Assessing Net Carbon Sequestration on Urban and Community Forests of Northern New England

By Daolan Zheng, Mark J. Ducey, and Linda S. Heath

Durham, NH (2013) – Urban and community forests play an important role in the overall carbon budget of the USA. Accurately quantifying carbon sequestration by these forests can provide insight for strategic planning to mitigate greenhouse gas effects on climate change. This study provides a new methodology to estimate net forest carbon sequestration (FCS) in urban and community lands of northern New England using ground based forest growth rates, housing density data, satellite derived land cover and tree canopy cover maps at the county level.

Researchers estimated that the region’s urban and community forests sequestered 603,200 tC/yr ($38.7 million/yr value), contributing 8.2% of regional net forest ecosystem carbon sequestration. The contributions at the state level varied from 2.3% in Vermont to 16.6% in New Hampshire with substantial variation at the county level up to 73.3%.

Spatially, contribution rates from urban and community forests at the county level were much higher and concentrated in southeast portion of NH and southwest portion of ME along the coast, and decreased toward inland areas. Researchers estimated net FCS compared reasonably with gross FCS in the region reported by a previous study.

On average, the net FCS was 34.2% lower (varying from 41.9% lower in Vermont to 28.1% lower in Maine) than the corresponding gross FCS mainly because of a lower regional average net growth rate used in this study, compared to the national average gross carbon sequestration rate used in the previous study.

Source: Assessing net carbon sequestration on urban and community forests of northern New England, USA,” Urban Forestry & Urban Greening, 2013.