Testando a Hipótese da Quantidade de Habitat e os efeitos da fragmentação em espécies de mamíferos no Cerrado goiano

Abstract

The intense deforestation of areas of the Cerrado led to the current configuration of this biome. The effect of these process on medium and large mammal species must also include landscape analyzes and not just local analyses. Among the various landscape metrics, the amount of habitat has stood out and, in many studies, is considered the most important for the persistence of animal species and environmental processes. In this sense, this dissertation is structured into two chapters. The objective of Chapter 1 was to carry out a bibliometric analysis of the Habitat Amount Hypothesis, aiming to provide understanding regarding the evolution of this line of research. A survey of the academic production available in the Scopus and Web of Science databases was carried out. In addition to identifying the main authors and journals dedicated to disseminating the topic and the most referenced works in the area, this study made it possible to verify the emergence of the Habitat Quantity Hypothesis as an influential perspective in the areas of Landscape Conservation and Ecology. Therefore, through the analysis of the results of Chapter 1, it was possible to observe the behavior of global scientific production on the topic, and despite the increase in research on the topic, the scenario is still incipient, considering the relevance of the hypothesis for future work focused on Ecology of landscape. Chapter 2 had the main objective of testing the influence of the number of fragments, size of the fragments studied and the amount of habitat in the local landscapes (Habitat Amount), on the species richness of medium and large mammals in the southeast region of Goiás. The areas studied are in the cities of Catalao, Ipameri, Urutai and Campo Alegre, all located in the Brazilian Cerrado. The satellite images were obtained through the USGS (United States Geological Survey) repository, and for both the current years (2014, 2016 and 2018) and for the year 2000 images from the month of July were selected. Subsequently, the data were processed using the ArcGIS versao software. 9.3, then a classification was carried out to measure the amount of habitat within the landscape. For this purpose, the landscape was mapped within a radius of 2,000 meters, creating a buffer from a point in the center of the sampled fragment. The results obtained show greater species richness of medium and large mammals in areas with a greater amount of habitat, which supports the hypothesis of habitat amount (Habitat Amount) as a better predictor for the richness of this faunal group found in the studied landscapes. Therefore, the results emphasize the importance of protecting large patches of habitat and maintaining a large amount of habitat in the local landscape around the patches. Therefore, to reduce the effects generated by removing vegetation, it is necessary to highlight habitat conservation, prioritizing the following aspects: quantity of habitat and size of the fragment sampled.