Urban System Interactions Model

A model of the system interactions in the Phoenix, Arizona, metropolitan area is attached below. Human activity has directly increased available resources, particularly water (shown in red), which has increased and stabilized productivity. This human activity, coupled with other direct effects, such as the introduction of domestic cats (shown in red), and indirect effects, such as the reduction of other vertebrate predators has increased the abundance of some biotic groups either directly (red solid arrows) or indirectly, while decreasing others.

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Urban Food Web (PDF)14.81 KB