Eliminating prairie dogs can lead to desertification

Prairie dog haters, be warned: Removing the species you consider a pest could ruin delicate lands.

North America is home to five prairie dog species, which live in various parts of the Great Plains from southern Canada to Mexico. The small, herbivorous rodents live in colonies in burrows beneath the ground. They are considered keystone species, because the loss of prairie dogs in an ecosystem leads to a large loss of biodiversity. Prairie dog burrows, for example, provide homes for many amphibians, reptiles, birds and mammals. And prairie dogs are prey for many species, including the endangered black-footed ferret. Their grazing also helps to keep grasslands open and devoid of trees.

But many people consider the prairie dog a pest, believing that they compete with cattle for grass (probably not true). Consider this recent comment on the Denver Westword website: “…prairie dogs are awful. They spawn like crazy, carry diseases and ruin whatever landscape they take over. If they’re not near extinction I see no problems with” eradicating them.

Three of the five prairie dog species, including the black-tailed prairie dog, are not threatened with extinction, so they’re not protected in any way. And so they’ve steadily been eliminated from many parts of their ranges, shoved aside to make way for humans and livestock. The black-tailed prairie dog, for instance, has disappeared from 98 percent of its original range. Scientists have documented the loss to biodiversity that comes from prairie dog eradication, and now researchers in Mexico have found that the disappearance of black-tailed prairie dogs also affects essential ecosystem services, such as soil erosion and groundwater recharge. Their study appears in PLOS ONE.

The research team studied grasslands and scrublands in the northwestern part of the Mexican state of Chihuahua, comparing three types of land: grasslands with prairie dogs, grasslands devoid of prairie dogs and scrublands that used to be home to prairie dogs and are now dominated with mesquite. In each of these three areas, the scientists documented five ecosystem services: groundwater recharge, soil erosion, soil productive potential, carbon storage and availability of forage.

For all five factors, the prairie dog grasslands won out. “Our results clearly demonstrate a strong link between prairie dogs and the provision of ecosystem services,” the researchers write.

The prairie dog’s burrowing behavior aerates the soil and distributes nutrients and organic material, generally improving the soil and helping water trickle through. As a result, the lands where they live have soils that are less compacted. Those soils can soak up more of the region’s sparse water, sequestering it for drier times. More water increases forage production, meaning there’s more food for cattle. And these grasslands store more carbon, which is a serious concern with the hammer of climate change hanging over all our heads.

Lands that have compacted soil that can’t soak up water are more vulnerable to desertification Northern Mexico, as well as much of the American West that is home to prairie dogs, has been suffering from drought, and desertification has been a concern. “Today’s environmental challenges require an understanding of the processes of ecosystems and wildlife populations and an ability to integrate scientific research into decision-making,” the researchers note. Prairie dogs, it seems, are an important part of that calculation.