Salinity Gradient of Plants in Salinity Gradient of Plants in the Hudson River Estuary, the Hudson River Estuary,

and their Application to and their Application to PaleoclimatePaleoclimate

Investigating Salt MarshesInvestigating Salt MarshesNASA Goddard Institute for Space StudiesNASA Goddard Institute for Space StudiesStudent: Carimaxy Benitez, Max LernerStudent: Carimaxy Benitez, Max Lerner

Mentors: Elsa Moralda, Miriam Jones, and Dee Mentors: Elsa Moralda, Miriam Jones, and Dee PedersonPederson

Scientist: Dorothy PeteetScientist: Dorothy Peteet

Research Question

•How do modern plants in a salinity gradient help us understand past climate change, specifically drought?

What are the characteristics of a Tidal Salt Marsh?

• A low coastal wetland influenced by tides• Plants that grow in salt marshes are tolerant

of two conditions: salt and water• Highly Productive Ecosystem, breeding

ground for many species (ie. fishes and birds)

• Protection against floods and storms: highly effective against soil erosion

• Cleans and filters water: salt marshes clean water by filtering sediments, heavy metals, and other toxins from upstream runoff.

What is Salinity?

• Salinity is the amount of dissolved salt per unit volume of sea water.

• It influences the types of organisms that live in a body of water and on the land fed by that water.

• The Hudson River is saline from the Hudson River Estuary to Newburgh, after which it is fresh water.

• Pollution slightly influences salinity.

Motions of the Water

Difference between a Low and High Marsh

Hudson River Estuary

Iona Marsh• Located within the Bear

Mountain Sate Park on the West shore of the Hudson River.

• This brackish, slightly salt river marsh 50 miles from the ocean receives its freshwater inflow from Doodletown Brook and the Hudson River.

• Dominated by Typha angustifolia, and Phragmites australis.

• Fresh to brackish-about 2 ppt

Piermont Marsh

• A brackish tidal marsh that is dominated by the common reed Phragmites australis, Spartina patens, Distichlis spicata, Spartina alterniflora, Scirpus americanus, and Scirpus robustos.

• Very sensitive to surface water salinity.

• Brackish-about 6 ppt

Jamaica Bay • Lies on the

southwestern tip of Long Island in the boroughs of Brooklyn and Queens, New York City.

• Saline to brackish, eutrophic (nutrient-rich) estuary.

• Low marsh is colonized by Spartina alterniflora while the high marsh is dominated by Spartina patens.

• Salt marsh- about 22 ppt

Percent data for Piermont Marsh pollen and spores

Data from Dorothy M. Peteet. and Dee Pederson.

Species Salinity TolerancesSpecies Salinity Tolerance Area LocationTypha latifolia Up to 0.5ppt High Marsh Stockport, Tivoli, Iona, PiermontPhragmites australis Up to 10ppt High Marsh Iona, PiermontTypha angustifolia Up to 15ppt High Marsh Stockport, Tivoli, Iona, PiermontScirpus americanus Up to 15ppt High Marsh PiermontScirpus robustus 3-22ppt High Marsh PiermontDistichlis spicata 15-35ppt High Marsh Piermont, Jamaica BaySpartina patens 1.2-39.1ppt High Marsh Piermont, Jamaica BaySpartina alterniflora 10-60ppt Low Marsh Piermont, Jamaica Bay

Pluchea purpurascens High High Marsh PiermontHibiscus moscheutos Low High Marsh PiermontPeltranda virginica Low High Marsh Iona

Conclusions

• By studying plant distributions along the Hudson River Estuary, we observed trends in salinity and water depth tolerances: less salt tolerant plants are upstream and more salt tolerant plants are found towards the mouth of the river.

• Changes in the pollen and seeds over time in Piermont marsh indicate times of drought with higher salinity.

• Understanding the magnitude and duration of droughts in the past is important for predicting future New York water limitations.