WINDHAM — When Dennis Hawkes first got involved in trying to save 105 acres near his childhood home, the Windham native couldn’t imagine the land around Black Brook changing from thick woodland into developments.

Now the longtime steward of the Black Brook Preserve can’t believe the preserve’s future will change again for the better as it comes under the direction of a larger conservation group.

The merger of the Windham Land Trust, the Presumpscot Regional Land Trust and the Presumpscot River Watch in September is an example of what experts say is next for land trusts. The newly merged trust has retained the name Presumpscot Regional Land Trust.

Kevin Case of the Land Trust Alliance in Washington, D.C., said land trusts combining resources is the wave of the future.

When Hawkes and his neighbors got together 16 years ago and formed the Windham Land Trust, it was with the sole purpose of preventing 50 homes from going in on 105 acres of fields and woods around Black Brook. However, a hiccup in the permitting for the developer caused them to jump at the lost momentum.

Hawkes and his neighbors convinced the developer to sell them the land for $375,000. They raised $100,000 in two months, got a bank loan and paid that off in two years. And the Windham Land Trust was born.

“Most folks in the immediate area couldn’t think about driving by and seeing houses all along (the open land). At the time when we started, we couldn’t imagine ever stopping the development,” Hawkes recalls.

Next Sunday, Hawkes will lead a tour at 10 a.m. along some of the nearly four miles of trails in Black Brook Preserve to celebrate the next chapter in the large preserve’s history.

As Hawkes, 67, hiked the Black Brook Preserve last week it was clear that he’s long had affection for its farm fields and undeveloped woodlands.

“Back in my youth my cousin and I hiked through the woods here from (Route) 302 to the Windham Center Road,” he said. “We had always followed the road. It was quite an adventure. It’s still an adventure.”

He pointed to the places he’s seen pileated woodpeckers and paused over a new bridge he helped build that was dedicated to his neighbor, John Hagar, who died this fall. And Hawkes spoke of the comfort this wild land has given him for more than a half-century.

So next weekend he’ll lead interested naturalists through the Momentum Trail, built by adults with disabilities whom Hawkes helps at the agency of the same name. He will point out pine trees that are 100 to 150 years old and a massive boulder that his 90-year-old neighbor recalls sitting on 70 years ago, when it was surrounded by farm fields.

It will be the kind of nature walk Hawkes has led since helping to protect this land in 2000, but now he envisions more being done here in the future.

As a member of the stewardship committee of the new Presumpscot Regional Land Trust, he said he will have the support of more land trust members who will bring additional trail-building skills and more ideas for getting the public out onto the land.

“By being on a stewardship committee with more people who are doing that, you learn more, you learn other useful things. It’s nice to have that collaboration,” Hawkes said.

The merged group will oversee 1,400 acres of conserved land in Gray, Windham, Standish, Westbrook, Sebago and Gorham. It has 300 members.

And because of the increased effort from a larger number of volunteers, there will be more trails to provide people in the area easier access to the outdoors, said Rachelle Curran Apse, executive director of the new Presumpscot Regional Land Trust.

The new organization will have 26 preserves with 14 miles of trails.

Having more people like Hawkes who are passionate about the land working together, more conservation work will get done, Apse said.

“A land trust is only as successful as the community that cares about it,” she said.