Wildlife management areas like these woodlands just outside of Bald Knob are protected public land set aside by the Arkansas Game and Fish Commission to conserve The Natural State’s wildlife and promote outdoor recreation. Hurricane Lake WMA is best known for its greentree reservoirs, human-made wetland structures that attract ducks — and duck hunters — from miles around.
Levees built around the forest are designed to hold water on the forest floor, imitating the seasonal flooding that occurred naturally in bottomland hardwood forests across the Mississippi Delta before dams and levees tamed the major rivers. Most of those ancient bottomland woods were long ago cleared for timber and to make way for agriculture.
A greentree reservoir is meant to reproduce a flooded forest environment in a controlled manner. Extensive hydrological infrastructure gives land managers control over the timing and depth of floods, allowing them to open and close gates to adjacent waterways. The Game and Fish Commission manages more than 50,000 acres of greentree reservoirs spread across more than a dozen wildlife management areas in the state, and private landowners manage reservoirs of their own. That’s made Arkansas a duck hunting destination.
Yet many of the forests are in poor health. For decades, scientists say, land managers flooded them too early and too deeply, and for too long. What was once believed to be the best strategy for conserving migratory waterfowl populations has inadvertently decimated the cornerstone tree species — specifically red oaks, like willow oaks and Nutall oaks — that make these precious wetlands attractive to ducks.
A 2014 Game and Fish Commission survey of willow oaks in the state’s greentree reservoirs found that 40% of the trees were already dead or irreversibly damaged.
While many private duck hunting clubs have modernized reservoir infrastructure and management strategies for their members, public lands have fallen behind. Now the Game and Fish Commision is trying to make up for lost time. But infrastructure updates alone could cost upward of $70 million over the next 10 years, according to an agency spokesperson.
Last fall, the agency announced major changes to water management plans at three of the state’s most popular greentree reservoirs, including Hurricane Lake WMA. The agency chose not to intentionally flood these highly sought-after hunting grounds during the 2021-22 duck hunting season, which ran from late November through January. The flooding regime will also shift so that the reservoirs are filled more slowly and to depths that will vary with the seasons of nature, not the hunting calendar.
It’s an investment in the future that ruffled feathers among some Arkansans frustrated by disruptions to access to public lands. The Game and Fish Commission hosted town halls across the state last year to educate duck hunters on the science behind the changes and build trust in a strategy that could take many years to show results. At one such event in November in North Little Rock, more than 100 community members attended a presentation and asked questions of state wildlife managers.
“I know people are bothered because they want to duck hunt this year. But I’m thinking 30 years from now,” said Jessica Homan, a biologist with Game and Fish. She wants to preserve this habitat not just for today’s hunters, but for generations to come. “I can’t do that if I don’t make changes now,” she said.
IF YOU BUILD IT, DUCKS WILL COME
The gleaming emerald plumage of a male mallard duck — and the flash of iridescent blue on the wings of the refined females — make this species “the poster child of the duck,” habitat biologist Jake Spears said. Mallards are the most abundant duck species in North America and are particularly important to hunters in Arkansas.
“More mallards spend their winter in Arkansas than any other state in the country,” said Spears, who works for the nonprofit waterfowl conservation group Ducks Unlimited. Mallards are good table fare, readily available and fun to hunt, he said.
“If they’re circling your decoy spread and you hit the call, it’s pretty magical to see them actually respond, turn and come start flying back towards you,” Spears said.
Though some mallards live in one place year-round, others prefer to breed in the northern United States and Canada before migrating south to spend the winter in habitats where food is easier to find.
Filled with starchy acorns and protein-rich invertebrates, Arkansas’s bottomland hardwood forests fit the bill. Though these wetlands once covered around 5 million acres of the state, more than 60% have been destroyed.
The first greentree reservoir was created by accident. In the late 1920s, a rice farmer near Stuttgart looking for a way to store irrigation water built a levee around the woodlands abutting his fields. The artificially flooded timber resembled the natural wetlands once prevalent throughout the state, and the ducks arrived in droves. Soon, private landowners across the state began building these modified forests, and the Game and Fish Commission recognized an opportunity to create its own greentree reservoirs on public lands.
“We have a lot of different habitat types that people can hunt on, but hunting in a greentree reservoir is the top of the line,” Homan said. “That’s what people want.”
Tens of thousands of duck hunters now seek out flooded timber and rice fields every year, according to the Game and Fish Commission.
But after more than 50 years of artificial flooding, the trees have paid the price. Without drastic changes, there may be nothing for the next generation of hunters to enjoy.
THE TREES ARE SUFFOCATING
The problem is that, like us, trees breathe. Though plants create their own food by taking in carbon dioxide and releasing oxygen through their leaves — a process called photosynthesis — they still have to convert that food into usable energy. This second process — called cellular respiration — requires oxygen gas and is the same reason humans need air to survive.
Tree roots do an excellent job of “breathing in” oxygen from the porous soil during the growing season. When the trees lose their leaves and go dormant in the fall, their energy needs decrease dramatically. This generally happens around the same time of year that water levels begin to rise on the forest floor, which saturates the soil and pushes out the oxygenated air.
If trees are flooded before they go dormant, or if water is still standing on their roots after they start waking up in the spring, they start to drown.
Cypress and tupelo species in greentree reservoirs are the most resilient to flooding, but what the ducks want are acorns, Homan said. Biologists working in these wildlife management areas began noticing forest degradation at some reservoirs in the early 1980s, but it wasn’t until the early 2000s that scientists discovered how poorly — and disproportionately — the keystone oak species had fared.
Looking out across the forest at Hurricane Lake WMA, the trees show a dark green watermark left behind by previous years’ floods. A natural bottomland hardwood forest would only hold water about a foot deep, but the sludge stains on these trees show they’ve been steeped in stagnant pools at least 5 feet deep. That has caused the base of their trunks to distend in what forest managers call “butt swelling.”
Above the waterline, you can also see open, weeping cracks where the trees’ bark has split open. Homan, who is working on restoring the forest at Hurricane Lake WMA, said these are all signs that trees are struggling to take in oxygen.
“The trees [have] just got to the point where they do what they need to do,” she said. “They’re being suffocated.”
A 2014 study of one greentree reservoir by Game and Fish Commission staff showed that 82% of willow oaks had been damaged by flooding, almost half of which were dead or irreversibly compromised. Of the two families of oaks found in greentree reservoirs, red oaks — such as willow and Nuttall oaks — are faring worse than white oaks like overcup oaks. That’s more bad news for ducks, because only red oak species produce acorns small enough for mallards to eat.
In a naturally flooded forest, insects thrive in sunken leaf litter and topsoil. But invertebrate populations suffer in the stagnant, nutrient-poor water of a greentree reservoir that’s been flooded too deeply, Homan said. This deprives ducks of another crucial food source to help them beef up for their spring sprint north.
MOVING LIGHT AND WATER
Though the Game and Fish Commission has been aware of the issue for years, it has only recently taken sweeping steps toward addressing the problems facing greentree reservoirs on its lands. Agency officials say that it’s taken time to conduct the forest health and hydrology studies needed to design an effective restoration strategy. This data has been important for building trust with land users and securing the necessary permits and money to execute the agency’s plan.
One such project was completed in December 2021 when the Game and Fish Commission installed a $2.8 million infrastructure upgrade at Hurricane Lake WMA that should make it easier for land managers to move water off the reservoirs. Of that amount, more than $1 million was contributed by Ducks Unlimited. The conservation group has secured a grant for an additional $2 million for continued work at the site.
If land managers can keep the land dry, the final step is to propagate the next generation of red oaks. Saplings need at least five years of healthy growth before they can withstand a full flood season, and these small trees need enough sunlight to establish a strong root system. Now, forestry specialists with the Game and Fish Commission and its partners are selectively killing undesirable trees and clearing underbrush to get light on the ground for the young red oaks in some reservoirs.
“If we can get some good establishment of seedlings and [the greentree reservoirs] can be drier longer into the season, I think we can really kick-start the forest,” said Douglas Osborne, a waterfowl ecologist with the University of Arkansas at Monticello and the Five Oaks Ag Research and Education Center.
Though many hunting clubs have already modernized flooding practices on privately owned greentree reservoirs, their membership fees can be expensive. That means hunters who rely on public lands could be disproportionately affected by restoration-related closures on WMAs. But this is also why it’s so important to take proactive steps to preserve this natural resource, according to hunters like Morgan Harris of Prairie Grove. Harris is an executive member of the Arkansas chapter of Backcountry Hunters and Anglers, which advocates for the protection of public lands to promote outdoor recreation.
Harris hunts on greentree reservoirs in eastern Arkansas and other states and says these wetlands are his preferred duck hunting grounds by far. He and other hunters have been frustrated by the recent disruptions, Harris said. But he also understands that flooded timber is doomed without drastic interventions.
“[The Game and Fish Commission] is going about the science and restoring these habitats in the right way,” he said. “I think long term we — the general public — will be much happier knowing that we took the time and the means available to us to improve these habitats.”
PLAYING THE LONG GAME
These steps are the first in a long-term restoration strategy that could take many years to show results. And due to the cyclical nature of climate systems and waterfowl migration patterns, scientists still have many questions about how current efforts will play out. In addition to studying forest composition, Osborne and his colleagues are tracking the movements of ducks fitted with satellite transmitters to better understand how waterfowl move through the reservoirs.
“We’re trying to let the mallard tell us what the forest needs to look like,” he said.
The restoration effort is further complicated by shifting weather patterns in the region. Though Hurricane Lake WMA remained dry enough for Game and Fish Commission construction crews to work through December, the last few years of wet winters have filled many of Arkansas’s watersheds to overflowing well into late spring. And wet cycles like this may become more frequent due to changing climate patterns that have increased flood risks across the southern United States.
Much of the flood control infrastructure built by the U.S. Army Corps of Engineers in Arkansas was authorized because of a similar series of wet seasons in the 1920s, said Mike Biggs, a hydraulic engineer with the agency’s Little Rock District. For example, the Corps operates dams on the White River for flood risk management.
When Corps reservoirs in North Arkansas grow full, engineers slowly release water into the White River Basin. That water eventually makes its way to Central Arkansas and onto Hurricane Lake WMA and other greentree reservoirs. Even with a key to the floodgates, Biggs said, the Corps only has control over about 45% of the water in the White River Basin.
“We’re pretty good at doing what we do, but Mother Nature always bats last,” he said.
Because Arkansas typically gets less rainfall in autumn, Game and Fish Commission land managers have less trouble controlling water levels on greentree reservoirs at the beginning of waterfowl hunting season. But the combination of upstream releases and increased precipitation creates a big problem in the spring, when it’s time to move water off the forest in time for the trees to start a new growing cycle, Homan said.
The changing forest composition on greentree reservoirs could have long-lasting implications not just for waterfowl, but also the songbirds and mammals that subsist on the bounty of oak trees. Only time will tell if these efforts are enough to restore the hardwood stands remaining on Arkansas’s public greentree reservoirs.
Looking out across the dying oaks at Hurricane Lake WMA, Homan says she doubts she’ll see the forest restored during her career. “It’s sad, but it’s also hopeful,” she said. “We’ve done a lot of work and I’m seeing progress, but it’s going to be a long-term project.”
This story is courtesy of the Arkansas Nonprofit News Network, an independent, nonpartisan news project dedicated to producing journalism that matters to Arkansans.