Sentinel Site for Climate Change

Sentinel Site for Climate Change Research in Tivoli Bays

The Reserve has initiated a long-term study that will establish the Tivoli Bays as a NERRS Sentinel site Site for assessing the impact of climate change stressors on estuaries. The goal of this study is to evaluate the ecological impacts of sea level change and increased storm surges on submerged aquatic vegetation and emergent tidal marsh habitat.

In the Hudson River Estuary, the anticipated increase in water level of about 50 cm by the end of this century is very close to the existing elevation difference between the vegetated lower intertidal community and the Typha angustifolia (cattail) high marsh community. With sea level rise, a significant conversion of cattail-dominated high marsh to a vegetated lower intertidal community is anticipated. Within submerged aquatic vegetation (SAV) beds, increased water levels and turbidity are expected to favor invasive Trapa natans over native Vallisneria americana. There are significant differences in plant productivity, organic matter dynamics, and biogeochemical processes among these freshwater tidal vegetation classes, so changes in cover may affect overall wetland function.

Four main protocols have been implemented to address these research questions:

Vegetation monitoring in Tivoli South Bay

•  Vegetation monitoring plots along transects have been established to analyze the current distributions of emergent marsh and SAV communities with respect to elevation, tidal range, and invasive species composition.

Installation of a groundwater well for deployment of tide gauges

• Tide gauges in groundwater wells have been installed to study the response (in terms of spatial distribution and community composition of emergent marsh and SAV habitats) to long-term changes in local water levels and tidal inundation patterns.

Surface Elevation Table (SET) pin reading

• Surface Elevation Tables (SETs) have been installed to study the response of sediment elevation of emergent marsh habitats to long-term changes in local water levels and tidal inundation patters.

Elevation surveys along a marsh transect

• Elevation surveys of all study components have been performed to establish a local geodetic network and provide vertical control of all vegetation data, water level data, and sediment level data along the elevation gradient of the study transects.