The D.C. Council gave preliminary approval yesterday to a bill requiring homeowners and developers to pay fees that could run several thousand dollars for cutting down large trees on their own properties.

Backers of the bill say it would help check the erosion of the city's tree cover, which has dwindled sharply in recent decades because of a combination of development, disease and neglect. A study reported that nearly two-thirds of Washington's trees had disappeared since the 1970s.

But opponents, led by the city's business community, have warned against imposing a new layer of restrictions on private landowners. Reservations among council members have led to a steady watering down of the bill's most stringent provisions -- including fees that once topped $10,000 -- since it was introduced a year and a half ago.

"This magnificent tree canopy that Washington, D.C., is known for is disappearing," said council member Carol Schwartz (R-At Large). As chairman of the Public Works and Environment Committee, she has shepherded the bill through the council, despite concerns about elements in the bill's earlier versions. "This is a much scaled-down effort to protect our tree canopy," Schwartz said.

The bill, which faces a final vote and possibly a final round of tinkering in two weeks, would require a permit for anyone seeking to cut down a tree with a circumference of 55 inches or more. That's equal to a diameter of about 18 inches. The city estimates that 170,000 of the city's 700,000 trees are large enough to be covered by the program. Many of those trees are in parks or on other public land.

The fee for the permit would be $35 for each inch of circumference, for a minimum of $1,925 for a tree with a circumference of 55 inches. A tree with a circumference of 100 inches, for example, would require a fee of $3,500.

Property owners could avoid the fees if they plant new trees whose combined circumferences are equal to that of the tree that was cut down. Also, species of trees that city officials would deem to not be valuable would not require removal fees. And property owners would not have to pay to remove diseased or hazardous trees.

City officials estimate that it would require four full-time staffers to administer the program, consuming most -- if not all -- of the fees collected. Any remaining money would go to planting new trees.

Mayor Anthony A. Williams (D) has expressed reservations about some versions of the tree bill, and yesterday administration officials said they preferred a smaller, flat fee for cutting large trees, with no enforcement staff draining away the revenue.

"Protecting the tree canopy is a very good thing, but we have remaining issues about the administrative costs," said Deputy Chief of Staff Gregory McCarthy. "The kind of bill the mayor wants is one the whole city can support."

Robert A. Peck, president of the Greater Washington Board of Trade, called the measure "kind of an arborists' employment bill. . . . It would be nice if the city could do this in a way that doesn't reinforce the impression that we're stuck in a very old-fashioned regulatory mode."

But Jim Dougherty of the D.C. chapter of the Sierra Club called the bill "a great compromise" and said the group's own fiscal analysis showed the program would raise $150,000 a year for tree planting.

"We've gone to great lengths to tailor it to the concerns of the business community," Dougherty said.

The bill passed on a voice vote yesterday. Several council members have sought to exempt homeowners from the bill's provisions, and another effort is likely at the Dec. 17 meeting.

"I'd prefer to have private homeowners exempted from the bill altogether," said council member Vincent B. Orange Sr. (D-Ward 5).

But after months of lobbying and revisions, supporters predict it will pass with few changes. "It's at a point where people are generally comfortable with it," said council member Phil Mendelson (D-At Large), the bill's author.

D.C. Council member Carol Schwartz says charging fees for tree cutting would help save D.C.'s tree canopy.