If the State Forest is the heart of the Island, then John J. Varkonda was the heart of the forest.

That’s what friends of the longtime Islander have been saying to each other in the days since Mr. Varkonda’s unexpected death Tuesday.

Mr. Varkonda, who served as superintendent of the state forest for 26 years, died suddenly at age 55. The cause was abdominal aortic aneurysm. He collapsed at home on Tuesday and was airlifted to Massachusetts General Hospital.

“I can’t say enough about the EMTs and staff at the [Vineyard] hospital,” said his wife, Jane Varkonda. “They did everything they could to save him, even though they probably knew it wasn’t going to work.”

John Varkonda’s legacy as conservationist, father and friend, spans the entire Island, but more specifically, the 5,343 acres of the Manuel F. Correllus state forest, a swath of land in the center of the Island cherished for its unique sand, plain ecosystem and high concentration of endangered species. He was singly responsible for the management of the former heath hen sanctuary, a considerable task which he embraced with seriousness, dedication and a sense of humor.

“The forest is the centerpiece of the Island,” Mr. Varkonda told a reporter in 1994. “It’s a unique and valuable resource.”

Mr. Varkonda in state forest he loved.

Mark Lovewell

Mr. Varkonda in state forest he loved.

Mark Lovewell

Mr. Varkonda was 29 when he assumed the superintendency of the state forest, only the second person to oversee the property. He married Jane Broderick, a biologist, days after beginning work here on the Vineyard, and they settled into a house on state forest grounds.

At first, “It was sort of just a job and it became our life,” Mrs. Varkonda said by phone on Thursday. “It became who we are.”

Mr. Varkonda came to the Island from Mashpee, where he served as the conservation agent. He had a degree in conservation from Kent State University in his home state of Ohio.

In his first days on the job, Mr. Varkonda encouraged Islanders to come out and introduce themselves to him at the state forest. Throughout the next 26 years, he remained a resource to all who came to study and admire the flora and fauna of the single-largest tract of land on the Island.

“He was one of the Vineyard’s treasures,” said Gus Ben David, a naturalist who often approached Mr. Varkonda for the wealth of knowledge he had about state forest ecology.

To the community of researchers and conservationists who worked alongside him, Mr. Varkonda was a constant presence, inextricable from the land he stewarded.

“It’s hard for me to separate my personal feelings about John and my personal feelings of the state forest,” said entomologist Paul Goldstein, who studies rare moths for the Smithsonian.

The state forest, once dismissed as a wasteland and often undervalued for aesthetic reasons, is a unique conservation landscape in the state, said David Foster, director of the Harvard Forest, who met Mr. Varkonda 1992, and praised his hospitality and vast knowledge of the history and ecology of the landscape. “The remarkable thing about John is that he was single-handedly responsible for the whole thing.”

Throughout his tenure, Mr. Varkonda upheld the legacy of his predecessor, Manuel F. Correllus, who managed the forest for nearly 40 years, Mr. Foster said.

Aerial view of Manuel F. Correllus state forest.

Aerial view of Manuel F. Correllus state forest.

“I think the great legacy of John is he has lived up to that history and more.”

Over the years, Mr. Varkonda’s duties included maintaining nearly 30 miles of fire trails and eight miles of bike paths that cut through the forest, and hosting a variety of researchers who came to study the forest. He also coordinated the hunting season, and managed a series of prescribed burns to improve the forest habitat.

“He was thought of as a one-man army there,” Mr. Ben David said. “He didn’t have much additional help. He ran the whole show.”

His first large project as superintendent was carving a meadow off Barnes Road, where he dreamed Islanders would eventually throw frisbees, and a more diversified collection of species would prosper.

This, and other visions of his, have come to fruition.

“He was sitting on the mother lode,” Mr. Goldstein said. “He was just incredibly important. That is a big chair to fill.”

Reached by phone Thursday, Mr. Varkonda’s family, friends and collaborators remembered him as a man of midwestern friendliness who loved his work.

“I take pride in what I do,” he told the Gazette in 2007. “And I still look forward to going to work.”

A state employee, Mr. Varkonda juggled local and state policies with grace, said Tom Chase, director of conservation strategies at the Nature Conservancy.

“He worked well with the local community. That is a very tight line to walk,” he said. “He walked that line well between being a consummate professional and a part of our community.”

On Thursday he was repeatedly praised for the hospitality he bestowed on the variety of researchers who visited the forest.

“He was so welcoming and friendly and collaborative, that would be the best way to describe him,” said Luanne Johnson, wildlife biologist. “He would do anything to get a project off the ground, get it completed, and make the state forest available to you.”

His forest friends will remember him smiling, mounted on his tractor, in his green DCR jacket, they said.

At home, he was leader of the pack, Mrs. Varkonda said. They raised two children together: Aidan, who is 16, and Kasey, who is 10.

Mr. Varkonda was also fond of public radio, camping and gardening. He was a talented cook, and, in his youth, an avid mountain climber. He loved South Beach in Katama, and imagined that in his retirement he would work there.

Recently, he was teaching his son to ride a motorcycle, a process he enjoyed thoroughly, Mrs. Varkonda said. “That was something he was proud of,” she said.

“He made me laugh,” Mrs. Varkonda added. “We laughed all the time.”

A visitation for family and friends will be held on Thursday, Jan. 9, from 4 to 7 p.m. in the Chapman, Cole & Gleason Funeral Home, Edgartown Road, Oak Bluffs. A funeral home service will be held on Friday, Jan. 10, at 11 a.m. Donations in Mr. Varkonda’s memory may be made to WCAI, the Cape and Islands NPR Station, 3 Water Street, P.O. Box 82, Woods Hole, MA, 02543 or capeandislands.org.