MOSCOW—In the 1950s, the Soviet government set aside a bit of land on the Moscow River for Maria I. Gurlynina's family and several dozen others to grow food. It was a barren plot, “;nothing but sand and swamp,”; Gurlynina said. But it was theirs.

Her family carted in soil and planted apple trees and berry bushes. Her grandfather died hauling in a heavy load. But several birch trees that he planted decades ago still stand in front of the family's gingerbread-style cottage, built in recent years.

“;They gave us this land and told us to develop it,”; Gurlynina, now 78, said. “;They said we could stay here forever.”;

Then, early one morning last year, the bulldozers arrived.

The municipal government had declared that the Soviet-era permits giving Gurlynina and her neighbors use of the land were invalid, and it had ruled that the 200 or so homes in Gurlynina's community, called Rechnik, as well as dozens of others in a neighboring community, had to be removed. Moreover, the city said, the residents would have to pay for the demolition themselves.

It is a predicament not uncommon in Russia. The Soviet government's land monopoly may have ended some two decades ago, but the ability of the authorities to give and take away territory has not, real estate experts here say.

While private land ownership is not forbidden today as it was in the Soviet era, current real estate laws are vague: Residents can buy homes and apartments, for instance, but not the land they stand on. In all cases, people are left open to the caprice of corrupt officials and businessmen.

In Moscow, where space is limited and valuable, the problem is most acute.

“;In different corners of Moscow, people are trying to defend their courtyards,”; said Yelena S. Shomina, a housing expert at Moscow's Higher School of Economics. City officials, she said, “;calculate not the losses to the family, but the losses to the construction company, which are losses to the city government.”;

Government critics have accused the Moscow authorities of using ambiguous land laws and the ignorance of residents to snap up lucrative plots and resell them to private interests.

Yelena Baturina, the wife of Moscow's powerful mayor, Yuri M. Luzhkov, is a billionaire who is one of the city's most successful real estate developers and Russia's richest woman. Her company, Inteko, has benefited from several major Moscow government contracts.

On the day the bulldozers came to Gurlynina's neighborhood, dozens of homes were demolished. Their owners were denied compensation and had to seek new housing on their own. Gurlynina's house still stands, but the government has vowed to tear it down along with others before winter.

Officially, the government plans to turn the area into a nature preserve, though for many residents, the golf course and newly built gated neighborhood called Fantasy Island up the road suggest other intentions.

Rechnik was originally founded as a gardening collective in 1956 for employees of the Moscow Canal, a water transportation route, which was dug mostly by prisoners and connects the Moscow and the Volga Rivers.

The workers were given a strip of land along the Moscow River to “;plant fruit trees and berries,”; according to a copy of the original agreement. Though under Soviet law they could never own the land, the agreement granted the workers its “;perpetual use.”;

In the years since, the region has become an oasis in this sprawling city. On a recent visit, the leaves were a rich gold, and a frost gilded the last of Gurlynina's roses. The birches have grown tall and thick in the last half-century, and gardens bring bountiful crops of apples, plums, berries and other produce, residents said.

In the legal vacuum that followed the Soviet Union's collapse, many of the original canal workers began passing their plots to their children or selling them, believing their lengthy stewardship of the land gave them the right to do so. The new owners have built sturdier and more luxurious homes, despite having no titles for the land.

As Rechnik has grown, so has the city around it. Today, the view from the river is obscured by gaudy high-rises that have been the hallmark of a Russian construction boom only recently curtailed by the economic crisis. As space has shrunk in Moscow, this sparsely populated property just inside the city's last ring road has grown more attractive.

City officials did not respond to numerous phone messages seeking comment on their plans for Rechnik.

But the Moscow government has said that the Soviet-era agreement on Rechnik does not envisage permanent housing or allow workers to pass on or sell their plots to others. Officials have also questioned the legitimacy of the original Soviet-era decision to hand over the land and have declared the region a protected ecological zone.

“;These are not residents here; they are temporary occupants,”; Luzhkov, the mayor, said during a visit to Rechnik in 2007 covered by Russian television. “;This village, like any other illegal construction in the city, does not have a right to exist.”;

Because laws on land ownership remain incomplete and cumbersome, it is not clear who in this case and many similar ones throughout Russia is legally in the right, said Dmitri I. Katayev, a former Moscow City Council member who helped draft the first property laws after the Soviet collapse in 1991.

Though there are bureaucratic mechanisms in place for Russians to assume ownership of former communal apartments and private homes, he said, “;The government just forgot about the issue of land.”;

Residents of Rechnik say the government has ignored their requests to register their homes even without the land they sit on.

Whatever the law, the government has the upper hand. Two years ago, the city cut off water and power to Rechnik. Today, the residents who still live there full time rely on generators.

Still, other than a few half-hearted protests, many residents—many of them elderly—have put up little fight to save their houses, in part because the concept of land ownership still escapes them, said Yuri A. Kladov, a member of Rechnik's self-appointed administrative council.

“;It turns out that the people of Rechnik are unprepared to see themselves as owners of this land,”; he said. “;This is a throwback, dating to the days when we had no rights. A person could not do anything for himself or think for himself and did not want to.”;