Wal-Mart, America's biggest retailer, has joined an initiative to conserve the world's most valuable and threatened forests.

In an announcement Monday, Wal-Mart said it would participate in the World Wildlife Fund's (WWF) Global Forest & Trade Network (GFTN), an effort to rein in illegal and unsustainable logging. GFTN promotes "responsible management" of forests in the Amazon, Russia, Borneo, Sumatra, Congo, Mekong (Southeast Asia) and other areas where forests are threatened, according to the environmental group.

"With nearly half of the world's forests already gone, action is urgently needed," said Suzanne Apple, WWF-US vice-president for Business & Industry. "Wal-Mart's commitment to support responsible forestry answers that call to action."

"One of our goals at Wal-Mart is to sell products that sustain and protect our resources. By joining the GFTN we can further this goal by providing our customers with a reliable supply of wood products that come from responsibly managed forests," said Matt Kistler, Wal-Mart's Senior Vice President of Sustainability. "This is just one way Wal-Mart is helping our customers save money and live better."

Under the terms of the agreement, Wal-Mart has one year to complete an assessment of where its wood furniture is sourced and whether the wood is from legal and well-managed forests. Following the assessment, Wal-Mart will eliminate wood from illegal and unknown sources within five years. The company will also jettison wood from forests that are of "critical importance due to their environmental, socio-economic, biodiversity or landscape values and that aren't well-managed."

"The United States is the largest consumer of industrial timber, pulp and paper in the world," said Wal-Mart in a statement. "The U.S. is also among the top destinations for imports of wood from areas where illegal logging and trade are common, such as Indonesia, China and Brazil. Thus, the U.S. market is critical to protecting forests worldwide."

The announcement comes as pat of Wal-Mart's push towards greater sustainability. Earlier this year, the retailer committed to purchasing 100 per cent of its wild caught salmon from sources certified as sustainable by the Marine Stewardship Council (MSC) within four years. Wal-Mart has also launched "green" initiatives for its suppliers in China (where the retailer accounts for 30 percent of total foreign purchasing) and has pushed more energy efficient outlets, promoted compact florescent light bulbs in consumer-awareness campaigns, and reduced the amount of packaging used for products sold in its stores.

Some other retailers have been slower to adopt responsibly-sourced wood and paper products. Woolworth's, Australia's largest retailer, has refused to sever ties with Asia Pulp and Paper, a firm found to be conducting destructive logging of the forests of Indonesia. Instead activists say Woolworth's has responded to criticism with a greenwashing campaign to mislead consumers about the origin of its paper products.