of Pittsburgh's total tree cover, which involved sampling more than 200 small plots throughout the city, showed a value of between $10 and $13 million in annual benefits based on the "urban forest" contributions to aesthetics, energy use and air quality. Energy savings from shade, impact on city air and water quality and the boost in property values were taken into account in the analysis. The city spends $850,000 year on street tree planting and maintenance.
approximately 18.8 GJ ODT of biomass, the energy output-to-input ratio for the crop can be up to 20:1. Samson, R. et al. Developing Energy Crops for Thermal Applications: Optimizing Fuel Quality, Energy Security and GHG Mitigation. In Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks. D. Pimental. (Ed.) Springer Science, Berlin, Germany. 2008. 395-423. This highly favorable ratio is attributable to its