From Salt Marsh to Mangroves

Monitoring emergent vegetation in the Reserve

Salt Marsh

System-Wide Monitoring Program

Measures long-term changes to salt marsh vegetation communities at several permanent stations throughout the Reserve.


Measures millimeter-increment long-term changes to salt marsh surface elevation and sediment accretion at several permanent stations throughout the Reserve.


Long-term monitoring of ecological changes to emergent intertidal habitats within the salt marsh-mangrove ecotone in response to mangrove population expansion.

Data Trends

Dominant salt marsh vegetation species within the Reserve averaged across all sites each sampling season.

Get Vegetation Data

Featured Project: “WETFEET

A federally-funded National Science Foundation project

Samantha Chapman, PhD

Associate Professor, Villanova University
Principle Investigator

Warming Ecosystem Temperatures In A Florida Ecotone Experiencing Transition

The existence of marsh habitats depends on their ability to build up soil in order to keep up with rising seas. The roots of plants found in marsh habitats “push up” the soil helping to increase the marsh elevation. However, with the oxygen provided by the marsh plants, bacteria in the soil are able to decompose the debris, resulting in decreasing marsh elevation.

Schematic of how mangrove invasion and warming may alter belowground processes and wetland surface elevation.

This project will investigate how warming temperatures and invading plants alter marsh elevation at sites along Florida’s east coast. In order to test this, the team will install warming chambers. The chambers will be placed over vegetation plots containing pure marsh vegetation (e.g., smooth cordgrass) or a mixture of marsh vegetation and mangroves. For three years the team will measure and compare root growth, root biomass, above-ground biomass, decomposition rates, and surface elevation among the plots.

  1. How do mangrove invasion and warmer temperatures alter surface elevation change and wetland persistence relative to future sea level?
  2. How does mangrove invasion into salt marshes alter root productivity and organic matter decomposition, key mechanisms that control coastal wetland viability?
  3. How will warmer temperatures alter root productivity and organic matter decomposition in mangrove-marsh ecosystems?
The warming chambers are placed in three sites within the boundaries within the Reserve. The criteria for these sites were to include: Black mangroves (Avicennia germinans), younger, solitary mangroves approximately two feet tall, and surrounding vegetation of smooth cordgrass (Spartina alterniflora) or sea pickle (Batis maritima) only.

Warming chamber installed in Batis maritima marsh within the GTM Research Reserve for the WETFEET project.

  • Samantha Chapman, Matt Hayes, and Adam Langley (Villanova University),
  • Mark Hester (University of Louisiana Lafayette),
  • Jim Morris (University of South Carolina),
  • Candy Feller (Smithsonian Environmental Research Center),
  • Nikki Dix (GTM Research Reserve).
  • Please do not disturb the warming chambers. Specific measurements of natural processes need to be recorded.
  • There will be constructed platforms through the marsh to protect other vegetation and ensure accurate measurements of soil elevation changes. Please do not step on or move the constructed platforms.
  • If the warming chambers have blown away or are found outside of the sites, please contact the GTM Research Reserve at 904-823-4500 or email with a photo and location description.