Flora da Bahia: Clethraceae

The floristic account of the Clethraceae from Bahia State, Brazil, is presented. One species, Clethra scabra, was recognized. Description of taxa, illustrations and general notes on the species are presented.É apresentado o levantamento florístico de Clethraceae para o estado da Bahia, Brasil. Uma espécie foi reconhecida, Clethra scabra. São apresentados descrição dos táxons, ilustrações e comentários gerais sobre a espécie

Novas ocorrências de angiospermas para o estado de Roraima, Brasil

Knowledge of the flora of the Brazilian Amazon is very incomplete and many areas are still botanically unexplored. This work reports new records of angiosperms to Roraima from two conservation units in the southwest of the state, the Serra da Mocidade National Park and Niquiá Ecological Station. New records for four genera and 23 species belonging to 15 angiosperm families were found. Leguminosae had the highest number of new records, with five species. The results brought an increase of 0.75% to the angiosperm flora in Roraima, highlighting the need to expand the collection effort throughout the state

Flora da Bahia: Caryocaraceae

The floristic survey of the Caryocaraceae from Bahia State, Brazil, is presented. Two genera and four species were recognized: Anthodiscus amazonicus, Caryocar brasiliense, C. coriaceum, and C. edule. An identification key, descriptions and taxonomic notes for genera and species are given, in addition to illustrations and maps of species distribution in Bahia.É apresentado o levantamento florístico de Caryocaraceae no estado da Bahia, Brasil. Foram reconhecidasquatro espécies distribuídas em dois gêneros: Anthodiscus amazonicus, Caryocar brasiliense, C. coriaceum e C. edule. Éapresentada uma chave de identificação, descrições e comentários taxonômicos para os gêneros e espécies, além deilustrações e mapas de distribuição geográfica das espécies na Bahia.É apresentado o levantamento florístico de Caryocaraceae no estado da Bahia, Brasil. Foram reconhecidas quatro espécies distribuídas em dois gêneros: Anthodiscus amazonicus, Caryocar brasiliense, C. coriaceum e C. edule. É apresentada uma chave de identificação, descrições e comentários taxonômicos para os gêneros e espécies, além de ilustrações e mapas de distribuição geográfica das espécies na Bahia

Decomposition rates of coarse woody debris in undisturbed Amazonian seasonally flooded and unflooded forests in the Rio Negro-Rio Branco Basin in Roraima, Brazil

Estimates of carbon-stock changes in forest ecosystems require information on dead wood decomposition rates. In the Amazon, the lack of data is dramatic due to the small number of studies and the large range of forest types. The aim of this study was to estimate the decomposition rate of coarse woody debris (CWD) in two oligotrophic undisturbed forest formations of the northern Brazilian Amazon: seasonally flooded and unflooded. We analyzed 20 arboreal individuals (11 tree species and 3 palm species) with distinct wood-density categories. The mean annual decomposition rate of all samples independent of forest formation ranged from 0.044 to 0.963 yr−1, considering two observation periods (12 and 24 months). The highest rate (0.732 ± 0.206 [SD] yr−1) was observed for the lowest wood-density class of palms, whereas the lowest rate (0.119 ± 0.101 yr−1) was determined for trees with high wood density. In terms of forest formation, the rates values differ when weighted by the wood-density classes, indicating that unflooded forest (0.181 ± 0.083 [SE] yr−1; mean decay time 11–30 years) has a decomposition rate ∼19% higher than the seasonally flooded formations (0.152 ± 0.072 yr−1; 13–37 years). This result reflects the dominance of species with high wood density in seasonally flooded formations. In both formations 95% of the dead wood is expected to disappear within 30–40 years. Based on our results, we conclude that the CWD decomposition in the studied area is slower in forests on nutrient-poor seasonally flooded soils, where structure and species composition result in ∼40% of the aboveground biomass being in tree species with high wood density. Thus, it is estimated that CWD in seasonally flooded forest formations has longer residence time and slower carbon release by decomposition (respiration) than in unflooded forests. These results improve our ability to model stocks and fluxes of carbon derived from decomposition of dead wood in undisturbed oligotrophic forests in the Rio Negro-Rio Branco Basin, northern Brazilian Amazon. © 2017 The Author

Volatile monoterpene ‘fingerprints’ of resinous Protium tree species in the Amazon rainforest

Volatile terpenoid resins represent a diverse group of plant defense chemicals involved in defense against herbivory, abiotic stress, and communication. However, their composition in tropical forests remains poorly characterized. As a part of tree identification, the ‘smell’ of damaged trunks is widely used, but is highly subjective. Here, we analyzed trunk volatile monoterpene emissions from 15 species of the genus Protium in the central Amazon. By normalizing the abundances of 28 monoterpenes, 9 monoterpene ‘fingerprint’ patterns emerged, characterized by a distinct dominant monoterpene. While 4 of the ‘fingerprint’ patterns were composed of multiple species, 5 were composed of a single species. Moreover, among individuals of the same species, 6 species had a single ‘fingerprint’ pattern, while 9 species had two or more ‘fingerprint’ patterns among individuals. A comparison of ‘fingerprints’ between 2015 and 2017 from 15 individuals generally showed excellent agreement, demonstrating a strong dependence on species identity, but not time of collection. The results are consistent with a previous study that found multiple divergent copies of monoterpene synthase enzymes in Protium. We conclude that the monoterpene ‘fingerprint’ database has important implications for constraining Protium species identification and phylogenetic relationships and enhancing understanding of physiological and ecological functions of resins and their potential commercial applications. © 2019 The Author

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Paullinia unifoliolata, a remarkable new species of Sapindaceae from the Atlantic Forest of southern Bahia, Brazil

A new species of Paullinia from the Atlantic Forest of southern Bahia, Brazil, is described and illustrated. Paullinia unifoliolata belongs to sect. Pachytoechus and is distinguished by its unifoliolate leaves. In addition, micromorphological characters of the pollen grains are described, and a comparison with P. carpopoda, the most similar species, is provided.Fil: Perdiz, Ricardo de Oliveira. Universidade Estadual de Feira de Santana; BrasilFil: Amorim, André M.. Universidade Estadual de Santa Cruz;Fil: Ferrucci, MarÍa Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin