Researchers Tracking Restoration Of Unique Wetland In Northwest Iowa
Iowa Lakeside Laboratory researchers are tracking the progress of a unique wetland in northwest Iowa that was reconstructed earlier this summer. This fen, an organic wetland fed by groundwater, near Estherville in Emmet County is one of the largest known fens in Iowa.
The U.S. Department of Agriculture’s Natural Resources Conservation Service earlier this summer removed the drainage ditches from the property that contains the fen so groundwater could flow back in. Researchers from the Iowa Lakeside Laboratory are monitoring it to see what happens. They wonder if the soil will expand as the water begins to saturate it and if native plants will return.
Rebecca Kauten, the scientist in residence at the Iowa Lakeside Laboratory, said if plant species that are unique to this fen return, the restoration will be considered a success. That includes a type of marsh arrow-grass and some rushes.
“We’ll probably see some of these plants come back,” Kauten said. “Some may be gone for good. That’s the inevitable truth of some of this.”
The team involved in the research is collecting data on vegetation and taking aerial photos of the site so they can visually document the changes over time. They’re also taking water samples from parts of the site where water is reaching the surface, to see how it changes throughout the land.
“We really have no idea what to expect,” Kauten said. “...Under ideal conditions, if [the fen] bounces back and everything is like it was in 1950, or if we see something in between that and where it was when the drainage ditches were intact.”
Kauten said the biggest noticeable change since the drainage ditches were removed is that the groundwater is already saturating the soils, indicated by the soils’ darker color. That’s despite the drought that’s affecting 99 percent of Iowa, including Emmet County.
The estimated 60-acre fen was thoroughly drained 70 years ago and farmed, “extensively altered” from the past, said John Pearson, an ecologist with the Iowa Department of Natural Resources. But Pearson said a small remnant of under an acre survived, sparking interest in if the site could be restored. Pearson has served as an adviser to the USDA NRCS’ restoration effort and to Kauten’s research.
“Some of the [species] are still there, which gives us hope that the site is restorable, or at least capable of some kind of a comeback,” Pearson said.
"We’ll probably see some of these plants come back. Some may be gone for good. That’s the inevitable truth of some of this."Rebecca Kauten
The U.S. Department of Agriculture’s Natural Resources Conservation Service got the opportunity to restore a part of this fen with a conservation easement. A little more than 56 acres of private land that contain a portion of the fen were enrolled in the NRCS’ Agricultural Conservation Easement Program as a wetland reserve easement in 2016. It took about 2 years to close on the easement with the landowner. Then the restoration plans started to come together.
Work commenced over this summer to restore the fen. John Paulin, an easement restoration specialist with the USDA NRCS in Iowa, said they first had to remove the two drainage ditches – the major disturbances – in order to restore the hydrology, the movement of water on the site.
Paulin said restarting that groundwater hydrology is the first step to seeing other pieces of the fen, like vegetation, come back.
“We are quite unsure of how many acres of the fen are actually going to be restored by our activities,” Paulin. “It’s going to rely heavily on how effective our engineering approaches to restoring the hydrology were.”
It could take decades before the fen is "fully realized," Paulin said.
The Emmet County fen, known as the “big fen”, piqued the interest of botanists and was visited extensively until the 1950s when it was drained, said the Iowa DNR’s John Pearson.
“It had many, many rare species on it. It was well-documented on these pre-1950 visits by a whole string of botanists,” Pearson said. “So we know it was a good site in good condition that had lots of various species on it.”
Fen research is limited, so Kauten hopes this research can provide a baseline for future projects like this one, in Iowa and the Midwest.
“I think in many cases, people see the alterations as so severe, as so dramatic, that there’s no looking back,” Kauten said. “…And what I’m hoping we can do is provide some optimism there. To say this was a dramatic alteration. It was a pretty dramatic restoration effort as well.”