Saving the Silver Maple Forest

Photo by David Mussina, courtesy of Friends of Alewife Reservation

If you’ve ever visited the Alewife MBTA station, the adjacent 118-acre DCR park known as the Alewife Brook Reservation, which covers areas in Cambridge, Arlington and Somerville, is probably a familiar sight. What many may not know is that this reservation is critical to the ecosystem of the area. And now, that ecosystem is in jeopardy.

For years now, the Friends of the Alewife Reservation and Massachusetts environmental groups such as Green Cambridge have been fighting developers who have further divvied up this already shrinking slice of urban wilderness. But now, a proposed 299-rental unit, $70 million housing development known as “The Residences at Acorn Park,” headed and financed by O’Neill Properties Group of Pennsylvania, is threatening to destroy a key part of the ecology of the reservation. The Silver Maple Forest, a 15-acre swath of dense woods in the Belmont Uplands “ecologically connected” to the Reservation, acts as one of the only natural havens and corridors for various animals traveling through the surrounding urban areas. As of right now, the proposed development calls for the removal of much of the Silver Maple Forest, leaving in its place a housing complex with accompanying parking and green space. The results would destroy the habitat of several species of animals, such as red and grey foxes, mink, fisher, beaver, river otter and more than 90 species of birds that inhabit the area and are rarely found elsewhere in these cities.

While the wildlife implications are far-reaching, changes to the forest may also have consequences for the human population. That’s because the area is categorized as a floodplain forest, which aids against heavy rains and rising waters by absorbing what could be severely damaging amounts of water before it reaches inhabited areas. “Right now the forest is acting as an important floodplain protecting these nearby residents from flood damage,” says Amy Mertl, assistant professor of biology at Lesley University and vocal supporter of the preservation of the Silver Maple forest. “Not so much sudden flooding like we had on July 28, when a brief but heavy rainstorm temporarily clogged sewers, but longer term flooding, when lots of rain over a period of several days builds up and floods rivers and streams,” she adds. “Considering that precipitation is on the rise due to climate change, with formerly ‘100 year’ storms now happening every 20 to 30 years, it’s another shortsighted move that will end up costing the cities much more in the long run than the value of [the development].”

The forest also helps to stave off pockets of urban heat, which slows down climate change, and the large amounts of healthy trees contribute to local air quality. Not to mention that the city may actually lose money by removing the forest.

“We estimated [that] the services provided by the forest would total at least 1.1 million dollars per year based on previous studies on air quality improvements, cooling and flood mitigation. Most of this comes from a 1996 paper that calculated the flooding damage prevented by floodplain forests in the Boston area was on average $72,000 per hectare, per year – considering the rising housing costs and increased precipitation levels since 1996, that figure is likely much higher today,” says Mertl.

Despite having supporters, such as State Senator Will Brownsberger, those seeking to preserve the Silver Maple Forest are still facing an uphill battle. For one, the developer already owns the land it plans to build on, and zoning permits have been acquired. One of the only things standing between the Uplands and developers is a building permit from the city of Belmont. The debate has also pitted environmental activists seeking to halt construction against local housing activists who point out that the development will provide some affordable housing units that are desperately needed in the area.

There still may be a glimmer of hope for preservationists, however. “Recently the Cambridge City Council passed a policy order to work with the towns of Belmont and Arlington to try and find a way to pool some money together and approach the developer about purchasing the forest,” explains Mertl, though city officials are also exploring other solutions. “We’re hopeful this will lead to some action,” she adds.

So next time you’re walking near Alewife Brook, take a few minutes to explore the Silver Maple Forest, admire the birds and watch the Little River meander down its course – it may be your last opportunity. For more information, visit