Mudanças espaço temporal da disponibilidade de serviços ecossistêmicos em uma microbacia hidrográfica do nordeste brasileiro

Abstract

Changes in land use and land cover (LULC) alters the dynamics of ecosystems and the provision of ecosystem services, which are essential to the maintenance of life and human well-being. Human settlement in developing countries generally occurs in a disorderly and unplanned manner, leading to environmental degradation. In Northeast Brazil, water is a scarce resource and urbanization tends to occur along the water network and increase pressure on the quality and availability of this resource. This paper analyzes LULC changes in 1989, 2007 and 2014 and the associated impacts on the provision of ecosystem services in the microwatershed Riacho das Piabas (Paraíba, Brazil). LULC changes were identified and quantified using remote sensing techniques and geographic information system. Ecosystem services value (ESV) were estimated using average monetary value available in the literature using the benefit transfer method. In 1989 the estimated total ESV was US$ 7.18 million, reducing to US$ 3.73 million in 2007 and US$ 2.72 million in 2014. There was a 115% increase of built area between 1989 and 2014 that resulted in reduction of ecosystem services of 62% between 1989 and 2014. The decline in ESV reflects the negative impact of the urbanization process on the provision of ecosystem services, especially those offered by vegetation. The arboreal vegetation was the most valuable LULC class in the study area, and the one that showed the greatest reduction in area. Planning, creating and maintaining green areas is critical to mitigate the impacts of urbanization on the provision of ecosystem services.

Keywords

• expansão urbana
• mudança da paisagem
• recursos naturais
• valoração de serviços ecossistêmicos
• espaço verde