NEW YORK » One of the strangest monuments to Hurricane Sandy’s lethal power is an ever-growing mound in Cunningham Park in Queens, an unwieldy heap of tree trunks, splintered limbs and leafy branches. Next to it rises an even larger pile, some 25 feet high, representing the fate of all the fallen oaks, silver maples and London plane trees: wood chips.

As the city continues to right itself from the storm, its toll on the natural landscape is coming into clearer focus. Perhaps not surprisingly, it turns out that the storm struck the city’s trees like a chain saw on methamphetamines, toppling more than 8,000 street trees alone and destroying thousands more in parks and woodlands. That is twice the number of trees that came down last year during Tropical Storm Irene, and triple the loss from a tornado the year before that.

"Sandy was a very, very powerful event, more powerful than we’re used to experiencing, and our trees were really whacked," said Bram Gunther, chief of forestry, horticulture and natural resources for the city’s parks department, which oversees trees on sidewalks as well as in parks.

The parks department’s forestry division started to marshal its resources days before the storm, directing the private contractors it uses in emergencies to bring in scores of additional tree crews. Inspectors and tree-service workers started their work on Oct. 30, as the storm slowly withdrew from the region. Since then, they have responded to 20,040 tree-service requests, which resulted in 14,014 work orders.

The first priority was to clear trees from highways and streets so that fire trucks and ambulances could get to stricken neighborhoods. In recent days, tree crews turned their attention increasingly to city trees that had collapsed on houses and other buildings.

On Friday, in the Jamaica Estates section of Queens, a crew that had driven all the way north from Gainesville, Fla., at the height of the hurricane was removing two enormous pin oaks from a stately brick house. The contractor used a knuckleboom loader, a vehicle as powerful as it sounds, with a giant claw capable of plucking mighty oaks as if they were twigs.

Frederick Quint, 49, who grew up in the house, at the corner of Midland Parkway and Henley Road, treated the workers to a couple of pizzas as a token of his thanks. The trees, each measuring 40 inches in diameter, had fallen at 8 o’clock Monday night, as the hurricane tore through the city. The trees hit two others on Quint’s property, and together, they smashed a parapet over the sunroom, as well as windows, gutters and roof tiles.

"It was a loud thud," he said, describing the impact on the three-bedroom house. Watching from his front door as the loader hoisted what remained of the pin oaks, he said: "There they go. It’s distressing. I grew up with those trees."

Throughout the city, the parks department has recorded 8,497 fallen street trees, as well as 3,358 fallen limbs and 1,280 hanging limbs. The northeaster, which on Wednesday added an insulting coda to the hurricane, resulted in yet more tree-service requests — 4,017 through noon on Friday. But the department’s forestry division had not yet determined how many of those were for fallen trees versus dangling branches. In any case, Gunther called the storm combination a "double whammy."

By contrast, during Tropical Storm Irene last year, there were 3,444 fallen street trees, 3,403 downed limbs and 1,577 hanging branches. And a tornado that cut a path across parts of Staten Island, Brooklyn and Queens in September 2010 razed 2,849 street trees and left an additional 6,624 with fallen limbs and 6,225 with drooping branches.

Officially, Hurricane Sandy caused the highest number of tree casualties of any storm since 2002, when New York instituted its 311 line for nonemergency calls. Unofficially, the storm laid waste to more city trees than any storm in memory.

The parks department has begun to assess damage inside parks and other natural areas across the five boroughs, but it has no estimates yet on trees. "We won’t get a keen sense of that for at least another two weeks," Gunther said, adding that the tally would be in the thousands. Many fallen trees in wooded areas can be left to decay, since that process adds nutrients to the soil.

In some parks, workers have already cleaned up trees blocking roads and trails. In Central Park, where 650 trees were destroyed or damaged by the hurricane, forestry crews have piled trunks and branches near the park drive at 102nd Street. The mound reaches 20 feet high and runs the equivalent of two long city blocks.

Gunther said that, as in past storms, trees of all types were vulnerable to the hurricane’s high winds, from younger ones with shallow root systems to mature specimens with large canopies that acted as sails. Under Mayor Michael R. Bloomberg, the city has started a campaign to plant 1 million new trees, and Gunther said that he had noticed that the storm had claimed some of the new additions. "Some were under warranty and we’ll replace them as soon as possible," he said.

Given the estimated 2.5 million trees across the city, both in parks and on streets, the storm’s mischief might seem negligible. Yet parks officials say that the very large trees that tumbled down would take decades to replace.

"Each tree is giving its block and community a suite of environmental benefits," Gunther said, referring to positive effects on asthma rates and so-called urban heat islands. "In terms of population numbers, it sounds like a drop in the bucket. But in terms of the environmental benefits, it’s a big loss."

If there was any upside to the mass casualties, it was the cycle of death and life that the storm accelerated. As trunks and boughs were fed through a grinder in Cunningham Park, they added to a mountain of wood chips. Those chips, Gunther explained, would become next spring’s mulch, which the parks department will use on tree and flower beds to keep moisture in and weeds out. "We will have a ton of mulch," he said.