Thursday, February 21, 2008

Upland Flatwoods

Before this week, I could sum up what I knew about upland flatwoods in one sentence: "Upland bent grass (Agrostis perennans) grows there, dependent on the perched water table." I've given myself a crash course in upland flatwoods, not only because they represent a somewhat significant acreage in the Ozark Highlands, but because I imagine that when all of this snow and ice melts, the community will play host to breeding salamanders.

Upland flatwoods are located on broad, relatively flat ridges, a topography which allows for rainwater pooling events to occur (imagine a wet-mesic bottomland forest from southeast Missouri, but in the Ozarks). They generally have open canopies, aided by a rigorous prescribed fire regime. The acid soils are silt and clay-based, comprised of loess and chert gravels. The fragipan layer underneath the topsoil drains slowly, thus encouraging a rich layer of sedges, wildflowers, and few, if any, shrubs. Upland flatwoods are traditionally populated by blackjack oaks and black hickories, with some blackberry canes in the understory.

This is another terrestrial community absolutely dependent on fire for survival. Without fire, the canopy closes and the ground layer, sparsely populated under ideal conditions, disappears. Because of the lack of fire to much of this community, the existing stands warrant a ranking of S2 (state imperiled) in the Conservation Concern checklist. Extensive grazing on these areas hasn't helped them much, either.

The invertebrate populations that may exist in upland flatwoods fascinate me. Imagine, if you will, an entire woodland setting with standing water for weeks at a time. The life cycles that must take place! No extensive surveys have been completed on micro or macroinvertebrates of upland flatwoods, but I hope they'll happen soon. In southeast Missouri, there's a shrimp (looks like a lentil) that lives in shallow, ephemeral pools. When the pools dry up, the invertebrates are dispersed by the wind, taking up residence wherever (or whenever) another pool of water appears, dormant until they reach water. Imagine the possibilities of an entire flatwoods community, acres of an ephemeral pool! Rest assured that I'll be out with a dipnet in a couple of weeks to see if salamanders are utilizing this interesting, imperiled landscape.

3 comments:

Anonymous said...

Hello. Do you know and can you tell me the name or Latin name of the shrimp you mentioned?

Allison Vaughn said...

Yes...I can't remember the name right now...I'll post it tomorrow when I have access to my files. I simply can't remember. Forgive me.

Allison Vaughn said...

Okay, the Missouri species is Triops longicaudatus. The eggs require desiccation. In fact, the eggs are viable for 20 years. I'm linking to a wikipedia article about them because my invertebrate specialist is out of the office with sleeping problems: http://en.wikipedia.org/wiki/Phyllopoda#Classification