Thursday, June 13, 2013

Vegetation Sampling Begins!

Oh, what a fun week of running my 50m tape across glades and carefully placing my homemade .25m2 quadrat tool repeatedly around the beautiful assortment of native glade flora to assess cover values of each plant in each plot. This year's sampling events takes me (initially) to glade restoration projects, areas that I've written about all winter wherein colleagues cut, piled, and burned green cedars over the course of five months. With the recent politicization of prescribed fire, however, these crews were most unfortunately unable to acquire burn permits to finish burning their slash piles (even when it was actively raining outside, we were out of drought status, and fuel moistures were incredibly high). Today, we're left with some awful red needle stage slash piles that will have to wait until snow on the ground to burn. [If they can get a burn permit. At one point this past winter, with five inches of snow on the ground, the local fire department wouldn't issue burn permits because wind speeds averaged 5-10mph. Hence, red needle slash piles -which no one should ever have to manage- litter the site. The dangers of red needle stage slash is that live red needle embers can travel over two miles on a windy day,and they burn so hot that they can sterilize the fragile glade soils. Burn when cedars are green and embers don't move around, for starters, and the skeletons burn completely. Wait too long until the needles turn gray and you're invariably left with massive skeleton piles that are absolutely unmanageable.]

And so, Tuesday morning began at 6:30 on a glade that 6 months ago was socked in with cedars with a scattering of little bluestem, highly eroded soil from years of abuse by grazing, patches of Liatris cylindracea, some Arennaria stricta, other little glade plants that may be recoverable if you cut and burn cedars. This glade restoration project occurred on 22 acres of a big bald, a typical "barrens" landscape in this part of the Ozarks, though few of these high, broad, flat dolomite glades have been restored in the area. Thanks to a long history of abuse from grazing by domestic livestock, we graded each section of the glade from B to D quality (very few if any examples of A quality glades exist after a history of grazing). Our first transects ran across a D quality glade that wasn't even slated for restoration because it was so degraded. Enthusiasm took the upper hand of the crews with chainsaws in early March, so it was free of cedars (and very little else), so we set up transects. Why not. Let's see what happens when you remove cedars from a totally overgrazed glade that hardly has any soil on it. There's very little cover of plant life, so we whipped through the transects pretty quickly on the D grade section of the glade:

Because this was the last area cut in late April, light availability is a new concept to this trashed out part of the glade. Lots of little Houstonia nigricans that may not mature this year, tons of Heliotropium tenellum, a few patches of little bluestem. Obviously, fire won't carry through an area like this, so we'll wait a few years until we get a thatch layer and then take the conservative route regarding burning. In the early stages of glade restoration in highly damaged systems, it's most vital to restore the soil layer through the development of a grass matrix. Even though this trashed out glade is in restoration mode, I wouldn't recommend a 3 to 5 year rotation of fire; I'd let the grass come back if the propagules are still there, let the thatch form, burn once every 5 to 7 years in the early stages. Throughout the transects in this part of the glade, bare soil accounted for over 60% of total cover. Not even a weedy Draba existed in this part of the glade.

Moving on to C grade glades, sampling grew fun again. These areas had far fewer hogwire fencing remnants and a scattering of good glade flora: Silphium terebinthinaceum, Sporobolus asper (grass!), lots of pretty coneflowers (which tend to explode in the absence of matrix species, so glades with little else than Echinacea paradoxa aren't really great glades because they probably don't have a lot of soil left on them. Note roadcuts in the Ozarks covered in Echinacea and Missouri evening primrose, both colonizers of scraped soil environments).

Bare soil still accounted for about 40% of the average quadrat. However, the C grade glades are much more restorable than the D grade glades since that grass matrix still exists. Two months ago, this area consisted of wall-to-wall cedars.

We ended sampling this site by 11am with a visit through a little woodland that saw some hardwood thinning (mostly little hickories) and onto the better quality restorable glade that represented the fun part of my morning. Lots of coneflowers, some Aster laevis, Aster oblongifolius, warm season grasses, even the annual weeds like Arennaria patula that took off like gangbusters this wet spring following last year's drought.

Cover values increased, species richness increased, grasses formed the matrix in this section of glade. There's hope for the rest of the glade, but it takes patience and diligence to restore a highly damaged ecosystem. Let's start at the very beginning: cut and burn cedars and keep cows out of native ecosystems.

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