Dendrochronological records of a pioneer tree species containing ENSO signal in the Pantanal, Brazil

Abstract

The Pantanal is subjected to a monomodal and predictable flood pulse of low amplitude which is the main driver of ecological processes and patterns of biodiversity in one of the largest wetlands in the world. Nevertheless, little is known about how the plant communities of this wetland respond to predicted climate changes. In this paper, we used tree-ring analyses of Vochysia divergens Pohl (Vochysiaceae), a light-demanding pioneer species that occurs in periodically or short-term flooded areas in the Cerrado and Pantanal. We evaluated the influence of precipitation and water level on the growth rates of this species, where it occurs, to determine how local climatic variables (precipitation and water level) influence tree growth and how a large-scale climatic driver in the tropical eastern Pacific (El Niño events) could affect both tree growth and local climate in the northern region of the Pantanal. The indexed tree-ring chronology of eight individuals had a significant relationship with annual precipitation (r = 0.22). Interannual variations of the water level did not affect tree growth. Sea surface temperature anomalies of the El Niño 1 + 2 region lead to decreased precipitation in the northern region of the Pantanal, resulting in decreased diameter increments of V. divergens. Our results demonstrated the dendrochronological potential of V. divergens for analyzing climate–growth relationships for developing climate-sensitive proxies for reconstructing past climatic conditions. © 2018, Botanical Society of Sao Paulo.