Even a degraded and fragmented once-frontier forest invaded by exotic species may not necessarily be gone forever: scientists practicing restoration ecology are developing techniques to regrow native forests.

One of the world's most ambitious -- and thus far successful -- forest restoration efforts is in northwestern Costa Rica, where local, national, and international researchers are together restoring a large tract of tropical dry forest in Guanacaste Conservation Area. [73]

Launched in the mid-1980s, the project features a three-pronged approach.

First, participants kicked off an aggressive fire-control program to stop human-caused fires, which were encouraging the growth of exotic grasses in cleared forest areas and killing native seedlings. Once fires were stopped, scientists allowed wind and animals to carry in native tree seeds from an adjacent national park, helping nature when there was money by planting typical species in appropriate places and combinations. They brought in cattle to help control the grasses.

Today, the incidence of fire in Guanacaste is down 90 percent, and the introduced grass, jaragua, is virtually gone from the area. Thickets of 10- to 15-foot native trees now dominate the landscape. Within 20 to 50 years, researchers expect the canopy to close, killing off all remaining jaragua and stopping set fires completely. They also hope that by then the forest will house viable populations of all the plant and animal species that once inhabited the area. [74]

References and notes

73. Such as certification efforts approved by the Forest Stewardship Council, (eg. Smartwood), which ensure that harvesting is environmentally responsible, socially beneficial (particularly to local communities), and financially viable.

74. David Tenenbaum, "The Guanacaste Idea," American Forests, Vol. 100, Nos. 11-12, November-December 1994, p. 28.