32 research outputs found
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.Ă apresentado o levantamento florĂstico de Clethraceae para o estado da Bahia, Brasil. Uma espĂ©cie foi reconhecida, Clethra scabra. SĂŁo apresentados descrição dos tĂĄxons, ilustraçÔes e comentĂĄrios gerais sobre a espĂ©cie
Novas ocorrĂȘncias 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 NiquiĂĄ 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.Ă apresentado o levantamento florĂstico de Caryocaraceae no estado da Bahia, Brasil. Foram reconhecidas quatro espĂ©cies distribuĂdas em dois gĂȘneros: Anthodiscus amazonicus, Caryocar brasiliense, C. coriaceum e C. edule. Ă apresentada uma chave de identificação, descriçÔes e comentĂĄrios taxonĂŽmicos para os gĂȘneros e espĂ©cies, alĂ©m de ilustraçÔes e mapas de distribuição geogrĂĄfica das espĂ©cies 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 yrâ1, considering two observation periods (12 and 24 months). The highest rate (0.732 ± 0.206 [SD] yrâ1) was observed for the lowest wood-density class of palms, whereas the lowest rate (0.119 ± 0.101 yrâ1) 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] yrâ1; mean decay time 11â30 years) has a decomposition rate âŒ19% higher than the seasonally flooded formations (0.152 ± 0.072 yrâ1; 13â37 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 30â40 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 âŒ40% 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
Recommended from our members
Volatile monoterpene âfingerprintsâ 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 âsmellâ 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 âfingerprintâ patterns emerged, characterized by a distinct dominant monoterpene. While 4 of the âfingerprintâ 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 âfingerprintâ pattern, while 9 species had two or more âfingerprintâ patterns among individuals. A comparison of âfingerprintsâ 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 âfingerprintâ 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,5â7 vast areas of the tropics remain understudied.8â11 In
the American tropics, Amazonia stands out as the worldâs 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.13â15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazonâs 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 regionâs vulnerability to environmental change. 15%â18% 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%â18% 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, AndrĂ© M.. Universidade Estadual de Santa Cruz;Fil: Ferrucci, MarĂa Silvia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; Argentin
Novas ocorrĂȘncias de angiospermas para o estado de Roraima, Brasil
Resumo O conhecimento sobre a flora da AmazĂŽnia brasileira Ă© bastante incompleto e muitas ĂĄreas sĂŁo ainda botanicamente pouco exploradas. Este trabalho reporta novas ocorrĂȘncias de angiospermas para Roraima, provenientes de duas unidades de conservação no sudoeste do estado, o Parque Nacional Serra da Mocidade e a Estação EcolĂłgica do NiquiĂĄ. Foram encontrados novos registros para quatro gĂȘneros e 23 espĂ©cies pertencentes a 15 famĂlias de angiospermas. Leguminosae apresentou o maior nĂșmero de novos registros, com cinco espĂ©cies. Os resultados trouxeram um acrĂ©scimo de 0,75% Ă flora de angiospermas em Roraima, ressaltando-se a necessidade de ampliação do esforço de coleta em todo o estado