Planting trees was the first step that led to Kenya's Green Belt Movement. Over the past three decades, the movement has restored not only the country's land, but a traditional way of life - defending human rights and democracy in the process. Taking Root is a new documentary on the woman behind this movement - Wangari Maathai, who, in 2004, became the first environmentalist and the first African woman to win the Nobel Peace Prize.

There was something inspiring about Wangari Maathai that attracted filmmakers Alan Dater and Lisa Merton.

"We met her in 2002 at Yale University of Forestry," she says. "We were asked to do an interview about her. During the interview, I realized that in her life and her work, she had made connections that most people do not make. She had connected environmental justice with social justice, women's rights, human rights and ultimately peace, in a very organic, beautiful way."

Maathai had been teaching at the University of Nairobi when women from her home village complained to her about the problems they encountered every day.

"Their children didn't have enough drinking water. Nobody had enough clean drinking water," she says. "They were walking many miles every day for firewood. Because they were not able to cook the longer-cooking [and more nutritious] food such as beans because they didn't have enough firewood, their children were suffering from malnutrition. Also there was massive soil erosion. So even if they did plant, the soil was disappearing from their fields."

Maathai suggested the women start planting trees as a way to fight deforestation and earn money. And - as she explains in the documentary - that's how the movement was born.

"When women started, nobody was bothering them, because nobody took them seriously," Maathai says in the film. "You know, who takes women seriously? Then the government realized that we were organizing women. So they started interfering with our organizing."

Tree-planting project grows into political movement

Then, says documentary co-director Merton, the movement took a political turn.

"They found themselves actually in a direct conflict with the dictator of Kenya, [Daniel Arap] Moi," she says. "The government was corrupt. Women had no rights. People were living in fear. So what Wangari did was she helped them to overcome their fear and to speak out and in a way empower themselves. It was a grassroots African organization for Kenyan people. That's why it was successful. It came from within that country."

Taking Root chronicles a series of battles Maathai led to end the government's environmental destruction and corruption.

"We begin with one of her first battles, which was to save Uhuru Park, which is the major park in the center of Nairobi," she says. "Moi wanted to build a 62-story skyscraper in that park with a four-story [high] statue of himself. She said, 'This cannot happen. We can't be planting trees and have this major park, the place people of Nairobi go and relax with their children, we cannot have this park destroyed.'"

Maathai launched a campaign to make the people's voice heard, getting attention from Kenya's newspapers and media, even coming into direct confrontation with President Moi. It took several years, Merton says, but the Uhuru Park project - like so many others Maathai opposed - was dropped.

"Wangari has been incredibly courageous," she says. "She has been jailed. She has been beaten. She has stood up where most of us wouldn't dare to stand up, but it took that for the change to take place."

A distinguished life and career

The change finally arrived in 2002, when a new coalition government was democratically elected and Wangari Maathai became a member of the new parliament and assistant minister of the environment and natural resources.

Her journey from a Kenyan village to the country's leadership began nearly 50 years ago, when she was selected for a Kennedy scholarship. She traveled to the United States with a group of other Kenyan students - including Barack Obama Sr. She studied biology and earned a master's degree from the University of Pittsburgh. This opportunity, Lisa Merton says, changed Maathai's life.

"She was deeply affected by the civil rights movement and what was going on in this country," she says. "I think that affected her deeply and also gave her an awareness about human rights and social justice. We cover that in the film. We give a biography about her. She then went back to Kenya and was the first woman in Central and East Africa to earn a Ph.D. and then taught for almost 16 years at the University of Nairobi. Then she started working with the Green Belt Movement and planting trees."

Following Maathai's footsteps and traveling to Kenya to make their film, Merton says, was an inspiring experience.

"I love the people there, I [have] great admiration [for] the women and men of Kenya," she says. "What I find so lovely is that people there are still so close to earth - the people that we spent most of our time with, the people in the countryside. And the women are strong. And the women are hopeful, and the women are joyous. I admire that."

Taking Root is now showing across the United States. Merton says Maathai continues to show people through her writings and work that everything is connected in the web of life, and we have to do whatever it takes to save our environment.