PRPG - Pró-reitoria de Pós-graduação

URI Permanente desta comunidade

http://200.137.215.59/tede/handle/tde/148

Navegar

Agora exibindo 1 - 4 de 4

Biodiversidade e padrões de distribuição da anurofauna do Parque nacional das emas e entorno
(Universidade Federal de Goiás, 2009-03-30) KOPP, Katia A; BASTOS, Rogério Pereira; http://lattes.cnpq.br/6015137404238990
Composition and diversity of anuran amphibians in preserved and disturbed environments in the Cerrado of the State of Goiás, Mid-West Brazil. The Cerrado is the second largest biome of Brazil, with an approximate area of 2 million km², which represents about 23% of the total area of the country. Despite the high conversion of natural areas of the Cerrado in agricultural areas and pastures, comparative studies that address aspects of the composition and diversity of frogs from adjacent areas in different states of conservation are lacking. Thus, this study aimed to address taxonomic richness and community composition of anuran amphibians in twelve water bodies located in preserved areas (inside the National Park of Emas - PNE) and disturbed areas located around the PNE to test whether the structure of frogs communities is different in preserved and disturbed areas and whether species richness is correlated with descriptors of the heterogeneity of habitats. Were recorded 25 species of frogs belonging to nine genera of five families in the 12 water bodies sampled. Species richness was higher in disturbed than in preserved areas. Diversity and equitability were significantly higher in preserved water bodies (P <0.05) while dominance was higher in disturbed water bodies. An analysis of percentage of similarity (SIMPER) showed that the percentage of dissimilarity between the compared groups was 52.26%. The analysis of similarity (ANOSIM) showed significant results on differentiation between groups (Global R = 0.17, P = 0.04). Species richness was not related to any descriptor of heterogeneity. Geographic distance was related to species composition between sampled water bodies (r = -0.35, p = 0.01). At least two non-exclusive factors may be responsible for patterns of species composition and diversity of frogs found in the environments studied: a) the disturbance caused by human action in the use of natural areas for agriculture and livestock enables greater richness of species in disturbed areas, which is consistent with the hypothesis of intermediate disturbance, b) the migration between adjacent ponds allows the maintenance of communities and patterns of species composition. Thus, although species richness was lower in preserved water bodies, the highest diversity recorded in such habitats demonstrates their importance for the maintenance of community integrity and viable frogs populations
A planície aluvial do médio rio araguaia: processos geomorfológicos e suas implicações ambientais
(Universidade Federal de Goiás, 2006-05-29) MORAIS, Roberto Prado de; LATRUBESSE, Edgardo Manuel; http://lattes.cnpq.br/7008643054366282
The Araguaia River is the most important fluvial system of South America. With an area of 380.000Km², it´s includes two phytogeography regions that have a good part of planet biodiversity: Cerrado, in the south, and Amazonia Forest, in the north of Brazil. The high level of Cerrado ecosystem destruction and changes in the land using, after 1965, promoted an intense sedimentation in fluvial system. This study is about the channel of Araguaia river, in a 580 km extension, between the city of Barra do Garças (MT) and the confluence of Cristalino and Araguaia Rivers. The multidisciplinary approach of this study has as aim analyze the channel geomorphic and middle reach alluvial plains processes causing environmental changes to the channel morphology and to vegetation succession, done by the erosive and sedimentary processes in the channel. The quantitative data were obtained through maps, air photographs and topographic charts from Landsat 1 MMS (1975) and Landsat 5 TM (1998). Using geoprocessing recourses were done areal reports of erosive and sedimentary plans and were applied mathematics equations to estimate sediments bulk and mass remobilized and stored in fluvial system. Were obtained also socioeconomics information about the Araguaia River basin area in Goiás, during the decades of 1960 and 2000, the cities of this same basin s GDP, the cattle growing statistics, vegetation and deforestation areas. The physical and socioeconomic data showed a correlation between the emergence of geomorphologic processes that had modified the channel, with the growth and development socioeconomics activities. The gotten results had disclosed that between 1965 and 1975, few changes had occurred in the fluvial channel. After 1975, a sped up erosion process of the channel edges and of islands has beginning, mobilizing the sediments, the bigger vegetation, as arboreal and bush arboreal type, that are associates to the oldest units of alluvial plain. With greater arrives of sediments that had entered in the channel, from the edges and the islands erosion, before steady, and in bigger degree, through the tributaries that drain the contribution basin area, modified for the use of the land (cattle and agriculture), the excess of sediments intensified the lateral sedimentation and the formation of bars of the central type, increasing the interlacement of the channel and, therefore, its morphology. It was estimated that between 1965 and 1998, about 233 million tons of sediments had been stored in the fluvial channel of Araguaia river. In the new sedimentation areas it was developed herbaceous vegetation adapted to the sandy surfaces. It was evident that it is occurring, in the plain, the substitution of a bigger vegetation, with bigger floristic diversity, for a grassy vegetation of the type herbaceous, associates to the formation of a geomorphologic unit younger and unstable to the erosive and sedimentary processes, because of the hydrologic channel behavior. This fact probably will bring consequences to the diverse biological processes associates to all alluvial plain. In one another approach, throughout the historical period of the analysis, was verified that as they increased the percentages of Cerrado natural vegetation areas in the area of the basin converted into agricultural areas and of cultivated pastures, the GDP of the cities also increased. The correlation between deforested areas, growth of the GDP, volume and mass of sediments stored in the fluvial system and increase of arenaceous bars in the channel resulted absolutely in satisfactory evidences in inferring that the economic growth of the region is in a relation of direct dependence with the changes in the use of the land of the Cerrado areas, and its ambient implications in the processes of morphologic changes in the Araguaia River channel and plain
Macroecologia do gênero Uca (Crustacea, Decapoda): padrões de diversidade, distribuição e respostas às mudanças climáticas globais
(Universidade Federal de Goiás, 2009-11-17) NABOUT, João Carlos; NICOLINO, Aline da Silva; http://lattes.cnpq.br/0105114059435356
Macroecology of the genus Uca (Crustacea, Decapoda): Patterns of diversity, distribution and responses to global change. The genus Uca, composed by 97 species, has a worldwide distribution on coastal marine regions, mainly in tropical environments. Many researches have used the genus Uca as a model of study, although the actual scientific knowledge about this group is dispersed. Moreover, few studies have investigated its global and evolutive patterns. In this sense, considering that the genus Uca has no taxonomic problems (there is a consensus about its distribution and species identification), presents wide geographical distribution and has phylogenetic topologies, this group can be used as an excellent model to test macroecological and evolutionary hypotheses, and to discuss the effects of climate change on coastal organisms. The aim of this study was to detect trends and biases in scientific literature about the genus Uca, as well as to assess macroecological patterns (at a global scale) and to evaluate the influence of climate change on the geographical range size and species richness. Moreover, we associated the information generated to improve conservation strategies for species of the genus Uca. Considering our goals, we generated four papers in this thesis. Among the most prominent results, we observed that, the number of papers about the genus Uca indexed in Thomson ISI database, did not increase between 1991 and 2007, which may indicate the lack of interest of the scientific community on this taxonomic group. Moreover, the majority of the scientific production about the genus Uca came from institutions in the USA. The studies about the genus Uca were mainly characterized as population papers (which analyzes population attributes such as density, distribution and ecological interactions). The results of species accumulation curve demonstrated that the total number of Uca species currently know (97 described species) is substantially lower than the number predicted by the asymptote of the Gompertz model (134 species predicted), suggesting that new species need to be described. However, a new species of Uca is not described since 1987. Models were generated to explain the date of species description based on the body size, geographical range size, human influence and the type of habitat of each species. These models were selected using the Akaike Information Criteria (AIC). The best model among the candidate ones (explaining 37% of the total variance) was composed by variables representing the geographical range size of species, their body size and the human influence on them. In other words, large-bodied species and those widely distributed, mainly in regions with elevated human influence, were described earlier. In another paper of this thesis, we evaluated the levels of phylogenetic heritability of species of the genus Uca on their geographical range size, shape and position. If a strong phylogenetic signal of geographic range sizes exists between close related species, we can predict the unknown geographic range of species through the known geographic range of its relatives, which is useful for conservation purposes. However, the absence of phylogenetic signal was evidenced for this trait. On the other hand, there was a strong phylogenetic pattern considering the position of the range (mainly along longitudinal axis), probably due to mechanisms of vicariant allopatric speciation and to the geographical structure of the cladogenesis of the group. In the last paper, the impact of global changes on geographic range size of genus Uca were modeled, producing a comprehension about a poleward shift and elaborating maps of species richness based in two scenarios of global change. The models generated presented good performance, and predictions are that the species will probably have reduced the geographical range size and some species will be extinct (considering two scenarios until 2050), mainly in the tropical regions. Moreover, the range of species with midpoints in both hemispheres changed towards to poles in the future scenarios of climatic changes. Finally, the results of this set of papers highlighted the urgency of detailed studies for some species of Uca, and in some coastal marine regions (e.g. Indo-West Pacific) to evaluate the actual status of the distribution of species of the genus Uca and the real species richness of this genus. This is essential to generate local strategies aiming to minimize impacts of global change on coastal organism
Conservação de espécies em áreas de monocultura de soja no sudoeste goiano: uma avaliação usando larvas de anfíbios anuros
(Universidade Federal de Goiás, 2009-11-06) VAZ-SILVA, Wilian; BASTOS, Rogério Pereira; http://lattes.cnpq.br/6015137404238990
The basic knowledge of the answer of the species to the anthropic and natural perturbations on environments is the first step in the development of management strategies to the conservation biology. This study analyzes the pattern of occurrence of anurans species in relation of habitat, considering two different landscape uses from Jataí municipality, southwestern Goiás State, Central Brazil. Anurofaunal composition on Jataí represented 24% of anuran diversity of Goiás State, with great similarity with Aporé municipality, hydrographic sub-basin of the river Corrente. The relation between the species richness in seven municipalities with environmental and social attributes were non-significant. Considering the tadpoles assemblages in Jataí were sampled 40 ponds (24 distant of the monoculture and 16 located in the proximities of the monoculture). The study registered 4.529 specimens, classified in four families, 18 anuran species, presenting Scinax fuscovarius, Dendropsophus minutus and Eupemphix nattereri the most common species. The mean richness of species by sampled pond was significantly different in the families Hylidae and Leptodactylidae. The results showed that ponds distant of monoculture were more heterogeneous and possess a biggest diversity of species. The Canonical Correspondence Analyses showed the biggest predictive power to the environmental variables: predator types; distance of forest fragments; depth; and, hydroperiod. Spatial and temporal attributes were important to the species composition. Ponds distant to the monoculture presented (in mean) a bigger number of types of microhabitat and significant relation between the availability and the utilization by tadpoles. Significant difference was observed between niche breadths in the categories, with biggest values in the ponds distant to the monoculture. The species in ponds distant to the monoculture showed high plasticity in the environmental occupancy. The relation between spatial niche overlap and ecomorphological and phylogenetic patterns to the pars of the species were non-significant in the multivariate context. The results will subsidize actions directed to the management in agricultural areas in the scope of Conservation Biology

Navegar

Navegando PRPG - Pró-reitoria de Pós-graduação por Por Área do CNPQ "CNPQ::CIENCIAS BIOLOGICAS"

Resultados por página

Opções de Ordenação