Source: UMass News and Media
Foresters and ecologists at the University of Massachusetts Amherst this month released a new statewide guide, Planting for Resilience: Selecting Urban Trees in Massachusetts, a manual designed to help tree wardens, urban foresters, professional arborists, nonprofit volunteers and private residents in selecting and planting trees well suited to thrive in the Commonwealth’s cities and towns. The manual is available online as a downloadable pdf; there is also a web-based video in which McElhinney discusses the work.
Graduate researcher Ashley McElhinney wrote the 106-page guide as part of her master’s degree work in environmental conservation with a focus on urban forestry with her advisor Richard Harper, an extension associate professor of urban and community forestry.
In addition to nearly 80 pages of tree profiles with original line drawings of their silhouettes, the guide includes brief descriptions of environmental conditions each needs to thrive. The guide also lists characteristics for each species such as expected mature height, width, growth rate, foliage, flower and fruit information, known pest vulnerability and other considerations. There are also helpful pages offering “tree planting 101” instructions, a “caring for new trees” guide and a list defining commonly used terms.
McElhinney says one key message she’d like readers to take away from her new manual is “how they can use trees to mitigate the effects of climate change and how to choose trees that can adapt to the changing climate.” The guide identifies trees with “an observed tolerance” to stressful urban conditions they may encounter such as competition for space, building shade, packed soil, poor drainage, salt and air pollution.
There is a discussion of potential risks of planting non-native trees, which can be as much as 40 times more likely to become invasive species and to displace natives. The guide contains a list of species excluded because they are either already listed as invasive and prohibited from being planted in Massachusetts, they have the potential to become invasive, or they are otherwise incompatible with urban environments, such as silver maple and white pine. Another message is that biodiversity matters, McElhinney says. “One thing that people do is overplant a single species. In some towns, 50 percent of the street trees are maples, and it shouldn’t be like that. In order to protect against a pest that could wipe out all individuals of that species, it should be only 10 or 20 percent. It’s important to have safeguards for biodiversity.” Harper adds, “If one out of every two tree species in your town is a maple, that means half of your street trees are at risk from the Asian longhorn beetle.”