Iraq's once-extensive southern marshlands, a region many consider the site of the biblical Garden of Eden, are slowly refilling with water after their almost complete drainage by Saddam Hussein's government. But the results are uneven and experts predict that only a fraction of the area can be restored.

By the time U.S.-led forces ousted Saddam Hussein two years ago, 93 percent of southern Iraq's wetlands had turned into a dry, salt-encrusted wasteland. The Iraqi dictator had ordered the water dammed and diverted for almost two decades, in part to punish the indigenous Marsh Arabs who opposed his rule.

Duke University ecologist Curtis Richardson says the desertification not only severely diminished the habitat for a variety of wildlife, but also impoverished a 5000-year-old culture of up to 500,000 people whose lives depended on fishing, raising water buffalo, and living on artificial islands in houses made of native giant reeds.

"It's a great tragedy once you go there to see,? he said.  ?Some of the things that really shocked me once I got there, first of all, was the abject poverty of the individual people who are there. The actual Marsh Arabs themselves basically are without a home, basically driven into Iran, 75,000 to 80,000 of them living in tents for almost a decade."

Mr. Richardson led an international group of experts who studied the soils, water, plants, and animals in the region under a U.S. government grant. Their analysis published in the journal Science finds that nearly 20 percent of the drained wetlands are filled again since Saddam's overthrow. The inflow has occurred because the Iraqi government and local citizens have rediverted water and because of high rain and snowfall in the Tigris and Euphrates River watersheds that supply the marshes.

As a result, half of the wild animal species have returned, as have thousands of displaced people.  Plant life is also coming back, according to Barry Warner of the University of Waterloo in Ontario, Canada, who worked separately under Canadian government funding.

"At least so far, provided that they are connected with the main water system and the water is there, the plant communities in the newly rewetted areas resemble the kinds of plant communities that existed in the early 1970s prior to destruction," he added.

But marsh restoration is failing in other areas. An excessive buildup of natural salts in some drained locations has prevented marsh plant life from returning after reflooding, especially near the Persian Gulf. The scientists also found abnormal increases of a naturally occurring toxic metal called selenium. However, they say the water flowing in from the Tigris and Euphrates Rivers is of higher quality than they had expected because of low amounts of pesticides and other toxic chemicals.

The researchers warn against expecting a complete restoration of Iraq's southern wetlands. They estimate that perhaps only 30 percent can return to its original state. The actual proportion depends on how much water is actually flowing into the system and on further studies that show where high salt content and toxic chemicals will prevent redirection of the water.

The team member representing the U.S. government's Agency for International Development (USAID), Peter Reiss, does not want to make a firm prediction.

"What we're all trying to do, all of these donors -- the U.S., Canadians, Japanese, Italians, UNEP -- are trying to have a comprehensive strategy for the marshes with the government of Iraq government in the lead to be able to come up with a reasonable number to answer that question within about a year," said Mr. Reiss.

Duke University's Curtis Richardson cautions that neighboring Iran and Turkey could impede Iraq's marsh rebuilding by holding back some or all of the water for their needs.

"Turkey and Iran control a tremendous amount of the water,? said Mr. Richardson.  ?It's a transboundary issue. Turkey could cut off almost all of the flow of the Euphrates, and, by the way, Iran is building a huge dike to cut the water off so that they can then divert the water and sell it to Kuwait. So you could have a situation where they could cut off all the water supply."

Barring such complications, Mr. Richardson says the potential for restoring Iraq's marshlands is highly promising.