Environmental advocate Richard Amper died of a heart condition Monday in hospice.

Amper was well known for his role as executive director of the Long Island Pine Barrens Society.

Under his leadership, the organization preserved 100,000 acres of land within the pine barrens by 2020.

News 12 spoke with two of Amper's longtime friends and collaborators, Suffolk County Legislator Steve Englebright and Nina Leonhardt, the acting executive director of the Pine Barrens Society.

"Dick Amper was one of the most consequential people in Long Island history ... he's an environmental warrior of the first order and to lose him, you know it's a real setback," Englebright said.

He also said of Amper, who he says he met in the early 1980s while teaching at Stony Brook University, "he opened the possibilities of what an informed public could do to protect their natural history."

"A giant personality with wonderful goals, he said to me when we first met, he said he lived by the notion, dream it up and make it happen and that's exactly what he did," Leonhardt said. "Dick Amper is responsible for saving the Pine Barrens, keeping Long Island as wild as it can be while understanding that development is important for economic reasons and ensuring that we have clean drinking water into the future."

Amper was 81 years old.