Climate Change and Biodiversity: An Analysis of the Ecosystem Integrity of the Eastern Cariri Region of Paraíba

Abstract

The study, conducted in Paraíba, analyzed the climatic conditions and the ecological integrity of the municipalities of Alcantil, Barra de Santana, and Riacho de Santo Antônio, located in the Eastern Cariri, over a 10-year time series. The research cross-referenced annual average temperature and rainfall patterns, highlighting climate variability and its impacts on the biodiversity of Eastern Cariri. In Alcantil, there was a strong fluctuation in rainfall, with extremes of 200 mm in 2016 and 550 mm in 2022, associated with an increase in average temperature in 2023 (25.9 °C), resulting in water stress and vegetation fragmentation. In Barra de Santana, rainfall ranged from 250 mm (2015–2017) to 700 mm (2022), while average temperatures also rose, intensifying the loss of plant and animal species. In Riacho de Santo Antônio, the hydrological regime showed strong irregularity, with minimums of 150 mm in 2015–2016 and maximums in 2022, contrasting with the rise in temperatures in 2023, which further increased the degradation of the native vegetation.

To assess the relationship between climate and biodiversity, an Eastern Cariri Ecological Integrity Index (ICECO) was proposed and developed, calculated from metrics of vegetation cover (VC), climate vulnerability (CVu), and ecological resilience (ER), supported by the R package and spatial analysis in QGIS. The results showed very distinct values among the municipalities: Alcantil (ICECO = 0.48), Barra de Santana (ICECO = 0.75), and Riacho de Santo Antônio (ICECO = 0.65). These indices revealed greater vulnerability in the municipality of Alcantil, due to reduced vegetation fragments and edge effects, while Barra de Santana shows greater adaptive capacity, and Riacho de Santo Antônio is in an intermediate condition, with potential for ecological recovery.

It is concluded that the semi-arid region of Eastern Cariri faces severe climatic instabilities; however, it presents resilient ecosystem conditions despite high temperatures, prolonged droughts, and anthropogenic activities. The use of ICECO proved effective in measuring the impacts on biodiversity and may even support conservation policies, environmental management, and socio-environmental justice in the studied region.

Keywords: Semi-arid; Eastern Cariri; Biodiversity; Ecological integrity; Climate change