Anne Arundel, Howard take steps to preserve trees as researchers develop a map of forest loss across Maryland

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Researchers are building a map of nearly every tree across Maryland to learn whether state forests need better protection — but leaders of some counties aren’t waiting for the results to act.

Lawmakers in Anne Arundel and Howard counties have in recent weeks adopted significant changes to forest conservation rules, requiring developers to replant more of the trees they cut down. Advocates already are pushing for similar actions in other parts of Maryland, after two years of debate produced no resolution over similar policies at the state level.


Reform of the state’s overarching forest preservation laws still could be coming. Aerial images being gathered now could settle a disagreement between environmentalists and builders about whether tree cover is dwindling as new housing and shopping centers pop up around the state.

Forest advocates say that, under current state law, builders can clear densely forested land with no requirement to replant any trees, but their opponents argue there is no evidence of a net loss in trees.


Analysis of the data, which was due to state lawmakers this month, is now not expected to be completed until next summer. But early glimpses of it suggest tree losses in Central Maryland, at least, could be mounting.

Satellite data traditionally relied on for forest cover estimates suggested a loss of about 1,400 acres of tree canopy in Anne Arundel County from 2013 to 2017, for example, said Jeff Allenby, director of conservation technology at the Chesapeake Conservancy, which is compiling the data in partnership with the Harry R. Hughes Center for Agro-Ecology at the University of Maryland. But he said the new maps, collected from planes at 900 times the resolution of the satellite data, show the losses over that period were actually 70% greater — closer to 2,400 acres.

“There is a lot more canopy loss that’s occurring that’s visible with high-resolution data,” Allenby said.

Forest preservation is increasingly important as Maryland and the rest of the Chesapeake Bay watershed work to restore the estuary by a 2025 deadline, advocates say. Forests help filter nutrients and sediments from rain runoff, preventing them from reaching the bay and fouling its waters, so preserving them means less effort to find other ways to reduce bay pollution, said Alison Prost, Maryland executive director of the Chesapeake Bay Foundation.

“Every time we lose a forest, we’re just making the rest of our to-do list that much harder,” Prost said.

But if the recent legislative debates in Anne Arundel and Howard are any indication, there still could be arguments ahead over how best to protect trees while also promoting smart development patterns around the state. Opponents of the county policies say they actually could promote sprawl and lengthen commutes, producing more vehicle exhaust.

“Both of these councils were urged to pass the bills in the name of Chesapeake Bay cleanup and to fight climate change,” said Tom Ballentine, vice president for policy for NAIOP Maryland, a state commercial real estate group. “The results of what they’re doing is undermining the state’s strategies to make improvements on bay water quality and reducing greenhouse gases.”

Both the county legislation and the new research are the product of stalled discussions in the General Assembly earlier this year. When state lawmakers were unable to find consensus on forest conservation reforms, they directed the Hughes center to help at least settle the debate over whether Maryland’s forests are shrinking.


And the delay in Annapolis helped prompt county leaders to act, said Joshua Feldmark, Howard’s director of community sustainability.

“In the absence of state leadership, it was time for the local jurisdictions to step up,” he said.

Anne Arundel’s came first, signed Nov. 25 by County Executive Steuart Pittman, who had campaigned on a pledge to address tree loss. The law reduces the amount of tree cover developers can clear before triggering replanting requirements and also increases the fees developers can pay instead of replanting.

At a bill signing ceremony at the Bacon Ridge Natural Area in Crownsville, Pittman said the policy would "encourage development to go into the areas that we wanted redevelopment, and discourage it in beautiful places like this.”

The Howard County Council followed suit Dec. 2, passing a similar bill that had been proposed by County Executive Calvin Ball and focused on residential development. The legislation doubled the replanting requirement of state law, demanding developers plant at least half an acre of trees for every acre they clear, and that 75% of that replanting be done on the same property.

Ball pushed the policy as part of a broader effort, Feldmark said, “to make sure the environment and sustainability were primary considerations in the work of the county.


“If we can put the trees and the forest in the places where we are living and working, it protects our overall quality of life as well as air and water quality,” he said.

Builders raised concern that both laws could drive developers to choose sites that have less tree cover but could sit outside the counties’ priority areas for development, and could slow housing growth and exacerbate affordable housing concerns.

“We need to make sure we’re taking a comprehensive look at this and not just doing it to slow down growth,” said Lori Graf, CEO of the Maryland Building Industry Association.

But advocates said such laws are steps toward ensuring development causes no net loss in forest cover. Now, they are shifting their attention to counties including Baltimore, Frederick and St. Mary’s, where they see the most evidence of and potential for forest loss.

Meanwhile, they are awaiting the results of the statewide forest study, which are not expected to be available until after the 2020 General Assembly session is over.

Nancy Nunn, the Hughes center’s interim director, said the researchers recently asked state legislative leaders for a deadline extension, to June 1. She said the center expects to solicit proposals in January for analysis of the data gathered by the Chesapeake Conservancy, as well as data from the Maryland Forest Service, Chesapeake Bay Foundation and other sources.


The final report is expected to take the higher-resolution mapping — at a scale of 1 square meter per pixel, instead of 30 square meters — and also account for data on land-use changes and permitted clear-cutting.

David Newburn, a University of Maryland associate professor of agricultural and resource economics, called it “really high-quality data.” He has studied forest loss in Baltimore County, and said the new data could provide new insights.

“It opens up all sorts of opportunities for much better monitoring and understanding of land use policies,” he said.

Baltimore Sun Media Group reporter Brooks DuBose contributed to this article.