The spread of industrial pollution and nuclear energy plants across the French countryside has sparked an aggressive new ecology movement that may succeed in planting some of its members on city councils in nationwide elections this month.

Known familiarly as "the greens," the political ecologists in France say they have gone well beyond the nature preservation and anti-pollution efforts of the environment movement in the United States.

The French ecologists say that they want to overhaul totally Western consumer societies. Unless lower economic growth rates and new energy consumption patterns in trying to save individual rivers and forests, they argue.

"We are revolutionaries," says Rene Dumont, 73, one of Europe's most respected agronomists and development experts, and the movement's guiding spirit. "What we are trying to do may sound utopian, but we are deadly serious. It is utopia, or death, for Western consumer societies today."

Campaigning strongly against what they call "the massacre of Paris" by skyscrapers, freeways and real estate speculation, the militant ecologists may hold the balance of power in the hard-fought race for mayor of Paris, a contest that has become and important test of national political currents.

As public opinion polls how the ecologist ticket doubling its projected vote in Paris in the past two months, to about 12 per cent, conventional French politicians are falling over each other in their rush to say how much they have always been for environmentalist measures.

Rather surprisingly, the polls show that ecologists are taking abut as many votes away from the conservatives as from the Socialist-Communist tickets.

President Valery Giscard d'Estaing has moved to proclaim a National Tree Day, and his candidate in the Paris race, Count Michel d'Ornano, is using a tree as his campaign symbol.

His main opponent - Gaullist leader Jacques Chirac, who was a Pompidou lieutenant during the most heated period of real estate speculation - now claims: "Ecology has always been one of my main concerns."

Renen Dumont welcomes Giscard's decisions to halt "some obvious idiocies" in the urban program he inherited, and the new interest of the mainline political parties in ecology.

"But none of the parties are talking about what we are talking about," he added, sitting in his suburban Paris apartment overlooking the forest of Vincennes. "We have three immediate sharply energy consumption so we can avoid nuclear energy.

"To do that, we advocate banning all privately owned cars from the center of all cities, including Paris, and replacing them with better organized public transport. Thirdly, we have to reduce sharply heating of residences and factories. These are realistic first steps."

"We started in 1974 talking about ecology to educate people. Now we are serious about getting on municipal councils to put it into effect," he added.

The movement is strongest in Alsand candidates who are running on ecology tickets throughout France and the chances they are given of winning are good indicators of the growing importance of the nuclear power issue here as well as the growing concern in the rural areas about industrial pollution.

The movement is strongest in alsace, where it has taken the slogan, "we refuse to be a French Ruhr," a reference to the West German industrial heartland.

While not yet gathering the momentum it did the Swedish national elections last year or in public demonstrations in the north of West Germany last month, the nuclear energy issue is also strongly felt in France's Grenoble region.

The ecologist candidates there are hammering on the recent discovery that the nuclear energy center in Grenoble dumped nearly 10,000 gallons of radioactive effluents into leaky sewers in 1974 and has top secret emergency plan in case of "civil nuclear accidents."

The movement also is strong on the Flanders coast, which the French call "the black country" because of industrial pollution and in Brittanny, where beaches and harbors have been hit hard by oil spills in recent years.

Organized ecology began in France as an offshoot of the worldwide wildlife preservation movement, which still exists here and does not take part in what it defines as partisan politics.

But the national branch of the Friends of the Earth became more militant under the leadership of Brice Lalonde, 33, astudent activist in the 1968 Paris uprisings and a leading anti-nuclear bomb demonstration organizer of the early 1970's.

Lalonde talked Dumont into running for president in 1974 on the ecologist ticket. Dumont was then best known for his then iconoclastic book, "False Start in Africa," which described in telling detail the adaptation of colonial bureaucracy and habits by the African elite that came to power on independence and the failure of development.

Dumont agreed to "take on an educational mission," he says now, and drew 1.33 per cent of the vote. Lalonde followed this with a race for a parliamentary by-election seat in Paris in 1976 and drew a more respectable 6.5 per cent.

With D'Ornano and Chirac fighting for leadership of the conservative ticket and the leftists sensing a chance to eke out a victory in the city council, the recent polls showing the ecologists with 8 to 12 per cent of the Paris vote were a bombshell.

Candidates getting 12.5 per cent of the vote in March 13 first ballot can try again on the March 20 ballot. Lalonde says the ecologists will stay in the race if they get 12.5 per cent, and will not tell their electorate to vote for either side if they are eliminated.

"Ecology voters are adults," he says firmly.