Saturday, January 31, 2009

On the Springfield Plain

Located on the southwestern edge of the Ozark Highlands, the Springfield Plain is a broad, smooth plain rich with karst features. Relief is slight here, averaging 150 feet, with most changes in elevation occurring primarily in the dissected streambeds that punctuate the landscape. The gently undulating topography fails to suggest to the average visitor to the area that the Springfield Plain represents some of the highest ground in Missouri. Thanks to a few hundred feet, the highest point in Missouri is on a dramatic igneous knob in the St. Francois Mountains rather than in a fescue field outside of Springfield.

Small springs are common on the Springfield Plain, feeding small streams and creeks throughout the region. Journals of early settlers to the area convey the significance of water features to settlement patterns, reiterating that families and native American tribes wouldn't live in a given area were it not for the springs. Because of the high elevation, the waterways that begin on the Springfield Plain radiate downward and often represent the headwaters of major rivers: The Sac River flows north into the Osage; the James and Finley Creek flow into the White River; the Spring and Shoal Creek feed the Neosho. Sinkholes are common here as well, now often used for livestock watering purposes.

Sloping off the dome of the Ozark Highlands, the high structure of the Springfield Plain is based on Mississippian limestones and chert. Soils here were once very deep, giving rise to vast stretches of prairie and savanna with open woodlands occurring along streambanks. Few traces of the historical landscape remain today as much of the area has been converted to agriculture. Native woodlands and savanna are unknown today in the Springfield Plain and most of the prairie has been planted in fescue or overgrown in invasive trees.

The Springfield Plain stretches from Hickory Co. in the north to Barry Co. and the Kansas and Oklahoma borders to the south and west. It's a large area that includes roughly 80,000 acres of public land. Few of these areas represent the native natural communities, and while they provide recreational opportunities like hunting and fishing, few if any ecosystem restoration projects occur here. Despite this fact, over 800 records of 145 plants and animals listed in the Heritage Database can be found in this subsection. Several can only be found in Missouri on the Springfield Plain. Among them, the diminutive Missouri bladderpod (Lesquerella filiformis), a federally listed species whose range in Missouri is relegated to a very small area of limestone glades in the Springfield Plain. (A hearty thanks to the fine folks of the Arkansas Natural Heritage Program who found this plant in Arkansas, quelle surprise, thus knocking off our list the only plant once thought endemic to Missouri's Ozarks. For every plant we find here, botanists in Arkansas find it there, too. Gah-lee. Isn't that just grand.)

So I headed south to Greene Co. recently to see the limestone glades that host bladderpod populations, prickly pear cactus, lemon-mint monarda and other glade plants. My colleague stationed there had big restoration plans for his tiny, degraded patch of land. Once hosting tallgrass prairie and post oak savanna with thick, knee-high bluestem, this small area has been converted to fescue pasture with third growth, weedy trees surrounding his limestone glade. The 6 spring branches that once coursed through the landscape here were dammed years ago to create a fishing pond, stocked with bluegill by a state agency.

Several weeks ago, I ordered land survey notes for the 400 acres so I could understand the character of the pre-European settlement landscape before we launched into a landscape restoration project (Fascinating documents, survey records, and you can order them for your own land, too! Contact the Division of Geology and Land Survey in Rolla with your Township, Range and Sections and they'll send you copies of the original survey records listing witness trees, the quality of land, and sometimes personal notes about the hardships of traversing the land, how cold it was, how thick the grasses were...Surveyor Moulder was particularly chatty in his records). As suspected, based on existing landforms and topography, prairie once dominated the landscape here. However, the land was "very hilly and stony, unfit for cultivation." Thick woodlands were uncommon in this part of Greene Co., attested by the surveyor's notes of "timber very thin with post oak, black oak, chinquapin, hickory and undergrowth of hickory and some hazelnut." Fire tolerant trees like these thrive in fire-dependent savanna landscapes. The small limestone glade that hosts Missouri bladderpod (or Arkansas bladderpod, or whatever) was described as a "ledge of limestone, good soil but too hilly and rocky for cultivation. All very thin timbered with pin oak, black oak and hickory."

As the land exists today, the limestone glade represents the only native natural community on the whole property. A small walnut grove described in the survey records no longer exists, and speculation holds that it was anthropogenic in origin to begin with, planted by native American tribes in the area. Successive burning has brought back some diversity in the historic prairie, Indian grass and big bluestem coaxed out of the fescue. My colleague has cleared cedars from his glade, an area so small in scale that it may officially be classified as a barren rather than glade.

But when the enthusiasm is there -standing right before me holding survey records!- to restore a prairie, barren and woodland to its natural state before settlers removed all the characteristic old growth trees and seeded the prairie with fescue, it's near impossible to dismiss the landscape, to swat it away as a lost cause. 400 acres in Greene Co. will never fully represent the native state of the Springfield Plain, but it's a start.

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