You are here

Everglades carbon dynamics

Status: 
Action
Dates: 
January, 2008

View of the Florida Everglades.
View of the Florida Everglades.

Florida Everglades Ecosystems

The objective of this project is to quantify seasonal patterns of carbon fluxes (CO2 and CH4) in two dominant marsh types in the Florida Everglades: short- and long- hydroperiod Everglades marshes. The Taylor Slough (short-hydroperiod) and Shark River Slough (long-hydroperiod) exhibit major hydrogeomorphological variations that lead to measurable differences in species form and composition, productivity, nutrient availability, and ecosystem sensitivity to climate. The strong spatial and temporal gradient in water flow has formed a unique network of subtropical freshwater and coastal wetland ecosystems and provides a unique opportunity to examine ecosystem function with differing hydroperiods while still experiencing similar climate.

Map of study areas in the Everglades.
Map of study areas in the Everglades.
Freshwater marsh ecosystems in Taylor Slough are subject to a greater range of water level change, which has led to the development of marl substrate and sparse sawgrass communities. Unlike the short-hydroperiods observed in Taylor Slough, Shark River Slough typically remains inundated with moisture throughout the year, except in years with below average precipitation. The northern part of Shark River Slough is dominated by sawgrass peat marsh that transitions to a brackish marsh with a mixture of sparse sawgrass and dwarf mangroves, and then to a saltwater coastal mangrove forest. The Everglades mangrove ecotone lies at the interface of land (i.e., freshwater marsh) and sea and has been one of the areas most impacted by changes in freshwater flows.

Approach

This project combines whole-system estimates of net carbon exchange, remote sensing data, and simulation modeling to quantify the drivers of wetland ecosystem carbon dynamics. The Eddy Covariance technique is being used to estimate net carbon exchange.

Key Findings

  • During the wet season, water depth limits photosynthesis and thus net CO2 uptake at Taylor Slough. This occurs through a reduction in exposed leaf area and reduced ecosystem respiration at the Shark River Slough leading to greater CO2 uptake (Jimenez et al. 2012; Malone et al. 2014).
    Eddy Covariance tower in the Everglades.
    Eddy Covariance tower in the Everglades.
  • As La Niña phases are concurrent with drought years and extended dry seasons, the Taylor Slough became a greater sink for CO2 on an annual basis (-11 to -110g CO2 m2 yr-1) compared to El Niño and neutral years.
  • Shark River Slough is a small source for CO2 annually (1.81 to 80 g CO2 m2 yr-1), except in exceptionally wet years that are associated with El Niño (-16 g CO2 m2 yr-1; Malone et al. 2014).
  • Under 100 years of current climate and atmospheric CO2 concentrations (380 ppm), Everglades freshwater marsh ecosystems had near CO2 neutral status.
  • Higher atmospheric CO2 concentrations made a small enhancement in the sink capacity of the sloughs.
  • Rising temperatures reduced net ecosystem exchange rates by less than 100 g C m-2 century-1.
  • Shifts in precipitation patterns altered cumulative net ecosystem exchange by less than 500g C m-2 century (Malone et al., 2015).

Publications

Malone, Sparkle L. ; Staudhammer, Christina L. ; Loescher, Henry W. ; Olivas, Paulo ; Oberbauer, Steven F. ; Ryan, Michael G. ; Schedlbauer, Jessica ; Starr, Gregory , 2014
Malone, Sparkle L ; Starr, Gregory ; Staudhammer, Christina L. ; Ryan, Michael G. , 2013
Jimenez, K. L. ; Starr, G. ; Staudhammer, C. L. ; Schedlbauer, J. L. ; Loescher, H. W. ; Malone, Sparkle L ; Oberbauer, S. F. , 2012

Other

Additional Publications

Schedlbauer, J.L., Oberbauer, S.F., Starr, G., & Jimenez, K.L. 2010. Seasonal differences in the CO2 exchange of a short-hydroperiod Florida Everglades marsh. Agricultural and Forest Meteorology, 150:7-8, 994-1006, doi:10.1016/j.agrformet.2010.03.005.

Schedlbauer, J.L., Oberbauer, S.F., Starr, G., & Jimenez, K.L. 2011. Controls on sensible heat and latent energy fluxes from a short-hydroperiod Florida Everglades marsh. Hydrology, 411, 331-341, doi:10.1016/j.jhydrol.2011.10.014.

Schedlbauer, J.L., Munyon, J.W., Oberbauer, S.F., Gaiser, E.E., & Starr, G. 2012. Controls on ecosystem carbon dioxide exchange in short- and long-hydroperiod Florida Everglades freshwater marshes. Wetlands, doi:10.1007/s13157-012-0311-y.


Malone, Sparkle. 2014. Hydrology drives Everglades ecosystem function: Implications for ecosystem vulnerability to drought, energy balance, climate teleconnections, and climate change. (Dissertation) University of Alabama. Available upon request.

Malone, S.L., Staudhammer, C.L., Oberbauer, S.F., Olivas, P., Ryan, M.G., Schedlbauer, J., Loescher, H.W., & Starr, G. 2014. El Niño Southern Oscillation (ENSO) amplifies precipitation extremes, enhancing CO2 exchange rates in freshwater marsh ecosystems in the Florida Everglades. PlosOne, 9(12): e115058. doi:10.1371/journal.pone.0115058.

Malone, S.L., Keough, C., Staudhammer, C.L., Ryan, M.G., Parton, W.J., Oberbauer, S.F., Olivas, P., Schedlbauer, J., Starr, G. (In review). Ecosystem persistence in the face of climate change: A case study from the freshwater marshes of the Florida Everglades.



Principal Investigators:
Gregory Starr - University of Alabama
Stephen Oberbauer - Florida International University

Co-Investigators:
Christina Staudhammer - University of Alabama