It’s not often in Minnesota that conservationists argue among themselves about exactly which types of habitat should be established to help restore populations of ducks, pheasants, songbirds and pollinators.

But in Big Stone County, in the far western part of the state, and one of the most fertile areas of Minnesota both for farming and wildlife, that’s what’s happening.

This story begins in 1999, when retired Star Tribune outdoors writer Doug Smith reported about “440 acres of grasslands, sloughs and woods” owned by Warren Schoen, then 82 years old, of Ortonville. Schoen, Smith wrote, “has owned the rolling, lake-strewn parcel, often flush with waterfowl, deer, pheasants and other wildlife, for more than half his life.”

Schoen knew he wouldn’t live forever. But he wanted the 440 acres to continue in perpetuity as a wildlife haven, and not be converted to cropland. So he struck a deal with the Minnesota Waterfowl Association (MWA) to donate the property to a “charitable remainder trust” overseen by the MWA, with Mike McGinty, then the organization’s executive director, as trustee.

The donation reaped tax benefits for Schoen, and upon his death and that of his wife, Vera, also provided a cash windfall for the MWA and its conservation mission.

Brian Naas of the Twin Cities read the Star Tribune story about Schoen’s property and he and a partner won a closed bidding process to purchase the parcel for $331,000. A longtime supporter of state and national conservation groups, Naas paid the money to the trust, from which the Schoens, per the trust, would be paid 6 percent from the trust’s principal and accumulating interest and dividends until their deaths.

Prior to the sale closing, $96,500 was also paid into the trust by the U.S. Fish and Wildlife Service (USFWS), which used duck stamp money to buy a perpetual easement on the property, the purpose of which was to conserve its grasslands and wetlands.

According to the Star Tribune story, the service restored eight potholes on the land and planted 180 acres of native grasses as part of its easement agreement.

Also prior to the purchase by Naas, the MWA struck a deal with the U.S. Department of Agriculture to place six separate tracts of the property in the Conservation Reserve Program (CRP).

Among habitat types the CRP contracts apparently intended to perpetuate were three shelter belts — one about 5 acres, the other two smaller — consisting of about 2,100 trees. Aligned in a shelter belt designed specifically for the property by the local Farm Service Agency (FSA), which is part of USDA, the trees cost $10,000, including materials.

Planted were Canada red chokecherry, common chokecherry, native plum, red dogwood, gray dogwood and other wildlife-friendly species.

Per the sale agreement, MWA paid for the trees. But the FSA planted them.

Dates here are important:

• The CRP contracts were signed Nov. 14, 1997.

• The USFWS easement was signed Sept. 27, 1999.

• The trees were ordered in February 2000 and planted in late spring 2000.

• And Naas closed on the property in April 2000.

• • •

Given this history, Naas was surprised recently when a USFWS enforcement officer called him and said — paraphrasing here — that the service “had a problem with the trees” on his property and that (paraphrasing again) “they would have to go.”

The officer said Naas’ property had been inspected last spring and that the trees were in violation of the USFWS easement on the property. The officer also noted a few other problems, including a tote road that had been minimally improved.

But the trees were the big problem, the officer said.

To which Naas said last week: “Those trees cost a lot of money, and have been there 17 years, and were required by the CRP contracts. Or at the very least designed and approved by the USDA as part of the CRP contracts. And the CRP contracts were signed before the USFWS easement was signed, both of which were signed before I bought the property.”

Bruce Freske is district manager of the USFWS Morris Wetland Management District in Morris, Minn. The district includes not only Big Stone County but also Stevens, Pope, Swift, Chippewa, Yellow Medicine, Lac qui Parle and Traverse counties.

The Morris office has a single enforcement officer who oversees some 900 easements similar to the one covering Naas’ property and adds as many as 15 easements to the district each year.

USFWS easements are straightforward, Freske said. They’re paid for almost exclusively with duck stamp money and their primary mission is to promote and conserve grasslands and wetlands needed by waterfowl.

And research clearly shows, he said, that trees are bad for duck nests, because trees next to grass where ducks (and pheasants and other birds) nest often harbor aerial predators such as hawks. Moreover, he said, shelter belts comprising many trees often are little more than killing grounds for coyotes, foxes and skunks.

Freske conceded that trees can be good for deer and wild turkeys. But the USFWS didn’t pay taxpayer money in this instance to sustain deer and turkeys.

“I agree we should have dealt with [the Naas property] earlier,” Freske said. “But we have a huge backlog of easement violations we’re trying to dig out from under, and most of them have to do with drainage of wetlands, which we’ve been trying to deal with first.”

Freske, whose degree is in wildlife biology, doesn’t have copies of the property’s original CRP contracts because the USDA, citing privacy rules, won’t give them to him, and Naas hasn’t provided them. Regardless, when the original CRP contracts expired in 2008 and were renewed by Naas (at the urging, Naas said, of the USDA, which notified him of the renewal opportunity), the Fish and Wildlife Service easement at that time should have pre-empted the CRP renewal, Freske said.

“If [USDA] renewed [the CRP contracts], it’s not valid,” Freske said. “It’s wrong in so many ways, because the government was already paying to conserve this land according to our easement.”

Naas’ trees, Freske said, are not serving the intent of the easement. Also, he said, if USFWS can prove an easement violation on Naas’ part, it may cite him.

Naas, for his part, said he “likes the trees.” Additionally, he’s proud of the property, and thinks it serves an important conservation purpose.

“The big problem around here for ducks, as I see it,” he said, “isn’t trees. It’s all the tiling that has occurred in the area. That and the rain we’ve received is why I have water everywhere. The wetlands I bought back in 2000 are now small lakes with no vegetation.

“As a result, the duck hunting on the property isn’t anywhere near what it was when I bought the property. It used to be ‘lights out.’ Not anymore.”

danderson@startribune.com