National Park Service

South Florida/Caribbean I&M Network (SFCN)

Mangrove-Marsh Ecotone Monitoring

SFCN crew established two mangrove forest plots and one gallery forest plot in Salt River Bay National Historical Park and Ecological Preserve (SARI)
SFCN crew established two mangrove forest plots and one gallery forest plot in Salt River Bay National Historical Park and Ecological Preserve (SARI).

Protocol

The SFCN forest vegetation monitoring protocol is currently under development.

Resource Briefs, Reports, and Data

There are currently no additional SFCN resource briefs, reports, or data concerning this monitoring topic.

For more information contact:

Kevin Whelan, Ph D.

Importance/Issues

Mangroves provide important juvenile fish and invertebrate nursery areas, habitat for birds and rare plants, as well as providing important shoreline protection. Over 50% of the mangroves in the Virgin Islands have been lost since 1950. Ecotones are transition zones between habitats and are generally dynamic locations for flora and fauna. Due to the sharp transition between habitats, tracking the position of ecotones can indicate the long-term trajectory of habitats. Understanding the physical conditions which drive changes in the ecotone location is critical for proper resource management. Examples of ecotones include mangrove- tidal marsh ecotones, mangrove-marsh-cypress, and mangrove-freshwater marsh ecotones. Ecotones are expected to move, for example, in response to changes in water management, sea level rise, and fire management. Tracking the position of mangrove-marsh ecotones can indicate the long-term trajectory of a wetland ecosystem, while accounting for regional water management changes and sea-level rise. Ecotone positioning can be effectively monitored by aerial photography. At selected sentinel sites in South Florida, ecotone movement across the landscape has been an important indicator for water management (e.g., "White Zone" in southeast Everglades).

Monitoring Objectives

  • Are ecotones shifting or changing in aerial size (widening or narrowing) due to physical conditions (e.g., sea level rise, hydrology, climate change, anthropogenic factors, fire, episodic metrological and storm wave events, etc.)?
  • What are the status and trends in plant community composition and structure?

Status & Trends

Figure 1. Digitization of the mangrove-marsh ecotone line at Ochopee was completed and installed with 16 ecotone marker locations. The digitizing process for the Shark Slough ecotone line was completed in FY13 and the ecotone markers should be installed in early FY14. Vegetation transects were installed and sampled at Mahogany Hammock and the Spreader Canal ecotone lines
Figure 1. Digitization of the mangrove-marsh ecotone line at Ochopee was completed and installed with 16 ecotone marker locations. The digitizing process for the Shark Slough ecotone line was completed in FY13 and the ecotone markers should be installed in early FY14. Vegetation transects were installed and sampled at Mahogany Hammock and the Spreader Canal ecotone lines.

In 2011 (FY11) and 2012 (FY12), SFCN installed ecotone markers at three mangrove-marsh ecotone monitoring areas: Taylor Slough, Mahogany Hammock, and Spreader Canal. In FY13, SFCN installed ecotone markers at a fourth mangrove-marsh ecotone monitoring area: along the Everglades (EVER)/Big Cypress (BICY) boundary at Ochopee (Figure 1).

A total of 16 ecotone markers were installed along the Ochopee ecotone line for the purpose of detecting future ecotonal change. The fifth and final mangrove-marsh ecotone monitoring area, located in southern Shark Slough, has been digitized. Initial scouting of the Shark Slough digitized line was completed by airboat and helicopter. The Ochopee and Shark Slough lines encompass over 120km of mangrove-marsh ecotone. Digitizing methodology combines remote monitoring with aerial imagery and on-the-ground field measurements in order to obtain a regional perspective. This project includes a 60m vegetation transect for each of the ecotone lines. In FY13, vegetation data was collected for two transects in EVER: one on the Spreader Canal line and the other on the Mahogany Hammock line (Figure 1). The SFCN staff spent 188 field hours working on this part of the vital sign in 2013 (FY13).

Approach

SFCN will coordinate with existing programs where appropriate, such as mangrove monitoring by Tom Smith of FIU.

  1. SFCN will evaluate ecotonal change using both aerial photography monitoring and field monitoring via belt transects or a series of plots set up along a longer transect. Revisit time is likely to be once every 5–10 years or after major disturbance event (fire, frost, hurricane) and administered in a rotating panel.

    Although porewater salinity was also identified as an additional indicator to monitor in this zone, this monitoring is deferred due to insufficient funds.

  2. SFCN will evaluate long-term change within plant communities via field plots revisited approximately once every 5–10 years. Soil Elevation Tables will be collocated with a subset of plots.

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Last Updated: March 28, 2017 Contact Webmaster