Tank bromeliads capture Saharan dust in El Yunque National Forest, Puerto Rico

Publication date: January 2018
Source:Atmospheric Environment, Volume 173
Author(s): Dana L. Royer, Kylen M. Moynihan, Carolyn Ariori, Gavin Bodkin, Gabriela Doria, Katherine Enright, Rémy Hatfield-Gardner, Emma Kravet, C. Miller Nuttle, Lisa Shepard, Timothy C.W. Ku, Suzanne O'Connell, Phillip G. Resor
Dust from Saharan Africa commonly blows across the Atlantic Ocean and into the Caribbean. Most methods for measuring this dust either are expensive if collected directly from the atmosphere, or depend on very small concentrations that may be chemically altered if collected from soil. Tank bromeliads in the dwarf forest of El Yunque National Forest, Puerto Rico, have a structure of overlapping leaves used to capture rainwater and other atmospheric inputs. Therefore, it is likely that these bromeliads are collecting in their tanks Saharan dust along with local inputs. Here we analyze the elemental chemistry, including rare earth elements (REEs), of tank contents in order to match their chemical fingerprint to a provenance of the Earth's crust. We find that the tank contents differ from the local soils and bedrock and are more similar to published values of Saharan dust. Our study confirms the feasibility of using bromeliad tanks to trace Saharan dust in the Caribbean.



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