VEGETABLE COVERAGE, ANTHROPOGENIC ACTION, AND PALEOCLIMATES IN THE CAATINGA

COBERTURA VEGETAL, AÇÃO ANTROPOGÊNICA E PALEOCLIMAS NA CAATINGA

COBERTURA VEGETAL, ACCIÓN ANTROPOGÉNICA Y PALEOCLIMA EN LA CAATINGA

Abstract

The Caatinga is dominated by a semiarid climate and a high plant biodiversity dealing with anthropogenic disturbance and climate change. Previous studies suggest that Caatinga became a completely soil-water pulse-dominated forest in response to reduced water availability at the end of the last ice age, around 10 cal kyr BP. This work aimed to identify vegetative and climatic evolution, and the human influence in the Cariri region, one of the driest parts of Brazil. We sampled soil in a temporal pond to identify pollen. The testimony is 170 cm in lenght and achieves 6,216 cal yr BP at the base. Pollen analysis indicates the presence of taxa representative of humid climates, between 6,216 and ca. 5000 cal yr BP, like Azolla, followed by implantation of Caatinga's modern configuration from ca. 4,900 cal yrs BP. After 2,700 cal yr BP, humid episodes occurred, possibly related to the El Niño - La Niña variation across the region, marked by increased algae and aquatic herbs concentrations. The occurrence of human activity species like Caryocar, Dioscorea, Spondias, and Licania suggest possibly landscape manipulation by pre - Columbian populations, and exotic Pinus and Prosopis reveal changes in the tree cover caused by European colonization in the Caatinga.

Keywords: Anthropocene; Dry Forest; Paleogeography; Semiarid Region; Sedimentology; Lakes; Lagoons & Swamps