Thursday, March 22, 2012
We stepped out of the fire-mediated woodlands and glades, both rich with buttercups and phlox, the glades covered in blooming bird's foot violets, we stepped down the limestone slab steps and into the moist protected forest system of a collapsed cave. Spring wildflowers steal the show in the Niangua Basin's uncommon true forests. In this part of the Ozarks, the only areas that don't burn regularly can't burn, areas restricted to ancient sinkholes harboring glacial relicts, the protected steep north facing coves with bluebells and bloodroot, the areas that were once underground.
So we entered the collapsed cave to find the whole suite of wildflowers: anemones carpeting a slope, the leaves of Hydrophyllum appendiculatum, Dutchman's breeches, pale corydalis, and of course, the requisite bottoms full of bluebells. These uncommon areas harbor Dirca palustris, enormous basswoods and sugar maples, these areas do not see fire. They didn't historically, and they don't today. The primary disturbance factors in forested areas are wind storms, ice storms, heavy snow events--these disturbances, rather than resulting in a slicked off landscape like a burned woodland, cause in tact forests to typically possess downed logs, perfect for mesic-loving salamanders like the little four toed salamander (restricted to sinkholes in the Niangua Basin).
My colleague charged ahead as I focused my almost-dead 100$ camera on a lovely patch of Dutchmans breeches. He settled on a mossy downed maple that's been there since the windstorm of 04, and peered over the bed of bluebells as the water dripped off the former cave roof and onto a series of boulders covered in walking ferns. The forest here is so very unlike the rest of the area, and just on the ridge outside of the forest stands a gnarled (fire-loving) post oak averaging 300 years old. The diversity of the landscape here is remarkable.
When I arrived at the sitting log, my colleague stood up to walk towards the bluebells and muttered "what is that....what is that..." Just past the bluebells, one pale corydalis poked through a thick mat of green vining vegetation. A Dutchman's breeches could be seen nearby, but the whole area past the bluebells was covered in a thick mat of a Veronica, a lawn weed, but we didn't know which one it was.
Away from the new Yatskievych Flora of Missouri, hours later we discovered that the dense mat of vegetation smothering the spring wildflower display was Veronica hederifolia, ivy leaf speedwell, not documented in Missouri in the 1963 Flora. This little exotic lawn weed is actually allelopathic, and is becoming troublesome in not only America but in China as well. Many of the species of Veronica seem to remain loyal to lawns, mowed areas, yards, but this one is in an ancient forest setting and causing serious problems.
We alerted the folks in charge here who went out the next day on a hand pulling exercise, the best way to treat this relatively new-to-Missouri exotic species. Speculation regarding its source population continued through dinner: on the terrace above the bottoms filled with wildflowers is a wildly popular footpath. Thousands of folks from urban areas like St. Louis visit this trail. Seeds from a hiking boot that had stomped through a yard or another compromised area could have quite easily traveled downslope into the lowest reaches of the forest.
Natural landscapes of high integrity are becoming less common in Missouri than even 7 years ago. Bush honeysuckle has run amok through closed canopy woodlands and forests. Miscanthus has compromised glades in the White River Hills country. Oh, and the list continues. I truly believe that if you have a healthy ecosystem, one that hasn't been damaged by grazing, logging, other forms of land abuse, and the proper disturbance factors are employed, high quality sites are resilient with native vegetation so thick that exotic species can't take hold. But the threats are great, ever burgeoning, and with the continued fragmentation and development at natural area borders, with exotic species vectors increasing, one must be vigilant. Constantly. Even on a casual walk through the woods to look for spring wildflowers in hopes of a false morel.
Posted by Allison Vaughn at 8:18 PM