PRINTDried Out: Lack of summer rain brings consequences for the environment
Like wildfire, drought leaves the environment devastated and ready for rejuvination
September 13, 2012 | 12:00 a.m. CST
As wildfires raged across the West, a historic drought burned the Missouri landscape into a hot, dry hell of withered plants and shrunken ponds. Although recent rains slaked the thirsty soil, the damage has been done.
The drought's affects can be seen in the food chain for animals across Missouri.
This is the sort of drought that hits once in a lifetime. But similar to a forest fire, droughts are part of nature’s balance — a ritual that feints death and destruction so new green life can rise from dried leaves, cracked earth and dust.
To see the drought from nature’s perspective, I head east to the woods, wetlands and prairie with natural history biologist Chris Newbold, who works at the Department of Conservation. He explains that nature moves in cycles, destruction can lead to growth and individual plants and animals die while other species survive.
On the Prairie
The old and the new all start with plants.
They take sun and water and turn it into food for everything they sustain. But what if there’s no water?
Our first stop is Prairie Fork Conservation Area, about 35 miles east of Columbia just outside of Williamsburg. Here, Missouri’s native shortgrass prairie, once crowded into mere acres by encroaching forest and farmland, is thriving again. Part-time prairie employees Bryan Knowles and Pat Westhoff, who joined the guided tour, point out that it’s usually not so easy to navigate through the big bluestem grass, which can grow more than 6 feet tall.
“Normally, the grass would be way over Pat,” Knowles says of his 5-foot-4-inch colleague Westhoff. “You wouldn’t even see her.”
But today, it’s easy to see her bending down to inspect aborted seed pods and withered flowers waving on stunted, dried-up stalks. Westhoff, a retired school teacher, shakes her head. “The flowers just kind of fried on top of the stalk,” she says. “They’re just brown, crunchy things.”
After a warm, wet spring, early-blooming plants rose up in earnest. The shooting stars, the violets and the cool- season grasses did just fine.
But those set to mature in summer soon withered; late-blooming plants might skip the year entirely. Wide spaces between each plant speak of missing species. This year’s prairie is too open, too quiet.
“Normally this time of year, there are insects all over you,” Newbold says. “Now there’s not much going on at all.”
It’s too early to tell how the birds and the small mammals will cope. They’re dependent on seeds and insects for food, but the open structure of the prairie also benefits them, and the arid weather helps keep quail and turkey eggs from getting too cold. It’s a balance that can easily tip.
Newbold says he saw many turkey poults early in the season, but now he doesn’t see any yearlings. Because turkeys often re-nest until they have a successful hatch, this could be positive or negative. Either the first nests were successful enough, or second and third attempts to reproduce were equally fruitless. It’s too early to tell.
Although the plants are clearly suffering, the occasional drought, even one as severe as this, can restore certain natural balances. Adverse conditions often slow the spread of more aggressive species, which allow wildflowers and other plants a chance to spread. Deep-rooted plants thrive as they reach for water out of their competitors’ range.
These prairies didn’t evolve with a life of ease, of fertilizers and irrigation. Suffering is their element.
By the Pond
The ephemeral wetlands are dry. Woody cattails protrude from cracked, dusty soil. Ponds retreat and lily pads are left on dry land beside the skeletal remains of a deer.
Part of the cycle of wetlands is to dry up. It keeps them viable and fertile as rich plant life grows and is then submerged by the returning water.
“These pools are dry as a bone this year and have been for months,” Newbold says. “Long term, it’s good for the wetlands. Short term, it’s bad for the amphibians and the crawfish. Either they’re picked up and left or they’re desiccated and gone.”
With their moist skin and amphibious reproductive cycle, frogs and toads depend heavily on water, as do invertebrates such as mussels. Some are able to leave dwindling pools in search of deeper water. But many are unsuccessful, and others, such as fish, have no way of leaving. They wait patiently for rain that never comes as their homes slowly vanish into dry air and earth.
Where there is water, it’s becoming shallower, and temperatures are rising. Hotter water holds less oxygen than cooler water, and fish can suffocate in hot, shallow ponds. The concentration can also make them easier targets for predators. Raccoons, herons and eagles can clearly see and catch trapped fish as they crowd into ever-smaller spaces.
We stop at a dry stream bed, drought-divided into puddles. A few minnows and tadpoles share the last inches of scum-topped water. As we approach, they swim a few inches away through the miniscule space they have left. Frogs wait until we’re almost upon them to jump weakly from one muddy den to another.
The fish could eventually escape but only if enough rain falls here, Newbold says.
The natural world is not without its cruelty.
In the Forest
At Whetstone Creek Conservation Area, the ground is already littered with dry, fallen leaves. The canopy is an uncertain mixture of yellows, greens and browns — far from the dense, vibrant spread that normally accompanies late summer.
Still, these trees are surviving. These woods have deep soil and cluster around ditches and riverbeds. They are less vulnerable than those in shallow soil, on hilltops and on bluffs where the bedrock comes nearly to the soil.
The trees that die in better conditions tend to be older and already stressed from external factors. More aggressive, quick-growing species also tend to be less tolerant.
Newbold says many of the trees killed by drought will benefit the forest by thinning the canopy and allowing more sunlight to get to the understory. “If it kills a tree in your backyard, it’s not very positive,” he says. “But it’s good for the forest.” It gives new trees a greater chance to grow in the opened-up spaces, often increasing species diversity.
And forests currently dominate Missouri’s natural landscape, so the drought helps the prairie region by keeping the many trees in check. “It’s similar to a prescribed burn,” Newbold says. “The drought is kind of doing that for us.”
For the same reason, conservation-managed woods see less mortality than other forests. The more drought-sensitive trees have already been removed. In natural woods, droughts, like fires, are nature’s way of thinning overstocked stands.
If the drought becomes too severe, that could change.
Trees are vulnerable this year after a dry winter and a severe lack of rain. Although some species, such as oak, are more drought-tolerant, they are not immune. Oaks that have sprung up in the middle of fields, farther from other trees and hollows where water can gather, are especially prone
to disease.
With trees concentrating their energy and resources on survival, acorn production has declined, affecting the animals that depend on them. Newbold says that there could be more does with single fawns instead of the typical twins and triplets because of the food shortage.
Emily Flinn, a deer expert with the Department of Conservation, says that thanks to a mild winter, the deer went into the summer with very good body condition. But the drought has made it more difficult for deer to forage. They’ve concentrated around the dwindling watering holes and traveled farther into human areas in search of food, leading to an increase in sightings and crop grazing. As the drought continues, stresses on deer are expected to increase as there are fewer things for them to eat. But because deer can store nutrients within their skeletal systems, Flinn doesn’t expect antler size to decrease.
By concentrating deer around watering holes, drought also increases the incidence of epizootic hemorrhagic disease, which is a yearly killer of deer in Missouri. There have already been an above average number of EHD reports, and Flinn says the disease will continue throughout the fall until the first frost.
Climate Change
With historic natural events on the rise throughout the country, many worry that droughts such as this one will become the new norm for Missouri’s ever-shifting climate. Where nature is concerned, however, experts remain optimistic.
“I wouldn’t be too concerned until it becomes a pattern of droughts over 10 years,” Newbold says.
For visible effects to change our landscape, the drought would have to repeat often over the course of a century. In such a case, the ecology of the Southwest would start to shift north. Eventually, according to Newbold, Missouri would begin to resemble the Texas panhandle. The landscape would become more grassy and sparse, populated by armadillos, rattlesnakes and gophers, as well as white-tailed deer.
“As you lose moisture, you move from hardwood forests and shortgrass prairies to arid landscapes,” Newbold says. “If climate change continues, that may happen in the next few hundred years. We don’t know if it’s going to continue.”
This summer, nature endured a drought that only comes every 100 years, but the previous three years had normal rainfall. Although there were mild drought conditions in 2006 and 2007, species have had plenty of time to recover. If the rains return next year, most species should revive.
A single drought might look striking, but it is not a concern in the long life of nature. Our native species are used to this cycle. In just a few years, lingering scars will vanish entirely beneath lush new growth.
Epilogue
Since Hurricane Isaac sent nearly three inches of rain this way, the pattern already feels broken. “I haven’t seen such a blue sky all summer,” Westoff says, as we meet by the barn once again. “The rain knocked the dust off the plants and out of the air.”
Certainly, the prairie seems greener. The trees are alive with insect noises. Crickets leap before our feet. Frogs have new energy as they dive into deeper water and float in the shade, closing their eyes to feel cool water on their skin.
But it is a temporary relief. A cloudy weekend gave the water time to penetrate the soil, but if the weather dries up again, the ponds will shrink, the trees will resume their patient famine and dust will again cloud the sky and cloak the prairie’s vibrant colors.
And all of this, from the bluestem to the oak trees, from the tadpoles to the white-tailed deer, will follow along in nature’s slow turning, withstanding our drought as they have a hundred others, because revolution and evolution are in their nature, and this is just part of the cycle.
