What are some of the main influences of urbanization in the WUI?

The direct influence of urbanization and other human activities on forests is the reduction of total forest area and fragmentation of remaining forest parcels. Human influences indirectly alter forest ecosystems by modifying hydrology, altering nutrient cycling, introducing non-native species, modifying disturbance regime, and changing atmospheric conditions. These changes significantly affect forest health and modify the goods and services provided by forest ecosystems.

Fragmentation of forests alters the biological diversity of native plants and animals by reducing the size of habitats and isolating plant and animal populations. Wildlife species differ in their response to fragmentation and habitat loss and degradation—some are habitat generalists and have adapted to the edge habitats where they thrive, while those that have specialized habitat requirements have not fared as well. A few non-native species, including plants, animals and pathogens that have been introduced into native ecosystems as a result of urbanization and agriculture have caused great harm.

Urbanization alters water flows in the interface and significantly affects aquatic habitats. Besides increasing impervious surfaces, urbanization also channelizes streams, drains wetlands, and increases the amount of pesticides and nutrients found in streams. Key issues related to ecosystem changes include air quality, water quantity and quality, wildlife habitat, species composition, biodiversity, and soil quality. Resource professionals are concerned with how to maintain the critical goods and services that forest ecosystems provide humans, such as recreation, climate regulation, beauty and inspiration. These benefits of forested ecosystems are increasingly valued over traditional forest products.