11 research outputs found

    Padrão geográfico de diversidade genética em populações naturais de Pau-rosa (Aniba rosaeodora), na Amazônia Central

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    Rosewood (Aniba rosaeodora Ducke, Lauraceae) is an Amazonian evergreen tree and a source of the purest linalool, the main component of its essential oil, which is very valuable in the international perfumery market. After decades of over-exploitation it is currently considered as threatened. We evaluated the genetic diversity and its distribution in four populations in Central Amazonia. Thirty-five reliable RAPD markers were generated, of which 32 were polymorphic (91.4%). Variation was higher within the populations (76.5%; p < 0.0001) and geographic distribution contributed to population differentiation (23.4%; p < 0.0001). The Amazon River had a small influence on gene flow (3.3%; p < 0.0001), but we identified evidence of gene flow across the river. There were significant differences in marker frequencies (p < 0.05), in agreement with the low gene flow (Nm = 2.02). The correlation between genetic distance and gene flow was - 0.95 (p = 0.06) and between geographic distance and gene flow was -0.78 (p = 0.12). There was a geographic cline of variability across an East-West axis, influenced as well by the Amazon River, suggesting the river could be a barrier to gene flow. Although threatened, these Rosewood populations retain high diversity, with the highest levels in the Manaus population, which has been protected for over 42 years in a Reserve.O Pau-rosa (Aniba rosaeodora Ducke, Lauraceae) é uma árvore amazônica fonte do mais puro linalol, o qual é o principal componente do seu óleo essencial e muito valioso no mercado internacional de perfumaria. Após várias décadas de intensa exploração, a espécie foi levada à categoria de ameaçada de extinção. Quatro populações naturais distribuídas na bacia Amazônia Central foram avaliadas quanto ao nível e a distribuição da diversidade genética. Trinta e cinco marcadores RAPD reprodutíveis foram gerados, dos quais 32 foram polimórficos (91,4%). A diversidade foi maior dentro das populações (76,5%; p < 0,0001) e a distribuição geográfica contribuiu para a diferenciação entre as populações (23,4%; p < 0,0001). A AMOVA indicou que pode haver uma influência parcial do Rio Amazonas no fluxo gênico (3,3%; p < 0,0001), mas foram identificadas evidências de fluxo gênico atravessando o rio. Houve diferenças significativas nas freqüências dos marcadores (p < 0,05) e o fluxo gênico estimado foi relativamente baixo (Nm = 2,02). A correlação entre a distância genética e o fluxo gênico foi de - 0,95 (p = 0,06) e para a distância geográfica e o fluxo gênico foi de - 0,78 (p = 0,12). Houve um padrão geográfico de variabilidade ao longo do eixo Leste - Oeste, influenciado também pelo Rio Amazonas, o que sugere que o rio poderia funcionar como uma barreira para o fluxo gênico. Apesar de ameaçadas, estas populações de Pau-rosa possuem alta diversidade, com o maior valor na população de Manaus, que vem sendo protegida por 42 anos em uma reserva

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

    Produção e predação de frutos em Aniba rosaeodora Ducke var. amazonica Ducke (Lauraceae) em sistema de plantio sob floresta de terra firme na Amazônia Central Harvesting and fruit predation of a Aniba rosaeodora Ducke var. amazonica Ducke (Lauraceae) ex situ tree population in a central Amazonian upland forest

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    O pau-rosa (Aniba rosaeodora) vem sendo usado desde o século passado para extração de linalol, produto usado como fixador de perfumes. Por causa do extrativismo houve redução drástica em suas populações naturais. Somando a este fato, esta espécie possui padrão irregular de frutificação e, quando frutifica, os seus frutos são consumidos por animais. Estes aspectos foram estudados utilizando uma população de plantio sob sombra parcial de floresta primária. A produtividade das árvores variou de 40 a 1.600 frutos (n = 21 árvores). No geral, cerca de 42,5% foram removidos por frugívoros (6.770 frutos, n = 10 árvores). Dos frutos não removidos, 0,5% foram predados por vertebrados, 81,5% continham larvas de insetos, variando de 36-96% entre indivíduos. Uma espécie de Coleoptera ataca os frutos em estádio imaturo, enquanto outra (Heilipus sp.) e uma espécie de Lepidoptera atacam os frutos em estádio final de desenvolvimento. Os resultados projetam perda de 59,5% dos frutos (54,5% por insetos) passíveis de coleta. Considerando a importância econômica do pau-rosa faz-se necessário aumentar a disponibilidade de sementes para planos de manejo da espécie. Para se atingir tais objetivos são necessárias algumas medidas: 1) coleta prematura de frutos para maturação em laboratório; 2) utilização de métodos de controle de insetos adultos (em plantios) e larvas (em frutos atacados); e 3) estudos de seleção genética para identificar plantas com maior resistência natural a pragas e doenças.<br>The rosewood tree (Aniba rosaeodora) has been exploited for linalol, a product used as a fixative by the perfume industry. As a result, its population has decreased to the point that it is at risk of extinction in some Amazonian areas. In addition, the species has an irregular phenological pattern and its fruits are a food source for animals. This study focused on the use an ex situ population planted under partial forest shade. The fruit set varied from 40-1600 fruits (n = 21 trees). Overall, 42.5% of fruits (6,770, n = 10 trees) were removed by frugivores. Of the remaining fruits, 0.5% were predated by vertebrates, 81.5% were attacked by insect larvae. Of fruit attacked by insects, 38% were still capable of germination. One Coleoptera (Curculionidae) attacks the fruits during this intermediate phase of development, and another one (Heilipus sp.) and one Lepidoptera attack during the final phase of maturation. This results in a loss of 59.5% (54.5% by insects) of the fruit set not removed. Therefore, it is necessary to increase fruit/seed availability as part of species management. To achieve this, three considerations need to be taken into account: 1) premature fruits should be collected for laboratory maturation; 2) insect control on adult trees (in plantations) and larva control on attacked fruits are recommended; and 3) genetic studies should be an alternative to identify plants with greater natural resistance to predators and diseases

    Community structure and diversity of tropical forest mammals: data from a global camera trap network

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    Terrestrial mammals are a key component of tropical forest communities as indicators of ecosystem health and providers of important ecosystem services. However, there is little quantitative information about how they change with local, regional and global threats. In this paper, the first standardized pantropical forest terrestrial mammal community study, we examine several aspects of terrestrial mammal species and community diversity (species richness, species diversity, evenness, dominance, functional diversity and community structure) at seven sites around the globe using a single standardized camera trapping methodology approach. The sites—located in Uganda, Tanzania, Indonesia, Lao PDR, Suriname, Brazil and Costa Rica—are surrounded by different landscape configurations, from continuous forests to highly fragmented forests. We obtained more than 51 000 images and detected 105 species of mammals with a total sampling effort of 12 687 camera trap days. We find that mammal communities from highly fragmented sites have lower species richness, species diversity, functional diversity and higher dominance when compared with sites in partially fragmented and continuous forest. We emphasize the importance of standardized camera trapping approaches for obtaining baselines for monitoring forest mammal communities so as to adequately understand the effect of global, regional and local threats and appropriately inform conservation actions

    Consistent diel activity patterns of forest mammals among tropical regions

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    An animal’s daily use of time (their “diel activity”) reflects their adaptations, requirements, and interactions, yet we know little about the underlying processes governing diel activity within and among communities. Here we examine whether community-level activity patterns differ among biogeographic regions, and explore the roles of top-down versus bottom-up processes and thermoregulatory constraints. Using data from systematic camera-trap networks in 16 protected forests across the tropics, we examine the relationships of mammals’ diel activity to body mass and trophic guild. Also, we assess the activity relationships within and among guilds. Apart from Neotropical insectivores, guilds exhibited consistent cross-regional activity in relation to body mass. Results indicate that thermoregulation constrains herbivore and insectivore activity (e.g., larger Afrotropical herbivores are ~7 times more likely to be nocturnal than smaller herbivores), while bottom-up processes constrain the activity of carnivores in relation to herbivores, and top-down processes constrain the activity of small omnivores and insectivores in relation to large carnivores’ activity. Overall, diel activity of tropical mammal communities appears shaped by similar processes and constraints among regions reflecting body mass and trophic guilds
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