From raising radishes at PS 19 to raising US environmental sights

Michele Perrault used to hang large pieces of kelp from the ceiling of her room. This was not, as you might think, the result of a neo-'60s approach to interior design. Then a schoolteacher in Rockland County, N.Y., Ms. Perrault tacked up the seaweed in class to help her pupils learn about the ocean.

''I was always big on creating environments for the children,'' Ms. Perrault says. ''I remember the seaweed particularly, because the principal came in one day and said, 'Michele, there's a limit to this. It's beginning to smell.' ''

Ms. Perrault no longer uses ocean plants in her work. The garden she kept next to a Bronx basketball court is gone, and she has stopped riding the New York subway with orphaned kangaroos. But her interest in the environment has never wavered - and today she is the newly elected president of the Sierra Club.

''I've always had a love of nature. she says. ''That started really at an early age. I've been able to build each year of my life on the same thing.''

An active Sierra Club member for some 20 years, Ms. Perrault is only the second woman chosen to head the 92-year-old organization. The first was Aurelia Harwood, a founder of the Camp Fire Girls, who was elected in 1927.

As club president, Ms. Perrault will receive no salary. Her most immediate duty will be to lead Sierra's charge toward its top 1984 goal: the defeat of Ronald Reagan. James Watt and Anne Burford, who to club members are the Darth Vader and Lady MacBeth of the environment, are long gone from Interior and the Environmental Protection Agency (EPA), respectively; but the Sierra Club remains bitterly opposed to the Reagan administration.

''A second Reagan administration, free of any election-year obstacles, would have free rein to ... once again put environmental laws before a firing squad,'' Ms. Perrault says.

Mrs. Burford's return to the national stage, in a bit part as chairman of a Commerce Department advisory commission, shows what Reagan's environmental attitudes really are, says Ms. Perrault. The prospect of having Mrs. Burford to kick around again, however, does not altogether displease environmentalists.

''I thought it was the most stupid thing Reagan could have done,'' Ms. Perrault says. ''He clearly has taken a lot of flack on it already.''

Ms. Perrault's harsh words contrast sharply with her mild, upper-middle-class appearance. She is a part-time legal assistant, who lives in the San Francisco area with a lawyer husband, two small children, and two large dogs.

She grew up in the Bronx, a part of the United States not known for nurturing young environmentalists. But it was while attending PS 19, raising flowers and vegetables in a school garden program, that Michele Perrault first developed ''a love of soil,'' she says.

While other little Bronx girls dreamed of being models or vice-presidential candidates, Ms. Perrault grew up wanting to become a soil conservationist. She wound up attending forestry college at Syracuse University, where she was one of only two female students.

Between semesters she worked at the Bronx Zoo. A friend of the family had pulled strings to get her the job. ''I figured that if you could love plants, you could love animals,'' she says.

At the zoo her duties consisted mostly of carting small animals to local schools, so concrete-bound children could have a wildlife experience. Sometimes she took the creatures home with her for special treatment. She thought nothing of riding the subway carrying a baby monkey or a young kangaroo that had been rejected by its mother and needed nighttime feeding.

Partly because of her zoo experience, Ms. Perrault ended up becoming a teacher. Children, she felt, could not learn about nature by filing into an auditorium and being given the chance to pet a goat.

Her suburban New York City pupils went on many field trips, bringing back souvenirs such as pebbles or kelp. They played with model streams in the back of the classroom and hung popcorn on trees at Christmas for the birds.

''For young children, to teach them about a polluted world, to teach them to be frightened of the world, is not the way things should happen,'' says Ms. Perrault. ''They should learn first to have constant contact with it, to feel good about it, and want to protect it.''

Ms. Perrault first became involved with the Sierra Club through the parents of one of her students. She quickly became a dedicated volunteer, serving in various high club posts. She was elected president at the national group's annual meeting May 5.

She ascends to her new office at a time when environmental groups have switched from defense to offense and are pressing attacks against what they consider the anti-environmental Reagan administration. The Sierra Club is not the most militant of the ''green groups,'' but it is by no means demure: Ms. Perrault says Reagan's early environmental actions were ''criminal'' and that he employs ''environmental naysayers.''

Reagan officials often respond in kind, leading to a rhetoric race that seems powered by the same sort of dynamic as the arms race. Anne Burford said upon her return that her enemies ''demagogue on environmental issues''; Reagan himself said last month that some conservationists are prone to ''blind and ignorant attacks'' on business and agriculture.

EPA chief William Ruckelshaus, at a July 12 breakfast with reporters, said that environmentalists are more strident today than they were in the '70s, even though the White House has recently softened somewhat on environmental issues.

Responding to these criticisms Ms. Perrault says that ''we have to speak out clearly for our issue. If they want to call that demagoguery, then that's (their problem).''

Ms. Perrault plans to be involved in more than presidential politics. She says she also wants Sierra to work more closely with antinuclear groups, on the theory that nuclear war would be ''the ultimate environmental disaster.''

She hopes to boost local Sierra Club chapters and strengthen the organization's ties with its counterparts overseas.

She also intends to continue taking time out for trips into the wilderness with her husband, 12-year-old daughter, and two-year-old son. ''We go for about 10 days. We backpack in on horses, usually, because the children are still young. I think it's a very valuable thing.''