Source or Sink
Is a working cattle ranch a carbon sink or source?
- Greenhouse gases trap heat in the atmosphere
- Three major greenhouse gases are carbon dioxide, methane, and nitrous oxide
- Carbon dioxide concentration in the air has increased by 30% since the 1940s due to burning of fossil fuels
- Concern about climate change has led to research on ways to reduce emissions and maximize uptake of greenhouse gases.
- Plants absorb carbon dioxide through photosynthesis
- Analysis of Buck Island Ranch production data documented emissions from MAERC’s cattle operation of 10,884 MT of CO2eq/yr with enteric fermentation responsible for 64%.
- Estimates of sequestration by Bahia grass pasture suggest that Buck Island ranch pastures take up 17,813 MT/year.
Current Research at MAERC
- Sequestration for other ecosystem types are needed – especially semi-native pastures and wetlands – as well as the effect of grazing on carbon dynamics.
- In collaboration with Cornell (Dr. Jed Sparks) and USDA ARS/University of Illinois (Dr. Carl Bernacchi), a new experiment was implemented in January 2013 at MAERC to refine on-site measurements of C sequestration and to measure methane fluxes.
- 5 eddy flux towers with methane sensors established in 2013 in 2 improved and 2 unimproved pastures (with and without cows) plus 1 wetland.
Why is this important?
- Understand how grazing land contributes to greenhouse gas dynamics – subtropical Florida grasslands have not been well studied
- Inform land managers of practices that can minimize fluxes to the atmosphere or even maximize uptake of greenhouse gases
- Eddy flux tower data and soil chamber data will provide full greenhouse gas accounting for a working ranch and differentiate among methane and carbon dioxide from cattle, pastures, and wetlands.
- This has policy implications for cattle greenhouse gas management and carbon payment for ecosystem services.
Click here to read about an analysis of Buck Island Ranch emissions.