Navegando por Assunto "Diversidade de espécies - Amazônia"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Abelhas das orquídeas (Apidae: Euglossini) e as plantações de palma de óleo (Elaeis guineensis Jacq.) na Amazônia Oriental: mudanças na composição de espécies, tamanho corporal e diversidade funcional
(Universidade Federal do Pará, 2018-08-02) BRITO, Thaline de Freitas; MAUÉS, Márcia Motta; http://lattes.cnpq.br/0976385386657517; CONTRERA, Felipe Andrés León; http://lattes.cnpq.br/0888006271965925
In this study, we evaluated the role of legal reserves (LR) and areas of permanent protection (APP) in the maintenance of orchid bee species, and we tested the influence of abiotic and habitat parameters on taxonomic and functional diversity of this group. In addition, we investigated the occurrence of phenotypic variations (body and wing size, and fluctuating asymmetry) in response to environmental stress caused by oil palm plantations. Orchid bee males were sampled in nine areas (3 RL, 3 APP, and 3 oil palm plantations) in the municipality of Tailândia, southeast of the state of Pará. In each area, we installed six separate sampling stations, 500 m apart, each one with six scent traps; totaling 36 traps per area, and 108 per habitat type. We compared differences in observed abundance and richness using a One-Way ANOVA, we evaluated species composition patterns with a PCoA, and we also used a species indicator analysis. A partial RDA was applied to evaluate the influence of habitat attributes, space and habitat type on taxonomic and functional parameters of bees. In addition, we compared body and wing size variations of the individuals through the types of habitat. Our results indicate that oil palm areas are characterized by the presence of few individuals and species, low functional diversity, and by larger bees. Despite this, we recorded four species associated to LR, which can be useful indicators of orchid bee’s communities in the Amazon rainforest. The habitat structure was not a good predictor of both functional and taxonomic composition, and no levels of fluctuating asymmetry were detected, but bees from oil palm showed larger wings compared to forest areas. Our research highlights that APPs play an important role in maintaining both taxonomic and functional composition of orchid bees, which could reinforce the fact that bees use these areas as displacement corridors in a matrix formed by oil palm plantation. Thus, both LRs and PPAs areas fulfill their purpose of protecting the biodiversity of orchid bees.
Acesso aberto (Open Access)
As aves do estado do Maranhão: atualização do conhecimento e conservação em uma região de ecótono entre a floresta Amazônica e Cerrado
(Universidade Federal do Pará, 2018-09-12) CARVALHO, Dorinny Lisboa de; SILVA, Daniel de Paiva; http://lattes.cnpq.br/1409353191899248; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
The state of Maranhão is located between the eastern Amazon and the northern Cerrado, presenting a wide variety of environments in its ecotonal area. Due to this environmental heterogeneity, Maranhão has one of the richest avifaunas in Brazil. Furthermore, this region includes one of the world's most endangered biogeographical provinces. In order to contribute to the knowledge and conservation of avifauna in this region, this study has as its main objectives: 1) review and update the checklist of birds species from Maranhão to identify possiblesampling gaps in the state; 2) test the effectiveness of the State Protected Areas (PAs) and Indigenous Lands (TIs) system in the protection of threatened and endemic bird species using SDMs and; 3) assess the potential impact of climate change on the distribution and conservation of 24 threatened bird taxa occurring in the state, comparing current and future distributions (2070) with the current reserve system, in order to identify potentially stable areas that can serve as dispersal corridors for the evaluated taxa. In chapter 1) we recorded the occurrence of 750 bird species, distributed into 88 families and 30 orders. We added 114 new species (95 residents, 13 migratory and 6 vagrants) to the last list compiled 27 years ago for the same region. In chapter 2) we observed that taxa with wider distributions are protected equally as taxa with smaller distributions and larger PAs are more efficient than smaller. Our results also showed that most Cerrado PAs are poorly allocated. We suggest six priority areas for conservation of Neotropical birds and highlight the importance of indigenous lands in conserving Neotropical biodiversity. In chapter 3) our results indicated that, although threatened Amazon and Cerrado taxa are potentially protected, for both present and future scenarios, most of the taxa are likely to suffer drastic population size declines or even global extinction in the near future. We highlight the importance of creating a system of dispersal corridors that interconnect PAs in this region, as well as the implementation of public policies for maintenance and mitigation of the areas adjacent to these corridors, aiming at the conservation of the richness and diversity of species in this region.
Acesso aberto (Open Access)
Efeitos ecológicos e evolutivos nos padrões de diversidade de aves na Amazônia
(Universidade Federal do Pará, 2018-09-20) ALMEIDA, Sara Miranda; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
Studies covering phylogenetic and functional diversity have been increasingly used to explain patterns of species diversity and organization of biological assemblages, constituting complementary tools to the traditional taxonomic approach (e.g. species richness). Biogeographical knowledge may also contribute to the understanding of these patterns, since the geographical distribution of different taxa depends on historical processes related to dispersion and speciation, in this manner influencing the formation of regional pools of species. In this thesis we evaluated the influence of historical processes and environmental factors on the diversity of Amazon bird assemblages. We compiled compositional data from 80 bird assemblages, 12 in savannas and 68 in terra firme forests, totaling 878 species. In Chapter 1 we evaluated the phylogenetic and functional diversity of passerine birds (Passeriformes order) considering two factors: the biogeographical history of each suborder (Passeri and Tyranni) and the habitat type (forest and savanna). We verified the importance of the different habitats for the maintenance of bird diversity since, although Amazonian savannas present low species richness when compared to forests, this habitat presents assemblages with unique combinations of ecological traits and specific lineages. We showed through the results found in this chapter that the greater functional diversity of Passeri assemblages in both habitats and the greater phylogenetic diversity of Tyranni in terra firme forests are related to the biogeographic history of each suborder and their adaptation to the habitat. In Chapter 2, we assessed the contribution of Amazonian biogeographic regions (a.k.a., endemism areas) and climatic variables to species composition and to the phylogenetic structure of canopy and forest understory bird assemblages. We hypothesized that differences in species composition are greater between interfluves for understory bird assemblages, which are composed of species with lower dispersion capacity, than for canopy birds. In this chapter, we found that the understory bird assemblages were more influenced by biogeographic barriers than canopy birds, corroborating our hypothesis. The climatic variables were important to explain the species diversity and phylogenetic structure of both groups. With the results generated in this thesis I concluded that the Amazonian bird diversity is result of processes related to biogeographic history, ecological traits of species, and environmental conditions.
Acesso aberto (Open Access)
Movimentos sazonais de vertebrados terrestres entre florestas periodicamente alagadas e de terra firme
(Universidade Federal do Pará, 2014-04-01) COSTA, Hugo Cardoso de Moura; PERES, Carlos Augusto da Silva; http://lattes.cnpq.br/9267735737569372
The flood pulse is the main factor structuring and differentiating the ecological communities of Amazonian unflooded (terra firme) and seasonally-flooded (várzea) forests as they require unique adaptations to survive the prolonged annual floods. Therefore, várzea and terra firme forests hammer out a spatio-temporal mosaic of resource availability, which may result in landscape scale seasonal movements of terrestrial vertebrates between adjacent forest types. Yet the lateral movements of terrestrial vertebrates between hydrologically distinct neighbouring forest types exhibiting staggered resource availability remains poorly understood, despite the important implications of this spatial dynamic for the ecology and conservation of forest wildlife. We examined the hypothesis of seasonal movements between two adjacent forest types at two contiguous sustainable-use forest reserves in Western Brazilian Amazonia, investigating the effects of water level, landscape and anthropogenic disturbance on the overall species richness, composition, and abundance of nine major vertebrate trophic guilds. Species richness differed in neighboring terra firme forests between the high-and low-water phases of the flood pulse and terra firme forests were more species rich than várzea forests. There were clear differences in species composition between both forest types and seasons. Generalized Linear Models showed that water level was the main factor explaining aggregate abundance of all species and three trophic guilds. Anthropogenic disturbance and geographic setting of camera trap stations, including distance to the nearest urban center, the number of residents of the nearest community, elevation and the surrounding area of várzea of each camera trap station, had a variety of effects on the terrestrial vertebrate assemblage. Overall vertebrate biomass increased with distance from the nearest urban center. Our results indicate that the persistence of viable populations of large terrestrial vertebrates adjacent to major Amazonian rivers requires large, wellconnected forest landscapes encompassing different forest types to ensure large-scale lateral movements by forest wildlife.