Friday, August 19, 2011

Glades ablaze


The recent rains saved the dolomite glades of the Western Ozarks from complete dessication. Several weeks ago, I had the great pleasure of sampling dried vegetation on a glade in 104 degree weather at high noon; even the stalwart glade-obligate Rudbeckia missouriensis was shriveling to nothingness, certainly not thinking of flowering. This week, following several rain events in late July and early August, the Rudbeckia is a showstopper on the glades, along with prairie dock and the first few flowers of the short, bright purple Liatris cylindracea. Liatris aspera (ice cream plant for deer) is tall these days, but the flowers aren't open yet. The season begins for brilliant bloom cycles on dolomite glades; even the diminuitive Heliotropium tenellum sent out a second round of blooms (thanks to all the rain).


As we move towards late August, thoughts turn towards glade burning. If the thatch layer is thick enough, late August-early September is prime time for burning off glades. The woods won't burn these days with all the moisture and average 50% rh everyday. No burn lines are needed for growing season burns on glades. The fire magically goes out at the edge of the woods...



9 comments:

beetlesinthebush said...

Late sumnmer rains are exciting for me to, as that is what prompts emergence of the fall tiger beetles. Cicindela splendida and C. obsoleta vulturina love the glades - make sure you leave a few unburned patches for them. :)
all my best--ted

Allison Vaughn said...

Thanks, Ted--As you know, we never burn everything at the same time of year. Only a fraction of a fraction of a fraction of glades are even on the list for growing season burns this season, and we'll only get to a few of them for weather constraints/staff/etc. It's destructive to burn everything at once at the same time of year.

Justin Thomas said...

I'm curious what the historical antecedent is for a glade burn in which the surrounding forest would not have carried it there. Are there data and analyses demonstrating a benefit? Did Native Americans spend thousands of years tending the fire needs of individual glades?

Allison Vaughn said...

Hi Justin--Be mindful that historically, the woodlands surrounding glades were much more open than they are today. Woods would have burned during the growing season historically, but today they won't--too overstocked and dense. Growing season burns on glades are a way to manage the glade when managers can't get around to burning their whole unit.

Justin Thomas said...

I worry about two things. First, there doesn't seem to be any historical evidence of growing season burns. Second, there isn't a documented benefit of growing season burns (might be just the opposite).

Growing season burns often seem more manager need driven than ecologically useful or relevant. I have seen a lot of woods lately where the flora is completely blitzed (potentially the seed bank as well)following growing season burns.

I hate to buck the powers that be, but given the fragmentation of our natural world and the corresponding alteration to source/sink dynamics coupled with the increase in invasive species, this doesn't seem well thought out or defended.

Paul Nelson said...

I recommend reading Ken McCartys section on Missouri,s historical fire regime and the application of growing season burns. Evidence does exist they occurred. The Mark Twain records lighting fires during the summer. We had two separate August lightning fires near Hercules Glade and they were spreading. I walked through a 300 Acre July lighting burn that killed all trees on Goggins Mountain. Do not discount Native Americans starting fires on purpose or accidentally. The Mark Twain will apply fires during the growing season. And I'm convinced that summer fires would have easily propagated in a world mantled in grass forb cover. As much as really use growing season fire I believe the meager acres burned pales when compared to the belief we should burn in spring. Settlers and early explorers noted Native Americans burned in the fall for the most part. It's always wise to monitor for results.

Justin Thomas said...

I guess that is my main point; that we should have a record of management results for differing management approaches. In a landscape that has been dramatically altered by fire suppression, there are bound to be unforeseen effects to the struggling remnants of our flora (I'm picturing the single leaf of Liatris scariosa that has hung on for 50 years and just manages to sequester enough energy to persist from year to year).

I have found some papers documenting the probability of lightning fires in the Midwest (mostly July and August), but nothing regarding the results of simulation of said fires in a contemporary landscape. One would assume that a glade would have the ecological toolbox to recover from a summer conflagration, but suppressed woodlands, turned forests, might not.

Please forgive my inquisitive nature. I just can't help wondering about these kinds of things. Also thanks for the great discussion. Scientist must be allowed and encouraged to share ideas as well as concerns no matter the forum.

Allison Vaughn said...

Knowing that 99.9% of Missouri's woodlands are so dense and overstocked that they lack a prairie vegetation understory, I know that only under extremely dry conditions will woodlands burn in the growing season. I don't recommend napalming woodlands, especially since the closed canopy structure wouldn't allow for any growth to occur for many months, just as I don't condone late spring fires in dense, thick, overstocked out of character woodlands that won't kill trees to allow more light to the floor. A few weeks ago down in the Elk River country, woodlands with a savanna structure burned until the fire hit a north slope and trickled out. But burn a glade down in white river with all those closed canopy woodlands, and the fire goes out at the woodland's edge. Next time you're home, go to my favorite woods, take the drive to the ruins, and just after the spur to the NB, check out the woods. There, the woodlands have been managed with fire for 29 years, and a growing season fire on the glades by the water tower and the surrounding woodlands was only possible because of extreme drought. The fire did a great job of knocking back some of the persistent brush that March and November fires couldn't knock back in the past 10 years. It's very lush, and extremely rich. But as you know, nice restored woodlands with prairie vegetation are very rare in Missouri. In the Ouachitas, they burn thousands of acres in September precisely because they have the same structure as my favorite woods. No, I think hot raging wildfires through crappy overstocked woods are destructive, though in the long run if they open the canopy they may come back (if the ground flora hasn't been grazed to hell). But glades with thatch are good candidates for burning during September; often, as we've seen in the St. Francois Mountains and in the niangua basin, following a September burn, a nice flush of green vegetation grows, providing cover and forage for wildlife. I think there must be diversity in a fire regime, and that others need to do a better job at monitoring effects. I'm working now on a manuscript on the results of a growing season v. dormant season v. spring burn cycle on a glade in the niangua. Also, as i've said before, with any rx fire implementation, don't start with crapped out overgrazed systems but work with restorable sites. There are thousands of acres that will never be restored despite years of thinning, burning. Cut the losses, and do the work will it will make a difference. During September, go to unburned glades with a torch for the most bang for the proverbial buck. By the way, as of this afternoon, Western Star is now Western Star Savanna Natural Area.

Paul nelson said...

Well I have to resurrect this discussion once more. I received a call today from our Ava Fire Management Officer that lightning started a fire in Hercules Glade Wilderness over the weekend. We are monitoring it's spread. More evidence that summer lightning fires do occur in Missouri. Recall I mentioned the two lightning fires last summer just outside of Hercules. Fire suppression in Hercules will otherwise mean red cedar will eventually smother the glades there.