Navegando por Assunto "Biodiversidade - Conservação - Amazônia"

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Acesso aberto (Open Access)
Avaliação dos efeitos de monocultura de palma de dendê na estrutura do habitat e na diversidade de peixes de riachos amazônicos
(Universidade Federal do Pará, 2018-03-30) RUFFEIL, Tiago Octavio Begot; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
In the Amazon, oil palm plantation has been growing exponentially in recent years, altering the landscape natural characteristics and being a possible threat to biodiversity. This environmental impact extends to aquatic ecosystems, which because they are highly related to the adjacent vegetation, also suffer the impacts resulting from this agricultural action, such as habitat structure alterations, affecting the species distribution and ecosystem processes. Thus, studies to test the impact of this monoculture in the Amazon are important to support more efficient strategies for reducing impacts and maintaining biodiversity. Therefore, this thesis aims to answer the following questions: I) How the presence of oil palm cultivation around the streams affect their habitat structure and fish assemblage structure in relation to streams that drain through forested areas present along of this anthropogenic landscape? II) What are the effects of the substitution on landscape of primary forest on the oil palm in the habitat physical structure and on the taxonomic diversity of neotropical stream fish? III) How do the patterns of taxonomic and functional diversity of Amazon stream fish assemblages responds to the habitat and landscape changes caused by oil palm plantation? To answer these questions, we sampled and analyzed 39 streams in the Eastern Amazon. For the habitat characterization, an extensive protocol of the evaluation was applied, resulting in 238 habitat variables, besides that, was used landscape characteristics based on the percentage of land uses adjacent to the streams. For fish collection was used hand net for six hours in each stream. Morphological measures and ecological information of fish species were taken for later calculation of the functional attributes related to the third chapter. The results showed that oil palm plantation affect the stream habitat structure, modifying mainly the channel morphology, the substrate structure and shelter availability, such as woods and roots, for fish assemblage. Consequently, the fish species distribution was affected, resulting in changes in the assemblage structure. On the other hand, no changes were registered in the functional structure of these assemblies. Finally, we showed that the oil palm plantation modifies the stream habitat natural characteristics, as well as the distribution of the species, however the functional structure of the fish assemblages is maintained.
Acesso aberto (Open Access)
Impactos de mudanças climáticas e desmatamento na distribuição geográfica de Cebus kaapori (Primates: Cebidae) na Amazônia
(Universidade Federal do Pará, 2018-04-02) GOMES, Letícia Braga; FREDERICO, Renata Guimarães; http://lattes.cnpq.br/3156181119549976; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581
Climate change and deforestation are among the greatest threats to biodiversity. In the Amazon, the establishment of Protected Areas is an important tool to reduce the negative impacts of these threats, favoring the protection of biodiversity. Amazonia holds the largest number of primates in the world. Primates are highly sensitive to forest loss and habitat modification, which directly threatens the survival of their populations. The Ka’apor Capuchin Cebus kaapori is considered the rarest and most threatened primate species in the Amazon, and is classified as Critically Endangered by the International Union for the Conservation of Nature. Here, we evaluated the impacts of climate change and deforestation on Cebus kaapori distribution area. We modeled the distribution of the species under current and future (2050) climates and overlapped these models with established protect areas as well as current forest cover and that expected for 2050 in two different economic scenarios acoording to a land-use model. We found that climate change might lead to up to 97% of loss of climatic suitable area for Cebus kaapori within the next 30 years. The situation worsens when considering current forest loss and future deforestation projections, both under a governance scenario and in under the business-as-usual scenario. We show that the restricted distribution of Cebus kaapori, coupled with likely high reduction in suitable areas for species occurrence, low coverage in protected areas and fragmentation of potential adaptive areas for occurrence in the future, might reduce species’ populations to an unviable level of survival in nature.