An informal consortium of District officials, urban forestry workers, several nonprofit organizations and hundreds of local residents overcame drought and years of underfunding and neglect last year to make some of the most significant strides in decades toward replenishing the city's endangered tree canopy.

A private group identified the city's existing street trees and moved to help the city protect the healthy ones. The city accelerated its companion effort to replace dead and diseased trees with a diverse assortment of sturdier stock. And D.C. residents became volunteer "citizen foresters" to help maintain the greenery, even as supporters campaigned for more participation in the effort.

"The city's trees were neglected for so long that there's a big backlog of trimming work and tree removal," said Mark Buscaino, the highly praised former head of the District's Urban Forestry Administration. "But now D.C. has the budget dollars and the leadership and is doing better than pretty much any city on the East Coast on urban green issues."

Buscaino, who left D.C. government last month to become director of urban and community forestry at the U.S. Forest Service, is being replaced Jan. 27 by Ainsley Caldwell, currently director of children's education and family programs at Brooklyn Botanic Garden. Caldwell, 44, is a specialist in urban ecosystem management and, Buscaino said, will do "a fantastic job" in building on the District's recent progress.

A major turnaround in the city's attitude toward trees began in November 1999. The Committee of 100 on the Federal City released a report saying that the District was losing 4,000 to 5,000 trees annually and that over the past 20 years, the nation's capital had lost 25 to 30 percent of its street trees. The city's tree and landscape division was woefully underfunded, the report said, lacked sufficient trained professionals, didn't have a modern approach to urban forestry and hadn't done a complete street tree inventory since the 1970s.

But the real eye opener was the simultaneous release of satellite images that showed a 64 percent drop since 1973 in the number of acres of heavy tree cover in the District. The photos, made public by American Forests, a nonprofit conservation group, made the loss starkly visible: a spreading dark image replaced green where trees once grew.

The dramatic satellite images helped people "get it," said tree advocates. And among those who got it, they say, was philanthropist Betty Casey. On behalf of the Eugene B. Casey Foundation, she set up a $50 million endowment earmarked exclusively for assisting the District in addressing the tree crisis.

Under the auspices of the 1 1/2-year-old Garden Club of America Casey Trees Endowment Fund, part of the roughly $2 million annual interest on the endowment is funding an inventory of all the city's trees. A major piece of the survey was completed last summer when teams of 35 paid college interns and 500 community volunteers counted and assessed the health and circumstances of every street tree in the District.

The detailed information, collected with hand-held computers and put into a sophisticated mapping database, is being entered into a computerized tracking system purchased by the city. The data will be used by the District in its daily tree operations and will be shared this spring with D.C. residents in a series of community meetings.

"Doing the tree inventory is essential," said Barbara Deutsch, program director for Casey Trees. "Without it, it's like trying to run a store when you don't know what's on the shelf."

The inventory, according to a preliminary analysis of the raw data, indicates that there are about 106,000 living street trees in the city and about 2,000 dead trees that need to be removed and replaced. The survey also identified about 25,000 sites without trees, including about 20,000 plantable spaces.

"We can show where dead street trees are, and where plantable places are, and where to prioritize," said Deutsch, whose group plans to inventory other trees on D.C. and federal land as well as private property. The group hopes to encourage more residents to volunteer as "citizen foresters" to nurture newly planted trees and to help water existing street trees during periods of drought such as last summer.

Preserving trees "makes sense," Deutsch said, and provides a return on the investment because trees improve air quality, reduce energy costs and storm water run-off, increase property values and enhance the streetscape.

The District, she said, is in danger of losing tens of millions of dollars in federal highway funds if it doesn't reduce its air pollution. Its high incidence of childhood asthma would lessen if neighborhoods had more trees. Also, the city would have more shade and be cooler in the summer.

Trees would also reduce the need for costly water and sewer infrastructure. The city has proposed spending $1.26 billion on a long-term plan for controlling water and sewer overflow into the Anacostia and Potomac rivers and Rock Creek. The problem has increased as the paving of more streets and parking lots has prevented water from being absorbed as easily into the ground.

During the time that Washington lost 64 percent of its heavy tree cover, the city's storm water run-off increased 34 percent, Deutsch said. "It's like putting Saran Wrap over the sponge," she said. "Trees help water get back into the sponge."

Casey Trees has also paid to treat about 200 trees for Dutch elm disease, with the city picking up the cost of treating an additional 100 trees.

Sally Boasberg, president of the year-old Green Spaces for D.C., said the Casey endowment inspired people across the city to start taking trees more seriously.

"This is not just a Ward 3 issue," said Boasberg, 65, the author of the landmark Committee of 100 report. "The greatest loss of trees has occurred in the eastern half of the city, and this is where we need to focus our efforts on re-greening."

Since that report, Boasberg said, Mayor Anthony A. Williams (D), D.C. Department of Transportation Director Dan Tangherlini and other city officials have revamped tree and landscaping operations; increased the professional staff of the urban forestry administration; boosted the budget to just over $7 million; and accelerated the pruning, stump removal and replanting of trees.

"The city hasn't done the crash program we asked for of planting 10,000 trees a year," Boasberg said. "But it's doing about 4,000 to 5,000 a year and taking better care of the existing trees."

The D.C. Council's recent passage of a tree preservation bill is also helpful, Boasberg said. The measure, which levies fees of $35 per inch for cutting down trees with circumferences of 55 inches or more, has been criticized within the business community and elsewhere because it affects trees on private property, but Boasberg said the legislation will safeguard the tree canopy and encourage preserving healthy trees.

"If a tree is sick or hazardous or invasive, of course, it can be cut down without paying a fee," she said.

Sometimes healthy trees are cut down for no apparent reason -- and without consulting city arborists.

Mary Hammond and Lillian Chatmon were distraught to discover a few weeks ago that four crab apple trees they planted 26 years ago in front of a small shopping center in Southeast's Randall Highlands had been mysteriously chopped down. The city gave the trees to the community as part of a beautification effort during the nation's Bicentennial celebration, and they were planted on a patch of District-owned land in front of the shopping center's parking lot in the 2500 block of Pennsylvania Avenue SE.

"They had grown up and were healthy and thriving and bloomed in the spring," said Hammond, 61, who chairs the Hillcrest Community Civic Association's tree committee. "To see them cut down was just devastating."

Chatmon, 81, a member of the Fort Davis Garden Club, said the trees provided some beauty in the shopping area. She and Hammond suspect the owner of the shopping center cut down the trees to make the stores more visible -- though Boasberg's tree report estimated that consumers will spend 12 percent more in stores with trees in front of them than in stores without trees.

The owner of the shopping center did not return calls about the trees, but Hammond and Chatmon plan to lobby for replanting trees there.

These latest tree stumps will be added to the backlog of 250 stumps and 55,000 trees in need of removal or pruning. A city team of three workers using a yellow stump grinder typically removes about eight stumps a day. Although the actual grinding takes only about 10 minutes, the machine takes considerable time to maneuver into place. Another group of workers follows to replant. "They've been rolling, putting in new trees," stump grinder Dwayne Crutchfield, 41, said last week as his crew completed removal of a stump at K and Third streets NE.

One area set to get an infusion of hundreds of new trees is Kingman Island in the Anacostia River near RFK Stadium. The mayor's office, Boasberg said, is committed to planting "a living local memorial of national significance" to the victims of the Sept. 11, 2001, terrorist attacks -- with smaller satellite groves in each of the city's eight wards.

The U.S. Forest Service has provided an initial grant of $160,000, and several environmental and conservation groups are working in partnership to raise additional funds. A landscape architect for the project has yet to be hired, and there is no final estimate on the memorial's price tag.

The memorial will likely feature more than 2,000 trees on the island and at least 50 trees at each ward site. Boasberg said there will be a memorial marker on the island and open space for children to play. The site, which will be managed by the D.C. Department of Parks and Recreation, will not be accessible by car.

"We want the memorial site to be like Theodore Roosevelt Island, with walking trails and, hopefully, a nature center," Boasberg said.

City worker Devon Montgomery grinds down a stump left at Third and K streets NE.City workers can grind down eight stumps a day, whittling at a backlog of 250 tree stumps that need removing. Tree activists Barbara Deutsch, left, and Sally Boasberg visit Kingman Island on the Anacostia, where recent plans call for the planting of hundreds of trees to honor the victims of the Sept. 11, 2001, terrorist attacks. Aerial photos of the city showed a dramatic loss of greenery from 1973 to 1997. The photos helped galvanize community action, including a significant upgrade of the city's Urban Forestry Administration.Diversity of DC Tree Species Plastic cones line a sidewalk on Eighth Street SE where trees once provided shade. A replanting is scheduled, once construction work in the area is completed.