William B. Critchfield, 65; Expert Pioneered Studies on Forest Genetics

William B. Critchfield, a pioneer and leading expert on forest genetics, died of a heart attack Tuesday in San Francisco. He was 65.

Before his retirement last year from the U.S. Forest Service, Critchfield’s work in identifying and establishing relationships among tree species was considered a breakthrough.

“He was one of the first to try to understand the role of genetic factors in the evolution of pine trees,” said Connie Miller, who took over Critchfield’s post at the Forest Service’s Berkeley station. “Before that, work had been done on plants and animals, but not trees.”

His 1966 book, “Geographic Distribution of Pines of the World,” continues to be considered the definitive text on the subject. He was internationally known for his work on pine tree evolution and frequently did consulting work in other nations.

He also worked closely with the University of California’s Forestry Department, helping graduate students with their careers. Miller said that future work on the so-called greenhouse effect will build on Critchfield’s findings.

The Minnesota-born Critchfield grew up in North Dakota, and the story of his family’s struggle during the Great Depression was recounted by his brother, Richard Critchfield, in the book, “Those Days,” published in 1985.

Critchfield attended North Dakota Agricultural College before serving in the U.S. Navy during World War II. He received his doctorate from the University of California, and was on the Harvard research faculty before joining the Forest Service and returning to Berkeley.

Survivors include two brothers and a sister. Services will be held Monday in Berkeley.