Opportunities for urban ecology at the United States and Mexico border

Border cities, straddling an international boundary, are distinct from most conceptualizations of urban ecosystems. With a similar biogeographical template, the underlying social template creates massive differences in urban processes across the border. From above, the border leaves an undeniable imprint on land cover and land use distributions. Walking across the border is striking experience of cultural differences on urbanization. Border cities exist as points of both regulated and unregulated exchange between nations with extensive regulated flows of people and goods across the border. In looking toward a more general theory of urban ecological dynamics, border cities must be included.