Hold That Soil, Please

Photo by Suzan Erem

Photo by Suzan Erem

 

Ours has often been a profligate society in using the vast natural resources with which it was originally endowed. We’ve improved our attitudes about conservation, but we have a long way to go. Among those resources we have been prone to waste in the interest of short-term gain has been the deep topsoil that made the Midwest superbly productive. Less than 200 years ago, according to Rick Cruse, an Iowa State University researcher, Iowa had an average of 14 inches of topsoil in which grew thousands of square miles of prairie. Now that soil is about six inches deep, less than half what we inherited—or more accurately, mostly took—from the Native Americans who first lived here.

Those estimates come from an August 12 article in the Chicago Tribune that I shall credit as the inspiration for my addressing this topic. However, those familiar with my first book, Raising Less Corn and More Hell, will be well aware that the topic is not new to me. In 1985, farmer Gary Lamb and I wrote an op-ed for the Des Moines Register decrying the lack of conservation and what it might do in the long term to the fabled productivity of Iowa farmland. In essence, we were saying, nothing lasts forever if we insist on killing the goose that lays the golden egg.

Farmers mostly tore up the prairie to plant the corn, soybeans, wheat, and other agricultural products that now grow on the vast majority of the land in states like Iowa, Illinois, Missouri, and Kansas. Prairie plants had deep roots that held topsoil in place and nurtured it. With prairie grasses removed, loose soil began to erode, clogging streams and rivers that feed the Mississippi River, which dumps its overload into the Gulf of Mexico, producing what has become known as a “dead zone.” This is an area suffering from hypoxia—a shortage of oxygen in the sea that chokes out life. This comes at the additional cost of stripping Midwestern farms of much of the topsoil with which they were originally blessed. We have unhinged that layer of topsoil by depriving it of the prairie root systems that once anchored it. In fact, we continue to do so.

But the problem is more serious and immediate than simply undermining the long-term productivity of the soil. Current practices also threaten the public health and welfare of people in states like Iowa. Not long ago, the Des Moines Water Works filed suit against three upstream counties for failing to control the nonpoint source runoff that is contaminating the capital city’s water supply. That suit is being met with a good deal of anger and skepticism, but it is symptomatic of a larger conflict. That conflict pits the priorities of agriculture versus public welfare, a dispute playing out in other forms in even larger venues like California. But there the issue often has more to do with drought and the protection of adequate water supplies than with polluted runoff. In Iowa, floods have been a more persistent danger in recent memory.

Lawsuits, however, are not the only rational response to such a major public policy problem. It is critical that public universities support research aimed at viable solutions, and at least some research at Iowa State University is pointing to an answer that should seem remarkably obvious: restore the prairie. The imperatives of modern food production may make it clear that we are not going to restore all the farmland in the Midwest to pre-modern conditions. But the prairie provides demonstrable ecological benefits that we can ignore only at the cost of prolonging current problems with flooding and water quality. In a sense, what we are learning about the value of restoring some prairie for the purpose of reducing runoff and improving downstream water quality is similar to what we are learning in more urban contexts about the value of green infrastructure—the urban forest, the green roofs, the living shorelines, and other nature-based features that enhance the environmental quality of our communities.

But green infrastructure is not a concept that need be limited to our urban areas. Nature provides vast ecological functions for human benefit in all sorts of settings if we are wise enough to investigate them and learn to use them.

In that sense, I think that Iowa State University is on to something. Researchers there have been demonstrating the value of prairie restoration with a project called Science-based Trials of Rowcrops Integrated with Prairie Strips (STRIPS). Test sites have shown not only that these prairie strips can capture much of the polluted runoff from farms and enrich the soil, but that they provide valuable habitat for birds and other wildlife, restoring some of the richness of the land in the process. For instance, one research project by Lisa Schulte and others showed that such treatments doubled or tripled the presence of bird species, both in overall abundance and variety. Other research has found that wider strips of prairie serve to trap greater levels of sediment that would otherwise clog streams and reduce water quality. It is as if, having been blind to the free benefits of natural systems for so long, we have at last begun to learn to sing nature’s tune anew.

But it will take time to change attitudes and perspectives in a farm sector that has often been rather conservative about adopting such techniques. There is still likely to be a lively debate between environmentalists and dominant sectors of the agricultural industry, with varying levels of resonance in different states, but results speak volumes and gradually help to change minds. There may be more lawsuits like the one that originated in Des Moines, and there may ultimately be some meaningful legislative debates about incentives and regulations. We can at least hope that the steady infusion of research-based information on the benefits of prairie restoration will make a difference soon enough to matter. There is certainly a great deal at stake.

Jim Schwab

Restoring the Chicago Area Landscape

Outside the Thornhill Education Center, a view of the gorgeous grounds of the Morton Arboretum.

Outside the Thornhill Education Center, a view of the gorgeous grounds of the Morton Arboretum.

Chicago is not terribly old, as world-class cities go. It was incorporated only in 1837. The area was essentially devoid of European settlers until the 19th century. In the preceding centuries, the resident Indians, including the Potawatomi, had created a landscape dominated by oak ecosystems as a result of actively managing the landscape through the use of prairie fires. On the open lands of the Upper Midwest, there were few meaningful fire breaks, and the fires drifted east over vast grasslands. This North American fire regime changed the land by preventing the establishment of woody species, allowing oaks to dominate because of their thick, fire-resistant barks. The oaks in turn allowed more sunlight through their canopy and provided a thriving ecosystem for numerous species, including more than 800 species of birds and moths that eat their leaves.

The settlers who arrived in the 19th century, however, whether wittingly or otherwise, made quick work of the landscape they inherited from the natives they largely pushed out. They suppressed the wildfires in favor of plowing the prairie soils and savannas to create farm fields. Natural wildfires are few in northern Illinois; the wildfires that preceded European settlement were almost entirely a native artifact, which served the purpose of clearing hunting grounds but also served natural purposes of preparing the land for the sprouting of prairie plants. As the oaks receded, other trees moved into the void where fields did not prevent them, and in time maples and basswood took over, followed later by the invasive buckthorn, an introduced species. Today only 17 percent as much oak coverage survives as was present in the 1830s, and the landscape is highly fragmented. By the 1930s, only one oak-dominated parcel of more than 1,000 acres remained; today none remain. The numbers of various smaller chunks of oak land have also shrunk, just as steadily.

Chicago Wilderness, an alliance of organizations dedicated to open space, and the Morton Arboretum believe the metropolitan area needs to reverse the trend soon. Last August, I wrote about the Chicago Region Trees Initiative (CRTI) being led by the Morton Arboretum. On April 7, I attended a pair of meetings at the arboretum’s Thornhill Education Center that aimed at advancing the initiative. CRTI, which benefited for a period of time starting in the 1990s from federal support for some of its environmental projects, is now seeking new sources of funds as federal grants have waned, and is sharpening its focus into six areas of interest in order to clarify its mission for potential funders. Restoring oak ecosystems is one of those six focus areas. Another is landowners; most of the land that could be used to restore the fragmented oak ecosystems is private, and its owners must not only be willing to cooperate with the larger effort, but understand the reasons for it and its potential ecological, economic, and social benefits.

Economic and social? Yes. That is part of the appeal, one we laid out several years ago at the American Planning Association with the publication of Planning the Urban Forest: Ecology, Economy and Community Development, which began with an exposition of the documented benefits of the urban forest across dimensions of human health, pollution reduction, stormwater management, energy conservation, economic development, and other factors. Michael Leff, a research urban forester at the Davey Institute, has been developing a guidance document that stresses how good urban forestry needs to take a three-part approach that is as aware of the social and economic aspects as it is of the environment. Humans are essential to the success of any ecological plan, particularly in an urban setting. Public areas of nature or forest preserves contribute only a partial solution to a much larger problem, and solving that problem contributes significantly to human quality of life. It takes considerable scientific and social awareness to make the urban forest work in a highly developed setting where ecosystem fragmentation has become the norm.

Hence the social mission of CRTI: the need to share the story of the oak ecosystem with a wide variety of audiences throughout the area in an engaging manner that motivates them to take part in the initiative and participate in coordinated stewardship efforts. In addition, CRTI is reaching out to municipal public officials and staff, including planners, to provide training around the issues of municipal tree management and a model tree ordinance that CRTI is still developing for use by communities to advance the goals of urban forestry, including the oak ecosystem restoration efforts. There is also a role for the nurseries that grow trees and a need to keep them aware and involved so that they can be supportive of the overall effort, as well as for landscaping professionals, arborists, and others. I will return to this subject as the initiative progresses and evolves.

Meanwhile, I learned at the meetings of one valuable resource of which I was previously unaware: Bringing Nature Home, by Douglas W. Tallamy, published by Timber Press. So I looked it up, and it draws rave reviews for explaining the value of native plants and ecosystems, just as people at the meeting had said. It’s probably worth a download.

 

Jim Schwab