Urban ecology principles: are urban ecology and natural area ecology really different?

To understand, even improve, the land of shrinking nature and spreading urbanization, a science applicable from remote natural areas to cities is needed. Today's scientific principles of urban ecology are articulated and compared with ecology based primarily on natural ecosystems; we either robustly merge the trajectories or watch them diverge. A literature review emphasizes that the field of ecology emerged from late 19th century and early 20th century research mostly in semi-natural environments, whereas urban ecology mainly developed from studying plants, habitat types, and ecosystem nutrient flows in late 20th century city environments. Ninety urban ecology principles are identified and succinctly stated. Underlying the principles, 18 distinctive types of urban attributes are recognized in four major groups: land uses; built objects; permeating anthropogenic flows; human decisions/activities. The attributes or objects studied in "natural area" ecology and urban ecology differ sharply, as do the primary objects present in late 19th century and late 20th century cities. None of the 90 basic principles would have emerged from research on natural areas, and all are readily usable for improving urban and urbanizing areas. Incorporating urban ecology science into ecology's body of principles and theory now should catapult the field of ecology to the next level, and noticeably increase its usefulness for society.