About the Project

Tidal marshes are facing tremendous pressures from accelerating rates of sea-level-rise. As sea level is rising, marshes are changing. This project was the first in-depth study to leverage a nationally-coordinated dataset generated by 20 National Estuarine Research Reserves across 85 marshes in 17 states to better understand how sea level rise is affecting tidal plant communities. The National Marsh Synthesis Team (NAMASTE) enacted a data synthesis framework that included in-depth conversations with all participating reserves to integrate local datasets into a standardized national dataframe. This dataframe was analyzed to quantify vegetation change across marsh characteristics at local, regional and national scales. The project produced site to national level trends, a data tool package aiding in analyzing tidal marsh data (e.g, data templates, coding script, coding user guides and training videos, data visualization apps, a GIS dashboard), and communication tools (e.g., illustrations, logo, website). As the NERR system continues to collect tidal marsh data, these tools can be used by reserve staff or collaborators to include newly collected data.

About the Resource

These companion reports provide detailed documentation of the methods used by the National Marsh Synthesis Team to evaluate climate change impacts (primarily sea-level-rise) on tidal marsh plant communities at both a national scale and a reserve-level scale. Summary results from the project’s analyses are also included in each report.

National-Level Methods and Results

A detailed analysis of National Estuarine Research Reserve (NERR) data, including methods and results, to evaluate impacts of sea level rise on tidal marsh plant communities at a regional and national scale.

Reserve-Level Methods and Results

A detailed analysis of National Estuarine Research Reserve (NERR) data, including methods and results, to evaluate impacts of sea level rise on tidal marsh plant communities at the local scale (e.g., reserve or site).

Interested in diving deeper into the project’s results? Check out Reserve-Level Analysis Outputs to learn more about the vegetative composition of the marsh at each reserve, and how it changes over time.

To view, files must be downloaded onto a local drive and opened in a web browser. Each reserve’s report includes:

1. Data exploration, including simple tables and summary figures, of each reserve’s vegetation data and associated metadata to summarize data attributes and help users identify issues related to QA/QC (e.g., accurate number of plots per year, zone assignment of plots, data outliers, etc.);
2. Univariate analysis in the form of linear mixed effects model (lme) used for each of several chosen response variables to estimate change through time and whether this differed by vegetation zone; and
3. Multivariate analysis (including NMDS, PERMANOVA, and SIMPER) to enable understanding of change through time at the community level, rather than at the level of an individual metric.

Also see the National Marsh Synthesis Technical Toolkit and Training for more resources on replicating the methods used during by the National Marsh Synthesis Team.