Tesis
Variação espacial e temporal da composição de assembleias de gafanhotos (Orthoptera :Caelifera) em áreas de cerrado na Chapada dos Guimarães-MT Brasil
Fecha
2014-06-30Registro en:
VECCHI JUNIOR, Kleber. Variação espacial e temporal da composição de assembleias de gafanhotos (Orthoptera:Caelifera) em áreas de cerrado na Chapada dos Guimarães-MT Brasil. 2014. viii, 35 f. Dissertação (Mestrado em Ecologia e Conservação da Biodiversidade) - Universidade Federal de Mato Grosso, Instituto de Biociências, Cuiabá, 2014.
Autor
Diniz, Soraia
http://lattes.cnpq.br/6025231624681875
Diniz, Soraia
621.522.386-72
http://lattes.cnpq.br/6025231624681875
Costa, Maria Kátia Matiotti da
882.670.830-49
http://lattes.cnpq.br/8443521595233040
621.522.386-72
Landeiro, Victor Lemes
950.975.621-00
http://lattes.cnpq.br/9787714069071448
Institución
Resumen
Studies of space and temporal variability of the composition and of the abundances of herbivorous insects may provide sturdier predicting models for the conservation of species, what is indispensable facing the accelerated process of natural habitats loss and anthropic alteration of landscapes, like the “cerrado” (Brazilian savannah) with losses of 47,8 of its coverage until 2008. Grasshoppers are a dominating group of herbivorous insects in the whole world, and its high diversity, functional importance, sensibility to disturbance and easiness of sampling make them potentially useful for conservation actions. In Brazil, there are records in all ten Neotropical families with 734 species, in 450 genera. Thus this study proposes to investigate the spatial and temporal variability of the composition of grasshoppers assemblies in the savannah areas and if the vegetation structure and the environmental hydric stress explain the spatial variation, and temporally if the composition of grasshoppers assemblies is explained by rain and drought seasons. The collections were made in ten areas with different savannah physiognomies at the end of the rain period, beginning of drought period, drought and rainy period in the year of 2011. An active search with the aid of an entomologic net by two collectors was used during three hours in three periods of the day, in an area of 10 x 250m parallel to a contour line. In 15 raffled spots along the central line of the collection area, minimally 5 meters away, the area of soil coverage by grasses, the height and diameter of all plants above 20 cm high were measured in an area of 1m2. The plants were distributed in 4 strata according to height and diameter. The structure of the vegetation was obtained through analysis of main component and the composition of assemblies by the aid a PCoA. The two first axis of PCoA (variable answers) and the ones of the PCA (predictor variables) were used to test the relationship of the vegetation with the assemblies. The variation of dry and humid sites and the temporal variation were tested with multivariate analysis through permutation (PERMANOVA) using the similarity matrix of Bray-Curtis. 6281 individuals were collected, being 3168 of them adults belonging to 100 species from 12 subfamilies and six families from the Acridoidea, Eumastacoidea, Proscopioidea and Tretrigoidea superfamilies. Gomphocerinae was the most abundant (N=1525) and diverse (S=38) subfamily. Amblytropidia robusta was the most abundant species (N=337) followed by Amblytropidia geniculate (N=192), Pellopedon brunneum (N=150) and Carbonellacris grossa (N=138). The spatial variation of the assemblies was not explained by the vegetation structure, but by the humidity of the sites. Dry sites were more abundant (N=1751) and richer (S=81), with 21 exclusive species, humid sites with 1417 individuals and 79 species, being 20 of them exclusive. The variation between the times of the year was meaningful and an assembly from humid sites in the rain period was different from the others. Twenty-four species were registered just in one time of the year, demonstrating the relevance of studies in temporal dimension.