Thursday, July 17, 2008
Leave it to the White River Hills to teach me that everything I know about landscape ecology in Missouri simply doesn't apply at the Arkansas border. I think I've explained that in the Ozarks, on south-facing slopes in dry rocky soils, you'll generally find a glade, a terrestrial community that harbors such species as glade coneflowers, side-oats grama, and in some cases, the charismatic Eastern collared lizard. Well, if you don't find a glade complete with big bluestem and prairie dock, you'll see an area choked with Eastern red cedars that could be a glade if it was managed properly (seedbanks are pretty resilient).
Glades are, for all intents and purposes, an upland community. Walk downhill from a glade, descend through (my favorite) dry chert woodlands into the deep, moist soils of north facing coves that harbor maples, basswood, ferns. Traditionally, these moist areas didn't burn. In fact, because they seldom saw fire historically, they are reluctantly labeled in The Terrestrial Natural Communities of Missouri as forest. True forest is pretty uncommon in the Ozark Highlands, the author of the book argues, except in the Current River Hills where the steep hills burned in 75 year (or more) intervals. Fire-adapted communities reign in the Ozarks, giving the woodlands a certain structure and herbaceous layer upon which early surveyors commented favorably.
I didn't grow up here. I don't own land here. But I spend most of my days tromping through Ozark woods, sometimes getting lost in an unintended effort to find what my boss calls "the sweet spots." I like to think I have some basic understanding of landscape ecology of the Ozark Highlands. And so, I volunteered for this project wherein I'm mapping the terrestrial natural communities of roughly 5,000 acres of the White River Hills. I sit here tonight, sweating, peeved that my project isn't finished yet. I thought that once I understood the landscape, these lower reaches of Missouri's Ozark Highlands, I could draw on previous knowledge of the Ozarks, consult soils maps, geology maps, and survey records to build an accurate community map. With the map, we could plan prescribed burns, ecological management projects, and even where to place a backpack camp (not in a sensitive area, by gum).
But you see, just last week, I entered the Current River Hills in an effort to develop a plant list using someone else's natural communities map for guidance. I wanted to hit the fens, the glades, the deep forested coves. Unsure how this map was made, I found myself in a typical dry chert woodland (which is fine!) that was mapped as forest. A true forest was mapped as a dry dolomite woodland. The demarcation lines on the map may have corresponded to soils and geology maps, layers, but they didn't match up to what was on the ground. Whoever made the map may not have actually stomped on the ground to see what it looked like firsthand. So my map can be used as a guide, I spend my days in the woods, merely consulting the GIS layers. Lots of fieldwork, lots of after-hours time at Cassville's nice restaurant, The Rib (spring mix salad, pan-seared walleye, serious vanilla ice cream..and they will special order pinot noir for me). I stay in these 1950s cabins with a pool, an oven for pie baking, a fire pit. If I actually tallied up my expense account for the past 3 months, I'd learn I was churning the wheels of commerce in Cassville with this project.
But this week marks a big stage in the process. By Tuesday, I realized that everything I've learned about the Ozarks simply does not apply in the White River Hills. I found glades running alongside a streambank where I expected boxelders and rushes. I traipsed through forests dominated by basswood, pawpaw, and maples on the tops of ridges where I thought glades would be. Climbing out of a steep dry dolomite-limestone woodland onto a ridgetop, I came across several acres of spicebush, ferns, and mayapples with a white oak canopy. In the Ozarks, I've learned, these plants generally don't grow on dry ridgetops. If they do, they've likely been planted or the landscape has been otherwise compromised. But down here, thanks to the deep soils on ridges, these associations are exactly where they're supposed to be. Further, I sighed in defeat after I speculated where forest would be based on trends in the landscape (expecting maple-fern-pawpaw) and instead came into a super dry dolomite glade. I was ready to quit. I felt like a fraud. What, pray tell, do I know about the Ozarks? The White River Hills are perfectly anomalous.
Unlike the rest of the Ozark Uplift, part of the White River Hills are perched on the Burlington Escarpment, a geologic structure that provides rich, limestone-basic soils to the uplands. Moist soils with chert residuum rest atop this limestone, allowing forests to occur on ridgetops. In the bottoms, areas that in other parts of the Ozarks consist of alluvial soils, Jefferson City-Cotter dolomite bedrock prevails, encouraging large swaths of glades. Glades, right to the water's edge.
The White River Hills harbor the largest acreage of restorable glades in the state of Missouri. With every bend in the woodlands, I'd walk into another glade. Check out Google Earth images of southwest Missouri and you'll see big tracts of exposed hillsides, glades in various stages of restoration. We have a long way to go for the area to resemble what it must have looked like before European settlement (or even the 1930s). But to really understand the landscape, I'll need to spend more time down there in the woods and in my cabin consulting all of my big fancy maps. I'll need to accept the bedrock geology. The White River Hills have literally turned my understanding of the Ozarks on its head, and this mapping project is proving a serious- hopefully worthwhile -challenge.
See the bright pink Sabatia angularis, a limestone bench, one of countless desmodia (Desmodium nudiflorum)--a pretty little member of the Fabaceae family, maidenhair fern, a sign of mesic woodlands and forests, and Helianthus tuberosus, called Jerusalem artichoke though it looks (and feels) a lot like bristly sunflower (H. hirsutus).
Posted by Allison Vaughn at 10:59 PM