The Novel Ecosystems of the Sertão Carioca: Landscape Transformation and Land Use History in the Piabas River Basin (1968-2018), Rio de Janeiro

Abstract

Landscape transformations are a historical product of social relationships with the environment. Thus, ecosystems modified by these agencies respond to these transformations by developing ecological novelties, most of all in ecosystem structure and composition. Nowadays, we understand these cultural landscapes as social-ecological systems composed of novel ecosystems. The areas which are distant from central Rio de Janeiro, known as Sertão Carioca, were originally used for agriculture and are now being affected by urban sprawl. The remnant ecosystems maintain traces of its land use history. Therefore, the Piabas river basin, an important part of the Sertão Carioca, was analyzed herein with the aim of identifying the land use history and land cover transformations which occurred between 1968 and 2018. Aerial photos from 1968 and satellite images from 2018 were used to compare the land use and land cover mappings for both years on the same scale 1:10,000. In 1968, the Piabas river basin presented a predominance of agriculture (63%), where permanent and temporary crop and banana plantations could be observed. We also verified remnant forests (25%) and fruit trees planted around houses (4.3%) in the mountainous areas. In 2018, there was a predominance of an emerging submountainous pluvial forest ecosystem (47%). The forest expansion occurred due to the decline in banana cultivation and the decree that created the Pedra Branca State Park (PEPB). As a result, only 10% of the permanent and temporary crops remain. The urban area growth stands out (539%) in comparing the variations of this 50-year transformation, registering the city’s arrival in the Sertão. This urban sprawl mostly occurred in lowland ecosystems. The lack of a territorial planning that reconciles and prioritizes biodiversity conservation and agroecological practices in the urbanization process will affect the quality of life conditions of people who live in this region.

Keywords:
Emerging ecosystems; Vegetation cover; Natural regeneration; Historical ecology