Jerry Boardman doesn’t remember exactly when he started collecting acorns in the fall.

But the thousands upon thousands of them he gathers to share with people working to improve habitat along the Mississippi River makes the 81-year-old resident of De Soto, a village of about 300 between La Crosse and Prairie du Chien, a pretty big deal.

“It’s like a myth or a legend,” Andy Meier, a forester for the U.S. Army Corps of Engineers who receives a portion of Boardman’s bounty, said of the integral role it plays in his work. “It just has always been that way.”

In reality, Boardman began collecting around the time that the need for acorns — a nut that contains the seed that grows oak trees — was becoming critical. For the past few decades, the trees that grow in the Mississippi River floodplain, known as floodplain forests, have been struggling. Although they’re named for their ability to withstand the river’s seasonal flooding, they’ve recently been overwhelmed by higher water and longer-lasting floods.

More: The Mississippi River’s floodplain forests are dying. The race is on to bring them back.

More: What to know about floodplain forests, a struggling ecosystem on the Mississippi River

Overall, forest cover along the stretch of the river from Minnesota down to Clinton, Iowa, decreased by roughly 6% between 1989 and 2010, according to a 2022 report on ecological trends on the upper Mississippi. In the years since, losses in some places have neared 20% — and were particularly acute following a massive flood event in 2019.

What exactly is driving the excess water isn’t fully fleshed out, but climate change and changes in land use that cause water to run off the landscape faster are likely factors.

The result is mass stretches of dead trees that can no longer perform their functions of providing wildlife habitat, sucking up pollutants that would otherwise run downriver, and slowing water during floods. Reno Bottoms, a sprawling wetland habitat on the river near Boardman’s hometown of De Soto, is one such example of the dispiriting phenomenon.

Boardman, who has been a commercial fisherman, hunter and trapper on the river for most of his life, called the change in forest cover in recent years “shocking.” To combat it, he puts in about 100 hours a year between August and October gathering acorns from the floodplain in De Soto, Prairie du Chien and La Crosse. The idea is that if the trees that produced the acorns were successful enough at warding off flood damage to drop seeds, those seeds might be similarly resilient if replanted.

He looks for acorns from the bur oak, pin oak and swamp white oak, the latter of which is particularly well-suited to the floodplain forest. And the numbers he puts up are impressive — last year, he collected about 130,000; this year, 65,000.

He splits up the total to give to the Army Corps and the U.S. Fish and Wildlife Service, both of which have foresters planting trees to restore floodplain habitat.

“Pretty much everything that Jerry collects, in one way or another, will return to the river,” said Meier, with the Corps.

Last fall, for example, they scattered between 20,000 and 30,000 of Boardman’s swamp white oak acorns near McGregor Lake, a river backwater near Prairie du Chien where the Corps is piloting an effort to protect trees from flood inundation by raising the forest floor a few inches.

More: A new technique could help save the Mississippi River’s floodplain forests: raising the forest floor

This spring, Meier said, he was “blown away” by the approximately 1,000 seedlings that had taken root there and begun to sprout.

Having access to Boardman’s acorns is important because it gives foresters the chance to experiment with direct seeding, instead of buying young trees and planting them. Direct seeding is both cheaper and more likely to result in a viable tree, because the seed is local.

“When we have an opportunity to get something we know came from the river, we know that it’s adapted to growing there,” Meier said.

To maximize his time, Boardman uses a contraption not unlike ones used to pick up tennis balls to scoop up the acorns. One small variety, though, requires collectors to “get down on your hiney or your knees” to pick them up, he said. For those, he relies on a little grunt work.

Ev Wick, a fifth grade teacher at De Soto’s Prairie View Elementary, has taken his students out for an acorn-gathering day with Boardman for the past several years. Boardman scouts the best trees ahead of time, Wick said, then the kids get to work. They can pick up between 5,000 and 6,000 in a day, propelled by friendly competitions to see who can collect the most or fill their bucket quickest.

They’re interested when Boardman tells them all the acorns they collect will eventually be planted on the islands they see in the river, Wick said. But most of all, they do it to thank Boardman for taking them out fishing and ice fishing in the winter and spring.

Acorn-gathering is just one of Boardman’s talents. Along with other members of Friends of Pool 9, a group of area residents who work to protect natural resources, he hosts fishing days, runs river cleanups and counts bald eagle nests to report to the Fish and Wildlife Service.

Whether it’s acorn-related or otherwise, Meier said it’s amazing to see the commitment Boardman has to ensuring the river continues to thrive.

To Boardman, the chance to donate acorns or otherwise help out is a no brainer.

“That river has given me so much,” he said. “I’ve just got to give back all I can give.”

More: 240,000 acres of the Upper Mississippi have been unspoiled for 100 years. But concerns mount.

More: Dutch elm disease came first. Then emerald ash borer. Now, an urgent push is on to restore trees.

Madeline Heim is a Report for America corps reporter who writes about environmental issues in the Mississippi River watershed and across Wisconsin. Contact her at 920-996-7266 or mheim@gannett.com.