Estuarine Shifts in Organic Matter and Plant Communities in the Meadowlands and lower Hudson River Marshes

European Impact

 

Peteet, D. M. , NASA/GISS & Lamont Doherty Earth Observatory, Palisades, NY

peteet@ldeo.columbia.edu, 845-365-8420

Pederson, D. Lamont Doherty Earth Observatory, Palisades, NY

Kleinstein, D., Columbia University, NY, NY

 

Sediment cores spanning the last millennium from Hackensack Meadowlands and the lower Hudson estuary marshes are compared. The Meadowlands pollen signature prior to European impact is unique in that the marsh is dominated by sedge pollen, while grasses and trees, primarily oak (15-20%) and pine (10%) play a minor role. In contrast, the Hudson marshes are dominated in Piermont by tree pollen of oak (30%) and pine(30%), and Staten Island and Jamaica Bay by oak (40%) and pine (20%). This dominance of Cyperaceae in the Meadowlands marshes is also reflected by the macrofossils in the sediment, comprised of Cyperus, various Scirpus types, Eleocharis, Cladium, and Carex. All of the marshes reveal dramatic increases in Ambrosia with the advent of Europeans to the region. Along with this Ambrosia rise are increases in grasses in the more saline marshes, while Typha and Phragmites rise dramatically in the Meadowlands and Piermont. Uppermost sediments in the Hackensack Marsh are dominated by Phragmites seeds, while Jamaica Bay marshes reveal mostly seeds of Salicornia. Organic matter increases in all of the marshes after European impact, and we are investigating the reasons for this striking increase to the present.