The 20th century witnessed exponential growth of the human population. A concurrent change was urbanization, with close to half of the world's population residing in urban centers at the beginning of the 21st century (McGranahan and Sat-terthwaite, 2003). Humans have domesticated nature with a net benefit to themselves such as enhancing food supplies, reducing exposure to predators and other dangers, and promoting commerce, often at a cost to other species (Kareiva et al., 2007). A concept, ecological footprint (EF, the amount of land required to produce the resources needed by a person annually), was first introduced in 1996 and immediately applied for cities (Wackernagel and Rees, 1996; Folke et al., 1997). The EF is comprised of resources used to meet a person's food, water, and most significantly, energy demands for housing and transportation that account for up to 90% of the EF. The concept provides a reasonable tool to demonstrate natural resource dependence of human activities to politicians andthe public, although much work is needed to employ it as a cohesive analytical tool for management. Fortunately, advances have been made to assess the EF of water supplies (Jenerette and Larsen, 2006; Jenerette et al., 2006a; Jenerette, et al., 2006b), of transportation (Muniz and Galindo, 2005), and of household energy demand (Lenzen et al., 2004) and of its application in urban settings (Luck et al., 2001; Kaye et al., 2006; Du et al., 2006) and other land uses, barring the difficulty of estimating the EF of aquaculture production (Roth et al., 2000). The attractiveness of the EF is that it represents a single, quantifiable measure of human impact on the environment
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