1. Carbon Fixation and Storage in Mangrove Forests University of Virginia
Jay Zieman, Jose Fuentes, Paolo D’Odorico, Deborah Lawrence, Mark White
University of Virginia

2. Coastal Interface Ecosystems
These consist of Seagrasses, Mangroves, and Salt Marshes
They are among the most productive ecosystems on earth.
Salt marshes are temperate.
Mangroves are tropical and subtropical.
Seagrasses run from the tropics to the boreal regions.

3. Mangrove Functions
Naturally High Primary Productivity – One of the most productive tropical ecosystems
Very High Habitat Values
Sites of Nitrogen Fixation
Rich Fisheries
Stabilization of Coastal Interface

4. Mangrove Losses Non-sustainable harvest for charcoal Deforestation for
- Development – Housing and Industrial
- Shrimp Ponds
- Cattle Ranching
- Tourism

5. Forest Response: Why Mangroves ?
Terrestrial forests sequester carbon from colonization to maturity.
When most terrestrial forests mature, they become carbon neutral -- Cin = Cout.
Exceptions: Mangroves; Boreal Conifer Forests
With sea level rise mangrove forests can sequester carbon, in the form of peat, indefinitely
The mature Florida mangroves have stored up to 6m of peat -- storing C for thousands of years

6. Distribution Pattern
Notice the distibution pattern. You can see that quite clearly Red Mangrove are going to be most important to fish. Black Mangrove do have a limited prop root system but not as extensive

7. Tall Mangroves in the Western Florida Everglades

8. Measuring Mangrove Productivity and Carbon Assimilation
Until year old manual methods used which widely underestimate assimilation – leaf litter fall and trunk diameter.
No belowground estimates
Since 2004, state-of-the-art: Eddy Covariance Flux Towers.

9. Mangrove distribution in Florida Everglades
Miami
Shark River
Slough
Taylor
Slough
Flux tower

13. Seasonal differences in carbon assimilation
Late winter/Spring
Summer
Reduced nighttime respiration and
maximum midday photosynthesis
Greater nighttime respiration and
midday photosynthesis deactivation

14. Carbon Assimilation Compared to FluxNet Sites
Amazonian forest (Malhi et al.)
Everglades mangrove forest for 2004
From: Baldocchi et al. 2001

15. New Findings
Everglades’ mangroves assimilated atmospheric carbon dioxide at the rates of 7-9 t C ha-1 during seasons.
Diffuse sunlight in humid mangrove canopies results in elevated light use efficiencies, meaning greater amounts of carbon assimilation for a given light level.

16. Trajectory and wind speed at landfall for hurricane Wilma in October 2005
Trajectory of hurricane Wilma during October 2005
Wind speed associated with October 2005

17. Hurricane Wilma destroyed nearly 30 percent of trees

18. Mangrove defoliation resulting from hurricane Wilma in October 2005
Courtesy of Thomas J Smith, USGS

19. Flux tower in the western Florida Everglades
Tower destroyed by hurricane Wilma
Tower installed after hurricane Wilma

20. Ecosystem Response to Hurricane Wilma
November
March
Averaged diurnal fluxes of carbon assimilation for November reveal equivalent levels of nighttime respiration, but reduced carbon fluxes during the day. The reduced carbon fluxes following Wilma are attributed to reduced canopy foliage, as an estimated 30% of the trees in this area were destroyed in the hurricane. We expected increase respiration as time progressed due to the great number of fallen trees in this area as a result of Wilma.

21. Panama vs Florida Studies
In Florida the carbon assimilation was measured in before (pristine wilderness) and after (heavily damaged) studies
In Panama, we would propose two towers, one in a pristine area as a control and one in an area undergoing restoration
Mangroves in Panama are ideally suited for carbon sequestration as they undergo fewer natural stresses that the subtropical mangroves

22. Motivation for future research in Panama
The ability of mangrove forests to provide the services of carbon sequestration remains largely unknown. Traditional approaches only provide carbon stocks and cannot provide net ecosystem carbon exchange.
Tower-based observing systems allow us to investigate carbon exchange processes at different time scales.
These field observations permit us to investigate the ecosystem response to on-going climate change, sea level rise, and disturbances.
With continuous and long-term data sets, we can quantitatively assess the contribution of mangrove ecosystem restoration to carbon assimilation.