1. Response of vegetation to hydroclimate changes in northeast Brazil over the last 130 kyrs.
- Author
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Piacsek, Patricia, Behling, Hermann, Stríkis, Nicolás M., Ballalai, João M., Venancio, Igor M., Rodrigues, Alice Maria da S., and Albuquerque, Ana Luiza S.
- Subjects
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VEGETATION dynamics , *WETLANDS , *TROPICAL dry forests , *MARINE sediment analysis , *PRECIPITATION anomalies , *CORRIDORS (Ecology) , *CYCLOSTRATIGRAPHY - Abstract
In this paper, we use palynology and geochemical proxies to reconstruct late Quaternary vegetation changes within the hydrographic basin of Parnaíba, Northeast Brazil, over the last 130 kyrs. Findings are based on the analysis of a marine sediment core (GL-1248) retrieved from the western equatorial Atlantic (0°55.2′S, 43°24.1′W), close to the coast. Geochemical proxies (Fe/K ratio and Ɛ Nd) indicative of soil erosion match changes in reconstructed vegetation, suggesting a dynamic pattern of hydrological disturbances and ecosystem evolution. Given that reconstructed vegetation does not present the same response to precipitation anomalies on the millennial scale, we sought the main drivers of vegetation changes in the Parnaíba watershed. Results indicate that vegetation succession was primarily influenced by austral insolation from March to May, which triggered changes in the pioneer vegetation types. Our study improves the knowledge of tropical vegetation dynamics in an orbital framework, suggesting 23-kyr precessional cycles as the main driver of landscape evolution in Northeast (NE) Brazil. We also infer that such past climate change events may have been a key causal factor of the high biodiversity of the Neotropics, mediated through the biological exchange of the Amazon and Atlantic rainforest species via ecological forest corridors in the semi-arid Northeast Brazil. • We discuss vegetation change and how it reflects hydrological changes within the Parnaíba Basin, northeastern (NE) Brazil, over the past 130 kyrs • Geochemical proxies (Fe/K ratio and ƐNd) in core GL-1248 are synchronous with reconstructed vegetation patterns, highlighting periods of enhanced or reduced local soil erosion during hydrological disturbances • We define three major vegetation groups (tropical dry forest, lowland rainforest, and wetland), and the discrepancy in water requirements between tropical dry forests and lowland rainforests is discussed • Analysis of the hydroclimatic mechanisms in NE Brazil that triggered the succession of vegetation during glacial phases is discussed [ABSTRACT FROM AUTHOR]
- Published
- 2022
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