Land-use and coverage in the structure of the landscape in a Tropical Dry Forest in northeast Brazil

Abstract

Landscape Ecology using GIS is applied to understand the effects of forest fragmentation and makes it feasible mainly for extensive areas, through the possibility of analyzing both the variety of units that compose it in time. This study aims to analyze the land use and coverage of tropical dry forests and to characterize their landscape structure in an area of the municipality of Floresta, Pernambuco, Brazil, in order to understand how the landscape configuration can influence the conservation. Orbital images were used from LANDSAT, and the classification was performed in the QGIS 2.18 software using the Maximum Likelihood methodification, for the years of 2007 and 2017. A circular buffer was incorporated around the area of study to analyze the structural patterns in the context of the landscape. Five thematic classes were used: dense vegetation, sparse vegetation, exposed soil, grassland, and water. The metrics were obtained through the Patch Analyst tool only to the class of dense vegetation. It is noted that much of the dense vegetation has become sparse. There was a reduction of exposed soil and an increase in grassland areas, which may indicate a regeneration process of the vegetation. The fragments of dense vegetation with more substantial dimensions are on constant exploratory actions and are the most affected with the reduction of size. Furthermore, climatic factors, periods of drought, and the presence of livestock may also affect the fragmentation of dense vegetation patches. Therefore, the landscape became heterogeneous, and a tendency was observed to increase the fragmentation, mainly in the more significant spots.

Persistent fire foci in all biomes undermine the Paris Agreement in Brazil

“…Caatinga showed the potential for high alteration, largely in in well preserved areas. In a study on Pernambuco-Brazil that analyzed Land Remote-Sensing Satellite imagery, Dos Santos et al 31 found that fragments of dense vegetation were more exposed to degradation and consequent landscape alteration, potentially increasing the burning and resultant carbon emissions in Caatinga. It is worth noting that Caatinga is the most populated biome and occurs in a drier region of Brazil.…”

“…It is worth noting that Caatinga is the most populated biome and occurs in a drier region of Brazil. As such, in addition to landscape changes as a result of increased fires, the acceleration of fires from climate change may lead to dramatic social consequences 31 .…”

Mapeamento da Vegetação da Caatinga a partir de Dados Ópticos de Observação da Terra – Oportunidades e Desafios

“…Os autores utilizaram dados Landsat (TM, ETM+ e OLI) em um intervalo de 31 anos (1985-2015) e compararam os índices espectrais Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI) e albedo de superfície, tendo o último apresentado a melhor acurácia. Em uma área de Pernambuco, Santos et al (2020) classificaram o uso e cobertura da terra utilizando a técnica de máxima verossimilhança em dados Landsat de 2007 e 2017. Por fim, Silveira et al 2018combinaram pela primeira vez a classificação das fitofisionomias da Caatinga com atributos físico-químicos do solo usando dados do Sentinel-2 e LiDAR.…”