Methods for Managed Wetland Systems
Effective beginning 5/20/2025: Please note this site is under review and content may change.
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- Recommended Citations
Ogle, S.M., P. Hunt, C. Trettin. 2024. Chapter 6: Quantifying greenhouse gas sources and sinks in managed wetland systems. In Hanson, W.L., C. Itle, K. Edquist. (eds.). Quantifying greenhouse gas fluxes in agriculture and forestry: Methods for entity-scale inventory. Technical Bulletin Number 1939, 2nd edition. Washington, DC: U.S. Department of Agriculture, Office of the Chief Economist.
Chapter 6: Quantifying Greenhouse Gas Sources and Sinks for Managed Wetland Systems
Wetlands occur across most landforms, existing as natural unmanaged and managed lands, restored lands converted from another use (typically agriculture), and constructed systems for water treatment, such as anaerobic lagoons. All wetlands sequester carbon and are a source of greenhouse gases.
The National Wetlands Inventory, available through the U.S. Fish and Wildlife Service, provides information on wetland habitats in the United States via the wetlands geospatial dataset and wetland status and trends reports, both determined via remote sensing technology. Wetlands can be broadly classified into five major systems: marine, estuarine, riverine, lacustrine, and palustrine. Four of those systems (marine, estuarine, riverine, and lacustrine) are open-water bodies and are not considered within the methods described in this guidance. Palustrine wetlands encompass the wetland types occurring on the land and are further classified by major vegetative life forms and wetness or flooding regime.
This chapter provides the following methods for estimating carbon stock changes and methane (CH4) and nitrous oxide (N2O) emissions from naturally occurring wetlands and restored wetlands on previously converted wetland sites:
- Biomass carbon
- Soil carbon, N2O, and CH4 in wetlands
The data required to apply these methods range from basic information on soils, vegetation, weather, land use, and management history to data on fertilization rates or drainage conditions. While some of these data are operation-specific and must be provided by the entity, other data can be obtained from national databases, such as weather data and soil characteristics.
