DECORAH -- Wangari Maathai said she doesn't have an extraordinary background.

"I'm an ordinary person who somehow stumbled in the right direction -- we all have opportunities, and we're lucky if we are able to embrace those opportunities. That's what makes the difference," the 2004 Nobel Peace Prize laureate said before giving the opening plenary address of the 18th annual Nobel Peace Prize Forum at Luther College on Friday afternoon.

Her entrance into the Center for Faith and Life's main hall was met with a standing ovation of the more than 1,500 forum attendees. Her belief in indivisible relationship between peace, democracy and sustainable management of the environment resonated with her audience.

Luther senior Joanna Simpson of Robert, Wis., was among those impressed by Maathai. Simpson shook hands with the Nobel laureate following her press conference Friday morning.

"We are so lucky to have her here," Simpson said.

The student said she was inspired by Maathai's message of how one person can make a difference.

"We think about how we can change the way the U.S. affects the environment, and it's good to be reminded change starts with the individual, and that can be me," Simpson said.

Maathai was born in Nyeri, Kenya, and was the first woman in East and Central Africa to earn a doctorate. Maathai is founder of the Green Belt Movement, which for more than 30 years has mobilized poor women to plant 30 million trees.

During her address, Maathai recalled a life-changing event. At a time when girls didn't go to school in her country, her brother, who she had followed him everywhere, convinced her mother she should go to school.

"Had my mother not made that decision, I would not be standing here today," she said.

By the 1960s, Maathai was planning to attend the only university in East Africa, but her principal told her about a chance to study in America. She credited the administration of President John F. Kennedy for encouraging African students to study in the U.S.

Maathai didn't hesitate and enrolled at Mount St. Scholastica in Atchison, Kan., where she said she had never seen so much flat land and never experienced anything as cold as a Kansas winter.

She went on to earn her master's degree in biological science in 1966 from the University of Pittsburgh.

But upon returning to Nairobi with her master's degree, Maathai recalled her colleagues weren't impressed. She was only one of three women on faculty at the University of Nairobi.

But she realized her problems were small in comparison to the situation facing rural women of Kenya.

They no longer had the firewood they needed for cooking because the brush and woods had been cleared for newly introduced cash crops of coffee and tea, and they had to cope with a male-dominated system of property ownership and a dictatorial government.

Maathai suggested the women plant trees to earn money for their families and to protect the environment.

The Green Belt movement grew, and the women were teaching each other how to plant trees.

Maathai started a civic and environmental education campaign. She said she spent time in jail after being arrested for having educational seminars.

She stressed the importance of participating in elections and said citizens also need to be aware and concerned about the way people get into powerful positions.

"In order for us to live in this world securely, because we have a limited amount of resources, we need to learn how to use those resources responsibly and equitably," she said.

If not, she said, "sooner or later we are going to be at each other's necks."