbook (PNLEM). In this paper, we report results of this evaluation. The evaluation criteria and processes are presented in a detailed manner, as well as the main flaws found in the textbooks not recommended to be bought by the Ministry of Education and the main positive aspects of the approved materials. Nine out of 18 textbooks satisfied the minimum quality criteria for approval. Seven excluded textbooks showed problems in all classes of evaluation criteria. All nine excluded textbooks exhibited problems related to conceptual correctness and adequacy, and accuracy of basic information. The most frequent qualities of approved textbooks concerned aspects of methodological adequacy and knowledge construction. We found no clear evidence that the frequency of choice of the approved textbooks by the high school teachers reflected the quality of the evaluated items, as established by the team which evaluated the textbooks.