Home and building construction practices often remove, destroy, or significantly impact the health of native soil systems in urban and suburban areas, and the high carbon sequestration rates and fibrous root systems of perennial grasses are one of the most effective ways of returning soil structure to a more natural state. Plants, including grasses, do this by capturing atmospheric carbon dioxide and using solar energy to convert it into complex carbon compounds, primarily sugars. This carbon can be deposited into stems, leaves, and roots where it is used for growth and development, but it can also be captured in the soil as aging plant roots die off and new ones are produced, thereby removing carbon from the atmosphere.
There are an estimated 40 – 50 million acres of urban grasslands in the United States alone, and recent research indicates that grasses managed in urban settings are a net carbon sink for atmospheric carbon dioxide even after accounting for maintenance emissions. Furthermore, carbon sequestration has been proposed to slow atmospheric carbon dioxide enrichment, and soil is the second largest global pool of carbon. Want to learn more about how lawns and other grasses capture atmospheric carbon dioxide? Check out some of the highlights from recent research below!
- Carbon modeling research of a typical suburban home on a half-acre lot, landscape beds, shrubs, trees, and a grass lawn indicate that between 81 and 90% of the carbon captured in the landscape is captured by the lawn.
- In a recent research study of a typical metropolitan area, low and medium-density residential lots account for over 50% of carbon captured in urban green spaces.
- In the same study as above, residential lots and open spaces such as golf courses, parks, and cemeteries had the highest carbon density per unit area when compared to other land-cover classes such as meadows and deciduous forests.
- Research suggests that grasses can accumulate and deposit carbon into the soil by approximately one-half ton of carbon per acre year for 30 to 40 years.
- Net carbon sequestration rates in urban lawns have been estimated at between 200 and 1,800 lbs of carbon per acre per year.
- Research modeling of carbon sequestration by lawns indicates that lawns in the United States alone can sequester between 12.5 million and 95 million tons of atmospheric carbon dioxide per year. That’s equivalent to the annual emissions of between 2.4 million and 18 million typical passenger vehicles.
- The leaf density of grass ranges from 75 million to over 20 billion shoots per hectare which is equivalent to 3.5 million to over 900 million shoots in a typical 5,000 sq. ft. lawn.
- The total root length in a typical lawn has been shown to range from 66 to over 3000 meters of root length per liter of soil. That’s equivalent to 0.2 to 1.8 miles of root length per liter of soil.