Monday, October 18, 2010

Indian Summer, Part II

From the Terrestrial Natural Communities of Missouri:
Many early explorers in Missouri chronicled numerous accounts of periodic fires....Add to this the overwhelming, universal and pervasive evidence for historic fires as presented in many other documents across North Anerica (McClain and Elzinga 1994, Williams 2000, Nowacki 2002, Vale 2002) and it becomes clear that the influence of fire is the primary explanation for the observed presence of otherwise fire-dependent natural communities distributed across the Missouri landscape. Pyne (1982) stated, "The evidence for aboriginal burning in nearly every landscape is so conclusive, and the consequences of fire suppression so visible that it seems fantastic that a debate about aboriginal fire should ever have taken place."

Fire scars provide valuable records in establishing fire regimes. Guyette and others reconstructed fire histories by tree-ring analysis of red cedar and post oak for various regions of the Ozarks (Guyette and McGinnes 1982, Guyette 1989, Guyette and Cutter 1991, and Guyette and Dey 1997). Their results showed evidence of frequent fires occurring during the last 500 years in the Ozarks. Historical records indicate that most fires occurred in the fall with less frequent fires occurring in the spring and a few taking place in winter or summer.

Fire scars do not necessarily equal fire frequency (Pyne 1984). Whether a tree registers a fire scar depends on varying fire intensities. A fire of greater intensity would kill or consume a tree while less intense fires may not register scars in certain years. Additionally, most of the signature trees that contained fire scar data are today gone due to the nearly complete clearcutting of Missouri's original forests, woodlands, and savannas. At best, fire scar data is only one piece of information in formulating fire regimes, and perhaps offers a conservative estimate of actual fire frequency. p. 20

In March, 2009, we burned half a dolomite glade as part of a larger unit. The fireline went down the middle of the unit. In September, 2009, we burned the rest of the dolomite glade, a piddling little fire that left the landscape looking like it had been doused with RoundUp. The fire went out when it hit the woodline, trickling around in the dried leaf litter but extinguishing immediately when it moved under the treeline.

In May, 2010, we set up six randomly located 50 m. transects on the glade. Three transects were located on the site of the March 09 burn and three transects were set up on the side of the glade burned in September 09. Using a random number generator, we plotted six .25 m2 quadrats along each transect. We recorded and assigned a cover value to each plant located in the quadrat. The results of the survey indicated that the relative importance value and floristic quality index of the quadrats located on the side burned during the growing season were higher than the same values in the transects on the side burned in the spring. Below you will find two tables. The top table is the analysis of the transects located in the area burned in March 09. The lower table is the same analysis of the transects located in the area burned in September 09.

The scale of this research is small. I fully recognize this. I am happy to report that a graduate student will be conducting a similar though much more extensive study throughout the next two years (we just completed the fires on the growing season plots).

The area burned during the growing season responded well to the fire, with a higher forb count and slightly higher FQI than the area burned in the spring. Burning available fuels during the growing season in Missouri is not destructive to the landscape. The fires that occur in Missouri during the growing season are not on par with late April fires--woods seldom if ever burn in Missouri during leaf on (barring drought conditions).

From Paul Nelson, the father of Missouri ecology, comes this:
"The Mark Twain NF is conducting growing season burning for two reasons: first, as a means of most effectively combatting vigorous woody regrowth resulting from decades of tree farming, and second, because we choose to emulate growing season fires. One major conservation restoration approach described in the 2005 MTNF management plan is the coarse filter approach to ecosystem restoration. This comes at a time when it's not possible to answer all the myriad of "effects" questions raised by hundreds of interest groups regarding proposed management actions. The approach is to base restoration on what we already know about achieving desire conditions for healthy ecosystems and emulating the historic disturbance regimes by which ecosystems evolved. I've always believed land managers would not sway far off the mark by emulating fire (and other processes), even the absence of studies. DNR had no data nor baseline research when it took a bold chance and commenced a burn program at Ha Ha Tonka nearly 30 years ago. Imagine all the scientists and managers screaming about burning woods back then. This is certain. It's an extraordinary fact that Missouri's 40 million acres of fire-adapted ecosystems is today reduced to scraps of small remnants. I would think that anything we can do to increase fire on the landscape would have extraordinary conservation outcomes. Missouri's best woodlands, glades, and prairies -along with their diverse biota- are owed to the restoration of fire regimes. The Mark Twain NF implements prescribed fire on 30,000 of it's 1.5 million acres each year. That's about 0.6 of 1% each year. Pitiful. I can't believe we are risking anything given we otherwise have so much former fire adapted landscape remaining unburned. Surely, the species those concerned about find refuge elsewhere. For detractors of naturally occurring fires, we suppressed two wildfires due to lightning just this past season. Finally, we, and you, don't burn vast amounts of acres during the growing season. Why would we want to suppress the burning of 20 to 90 acres during late summer within a 5,000 acre burn unit? That's not extraordinary nor extreme."


Justin Thomas said...

Many great and agreeable points are raised here. I certainly an not trying to be a thorn in the side of progress. I just feel these are questions that need addressing when fire ecology is stretched into unfamiliar territory.

That being said, I not fully convinced that growing season fires are a proven method of managing biodiversity. At least not to the level that they should be "popularized" without mentioning the context in which they are being applied; that being as an example of a stocastic event rather than a normally occurring phenomenon. It would certainly be interesting to see some baseline data and to follow these results into the future.

Thanks for going to such efforts and providing so many details to alleviate my ignorance of the subject. I have much to think about.

Allison Vaughn said...

You're not a thorn, silly, you're the best botanist in the state and an all around stellar guy. I don't condone burning anything at the same time at regular intervals ever--others in the state tend to burn in April every year, or those on the more conservative side (like one of my colleagues) burns only in November every year. The value of ecosystem management is in mimicking the natural processes that occurred in varying seasons, varying intensities, varying fire return intervals. I think there are a lot of folks out there who don't know how to use fire effectively. I'm pleased to tell you that the guy in charge at HHT is the best land manager in the state, bar none, which not only speaks well for the park but also for his two mentors, my boss and our mutual friend. I understand the concerns from entomologists who see fire as destructive to localized populations, but I reiterate every fire season that in small, relict glades like little piddly things in the middle of St. Louis, other urban areas or even tiny tracts of managed woodlands surrounded by thousands of acres of depauperate, unburned trashed out landscapes, fire should be spread out. Please understand that managing to maximize biodiversity on all levels remains my top priority. I urge those concerned with the negative effects of growing season fire to submit research proposals. I know how to get them approved if they're based in science and not in authoritative pronouncements, and I know how to get them funded if the application doesn't show obvious bias. I support research (you know that), and right now, with the botanical work going on through SMS or whatever it's called now we have a great opportunity to study all biota in the same study area. I'm not qualified to do anything but plants and small mammals.