Working Trees for Carbon Cycle Balance Agroforestry: Using trees and shrubs to produce social, economic, and conservation benefits.

Carbon based energy sources like coal, gas and oil all originated from the conversion of sunlight energy by plants. A dominant consideration for rebalancing the global carbon cycle is to find ways to promote the increased growth of trees and shrubs. In that agricultural activities occur on approximately half of the land in the contiguous U.S., much of the opportunity to store carbon through afforestation will occur on farms and ranches.

Agroforestry does not convert agricultural land to forests, but rather leaves the land in production agriculture, while integrating trees into farm and ranch operations to accomplish economic, environmental, and social goals. Several agroforestry practices can lead to substantial storage of carbon and removal of atmospheric carbon dioxide:

Windbreaks - store carbon while also protecting farmsteads, livestock, roads, people, soils, and crops. Field windbreaks reduce evaporation and plant transpiration rates such that per field crop yields are typically improved, even though a portion of the field has been converted to windbreaks. Optimal tree planting levels have been estimated at 5 percent of the cropped field (Brandle et al. 1992).

There are 185 million acres of tilled land in the Great/Central Plains. Planting only 2.5 percent of this field area to tree windbreaks would span 1.3 million miles (30-ft width) and cover 4.6 million acres. As trees mature, more carbon is stored. Carbon dioxide removal, based on 20-year old planting, would exceed:

Additional CO2 reductions would result from: