Returning diversity - and nuts - to bottomland forests.

"They're not far away now. Up on that ridge ahead," said U.S. Army Corps of Engineers Forester Kevin Porteck as he led me through a tangled mass of nettles.

A ridge usually means a fairly drastic change in elevation. But only for those not used to rambling the bottomlands of the Mississippi River. For Porteck and follow forester Gary Swenson, ridges mean elevation rises of just a few feet above the pancake-flat mud of river islands.

When I climbed the tiny ridge I caught the forester's excitement. Before me were ancient and massive pecans, Kentucky coffeetrees, and oaks - a diverse contrast to the monotonous stands of silver maple that cover nearby islands and most of the shoreline.

Porteck dug around in the leaves and came up smiling. "Here's what it's all about," he said, as he showed me a smallish wild pecan nut. "Wildlife love pecans and acorns."

Although many foresters and most lay people assume the big river's banks and islands were always covered with pure stands of silver maple, broken by only occasional cottonwoods and box elders, Porteck and Swenson disagree.

"The islands once held stands of hard mast-producing oaks and pecans," said Swenson. Hard mast trees - including oak, hickory, walnut, and other species - produce nuts generally useful to wildlife. According to Swenson, diverse forests were cleared for farming and early settlers cut hardwoods for slae as steamboat fuel, finding pecan and oak fetched a higher price than cottonwood or silver maple.

After the Corps of Engineers bought thousands of acres of land in the 1930s to construct navigation dams, farms were abandoned. "There was no seed source remaining from many mast trees, but silver maple seeds washed in with every flood and established pure stands," said Potreck.

Swenson and Porteck found a few remaining stands of mast-bearing trees on high mounds surrounded by maples. They dreamed of restoring more stands in groves of maples and on newly abandoned farms. Section 1135 of the Federal Water Resources Act, passed in 1986, gave them an opportunity to proceed. The Act requires the Corps of Engineers to seek private funding for 25 percent of the costs of proposed projects.

Cost-sharing was a new endeavor, and it helped Corps employee Dorrie Bollman schedule plantings last fall by forging a cooperative relationship between the U.S. Fish and Wildlife Service, AMERICAN FORESTS through its Global ReLeaf Forests program, and Trees Forever, a private Iowa-based group.

In October, a contractor loaded hundreds of seedlings in boats, motored out to the Huron Island Planting Area - a complex of islands near Oakville, Iowa - and planted them in clearcuts. Other trees were planted further north at Pleasant Creek, near the town of Green Island, Iowa.

Long Island, in the Mark Twain National Wildlife Refuge, is being planted with oak, hickory, sycamore, and other trees needed by birds and animals. AMERICAN FORESTS has made this portion of the project a part of its Global ReLeaf Forests program. Supported by outdoor outfitter Eddie Bauer through its in-store and catalog "Add a Dollar, Plant a Tree" program, the plantings will stabilize soil and protect nearby communities from flooding.

AMERICAN FORESTS has pledged support over the five-year life of the project. Trees Forever raised contributions from Iowa Southern Utilities Company (now IES) and the American River Transportation Company.

Within 20 years these trees should be providing shelter for wildlife and producing nuts to feed squirrels, wild turkeys, deer, wood ducks, and many other animals. And the Mississippi bottom-land forest will be on its way back to its former diversity.