THE RELATIONSHIP OF ARKANSAS DARTER AND HENSLOW'S SPARROW Wilson Springs and its grasslands Fayetteville, Arkansas The City of Fayetteville was originally located wholly within Prairie Township. The pioneers of the 1820s and 1830s who originally settled here passed through the mountainous country to the south, and settled here where the forested mountains met grassy prairies. This gave them the best of both worlds. The core of Fayetteville still is Prairie Township, though most of the original prairie is gone to homes, streets, businesses, and many tens of thousands of trees that weren't here 180 years ago. As the pioneers recognized in their practical way, Fayetteville is astraddle two ecosystems. Geologically speaking, both are sections of the Ozark Plateaus. The southernmost area is the Boston Mountains. These rugged, heavily forested uplands appear in Fayetteville in familiar places like Mt. Sequoyah and Markham Hill, and are well represented at Devil's Den State Park. The Springfield Plateau (or Plain) lies north of the Bostons. This part of the Ozarks is relatively level, has few of the Boston's rugged mountains, and includes extensive grassy prairies, many of them well-watered with springs. The Springfield Plateau forms much of the area from the Fayetteville Square northward. Springdale, Rogers, and Bentonville are built on the Springfield's old prairies. Wilson Springs, where the City of Fayetteville has proposed development of a business and technology park, is a remnant of the original prairies of Prairie Township and is typical of the Springfield. Erosion of the Boston Mountain uplands has produced soils derived from sandstone and shale conducive to tree growth. While trees will certainly grow on the Springfield Plateau, its dense clay soils, derived primarily from limestone, naturally favor grasses and hence prairie. These clay soils, derived from disintegration of the underlying limestone bedrock, also hold water. The Springfield is spring country. This is key to understanding the presence of Arkansas Darter (a small, rare fish) and Henslow's Sparrow (a small, rare song bird) at Wilson Springs, now in the middle of heavy commercial development along the I-540 bypass. Prairies in western Arkansas exhibit a pattern of low conical mounds. These formed in the geological past during a time of low rainfall when arid conditions typical of western deserts extended into what is now the eastern United States. The soils in these mounds differ from surrounding soils and hence foster local variations in associated fauna and flora. Mounds are an impediment to plowing and other farming operations. As a result, most were plowed down to near level more than a century ago, when northwestern Arkansas's prairies were converted to wheat fields. Plowing and reshaping continued with corn and other field crops. However, mound leveling was difficult in low-lying fields, because the clay soils between the mounds hold water. These fields comprised seasonally wet prairies. They remain extensively wet during seasons of rainfall. Therefore, mounds or evidence of them can still be found in such areas, including Wilson Springs and many other places in the Clabber Creek bottomlands, because they were hard to plow and of little value as cropland. During wet seasons they are full of intricate drainage patterns. These drainage patterns host many bird species, crawfish, box turtles, and doubtless others. This background brings us to the present situation with Arkansas Darter and Henslow's Sparrow. Both species occur within either designated wetlands or within the seasonally wet grassland. Bedrock below the Springfield Plateau is highly fractured limestone, which is easily dissolved by water. Underground channels form (large ones are called caves) and transport water. This transported water is termed a spring when it appears at the surface. The spring continues to flow as long as it continues to receive water from recharge zones. Recharge zones are features at the ground surface capable of collecting, holding, and releasing rainwater to the underground channels. The dense clay soils between prairie mounds are water-holding basins that help recharge springs. Arkansas Darters depend upon the surrounding former prairies (now grasslands) that holds rainwater and slowly releases it to recharge the springs. Henslow's Sparrow and other grassland birds live in the recharge zone, frequently using the old mounds and their different vegetation as song posts and likely as nesting habitat. Other than that it is rare and declining over most of its range, we knew nothing about Henslow's Sparrow at Wilson Springs prior to Fayetteville resident Mike Mlodinow's discovery of them there in 2001. Henslow's has been found in Arkansas in the nesting season on only a few prairies. The only record in the last 10 years is from a protected prairie south of the Arkansas River. We know more about Arkansas Darter, specifically that the population is vulnerable because of damage to the recharge zones from construction of the I-540 bypass, bulldozing within the wetlands, and destruction of the natural streambed of Clabber Creek. Channelization of Clabber Creek in 1990 has caused as much as five feet of downcutting in small tributary streams, changing water flows that recharge the spring, with detrimental affects to the prairie ecosystem at other levels. In short, the old prairie has been hindered in its ability to hold and slowly release rainwater. We know these rare species currently occur at Wilson Springs and its surrounding grasslands. But if the City of Fayetteville proceeds with its plan to turn the grasslands into a business technology park, can these species survive there? Could resources employed to protect these species midst a development be better invested elsewhere? "Invested elsewhere" is a non-starter. There are three known springs with Arkansas Darters in Arkansas. No other Henslow's Sparrow populations are known from northwestern Arkansas. Of course there is a need for protection of springs and seasonally wet prairies, wherever these can be found. Abandoning rare species at Wilson Springs won't necessarily lead to discovery of more Arkansas Darters or Henslow's Sparrows, no matter how much money is spent in other places. The City could modify its current plan to include protection of the entire seasonally wet grasslands, then undertake active management designed to emphasize a prairie ecosystem. It could do so in honor of the pioneers of Prairie Township. Only time will tell if enlightened proactive management would lead to retention of Arkansas Darter, Henslow's Sparrow, and other rare and declining species. In the halls of government, such proactive management could be considered an experiment in responsible use of public lands. This is, after all, a university town, which prides itself on research and bold new thinking. This is a town that broke with the bloody acrimony of the post-Civil War era and established a university rather than a klaven for the Ku Klux Klan. This is a town that enacted legal protection for trees, sidewalks, and even the visual skyline. Why shouldn't old Prairie Township now once again rise to the occasion and protect this valuable, still functional remnant of the old prairie? If in future years the experiment fails, Wilson Springs would still be out there-in the bank, so to speak--available for other uses. I don't think anyone who has lived in Fayetteville during the last two decades believes the land will lose its value just because it isn't developed now. Joseph C. Neal May 15, 2002 (revised August 22, 2002) Back  |  Home