City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: https://read.dmtmag.com/i/1386860
Edgy Forests Our modern landscape, especially in the temperate region of the eastern United States, has become very "edgy." A landscape that was once a vast and mostly uninterrupted forest was cut down as European col- onists built homes, cleared farmland, and used wood for fuel. This trend began reversing in the early 1900s as agriculture moved west. Paved roads and city- scapes created a matrix, with abandoned farmland and riparian areas left available for forests to return. This is the eastern landscape of today. The smaller forests (forest patches or woodlands) in cities and suburbs have a much higher ratio of edge habitat to deep interior habitat. Standing in the center of an urban forest in Baltimore, for example, it's very likely you'll hear traffic and see houses or apart- ment buildings peeking through the trees. What does this new landscape mean for animal and plant biodiversity? Small forests in cities are warmer, less quiet, and at risk for invasion by nonnative insects and plants (D'Amico 2012). USDA Forest Service research shows that there are more nonnative plants—like mul- tiflora rose and bittersweet—in the understory of some forests than there are native plants (Shriver et al. 2020). Other research in the Forest Service network of urban forest sites has shown that dense understories of non- native plants make good habitat for ticks (Adalsteinsson, Shriver et al. 2018). Even more disturbing, the ticks in such habitats are more likely to be carrying the bac- teria that cause Lyme disease and other diseases. That may be due to greater numbers of small mammals that carry the bacteria—animals like white-footed mice, which do well in places with lots of dense ground cover. Other forest-dwelling animals find it much harder to thrive in small, edgy forests. Bird species like wood thrush and ovenbird are not likely to put up with the disturbances of nearby streets and houses (Adalsteinsson, Buler et al. 2018). Other species, like catbirds, are more willing to nest in nonnative plants and ignore human activity. The keys to the future health of our human-dominated ecosystems may well be the management choices we make in and around our small forests to prevent further fragmentation and encourage native species, combined with what we do in our own front yards to support wildlife habitat. 36 CityTREES Small public forest patches like HEPP Park, embedded in the Hamilton neighborhood of Baltimore, Maryland, provide critical habitat and refuge for local wildlife. Photo by Vince D'Amico, USFS