Urban forest naturalization has gained momentum within municipal planning and non-governmental organizations. As the interest in naturalization increases, so does the impetus for exploring its conceptual and practical dimensions. Naturalization is a form of ecological restoration with prominent social dimensions. One motivation is reintegrating the urban forest to a greater extent into its surroundings, increasing the habitat available for native species. However, naturalization is not always desirable, as we may want to use and modify certain areas for cultural purposes, or feasible, as some species may be unable to establish in an urban setting. This paper examines the concepts underlying naturalization and how they influence naturalization decisions and goals. It then provides a framework for urban forest naturalness and explores potential applications of naturalness assessments in urban forest management. The framework outlines 37 different biotic and abiotic dimensions of naturalness that can help urban forest decision-makers visualize and manage the urban forest through understanding its individual parts and thus the whole. If a site is weak in particular dimensions, actions can be directed to increase the naturalness of these components. Similarly, some dimensions may be of more interest than others, such as increasing habitat suitability for a particular species. We then offer real and hypothetical examples of applying the framework to urban forest management. The benefits of a naturalized urban forest are many. It provides habitat for native species and has an important role as a biological teaching tool for urban residents. In developing this framework, we hope to expand the discussion on naturalization beyond simply planting native species and ceasing mowing to positioning urban forests in a broader landscape.
Citizen Science for Urban Forest Management? Predicting the Data Density and Richness of Urban Forest Volunteered Geographic Information