Sentinel Site Synthesis for Four New England Reserves
Goal
Synthesize SWMP data and identify significant changes over time in plant species abundance and marsh surface elevation, distinct from annual variation.
Project Period
September 2018 to November 2019
Summary
Sea level rise and climate change present major threats to salt marshes nationwide. Research reserves responded by establishing Sentinel Sites to track and understand impacts on marsh vegetation and sediment accretion. However, most reserves had not analyzed their data and no regional syntheses had been attempted.
At the outset of this project, the researchers solicited questions from saltmarsh scientists and managers. Among them were:
- Have there been significant changes in individual salt marshes? If so, how are these changes reflected throughout New England?
- What are the best methods for assessing changes in plants and elevation that are relatively unaffected by natural annual variation?
In this project, researchers combined monitoring data from 8 salt marshes in 4 New England reserves, collected between 2010 and 2017, to identify changes in plant abundance and surface elevation over time.
Graphic analysis, followed by univariate and multivariate statistics, revealed changes in plant communities and marsh elevation over time and across most sites.
New England salt marshes are becoming wetter, with low marsh areas losing plant cover and high marsh areas becoming more like low marsh over time. Southern New England salt marshes, where tidal range is smaller, showed a more pronounced change.
Products
- Report: Synthesizing NERR Sentinel Site data to improve coastal wetland management across New England (PDF)
- Fact Sheet
- "How to" Guide for Synthesizing NERR Sentinel Site Data
- A Guide to Integrate Plant Cover Data from Two Different Methods: Point Intercept and Ocular Cover
- Reserve-specific database in common format
- Monitoring recommendations
Partners
- UNH Jackson Estuarine Laboratory (project lead)
- Great Bay NERR (technical lead)
- Wells NERR (collaborative lead)
- Narragansett NERR
- Waquoit Bay NERR
Funding
$105,298 NERRS Science Collaborative catalyst grant to David Burdick, University of New Hampshire