Floristic and phytosociology in dense "terra firme" rainforest in the Belo Monte Hydroelectric Plant influence area, Pará, Brazil

Wild food plants of Brazil: a theoretical approach to non-random selection

Ethnobiological investigations have focused on identifying factors that interfere with the criteria adopted for selection of plants, especially medicinal plants, by different populations, confirming the theory that plant selection is not random. However, regarding wild food plants, little effort has been made to confirm the theory in this context, especially in Brazil. Therefore, this systematic review aimed to contribute to the establishment of theoretical bases of the non-random selection of wild food plants by local populations in Brazil. For this, searches were made in 4 databases, namely, Web of Science, Scielo, Scopus and PubMed, using 8 sets of keywords in English and Portuguese in order to identify wild food plants occurring in Brazil. The steps were: application of inclusion and exclusion criteria, screening of articles, selection of studies based on risk of bias, data treatment and, finally, data analysis. Eighty articles met the inclusion criteria of this review. However, 45 of them were considered to present high risk of bias and thus 35 articles were kept for the identification of overused and underused families. The results were inferred through two different approaches (IDM and Bayesian). Annonaceae, Arecaceae, Basellaceae, Cactaceae, Capparaceae, Caryocaraceae, Myrtaceae, Passifloraceae, Rhamnaceae, Rosaceae, Sapotaceae, Talinaceae, and Typhaceae were considered overused. Eriocaulaceae, Orchidaceae, and Poaceae were considered underused. Therefore, considering that some families are more (or less) used than others, we confirm that the wild food plants occurring in Brazil, known and used by different populations, are not chosen at random.

Assessing Drought Response in the Southwestern Amazon Forest by Remote Sensing and In Situ Measurements

Long-term meteorological analyzes suggest an increase in air temperature and a decrease in rainfall over the Amazon biome. The effect of these climate changes on the forest remains unresolved, because field observations on functional traits are sparse in time and space, and the results from remote sensing analyses are divergent. Then, we analyzed the drought response in a ‘terra firme’ forest fragment in the southwestern Amazonia, during an extreme drought event influenced by ENSO episode (2015/2017), focusing on stem growth, litter production, functional traits and forest canopy dynamics. We use the Moderate Resolution Imaging Spectroradiometer (MODIS), corrected by Multi-Angle Implementation of Atmospheric Correction (MAIAC) to generate the enhanced vegetation index (EVI) and green chromatic coordinate (Gcc) vegetation indices. We monitor stem growth and measure the functional traits of trees in situ, such as the potential at which the plant loses 50% of hydraulic conductivity (P50), turgor loss point (πTLP), hydraulic safety margin (HSM) and isohydricity. Our results suggest that: (a) during the dry season, there is a smooth reduction in EVI values (browning) and an increase in the wet season (greening); (b) in the dry season, leaf flush occurs, when the water table still has a quota at the limit of the root zone; (c) the forest showed moderate resistance to drought, with water as the primary limiting factor, and the thickest trees were the most resistant; and (d) a decline in stem growth post-El-Niño 2015/2016 was observed, suggesting that the persistence of negative rainfall anomalies may be as critical to the forest as the drought episode itself.

CARACTERIZAÇÃO FLORÍSTICA, ESTRUTURAL E QUALITATIVA DE UM FRAGMENTO DE FLORESTA ESTACIONAL DECIDUAL, NA REGIÃO NORTE DO RIO GRANDE DO SUL

O presente trabalho teve por objetivo realizar a caracterização florística, estrutural e qualitativa de um fragmento de Floresta Estacional Decidual, na região do Alto Uruguai, em Frederico Westphalen-RS. Para a amostragem da vegetação foi instalada uma parcela permanente de 100 x 100 m, composta por 100 subunidades de 10 x 10 m. Todos os indivíduos com CAP≥31,4 foram mensurados e identificados em gênero, espécie e família botânica. A estrutura foi caracterizada quanto à densidade, dominância, frequência e índice de valor de importância. Na caracterização qualitativa, os fustes foram qualificados visualmente quanto à forma e à sanidade. No total foram mensurados 580 indivíduos e, dentre estes, 49 gêneros, 57 espécies, 28 famílias botânicas e apenas 1 espécie não identificada. Fabaceae foi a família que mais se destacou em número de gêneros (n=9), espécies (n=10) e indivíduos (n=146). As espécies Trichilia claussenii C. DC., Nectandra megapotamica (Spreng.) Mez e Holocalyx balansae Micheli, com valores de IVI de 14,0%, 9,1% e 7,3%, respectivamente, foram as mais importantes do fragmento florestal. Quanto à estrutura vertical, 95,2% dos indivíduos pertencem aos estratos inferior e médio. Em termos de números de indivíduos e dominância por espécie, destacaram-se T. claussenii no estrato inferior (26,8% e 21,5%), N. megapotamica no estrato médio (19,4% e 13%) e H. balansae no estrato superior (25,0% e 32,9%). O fragmento florestal caracteriza-se por apresentar indivíduos com fustes levemente tortuosos e saudáveis, sem a incidência de danos que possam impedir um eventual aproveitamento madeireiro.