Trees are beloved in spring and summer when they provide beauty and shade to our neighborhoods, and sometimes reviled in autumn when their fallen leaves must be raked and composted. Even in winter, their bare branches can create a familiar skyline, hinting at the next seasons to come. Although pleasing to the eye, those same trees play a much more important role. A healthy tree canopy – encompassing forests, woodlands, and individual trees – provide significant levels of environmental and ecological services. Healthy trees improve air and water quality, reduce carbon dioxide emissions and heat island effects, and sequester and store carbon. As the planet warms at a dangerous pace, trees are among our best defenses against the deleterious effects of climate change.

Preservation and enhancement of the tree canopy is a shared responsibility between local jurisdictions and constituents, but the effort must be regional, not encumbered by jurisdictional boundaries. In mid-April, the Metropolitan Washington Council of Governments (COG) took its latest step in a decades-long history of initiatives relating to the regional tree canopy and endorsed a goal of maintaining a minimum tree canopy coverage of 50 percent across the region. Previous efforts include voluntary ozone mitigation measures in 2005, establishing a Regional Tree Canopy Work Group in 2012, and a Tree Conservation “Cookbook” that provides detailed approaches to achieving tree canopy goals. COG Board Chair Charles Allen noted that the “best time to plant a tree was 20 years ago; the next best time is tomorrow,” and added that “maintaining healthy tree canopies and preserving our region’s natural assets is one way we get closer to a more sustainable, livable, prosperous, and equitable future.”

The COG report, “Conserving Trees and Forests in Metropolitan Washington,” was adopted unanimously by the COG Board of Directors and will be followed by a regional tree action plan for consideration next year. The new regional tree canopy goal was a long time in coming. The COG Board established a Regional Tree Canopy Subcommittee under its Climate, Energy and Environmental Policy Committee in 2019. Members of the subcommittee were volunteers whose professional credentials support many of COG’s member jurisdictions in their “day” jobs. Then the Covid pandemic intervened. The work continued virtually but agreement about recommendations faced some hurdles which, fortunately, were worked out.

Three tiers of goals were adopted: an overarching goal of 50 percent minimum tree canopy coverage; intermediate goals based on population density and urbanization; and smaller scale target goals for general land use categories. The recommendations are aspirational and are not intended to be prescriptive or universally applied in every scenario. Localities must base their tree canopy objectives on the unique sets of conditions within their jurisdictional boundaries. An analysis of land coverage data suggests that it is feasible to support a tree canopy coverage of 45 to 50 percent over the next 25 years, which essentially takes the region to 2050. The adopted recommendations include reevaluating the target goals once every five years. That re-evaluation may change when new Chesapeake 2025 goals are promulgated by the federal Chesapeake Bay Program next year.

Residents can take their own actions by planting trees on private property (fall is a good time to plant; the cooler weather gives roots time to establish before winter sets in) and by maintaining the health of existing trees, especially by carefully removing invasive plants and vines that use tree trunks for their infrastructure. It takes some time and effort to cut back ivy and clear the area around a trunk, but the result can be very satisfying, and much healthier for the tree. Earlier this year, the Virginia General Assembly passed bipartisan bills, introduced by State Senator Saddam Salim and Delegate Holly Siebold, that would have required garden retailers to educate consumers about invasive plant species and encourage alternatives, but the bills met with a gubernatorial veto. Senator Salim plans to try again next session.

COG’s Tree Canopy Goal is one of the first efforts in the nation to take aim at conserving tree canopy at such a large scale (the landmass of COG’s 24-member jurisdictions exceeds 2.2 million acres). Some of those jurisdictions already have estimated tree cover of more than 50 percent at this time, but many do not, and the annual loss of regional tree cover – due to weather, health, or development, is growing. The 50 percent goal is considered a floor, not a ceiling, so the idea that a jurisdiction could reduce its above-the-goal tree canopy is a fallacious assumption. The regional goal is to preserve and enhance the tree canopy, not play numbers games!