Holocene vegetation and soil changes in the driest region of caatinga dry forest – phytolith contribution

Fonseca C.F.; Beninca C.G.; Isminio D.A.L.; Bennert A.; Ruiz Pessenda L.C.; de Queiroz R.T.; Xavier R.A.; de Souza B.I.; Calegari M.R.; de Souza J.J.L.L. · Catena (2025) · DOI: 10.1016/j.catena.2025.109016

Resumen

This study investigates Holocene environmental changes in the driest region of the Caatinga dry forest, using a multiproxy approach integrating phytolith analysis, isotopic data (δ13C, δ15N), radiocarbon dating, and comparisons with regional paleoenvironmental records. Three soil profiles from the Borborema Plateau were analyzed to study the vegetation dynamics (time and space) and soil formation processes. Three distinct environmental moments (EM) were identified since the last approximately 8 cal kyr BP, marking transitions from humid to semiarid conditions in the study area. EM I (before 3.5–2.7 cal kyr BP) represents the wettest phase, with a predominance of C3 plants and increased soil organic matter accumulation. EM II (2.7–1.1 cal kyr BP) marks a drier phase, with the expansion of C4 grasses and reduced tree cover, signaling the establishment of Caatinga vegetation. EM III (1.1 cal kyr BP–present) indicates environmental stabilization, with vegetation and soil characteristics resembling current conditions. The findings highlight the role of climate fluctuations, sedimentary processes, and soil development in shaping the present-day Caatinga, reinforcing the importance of local landscape features in moisture retention. These results contribute to understanding the long-term environmental history of the region and its implications for vegetation resilience and land-use strategies in semiarid environments.

Instituciones: Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas