Efficient assessments of urban tree planting potential within or near the southern Piedmont region of the United States
Urban forest carbon offset projects have the potential to draw substantial amounts of carbon dioxide (CO2) from the atmosphere, increase green space, and possibly generate revenue for landowners in cities capable of trading credits associated with these projects. The area of 15 cities in or near the Piedmont region of the southern United States on which trees could be potentially planted was explored in this analysis. The objectives were to assess a straightforward time-efficient method of classifying land and to determine the extent of the open and plantable areas in these cities. Overall accuracy of the classification process ranged from about 69% to 95%, and on average was 80.1%. The average producers accuracy for all land classes in all 15 cities was 84.2%, while the average producers accuracy for the open land class was 78.7%. The average users accuracy for all land classes and the open class was about 80%. We estimate the amount of open, tree-plantable area in these 15 cities to be a little over 43,300hectares (ha), comparable to the size of Washington, DC, or about 36 new Harvard Forests (Massachusetts). Extrapolating these results to the entire Piedmont region, the total plantable area in cities would amount to about 438,500ha, and potentially allow 108 million tons of CO2 to be sequestered, with a value of about 1.084 billion U.S. dollars. Given the small sample size and the variation within the results, the most conservative 95% confidence interval around these estimates suggests that the plantable area today is between about 274,300ha and 645,100ha.
urban forests carbon sequestration carbon credits supervised classification landsat satellite imagery