Agroforestry's Role In Greenhouse Gas Mitigation In the United States.

Agroforestry, an ecologically and environmentally sustainable land use, offers great promise to mitigate greenhouse gases, in particular CO₂.  This presentation will provide an overview of C sequestration opportunities available under various agroforestry practices in the United States.  Since accurate land area under agroforestry is not available, the potential C sequestration is estimated based on several assumptions about the area under different agroforestry practices in the US: 1.69 million ha under riparian buffer, 17.9 million ha (10% of total cropland) under alley cropping, and 78 million ha under silvopasture (23.7 million ha or 10% of pasture land and 54 million ha of grazed forests).  Based on these, we estimate C sequestration potential for riparian buffers, alley cropping, and silvopasture in the US as 4.7, 60.9, and 474 Tg C yr^–1, respectively.  Establishment of windbreaks to protect cropland and farmstead could sequester another 8.79 Tg C yr^–1.  Thus, the potential for C sequestration under agroforestry systems in the US is estimated as 548.4 Tg yr^–1.  The C sequestered by agroforestry could help offset current US emission rate of 1600 Tg C yr^–1 from burning fossil fuel (coal, oil, and gas) by 34%.  These preliminary estimates indicate the important role of agroforestry as a promising CO2 mitigation strategy in the US, and possibly in other parts of North America.