by David and Shelley Hamel
Since 1988 we’ve been enthusiastic burners, cutters, herbiciders, pullers, weeders, planters, seeders — while not really knowing evidence-based facts about what we’re doing to our 120-acre sandy restoration. It’s been mostly a do-it-yourself operation here in Marquette County, and yes – we read, we listen, we ask, we go to conferences, we join groups, we get help from DNR, NRCS, US Fish & Wildlife, and we try to be responsible stewards to this island of Karner Blue butterfly habitat. And if you measure success by the numbers of lupine stems and Karners here after thirty years, we’re successful. In fact, we’re awash in lupine and the Karners are abundant.
So what’s the beef? It’s what we don’t know after all those years — many questions specifically fire-related — but here’s some of what we don’t know:
- The current inventory and detailed phenology of native and non-native plants living here. We have some guesses, but we’re not botanists.
- Which plants, seeds, stems, and underground tissues of plants will benefit by burning and which will not. And based on the phenology (mostly unknown to us) of each plant, what’s the burn prescription: what frequency, intensity, duration, size, site conditions, site location, moisture content, disturbance history, time of year?
- The current inventory and detailed life cycles of our invertebrates. We don’t even have a guess. We’re not entomologists, but we do know there are orders of magnitude more invertebrates than plants. The rest is a mystery.
- The adaptation or mortality of invertebrates to burning– insects, pupa, larva, nymphs, eggs, cocoons, chrysalises, et cetera — based on those abstruse life cycles we don’t know and some maybe no one knows. For instance, what was in those smoldering patches of leaf litter, plant stems, under bark, hanging from webs, hiding in galls, at the ends of leaf mines, bored into tall grass stems, lying on the soil, in the coarse woody debris, buried 1 cm under the soil?
- How ‘patchy’ is ‘patchy’? Our best never-grazed, never-plowed remnant – the one with pasque flowers and prairie smoke and goat’s rue – is one acre. As far as we know, there are no other remnants like it in the township. So if we burn it all, we’re burning the universe of pasque flower/prairie smoke/goat’s rue habitat in this 20,000 acre township. Is that smart? Would it be better to burn 1/5th of an acre at a time?
- What elements of our secondary-successional habitat – native and non-native — does the term ‘fire-adapted’ apply to, and where’s that evidence?
- How as laypersons do we measure biological diversity and are we smart enough to track changes or should we bother?
- And finally, should we burn through the ‘fire-adapted’ oak woodlands in an attempt to maintain an open savanna? The advice from virtually everyone including professional land managers: fire will get rid of the duff, bring in light, stimulate the natives, and the oaks are adapted to fire so: Go For It.
Here’s something we’ve learned about that last one. Picture the scene: twenty acres of historically grazed oak/cherry woodlands, no sign of ever having been burned. Many small, grubby 3-6 ft. red and black oaks; large red, black, and white oaks between 100-150 years old; oak wilt scattered throughout with many, standing dead snags; a few pines and red cedars; many 20 ft. black cherries and a Pennsylvania sedge understory.
So we Went For It. After all the breaks were in, a big, big head fire. High intensity, flames 8-10 feet through the woods. Required cutting down standing dead trees on fire – the ones saved for Red-headed woodpeckers, which are not uncommon here. Completely top-killed almost all the small stuff and killed the pines and cedars. Burned up the duff, slash, fallen trees and hollow (habitat) logs dead from oak wilt, and it left burn scars – some little and some big – on many big oaks. And then after just two years, the 20 ft. tall cherries were replaced by ‘fountains’ of 4 ft. cherry stems around the burned stumps. Likewise with the small oaks: fountains of 2 ft. stems around the old stumps. Fire even top-killed ‘fire-adapted’ white oaks as big as 4 inches DBH. And in between, lots of brambles.
We burned again in three years. Not such a big fire (less duff), but not sure why we did it, what the goal was, just that it was ‘time’ to burn again. After all, we’d been told repeatedly that some managers burn their restorations, or parts of them, as frequently as every year and typically every two or three. So here on our Plainfield outwash plains, a soil so sandy and susceptible to drought, we burned again. Our skepticism hadn’t yet been triggered: ‘fire-adapted’ was the convention. (And, if we’d had a spring rather than fall burn prescription, how do you predict a summer drought in April anyway?)
Here’s the saddest part: some of the healthy, ‘fire-adapted’ old red and black oaks – the ones that were the foundation of the oak opening and savanna attempt – were doomed by the fire scars. Those wounds from a hot fire on the downwind sides of big old trunks became entries for rot and eventual weakness at the base. The extent of the damage wasn’t noticeable at first. It took seven to fifteen years, but the big, scarred oaks are now toppling, and not from oak wilt. (In fact, we wonder if they’d been somehow resistant to the wilt that killed some of their neighbors?)
Had we known what the effects of fire in the woods would be, namely an exponential explosion of cherry and oak grubs and a large percentage of big fire-scared oaks dead on the ground, we would not have burned. Even raking and wet-lining around the base of each of these oaks (an impossible task) was unlikely to protect these trunks from such a big, big fire.
But now we have evidence – anecdotal – about what happens to an oak woods in northwestern Marquette County when you do an October burn followed by another October burn three years later. You battle by hand with cut-stump and/or basal bark herbicide applications the multitudes of top-killed re-sprouts and you lose your ‘fire-adapted’ big oaks. It took just two years to learn the first thing, but fifteen years to learn about the oaks; not everyone has the luxury of so much time to monitor.
The unintended consequences of working with only the most cursory information about restoration is troubling. It’s the DIY equivalent of building the Mackinac Bridge with tools from your garage and an illegible blueprint. Many of us come to restoration as laypersons, novices, enthusiastic about plants, idealists about natives, pleased to identify a butterfly or a grassland bird, but basically blank slates when it comes to the nitty-gritty of evidence-based management of our hobbylands. Even though we’re exaggerating the breathtaking amount of stuff one should know or – at the very least – be aware of before writing and executing a management plan, absent long-term monitoring (fifteen years or more) of habitats like ours, we enter an arena of variables with too many unknowns. It’s not for lack of trying, and that’s the beef.
We cannot ‘not’ manage: benign neglect is not an option. Instead, we’re more conservative, believing less in broad-brush definitions for terms like ‘fire-adapted,’ applying herbicides more selectively, skeptical about using big tools like fire when hard evidence is thin, and like Hippocrates, trying like mad to “do no harm.” Plus we’re continuing to learn: we just read Wildland Fire in Ecosystems: Fire and Nonnative Invasive Plants, 355 pages published in 2008 by the USDA Forest Service, with even a reference to TPE’s own Rich Henderson.
That book is full of questions.
David and Shelley Hamel are working to protect and restore prairie and oak savanna and Karner Blue butterfly habitat on their land in Marquette County, Wisconsin.