Monday, January 14, 2008

Upland battle




When I first moved to southeast Missouri, I decided that I wanted to learn the soils of the area. If you know the soils, you can generally assess the landscape--what should be growing where. I was almost overwhelmed by the soils of Crowley's Ridge, all complex, ancient, loess-based, Ordovician series with names unfamiliar. It didn't take long for me to learn the soils, to be able to look at a soils map of the Mississippi Alluvial Basin and determine, despite what crop was growing there presently, what should be growing there. High oak woodlands, for example, prefer the Tunica series. Pignut hickories grow on series with "silt" in the name. Cane, in particular, likes Tunica Sharkey Silt Loam. Soil series are truly fascinating; they are, indeed, the basis for our knowledge of terrestrial communities. After all, the length of time certain soils hold water, the nutrients they contain, and the rocky base upon which they rest all dictate what plants grow there. A key element in understanding all of natural history.

Since I've moved to the Ozarks, I've jumped into learning a fabulous computer program called ArcView. All of the data in this program come from global positioning units, historical maps, and other satellite-based informational sources. With a click of the mouse, you can see topographical lines, historical waterways, land types, current land uses, geology, Quaternary geology, Ordovician layers. The list goes on...all schools in the area, all water wells, every gravel road. Today, I, for a lark, pulled up all of Missouri's former missle silos. It's no surprise that they are located primarily in the western prairies, but satellite imagery merely shows depressions in the soil, all in a uniform rectangular shape.

When I started mapping the Ozark soils for the parks in the district, I was almost overwhelmed by the program (but with unflappable support from my colleagues, I tackled it). All of these series I don't know. All of the plant associations I don't know. Fifteen different varieties of the same soil, but different based on the percentage of slope upon which they are found. To show you just how overwhelming this can be, I'm attaching two maps (which I made!): the first is of a Mississippian Mound Builder site located in southeast Missouri. Dominated by recent deposits of alluvium, I know that this area, before being altered by anthropogenic forces, was once a cypress swamp and bottomland forest full of cottonwoods, ash and maples. The second map is of a small state park in the Ozarks. Within the confines of this 3,500 acre park are south facing slopes full of prairie plants, seeps, springs, caves, woodlands, savannas, even some forest. Knowing that soil maps never lie, and that you can tell a lot about a landscape based on its soils, I recognize tonight that I truly have my work cut out for me. I have, in fact, an upland battle.

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