Adriana Hoffmann, a botanist who roamed Chile deciphering its flora and who as a scientist, activist, author and policymaker tirelessly sought to protect her country’s vast forests from big-business exploitation, died on March 20 at her home in Santiago, the capital. She was 82.

She had been struggling with health problems for the last several years, her daughter Leonora Calderón Hoffmann said, and died of an acute clot in a lung.

The presence of two Chilean cabinet ministers at her funeral made clear the importance of her legacy to the country, where scientists-turned-politicians are helping to make a new constitution shaped by the climate crisis.

Her friends and colleagues said Ms. Hoffman had a well-trained eye for identifying rare plants as she traversed the deserts and forests of Chile either on foot or in her Jeep. She classified more than 100 species.

This was the essential skill behind the dozen books she wrote beginning in the 1970s, documenting the wealth of the country’s flora and singling out its myriad native species, medicinal plants and cactuses and the flowers that bloom in the Atacama Desert. Her books often came with illustrations by Andrés Jullian and Francisco Ramos.

Ms. Hoffman’s activism unfolded in the early 1990s, as Chile started to recover from a military dictatorship that had killed and tortured thousands while giving corporations ample power to capitalize on natural resources.

At the time, activists were beginning to fight a number of projects they saw as harmful to the environment, such as hydropower plants and timber plantations. In 1992, two years after the fall of the dictatorship, Ms. Hoffmann headed a nonprofit organization, Defensores del Bosque Chileno, dedicated to protecting Chile’s native forests.

One of her most remembered books, which she edited, is “La Tragedia del bosque chileno” (1998), documenting how Chile’s extractive industries were destroying the country’s forests.

Ms. Hoffmann championed the forests at a time when doing so was seen by many as an attack on economic development, especially in a country whose economy heavily depended on exporting commodities.

It was only in 1993 that Chile created the National Commission of the Environment, or Conama, an agency that would later profoundly change her life and legacy.

In her last interview before she died, published in January, she was asked what she had learned from nature, having dedicated her life to it. “Love,” she responded. “Nature has given me love.”

Adriana Elisabeth Hoffmann Jacoby was born in Santiago on Jan. 29, 1940, the daughter of a renowned Chilean doctor and scientist, Franz Hoffmann, and the pioneering psychiatrist and spiritual guide Lola Hoffmann (born Helena Jacoby). Ms. Hoffmann went on to study agronomy at the University of Chile before dropping out. She later switched to studying botany when she spent some time in Germany with her mother.

She credited her parents with nurturing her love for nature. “I have pictures of myself, very little, always with flowers and plants,” she said in an interview.

In the early 1990s, she met Douglas Tompkins, a conservationist and the founder of the North Face and Esprit clothing brands, and his wife, Kristine Tompkins, who together bought about one million acres of Chile’s forests to protect them.

Ms. Hoffmann advised and supported the Tompkins’ conservation efforts, Ms. Tompkins said in a phone interview, and once joined other conservationists in obtaining the couple’s help in preserving a vast stretch of precious but threatened land on the border of Chile and Argentina. In 2014, the area became the mountainous Yendegaia National Park.

“Everything, really, of our understanding of the flora of Chile I would say came through Adriana,” said Ms. Tompkins, who heads the nonprofit group Tompkins Conservation. “She was generous with her knowledge of ecosystems at a time when nobody was thinking about that very much.”

In 1997, Ms. Hoffmann was recognized by the United Nations as one of the top 25 environmental leaders of that decade. Two years later, she was awarded Chile’s National Environmental Prize for her contribution to documenting and protecting the country’s natural ecosystems.

In 2000, Ricardo Lagos, the third president of Chile to take office after the transition to democracy, invited Ms. Hoffmann to head Conama, the country’s top environmental agency, which would later become the Ministry of Environment.

Friends warned her against taking the job, seeing the agency as too weak to challenge the great business interests that profited from the country’s lack of environmental protections at the time.

But Ms. Hoffmann saw President Lago’s invitation as an opportunity to fight for legislation to protect native forests and accepted the post, becoming the first scientist to hold it at a time when environmentalists and women were rare sights in Chile’s halls of power.

The forces against her turned out to be too great, however. She managed to roll out projects that she felt were important, like Senderos de Chile, a nationwide hiking trail, but she resigned from Conama 17 months later, facing pressure against her agenda. It would be eight years before a law protecting forests would be passed.

She later described her time in office as the worst decision she had ever made, having found herself caught between the overwhelming power of corporations and the deep disappointment of fellow environmentalists.

She never fully recovered from the experience, her daughter Leonora said. From then on, Ms. Hoffmann struggled with health issues, including strokes.

She is also survived by another daughter, Paz Hoffmann; two sons, Álvaro and Francisco; and five grandchildren.

But by the time of her death she had become an inspiration to many environmentalists and scientists. In 2015, the Ministry of Environment created the Adriana Hoffmann Environmental Training Academy to train teachers, public servants and the general public. More than 12,000 students have completed courses there.

Speaking at Ms. Hoffmann’s funeral, the newly appointed minister of the environment, Maisa Rojas, an accomplished climatologist, recognized the environmental obstacles that her predecessor had faced and that still challenge Chile and the rest of the world.

“Now more than ever, we have been called to take care of a threatened and very degraded nature,” she said. “As a woman and a minister of the environment, I put Adriana’s shoes on, and they are too big.”