Programa de Pós-Graduação em Ecologia - PPGECO/ICB

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/8937

O Programa de Pós-Graduação em Ecologia (PPGECO) foi criado em 2015, por meio de um convênio firmado entre a Universidade Federal do Pará (UFPA) e Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) e visa avançar no conhecimento teórico e empírico da Ecologia, incluindo suas abordagens básicas que são a autoecologia, a biologia de populações e os estudos de comunidades e ecossistemas.

Navegar

Agora exibindo 1 - 7 de 7

Acesso aberto (Open Access)
Aspectos ecoepidemiológico associados à fauna flebotomínica de um fragmento florestal urbano
(Universidade Federal do Pará, 2017-03-31) ROSÁRIO, Ingrid Nazaré Garcia; MÁLAGA, Sérgio Marcelo Rodríguez; http://lattes.cnpq.br/4348571126707708; SILVA, Ivoneide Maria da; http://lattes.cnpq.br/5206284058104362
Sand flies are insects vectors of several disease-causing pathogens, responsible for the transmission to animals and humans of numerous diseases, the main being leishmaniasis. The present study evaluated the ecoepidemiological aspects of the phlebotominal fauna in a forest fragment in the urban area of Belém (PA). From December 2015 to November 2016, monthly collections of sand flies were carried out in the forest fragment and in the peridomicile of nearby residences, with the aid of a CDC type light trap. A total of 4070 phlebotomines were collected, with identification of two genera and 24 species. The predominant species was Lutzomyia (Trichopygomyia) longispina (32.16%), followed by Lutzomyia (Evandromyia) infraspinosa (21.72%). The wealth estimators indicated that the sampling effort was satifastory for the studied area. There was no significant relationship between accumulated precipitation, temperature and relative humidity when analyzed with sandfly abundance. When related to climatic variables with species richness, only the accumulated monthly rainfall presented a negative relation on the richness of captured species. In the analysis of the vertical distribution the number of sandfly specimens captured at ground level was significantly higher than in the canopy, where 21 species were found in the soil, four of them exclusive to this stratum and 20 species in the canopy, with three occurring exclusively in the canopy. Four species with epidemiological importance were found: Lutzomyia (Nyssomyia) flaviscutellata, Lutzomyia (Psychodopygus) ayrozai, Lutzomyia (Psychodopygus) paraensis and Lutzomyia (Nyssomyia) antunesi. The females evaluated by PCR were negative for Leishmania spp. And most of the engorged females analyzed were fed on mammals. The knowledge of the fauna in an area of preservation under intense anthropic influence, can help in the understanding of the relation between the species and the degree of preservation of an area, and also in the knowledge of species that may play an effective role in the transmission of pathogens to man and animals.
Acesso aberto (Open Access)
Clima, solo e água: importância de variáveis ambientais na determinação da distribuição potencial de peixes de rios e riachos amazônicos
(Universidade Federal do Pará, 2017-10-19) ALVAREZ, Facundo; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099; GERHARD, Pedro; http://lattes.cnpq.br/5621269098705408
Estimating the spatial distributions of species is one of the main objectives of macroecology, especially when sampling efforts fail to reach the demographic knowledge of the target species. In this sense, the species distribution models (SDM) allow us to approach the fundamental niche of the species from the extrapolation of predictor variables. The Amazonas-Tocantins basin is characterized by a strong environmental and physical dynamics that act differently in the regional ichthyofauna at different spatial scales. Due to the differential perception of hábitats by the species, four species of rivers were included, Ageneiosus inermis, Acestrorhynchus falcatus, Pygocentrus nattereri and Plagioscion squamosissimus, and four species of streams, Crenuchus spilurus, Helogenes marmoratus, Helogenes marmoratus and Trichomycterus hasemani. The objectives of the study were: (i) To determine which set of predictor variables allows better spatial representations for the species of rivers and streams using SDM; and (ii) To evaluate the predictive power of MaxEnt to generate SDM of rivers and streams using different sets of Predictor variables. The spatial records that presented spatial autocorrelation were processed from the spThin package. To characterize the environmental dynamics, 78 predictors were divided into three treatments: PCA1 (climatic variables), PCA2 (climatic variables, slope and accumulated flow) and PCA3 (climatic variables, slope, accumulated flow, topographic and edaphic variables). MaxEnt software was used and configured from the ENMeval package. Two aspects can be observed in the results: the use of hydrological, topographic and edaphic variables allows to obtain more precise and spatially restricted representations than only climatic variables. In the second place, it is evident that, regardless of the dimensional complexity of the system, MaxEnt allows to obtain MDEs with high predictive power for both river species and species of streams. In the case of river species, the macroscopic predictors (climatic variables - PCA1) allowed to represent their environmental requirements and their wide spatial distributions. Meanwhile, climatic, hydrological, topographic and edaphic variables (PCA3) acted as environmental filters restricting the spatial distributions of both species of rivers and streams. The dimensional complexity of the system does not affect the spatial representation capacity of Maxent, observing that, in the case of species of streams MaxEnt showed greater capacity of spatial representation.
Acesso aberto (Open Access)
Efeitos da inundação e da antropização sobre padrões de diversidade de árvores da floresta de várzea amazônica
(Universidade Federal do Pará, 2019-05-29) MAGALHÃES, Jose Leonardo Lima; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627; https://orcid.org/0000-0002-6296-5487
The white-water floodplain forest in Amazon (locally várzea) is a highly heterogeneous floodplain ecosystem that encompasses a large number of adapted species. It is distributed along the entire length of the main channel of the Amazon River and of tributaries of Andean origin. In addition, due to periodic flooding by waters with high sediment load, it has high fertility when compared to other Amazonian systems. What on the one hand is important for high primary productivity also makes it the target of human colonization for its benefits to food production. In this sense, because it presents continental dimensions and crosses almost all the biome from East to West, it has been the main access route of present and previous human populations to the most distant points of the basin. All these factors contribute to these forests being an important model for testing diversity patterns along natural and anthropogenic gradients. This thesis is presented in two chapters that use distinct approaches, focusing on different aspects of forest diversity and structure. Chapter 1 examines the phylogenetic structure of the arboreal component of floodplain forests in the Central and Eastern macro-regions and investigates whether the current human presence has modified it, specifically reducing the number of tree lineages present and leading to the phylogenetic homogenization of these forests. Chapter 2 investigates whether the taxonomic diversity and the local and regional tree species found today in the macro-regions of the study are associated with historical patterns of human density since the arrival of Europeans in the region. To reach the objectives, seven areas were sampled along the 2,400 km stretch of the Brazilian portion of the Amazon River, which covers different flood regimes and human influences. Thus, tree individuals with DBH ≥ 10 cm were sampled and data were collected in situ and in databases available to be used as predictors variables in modeling tree diversity at different scales. With the results, it was detected that the flood regime is the main factor that influences the phylogenetic structure whereas the human density of almost three centuries ago is responsible for the patterns of taxonomic diversity that are currently found. The diversity patterns were detected in the evolutionary and ecological scale, where it was shown that human influences may have a long-delayed response after they have occurred. Because várzea is a system of relatively easy access in the region and has few protected areas, it is necessary to understand how these forests are important for the maintenance of essential ecosystem services, even though they have been affected by human influence for a long period.
Acesso aberto (Open Access)
Fatores determinantes do uso de habitats por mamíferos ungulados (Artiodactyla e Perissodactyla) na Amazônia Oriental
(Universidade Federal do Pará, 2022-04) ALVES, Michel Jacoby Pereira; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581; https://orcid.org/0000-0002-7863-9678
Land use by human activities in landscapes of the eastern Amazon has been modifying and suppressing the native habitats of this region, altering the dynamics of ecosystems and negatively affecting biodiversity. Herbivorous-frugivorous ungulate mammals are among the groups of mammals most affected by these changes in ecosystems. Through the use of camera traps, we recorded ungulates and measured hunting pressure. Using satellite images, we evaluated the environmental characteristics and human pressures that may be influencing the abundance of tapirs (Tapirus terrestris), deer (Mazama americana and Mazama nemorivaga) and wild pigs (Pecari tajacu and Tayassu pecari) in habitats with different levels of disturbance. The species showed different responses to landscape and land use variables. Our result demonstrates that all species studied showed some degree of tolerance to disturbed habitats, except for abandoned pasture and oil palm plantation habitats. We also demonstrate that although the species use degraded habitats, they have a high dependence on forested habitats.
Acesso aberto (Open Access)
Filtros ambientais determinando caracteres funcionais de assembleias de Odonata
(Universidade Federal do Pará, 2017-03-24) PEREIRA, Diego Fernandes Gomes; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029
Species distribution is affected by availability of habitas that fit within the limits of variation of their niche and by interaction with other species. Environmental modifications, especially those of anthropic origin, are increasingly common, and are considered major causes of species extinction during the Anthropocene. Aquatic ecosystems are considered among the most vulnerable on the planet because of its dependence on the surroundings and the drainage system. However, species responses to these changes are not random, and can follow patterns that are caused by the specific functionality or morphology of each taxon. This work’s goal was to evaluate if environmental factors work as ecological filters for the establishment of Odonata species through selection of their functional and morphological characters, testing the hypotheses that a) the environment works as a filter over species, by facilitating or hindering characters and b) that due to their thermoregulatory and reproductive requirements, indispensable for colonization and population maintenance, thorax width and oviposition type will be the most affected biological variables. Considering that, we sampled 97 streams in the oriental side of the Brazilian Amazon Forest, distributed over an environmental gradient which covers areas ranging from untouched primary forest to areas extremely modified by agriculture and livestock. We used six functional traits (total body length, fore wing length, fore wing width, thorax width, abdominal length and oviposition type) and seven environmental variables (habitat integrity index, dissolved oxygen, water temperature, canopy cover, macrophytes cover, pH and condutivity). To evaluate if the environmental variables affected the odonate communities, we used the combination of the RLQ and Fourth Corner analysis, with which we assessed the relation between each of the selected traits with each of the habitat descriptors. Among the studied environmental variables, habitat integrity index presented the largest effect over the community of Odonata, having a negative relation with fore wing width, thorax width and exophytic oviposition, and a positive relation with endophytic oviposition. Macrophytes cover showed a negative relation with abdominal length and a positive relation with thorax width and exophytic oviposition. No other environmental descriptor presented significant relations. The results show that poorly preserved habitats facilitate the occurrence of organisms with larger thorax and the substitution of the endophytic by the exophytic type of oviposition. Since environmental impacts usually do not change Odonata species richness, only community composition, these results point that there is favouritism towards groups of species with those characters, like the Libellulidae family, with detriment to other families or groups (specially of the Zygoptera suborder), what might result in community homogeneity and loss of functional and phylogenetic diversity. Thus, the preservation of primary forest is indispensable for the maintenance of Odonata, being the best way to conserve the different ecophysiological and behavioural groups in the order. The dragonfly communities’ responses, directed by morphological and behavioural traits, enlightens ecological response patterns, and the addition of oviposition categories to conservation policies for the Odonata is critical in making them more effective, as they are absolutely necessary for population stability and colonizing new sites.
Acesso aberto (Open Access)
Influência da perturbação ambiental na assembleia de pequenos mamíferos nãovoadores na Amazônia Oriental
(Universidade Federal do Pará, 2019-06) SOTOMAYOR, Omar Santiago Erazo; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581; https://orcid.org/0000-0002-7863-9678
Anthropogenic environmental disturbance results in different structural modifications of the forest, which can lead to changes in species composition patterns, taxonomic and functional diversity. We evaluated the influence of environmental disturbance on the structure and diversity of assemblies of non-flying small mammals in the eastern Amazon. We analyzed species composition, richness and abundance and their functional characters as assemblage descriptors, considering their environmental variations, in three levels of environmental disturbance: (i) forest interior; (ii) edge of the forest; and (iii) rural space. The diversity α (taxonomic and functional) remained relatively constant through the levels of anthropogenic environmental disturbance. However, in the taxonomic diversity β, the assemblage of the forest-edge community presents abundance gradients, where they share most of their species, but some individuals of the edge are lost in the forest. On the other hand, the rural forest and rural edge assemblages present a balanced variation of abundance, in which individuals of some species of forest and border areas are replaced by individuals of different species in rural space. Among the morphological attributes we observed subtler responses of the community, small mammals characterized by a larger tail predominate in forest areas and those characterized by a larger foot predominate in rural areas. We conclude that the morphological attributes (tail and foot length) are determining factors in the assemblage composition patterns of the small non-flying mammals and their habitat selection in environments facing anthropic impacts. The changes and patterns identified in our study are of crucial importance for biodiversity management and conservation plans.
Acesso aberto (Open Access)
Padrões de diversidade, ocupação e coexistência de mamíferos terrestres na região neotropical
(Universidade Federal do Pará, 2019-05-10) SANTOS, Fernanda da Silva; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; PERES, Carlos Augusto da Silva; http://lattes.cnpq.br/9267735737569372
Community structure and diversity result from a complex and dynamic phenomenon, determined by a large number of processes in space and time, which are driven by environmental conditions, spatial factors, resource availability, and species interactions, including competition and predation. This study used the terrestrial mammal group as a model to investigate part of the processes shaping communities, and to understand patterns of diversity, occupancy, and coexistence in the Neotropical forests. Data from a long-term camera trapping monitoring of terrestrial vertebrates across eight protected area sites were combined. The study sites comprise eight areas distributed through six countries (Costa Rica [1], Panama [1], Ecuador [1], Peru [2], Suriname [1] e Brazil [2]), and include both intact forest and fragmented forest landscapes. Firstly, β diversity was estimated among the eight mammal communities to identify: which sites and species contributed to differences in the variation of community composition (LCBD and SCBD, respectively); which process (species replacement or richness difference) explain the observed β-diversity patterns; and which factors affect local contribution (LCBD) and species contribution (SCBD) to β diversity. Posteriorly, data from five sympatric cat species [jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii)], that potentially occur across the eight sites, were used to examine mechanisms that allow coexistence among ecologically similar species. Finally, data from one of the sites was used to test the hypothesis that terrestrial mammals, mainly frugivores and granivores, move seasonally as a response to resource availability fluctuation (e.g., water and fruits) between rainy and dry seasons in a terra-firme forest. The results indicated that fragmented forests contribute more to β diversity than intact forest sites, and that variation in species composition is determined by richness difference rather than replacement. The eleven species ranked as the most important in structuring the communities were also the ones with the highest abundance variation among sites. Regarding felids’ coexistence, the study reveals an apparent spatial and temporal partitioning for most species pairs, with prey abundance being more important than species interactions to the local occurrence and spatial distribution of Neotropical forest cats. Concerning seasonal dynamics, only three species presented differences on occupancy between dry and rainy seasons, while the other analyzed species did not seem to move as a response to variation in water and food availability. In summary, the results provide a broad characterization of terrestrial mammals occurring in the Neotropical region, assessing their conservation status, factors that influence their occurrence, as well as the spatial and temporal patterns of several felid species along eight Neotropical protected forests.

Navegar

Navegando Programa de Pós-Graduação em Ecologia - PPGECO/ICB por CNPq "CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA"