MEXICO CITY -- The residents of Ixtapalapa did more than accept the government's call to protect the forest next to their homes. They began their own beautification campaign.
Digging into their pockets, they bought the materials to pave their streets and in lots that once were arid they planted grass and trees.
But it turns out that the forest's worst enemy is the Mexico City government, which says it is protecting the forest.
On April 1, a caravan of city trucks -- the open type which normally carry garbage here -- converged at the edge of the designated protected zone, identified by two billboards that say "construction in this area is strictly prohibited."
Out of the trucks emerged dozens of people in dusty, tattered clothes. They began to unload cardboard, tin siding, mattresses and boxes of food. By nightfall, a shantytown had been erected atop the field of saplings.
And the billboards marking the zone had been moved 500 feet up the mountainside, the residents say.
"We went to our delegate [neighborhood president] and demanded to know how this could happen," said Marycarmen Aguilar, a resident of the neighborhood which sits on a mountainside overlooking the southern half of Mexico City.
"He told us that what he was doing was perfectly legal and that he didn't have to explain one thing to us."
"It's frustrating that the government asks us to please protect the land, and then the same officials come and destroy it."
A spokeswoman for the Ixtapalapa delegate said the camp was legal because the planted area was outside the conservation zone designated by President Carlos Salinas de Gotari two years ago. Residents say the fields were included and that the signs indicating this were moved after the trucks came.
Environmentalists lament that this kind of ravaging is common throughout Mexico -- from the devastation of forests that are the winter home of the Monarch butterfly to the poisoning of lakes in Veracruz.
But they say it is especially frustrating when green space is devastated to create slums in Mexico City, where smog and overcrowded living conditions already have topped dangerous levels.
Homero Aridjis, leader of a prominent ecological group, said that while the Mexican government makes regular announcements about the number of plants it has closed because of environmental violations, it is still unable to control the most consistent violators, lower government officials looking to make a quick buck.
"Because city delegates are appointed instead of elected, they use their power to make money instead of to defend the rights of the people," he said. "The delegates sell the plots of land to the peasants and that money goes right into their pocket."
A story in the Mexico City daily La Jornada said that the city's rural neighborhoods have suffered a marked increase in the number of makeshift camps erected in conservation areas.
The camps, set up to accommodate Mexico City's burgeoning population of poor workers, often are inhabited for years without running water, plumbing or electricity.
"If the government wanted people to live there, why didn't they bring water and electricity before moving the people in?" said Mrs. Aguilar. "They know that it is easier for us to fight against machines than it is to fight against people. If we demand that these people leave the camp, where will they go?"
"They are victims as much as we are," she said.
At a heated community meeting April 1, about 300 residents of Ixtapalapa recounted the end of their conservation effort.
Daniel Alvarez, a resident, reflected on the irony of the invasion. He said that for years the community, whose population reportedly has grown 16 percent in 30 years, had been asking for more land to accommodate its growing families -- often three or ** four families share one four-room house.
The residents also wanted to build schools so that their children wouldn't have to travel to far-away neighborhoods.
But the government pleaded with them to preserve the land.
Marta Morelos, of the Ixtapalapa delegate's office, said the residents were angry because they wanted to build houses on the land and the government beat them to it.
"If we had wanted to invade the land, we could have done so long time ago," said Joaquin Salazar. "Why would we plant trees if what we wanted was to build houses."
He sighed. To the local government all that is at stake is a 3,000-square-meter plot of land, he said. But this is not the first plot of green space Mr. Joaquin has seen destroyed in his neighborhood.
"That billboard used to be hundreds of meters down the mountain," he said, pointing at the sign that marks the new, smaller conservation area.
"But as the government moves more people in, the sign gets pushed farther up the hill.
"They will keep going until not one tree is left in this city."