Soft morning light filtered through the trees and made the snow glisten.

Matt Johnson pointed to a tree in the distance. Two large wild turkeys huddled against the cold on a high branch.

Johnson is very familiar with this 31-acre preserve across from Lake Harriet and the Rose Garden. He volunteered here for a college project, ripping out buckthorn and tending trails, and now he's president of the Friends of Roberts Bird Sanctuary.

"Everybody agrees this place is really a gem," said Johnson. "Last year people saw two trophy bucks in here, a 10-point and a 12-point. Last week someone saw a Cooper's hawk chasing a pileated woodpecker."

But on Wednesday, Johnson and his group will attend the Minneapolis Park and Recreation Board meeting to address concerns about work planned for the sanctuary this fall.

An old Minneapolis sewer line that serves a large swath of the metro area runs through the sanctuary, and needs to be fixed. While public meetings were held last year, Johnson and others say changes in the plan will widen the impact and could alter bird migration, something the Minneapolis Park Board denies.

Opponents also say that as plans have evolved, they have been largely left out of the process. Johnson said questions about the project have bounced between the Park Board and Metropolitan Council, or ignored.

Friends of Roberts, along with the state and city Audubon Societies and two neighborhood groups, are concerned enough to have sent a joint letter to officials.

"While everyone understands the necessity of upgrading the sewer line, the Met Council's current plan ignores the fact that this area is a bird sanctuary and would result in unnecessary devastation and loss of habitat that would last for decades," the groups said in a news release.

"We are very concerned about the lack of an explicit mitigation plan that acknowledges and accommodates the value and fragility of the bird sanctuary, and with the lack of transparency over the past few months as the Met Council met with the Minneapolis Park & Recreation Board staff to finalize plans."

But Cliff Swenson, director of design and project management for Minneapolis parks, said the process has been transparent, from a series of open houses to meetings with "stakeholders" such as Friends of Roberts to go over plans.

They also worked with independent wildlife experts to help mitigate damage. Swenson said little has changed since the public meetings, and he's confused by the complaints.

"What we are most concerned about is that we don't have a failure" while fixing the sewer that would cause damage to the lakes area, Swenson said. He said that replacing trees and other vegetation lost during construction could actually "increase the potential for habitat."

What we have here, it seems to me, is a failure to communicate between the tree-huggers and pencil pushers — that and perhaps a predictable reaction to the lag between public meetings and actual work, when people really begin to pay attention.

Jerold Bahls, president of the Audubon Chapter of Minneapolis, calls Roberts a "legacy" left for bird watchers.

"It has a lot of old-growth forest feel to it, even though it's very small," said Bahls.

Bahls commends the council and park system for routing the temporary sewer around the park, saving more from destruction, and planned attempts to leave some of the larger trees.

"They are doing some good things," said Bahls.

Walking the trails through the sanctuary Tuesday, Johnson pointed to trees already tagged for removal. He hopes the nature groups and city planners can work together to limit the damage as much as possible in this little hidden forest in the city.

"We all agree this is a really great place," Johnson said.

Swenson agreed.

"If you look at the Friends' goals, they're our goals, too," he said.

jtevlin@startribune.com • 612-673-1702 Follow Jon on Twitter: @jontevlin