Unity College will graduate 128 students at Saturday’s commencement ceremony.

International conservationist, activist and writer Rue Mapp, who has spoken of a “nature deficit disorder” in America will speak at the 11 a.m. event, to be held in the college’s gymnasium.

The 128 graduation candidates represent 20 states, and 25 of them are from Maine, school spokesman Bob Mentzinger said Tuesday.

Mapp is founder of the Oakland, California-based nonprofit organization Outdoor Afro, which “uses a multimedia approach grounded in personal connections and community organizing to build broader community and leadership in nature,” according to a news release from Unity College. From its grass-roots beginnings, Outdoor Afro has been recognized for emphasizing the importance of racial and economic diversity in the outdoors, the release said.

College President Melik Peter Khoury said in the release that “the world’s global environmental problems are inclusive. We need inclusive solutions, like those provided by Rue Mapp.”

“Her innovative approach to organizing and educating has successfully connected thousands, especially from the African-American community, to direct experience of nature, to the benefits of spending more time outdoors, and to consideration of the environmental professions,” he said.

“It is imperative that we at environmental education institutions and in the sustainability professions do a better job of communicating the value and efficacy of a career in an environmental field — especially to those who are most impacted by environmental problems,” Khoury said.

A graduate of the University of California-Berkeley with a degree in art history, Mapp started Outdoor Afro as a blog in 2009, according to the release, and it has since become a leading national network “that celebrates and inspires African-American connections and leadership in nature.”

“Like Unity College, Mrs. Mapp understands the importance of infusing sustainability science into everything we do as a society, educating people from all walks of life to solve global problems and engage a wide range of people in creating global solutions,” Khoury said. “She is engaging the people who are perhaps most at risk of upheaval from changes taking place in this, the environmental century.”

Khoury said Mapp’s presence as an honored guest of Unity College signals the school’s enduring commitment to upend traditional modes of higher education to bring environmental education to everyone at a time of dire global need.

Unity, which is celebrating its 50th anniversary this year, also graduated 27 students in a December ceremony.