Paper No. 5
Presentation Time: 9:00 AM-6:00 PM
INFLUENCE AND IMPACT OF PHRAGMITES AUSTRALIS ON PIERMONT MARSH
LEAL, Berenice1, PEREZ, Cindy2, RAMIREZ, Nancy2, GALLARDO, Tatiana2, NAHAR, Tazrin2 and KHANAM, Nusrat2, (1)Smith College, 8292 1 Chapin way, Northampton, MA 01063, (2)The Young Women's Leadership School of East Harlem, 105 East 106th Street, Manhattan, NY 10029, bleal@smith.edu
Piermont Marsh is a brackish marsh occupying 1,017 acres, which is located approximately 40 km North of New York City and west of the Hudson Bank. Piermont Marsh has an abundant supply of plant species that contributes to its diversity. The biodiversity of Piermont Marsh includes
Phragmites australis, Typha angustifolia,
Spartina alterniflora, and
Hibiscus palustris L. An invasive genotype of Common Reed,
P. australis, has colonized at least 75% of the marsh with its rhizomes system stretching about 12 meters and up to 1.5 centimeters in diameter. It is not well-established by what mechanisms
P. australis has been able to outcompete the native species, thus altering the biodiversity of the marsh. The objective of this project was to determine the impact and influence of
P. australis on the native vegetation of Piermont, and to investigate mechanisms underlying its dominance.
We report on succession plots that have been occupied for four summers and an experimental cut-back in a meadow that has transitioned from Spartina alterniflora to P. australis during the study period. Initial results show a relatively constant rate of growth of P. australis across several diverse settings, pristine vs. disturbed, Salt Hay vs. typha, etc. We place these succession plot results in the context of an ongoing study of the Piermont Marsh ecology that includes measurements of nutrient concentrations, surface sediment accumulation, fish concentrations, phytoplankton diversity, and soil carbon. We discuss alternative theories regarding the underlying mechanisms of colonization and the impact of colonization on the Marsh as habitat for diverse floral and faunal communities.
All samples were collected, processed and analyzed by NYC public high school students from the Lamont-Doherty Earth Observatory Secondary School Field Research Program.
