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Tuesday, May 16, 2023

Blunt Answers to Nine Questions about Saving Oak Woodlands

By Christos Economou, Matt Evans, Eriko Kojima, and Stephen Packard

We have been too cautions. The increasingly-rare plants and animals of a hallowed community have suffered from reverence and indecision. 

A healthy woodland is now rarer than a healthy prairie or savanna. But we've been blind. 

The previous conservation strategy – to leave the woods alone – is a bad failure. Now this region's only Globally Threatened (G1) community is oak woodland on rich soil, formerly our major forest type.

Most surviving remnants are losing species fast. Don't be fooled by a "rich looking" spring ephemeral flora. In the photo below, the ground will soon be bare. The summer and fall flora did not survive here, nor did the pollinators nor other animals that depend on the hundreds of summer and fall plant species.

Or, below, with most species now gone, what's left? Bur oaks, not reproducing, nearly all plant and animal diversity under their canopies smothered by buckthorn:

A long-degraded woodland - before restoration

Same woodland - with restoration under way. Spring flora mixed with summer and fall flora. Many animals returning. See detailed spring and summer photos below.


Spring - after thirty years of restoration - turf under bur and Hill's oaks.
May 6
Species in the photo above include rue anemone, wood betony, golden Alexanders, toothwort, thicket parsley, Pennsylvania sedge, beardtongue, starry campion, awned wood grass, large-flowered trillium, trout lily, cow parsnip, meadow rue, and wild geranium. Only two of these species are spring ephemerals. 


Summer detail in same area.
August 11
Admittedly not all that perfect a photo, but the best we could find. 
Illustrating that healthy woodlands have diverse flora blooming all growing-season long.
Species in the photo above include big-leaf aster, awned woodgrass, cow parsnip, silky rye, woodland sunflower, carrion flower, and purple Joe-Pye-weed. 

Healthy, sustainable, reproducing, natural woodlands have barely been studied because they barely exist. Though there is little study of it, woodlands are probably losing important and irreplaceable 
genetic alleles even faster than species. Most studies tell us little about long-term best management. Fragments of ancient oak woodlands on rich soil survive in the Midwest and perhaps in few other places. We look for life on the Moon and Mars, but we let biodiversity fade out on Earth.

If we want to be good stewards of woodland biodiversity … should we thin trees? … burn every year? … burn every five years? … plant no seed? … plant local seed only? … plant seed from further south? For answers, we’d prefer not to rely on just theories. We need data that we don’t have. For most questions the best we can do is to rely on the informed judgment of people who do their best to be objective and who’ve compared various initial approaches. Getting statistically significant and actually useful data takes more years than most scientists have time for. At this time, controlled experiments are not answering most practical questions. 

This post is written for three (or possibly four) audiences: 1) conservation staff who want to conserve oak ecosystems, 2) volunteer stewards, 3) private owners of woods, and 4) if we might be so lucky, researchers who’d like to design experiments to answer basic woodland biodiversity conservation questions. 

Nine Questions for Those Who Care for Oak Woodlands
1. Is it good enough to just burn? 

2. Is it good enough to just burn and control invasives? 

3. Under what conditions should we broadcast seed? 

4. Should we cut native trees? 

5. What is the role of shrubs in woodlands?

6. Should we use herbicide?

7. Should we control deer?

8. What does it mean to employ holistic approaches? 

9. Do sites need both volunteers and staff?

Do the answers given here reflect sound science or expert judgment? See Endnote 1. The discussions below certainly reflect our own experience and observations. Many people have used different approaches, and their experiences should be considered too. 

1. Is it good enough to just burn?

In most cases, the answer is no. Here’s a scary case study: 

When we discovered the site in the 1980s, about ten acres of it came to be considered the finest "open oak woodland" of "closed savanna" we knew. People came from distant states to study and admire. Here (in a site being unnamed in this account) light-loving species like purple milkweed and white false indigo were common. Yellow ladyslipper, cream vetchling, and scarlet painted cup added to the sense of quality. Commissioners and staff of a local conservation agency, to their great credit, acquired it and have burned it on average every second year ever since. We took start-up data in 1986 (as part of the process that resulted in the Illinois Nature Preserves Commission first approving woodland burns). That monitoring was followed up three times at roughly ten year intervals since then.

The density of tree trunks has doubled. Most of the additional trees are young hickories. Although the site still appears wonderfully rich, many of the conservative open-woodland species that require the most light (for example purple milkweed, false indigo, and painted cup) are gone or much reduced. 

Shade from buckthorn had decreased, thanks to control of that species. The shade increase came from species native to the site. Some argued that, given regular burns, what we were observing was not a problem – but simply nature – and we should not “play God” with native species. Others argued that the burns must have been conducted on days that were not hot, dry, or windy enough to maintain the ecosystem and its biodiversity. If necessarily-restrained burning didn’t maintain enough sunlight to conserve the biota, then perhaps the thinning of trees was needed. Indeed, the latter argument won out in 2020, and trees are now starting to be thinned there, a bit. 

A study from Iowa by Wilhelm and Rericha makes a strong case for the success of both annual burning and thinning over-dense trees. 

Today most oak woodlands under "conservation management" are too dark. (For more perspective on this, see Discovering Oak Woodland: history and theory.) We know they are too dark because the canopy bur or white oaks are not reproducing, because many animal and plant species are dropping out, and because the populations of those declining species rebound when light is increased by fire and tree removal. A lot of the insights into oak woodland conservation are new and urgent, and many conservation organizations are wisely revising their standards.  

What sorts of burns are most therapeutic, under today’s conditions?

It’s not sufficient for fire today to be natural – meaning “whatever happens is good enough.” The “prescription’ needs to be sufficient to “cure” or “repair” a long-term malady. We cannot match the often-extreme conditions of the past, but we do have to be effective. As a thought experiment, consider what natural lightning-ignited burns would have been like for millions of years. Fire for the average piece of ground would tend toward the extreme because, if lightning starts a fire on a cold wet day, that fire won’t burn a very large area. On a hot, dry, windy day a single fire might burn hundreds of square miles. 

It’s not uncommon to hear advocates recommending pyrodiversity. That is, burn at varied intervals, at varied times of year, with varied wind directions, and varied intensities. Some also recommend including burns during the growing season. We are sympathetic to these recommendations, but we don’t find them to be based on convincing science. Good science is needed. And if the prescriptions “don’t work” – that is, if the conservative diversity is being lost, then the prescription is failing.

But if the patient dies while the research proceeds, we’ve failed. We worry that managers of important sites may consider research goals to be a reason to withhold badly needed burns. The first priority is to save the patient. If an important site for woodland biodiversity exhibits shrinking populations of characteristic, conservative, rare woodland species with those being replaced by forest species (or bare ground), it’s not unreasonable to make the judgment that more fire is needed. Perhaps other, less critical sites can continue to study the long-term less-burned approach. See Endnote 2 on needed fire research.

In the case of sites that are not part of research, that is, if the site goal is just good conservation, it’s our impression that burning these days is too infrequent and too mild to do the work that’s most needed. Burns need to be safe, but that’s not the only criterion. Burns also need to be as effective as is practical. Burn crews often make the mistake of standing down on days that are too hot, dry, or windy to burn a prairie. That kind of day is very much the kind of day that produces best results in the oak woods. On such days, burns can be fully safe in the oak woods. Winds, fuels, and drying times in the woods are quite different from those in the prairie, and standards for safety and effectiveness for woods burning need to be distinct from prairie standards. 

2. Is it good enough to just burn and control alien invasives?

No, it’s not remotely good enough. In many better-quality woodlands, the most damaging “out-of-balance” species are not aliens. They’re native species growing out of control, like cancer cells. 

Extensive bur oak savannas and woodlands were a major part of our natural landscape. White oaks were a minor component of these ecosystems. But when the fires stopped, white oaks reproduced more readily in the increasing shade. Soon it became too dark for any bur oak seedlings to survive. At the same time this ecosystem was losing other components that depended on its bright-dappled-light: shrubs, grasses, wildflowers, butterflies, fungi, now-rare bacteria – it’s a very long list. In the early stages, most likely, vigorous burns could have restored natural diversity and function. But when species are gone, or when many occasionally needed alleles of some species are gone, they may need help to recolonize. Bottom line: White oaks are generally good, but if they make a bur oak woods too dark for its full biodiversity to survive, they are a problem. 

Or consider white oak woodlands – the other major component of our forested heritage. Yes, there was a bur oak here and there, some shagbark hickories, some red oaks, and an occasional ash or cherry, or maple tree. They were native – not invaders. But they were held to secondary status by regular fire. After protection from burns, the hickories, maples, and all grew dense and dark. White oak reproduction and associated animals, plants, and other biota then faded out. 

Certainly, if a bur or a white oak ecosystem is to recover natural biodiversity and sustainability, it needs conditions – including the amount of sunlight required for reproducing bur or white oaks and associated animal and plant species. 

3. Should we broadcast seed? 

In most cases, yes. 

There is a common belief that the “soil seed bank” is sufficient. That “bank” is largely a myth. Research by Arnold van der Valk in Iowa found meaningful seedbanks persisted in wetlands but not in prairies or woodlands. Nathan Lamb and colleagues at the Chicago Botanic Garden studied oak woodland seed banks and found little beside common weeds.  

More importantly, we’ve tested the seedbank theory in restoration, over and over. Some species increase vigor and bloom once again following brush control and a burn, but they seem mostly to be ones that were surviving as suppressed plants, rather than seeds. We have compared seeded with non-seeded areas. Indeed, we first tried the “no seeding” experiment in many forms. It did not produce much. Most plant diversity at most sites does not return without doing the work of finding remnants where missing plants survive, gathering their seed, and broadcasting it into the burned remnant ecosystem. Many plant refugee species, absent for decades, begin to thrive again as part of a rich community when their seed is restored.

Aside from the belief in the seed bank, there is a common attitude that opposes “meddling” with nature by moving seeds between natural areas. Given people’s history of detrimental meddling, this concern is understandable. For some sites to continue the experiment of discovering what comes back without assistance seems fine. But what we have seen suggests that those sites will not be the most significant biodiversity conservation sites. 

It seems especially important to have in each region at least a few “full ecosystem re-assembly” sites. In these, the goal would be to restore all species that might likely have been there (including, potentially, insects, fungi, and more) and to promote the most sustainable, genetically diverse populations possible. The intent would not be to re-create the original. Instead it would be to give the ecosystem the opportunity to reassemble its diversity in whatever way comes “naturally” now, under conditions today. Our experience has been that relatively rare conservative plants often become increasingly central to such “re-assembly” communities, as they are in the better-quality remnant natural woodlands. Without such reassembly sites, much biodiversity may be lost permanently. Though little studied, it seems reasonable to hypothesize and hope that what’s true of plants would also be true of other conservative biota. 

Perhaps the best sorts of site to choose for ecosystem assembly are large sites with diverse habitat of as much remnant quality as possible. They are the ones most likely to have a starting diversity of plants, pollinators and other animals, fungi, bacteria, and other ecosystem components.  

From how close should seeds come? There’s no one-size-fits-all answer. If we had the capacity to study it, there are certainly arguments in favor of genetic testing to determine whether there are highly-local alleles that can be preserved best by excluding plants from farther away. For comparison, we would also want to study whether adding alleles from other populations would provide species with sufficient genetic diversity that they could then adapt themselves to ongoing changes like global warming. Thus it makes sense to seek seeds from further south for some sites, exclude them from others, and compare. There is common belief that these concerns are less apt for seed of wind-pollinated plants, as pollen has long blown in from substantial distances. 

Whatever the sourcing strategy, planting into an ecosystem requires different thinking and approaches than planting into bare soil. Some principles and tips can be found here and here.  

4. Under what circumstances and how much should we thin native trees?  

The basic answer is: “Thin all species of trees sufficiently that the full biota of the ecosystem has enough light for recovery.” Many people were initially troubled by cutting any native trees at all, especially in a place reserved for nature. But research demonstrated clearly that maples and associated species were destroying the biodiversity of the oak woods, so control is now widely accepted among conservationists. But questions persist about some species, four of which are discussed below. 

Red oak, like sugar maple, is a fine tree. But not every last one contributes to conservation everywhere. Many savannas and woodlands that originally consisted of bur and/or white oaks (as indicated by the older trees and the Public Land Survey of the 1830s) today have increasing numbers of younger red oak “pole trees.” Bur or white oaks grow more slowly than red oaks in shade. As red oaks overtop them, the young bur or white oaks die. Their skeletons are sad reminders. We wouldn’t recommend eliminating every red oak from a woodland, but we should thin them sufficiently for reproduction of the old canopy trees.  

Shagbark hickory is a natural component of oak woodlands. But it’s another species that proliferates excessively in the absence of fire. It should be thinned as needed, with a clear conscience. Bitternut hickory seems to be a weedier species, less adapted to most oak woods but also sometimes proliferating explosively in the absence of burns. We retain many fewer of them compared to the shagbarks. 

Hop hornbeam is a lovely, slow-growing understory tree that many people are especially reluctant to cut. But it too is a major shade producer and in many situations it seems best to reduce their numbers substantially. In more open savannas and woodlands, the hop hornbeams seem to burn out once the fires have resumed; it may seem fine to just wait for that. But at many sites it seems best to cull many of them, to save what’s surviving underneath while we can, to expand the size of functional habitat for the species that need brighter light, as those are the species being lost at so many sites.  

Bur oak. Do we thin even them? Yes we do – especially where they have formed stands of pole trees (see next item). Many studies have demonstrated that most trees in oak ecosystems were historically much farther apart under their natural fire regime. These widely spaced trees may have supported understory herb communities uniquely adapted to their thin, patchy canopies. Today, where dense bur oaks grow together, the ones that likely lose out are the ones most in need of conservation, those better adapted to fire. We have the impression that some young bur oaks put their energies into building thicker bark and spreading branches. Side by side with them grow others that put their energies into growing taller. In the absence of hot burns, the apparently more fire-adapted oaks die out in the shade of the taller ones. If we want all the alleles, we may have to manage so as to retain some of the trees that may be the more fire-adapted ones.  

Pole trees. 

They may be maples, oaks, or most any kind of tree: all saplings grow into skinny poles when they have to compete in a dense pack of saplings. Perhaps in a natural maple forest, the end result is that “the best tree wins” and makes it into the canopy. But oak ecosystems don’t work that way. The majority of their biodiversity thrives in a dense, sunny herb layer under well separated trees. Dense pole trees don’t grow into oak biodiversity habitats in the short run, and perhaps never. It seems best to us to cut most of them. In some cases, we have left a few, which then tended to blow down sooner or later without the windbreak of the dense pack surrounding them. They’re malformed. It may be best to cut all of them and let mostly the principal canopy species resprout. Then we (or, preferably, fire) keep them thinned enough that a few better-adapted individuals win out.  

Girdling.  

An especially good way to open the canopy in many situations is to forget herbicide and girdle. By cutting off the phloem and leaving the xylem (see diagram) we allow the roots to keep feeding the leaves and branches but prevent the miracle of photosynthesis from sending needed products down to the roots. Then the roots die, as does the rest of the tree, after a year or three, depending on the size of the tree and roots’ energy storage. 


Girdling does not work for some species (notably black locust and tree-of-heaven). If we try the trick of girdling, those species don’t fall for it. They put up new shoots from their widespread roots, massively. For these we use a technique called “frilling” or “chemical girdling.” In this case we saw or chop a circle around the trunk and put herbicide into it. If the bark is thin enough, we can just “basal bark” it; that is, rubbing herbicide on thin bark at the base of the tree can kill it. But no-herbicide girdling lessens the chances of negative side-impacts of the herbicide.  

The basic issue in this question #4 is: How open a canopy is open enough? Our answer is that we need every part of the continuum. So far as we know, every part of the shade continuum from prairie to forest was part of biodiversity. So we want all degrees of openness. But in most cases of oak savannas and woodlands, we now mostly lack the more open components, so we work hardest to restore those.  

Savanna (top), Woodland (middle), and Forest (bottom, oak forest to the left).
For biodiversity conservation, we want to maintain substantial areas representing every point along the oak savanna-woodland-forest continuum shown above. 

With remnant areas, one good approach is to decide openness targets on the basis of old trees. Many sites still include trees that are three hundred years old. The structures of these trees represent ecosystem conditions as they were before Europeans turned off the fire regime. If such trees show the remnants of large, spreading limbs, that tells us that those trees were spaced well apart. If they are bur or white oaks, and we want them to reproduce naturally, they need much more light than they are getting on most conservation land today.  

5. Should we plant shrubs as part of restoration?  

In most cases, probably not. 

Shrub thickets were part of the natural landscape. We know that because of some written records (although these are rather few). Many animals and plants are adapted to shrub communities.  

We also know from written records that large areas of prairie and woodland had few or no shrubs. Prairie birds won’t nest in shrubby prairies. Many accounts of 1800s woodlands emphasize the ability to see deer far away and the fact that it was often possible to gallop a horse or drive a team and wagon through the woods.  

In our experience, efforts to plant shrubs have mostly not worked. Shrubs burned off with every fire, grew slowly, and failed to thrive.  

One exception, a trivial one in this context, is the experience with leadplant, prairie willow, and New Jersey tea in prairies. These are natural prairie species and do just fine even if burned off every year. 

A more meaningful exception is the experience with shrub thickets in wetlands or other areas that tend not to burn. Here, substantial populations of shrubby willows, wild plum, nannyberry, elderberry, prickly ash, dogwoods, and other species may do fairly well. A challenge for them is infestation by common or glossy buckthorn. These invasives may become dense enough to out-compete the native shrubs unless regularly cut back by stewards.  

Thus, for conservation, we may want to conserve shrubs in some places but not most.  

See also "Shrub Thickets of the Future: nature or gardening?" 

6. Should we use herbicide? 

Simple answer, yes, definitely. But be sure to read at least the last paragraph of this answer. Herbicide for an ailing ecosystem is comparable to medicine for a sick patient. No one defends misuse. Wise use can make a life-or-death difference.  

In the early days of restoration, many new stewards objected to herbicide on principle. The Nature Preserves badly needed stewards, so we advised people to the effect that “We recommend using herbicide on cut stumps. But if you want to experiment with working without it, give it a try. But do test your results and be in touch with others as we work through this.” In the end, every steward that tried the “no herbicide” approach either quit being a steward … or began to use herbicide.  

In very small areas, it could be possible to refrain from herbicide and just re-cut the brush re-sprouts over and over again. But the area restored would remain too small for most animal populations and probably most of the rest of the biota. If our goal is to save biodiversity, more time-efficient methods are needed. 

Reed canary grass has become an expanding bad pest in woodlands. No one has made progress against it by trying to pull it. There’s no practical alternative. The same is true for other species including crown vetch, purple loosestrife, and teasel. Herbicides are getting more sophisticated. A grass-specific herbicide can kill reed canary grass while maintaining the health of intermixed sedges, rushes, wildflowers, and the rest of the ecosystem.  

We’ve come to think of herbicide as an ecosystem medicine. Our ecosystems are degrading in ways that have parallels with human illnesses. Medicines used wrongly can harm and even kill the patient. That’s true of herbicides as well. They are helpful or even unequivocally needed in many cases, but they should be used with knowledge and care.  

7. Should we control deer?  

On most sites, yes. Over-populated white-tailed deer have badly degraded the ecosystem and even eliminated many species, of both plants and the animals that depend on those plants. Control is utterly crucial.  

Predation is an essential part of nature. For as long as these ecosystems have been here, deer numbers have been kept in balance mostly by mountain lions, wolves, and human hunters. If we have eliminated the first two of those, we must rely on the third.  

Deer control needs community support and therefore thoughtful outreach and education. 

8. What does it mean to employ holistic approaches?  

Respect the complexity and resilience of the ecosystem. 

We necessarily make ecosystem health decisions on the basis of very limited knowledge. Our therapies need to be good for the whole “patient” – meaning the overall biodiversity of animals, fungi, plants, soil biota, and all. (See also Endnote 3.) Of these, we need to be sure what we’re doing works for the rarest and most conservative components of the ecosystem.  

But shouldn’t we just work on the basis of the best science? More easily said than done.  

Barbara McClintock, not a bad scientist, won the Nobel Prize for her work on maize genetics. She describes plants as extraordinary “beyond our wildest expectations.” Not because they have found ways to do what humans can do but because a life lived rooted to one spot has coaxed then to evolve countless “ingenious mechanisms” to deal with challenges that animals might avoid by simply running away.” 

In achieving the revolutionary insights she came to, McClintock emphasized how important it was to acquire “a feeling for the organism,” to develop the patience to “hear what the material has to say to you.” In honoring her work, Merlin Sheldrake wrote: “When it comes to fungi, do we really have a chance? Mycelial lives are so other, their possibilities so strange. But perhaps they aren’t quite so remote as they seem at first glance. Many traditional cultures understand life to be an entangled whole. Today, the idea that all things are interconnected has been so well used that it has collapsed into a cliche.”

But it’s a cliché honored mostly in words. We have these suggestions for people trying to figure out woodland conservation: 

  • At one level plant diversity is the most practical indicator of site quality, but there are six to ten times as many fungi as plants. There are incomprehensibly many animals, bacteria, algae, and other micro-organisms, most poorly understood. Some seem to survive only in remnants. Entomologist Ron Panzer found that monitoring plants as indicators was insufficient to assess the health of most invertebrate populations. No one has researched these questions for most parts of biodiversity. Start with the best quality and biggest site you can, and trust it. 
  • Monitor as much as you can. Make decisions based on what’s best for biodiversity priorities overall, considering what data you can assemble. Realize that every action will benefit some species and impair others. The species groups most likely to benefit from the restoration of woodlands (of a few to a few hundred acres) are plants, invertebrates, and soil biota.
  • Is there any way to help soil biota? We hope that transplants from quality areas that are being destroyed may help. Rich woodlands are often destroyed for housing. When that happens, when we can, we transplant some of the more conservative plants to an “ecosystem re-assembly area” with hopes that bacteria, fungi, nematodes and other unknowns may respond well to the new, fire-maintained community. 
  • One person can’t manage, monitor, and make the decisions alone. Collaboration is needed. 
See also Endnote 4.  

9. What’s most important to success: Volunteer stewards or staff?  

Both, in collaboration, are essential for first class results. No site would have the resources it takes otherwise.  

We have watched and admired many agencies and individuals do good restoration without the kinds of collaboration we’ve enjoyed. Admired, yes; but our perception has been that results were not as rich and full as they could be with the benefit of a larger team. Staff do many things best: some kinds of planning, funding for “heavy lifting” work, land preservation in metro areas with good numbers of potential volunteers, empowerment of expert volunteers, and more. Citizen volunteers, on the other hand, frequently can accomplish more detailed work, of great complexity and delicacy, and often attain Phd-levels of expertise from the Eco-university of Hard Knocks, by spending years and decades focused on details a paid person would not possibly have time for among other responsibilities.  

Most of the work at Somme has been planned and done by volunteers. The hours that some people devote to sports, or the Internet, or the long list of other pursuits people spend “spare time” on – we can’t wait to spend with the ecosystem … being stewards. 

There are advantages in many differing approaches. But our experience is that an intensive professional-volunteer collaboration is an especially valuable one.  

For sample details about we authors as individuals, see Endnote 5.  

Wrap-up 

In the 1980s, there were good scientists who argued that open oak ecosystems were “Gone! Gone! Gone!” – and we should forget about them – because they can’t be restored. We now know that healing is possible. One key is to recognize that we cannot put anything back the way it was – or keep it that way – because nature evolves. That’s especially true as the world’s rainfall patterns, rain acidity, hydrology, climate, invasive species, fragmentation, and more are all changing mercilessly – and, to survive, ecosystems need to evolve. We seek to restore as much as possible self-regulating, changing natural communities with full animal, plant, and other diversity.  

Thriving communities can help mitigate climate change and provide ongoing resources for medicine, agriculture, industry, and research – to say nothing of the inspiration and beauty that almost everyone can appreciate.  

In our oak savannas and woodlands, our hard work allows us to experience something new on the planet – the recovery of badly wounded, incomprehensibly rich nature. We have the opportunity: to see real oak woodlands on fertile soil for the first time in a long time. Native Americans lived amongst and promoted such riches; Euro-American pioneers saw them and recognized them as prime farmland. But no ecologist ever – and no person of any kind for a couple of centuries – has had the experience. It’s like discovering a new continent. We can be part of an ecosystem previously unseen by ecologists and the modern world. It’s like archeology – if we could discover and restore an ancient civilization to life. But even that would be dull in comparison. Restore living remnants of great importance, beauty, and biodiversity? Yes, we can. 

Endnotes 

Endnote 1.

Who are the experts on the conservation and restoration of woodlands? 

Volunteer and staff practitioners are making some of the fundamental discoveries. Are we the eco-counterpart of the Wright Brothers? That analogy was made compellingly by Bill Jordan (William R. Jordan III), founding editor of Ecological Restoration. Unlike the well-funded experts that Orville and Wilbur were competing with, the Brothers invented and discovered how to fly because they were immersed in the physical details of it. They made the parts, applied the grease, flew the prototypes, hammered, twisted, and shifted their body weight during flight until, bit by bit, it they figured it out. That analogy falls apart at the end. Their contraption could obviously fly, and the others could not. To demonstrate whether biodiversity conservation is working, we have a harder challenge. We have understand ecosystem function better than we currently do. And we have to know the alleles.  

Alleles are the basic building blocks of conservation. Most alleles can be lost long before a species goes extinct. In their millions of years of evolution, the animals and plants associated with oaks have developed the genetic riches that allow them to cope with competition, predation, fire, disease, climate, weather, and soils of various types. A rich woodland with full biodiversity has countless genes and alleles that could, in the future, be of huge benefit to people and the planet.  

We can imagine a distant time in which one form of agriculture would be little woodland gardens of Eden growing holistic polycultures of edible acorns, walnuts, hickory nuts, plums, apples, hazelnuts, blueberries, grapes, legumes, mushrooms, grains, spices, and medicines. But only if we conserve the alleles that could make it work. 

Our biodiversity heritage may include alleles that would help solve climate change, give rise to new medicines or better foods, and be the raw materials for scientific discoveries and economic benefits. To say nothing of beauty, art, ethics, and inspiration.  

To improve our answers to the questions discussed in this post, are there discoveries that unfunded volunteers and private landowners can make? Oh, yes there are. We without grant money may be in the best position to answer certain questions, because they require longer time periods than academics can typically invest … and because we can be more flexible in many ways, which may benefit this new field. 

Endnote 2. Fire research 

It’s essential. Short-term research won’t tell us what we need to know. Some parts of some sites might best have one consistent fire regime for at least five or ten years. Then that approach can be compared to others. Possible approaches for a site might include consistent a) early fall burns, b) late fall burns, c) spring burns, d) less intense burns, e) more intense burns, and f) various combinations of varied burns. For good science the key is to be consistent, keep good records, study the biota over substantial time periods, and publish results. Short of good research, the best approaches depend on observation, judgement, and a variety of approaches from site to site. 

Endnote 3. Recognizing the importance of Fungi to conservation 

Fungi are fundamentally important to plant communities, and little monitored on conservation lands.  

In the 1980s and 90s, we conservationists were initiating focused monitoring programs for rare plants, breeding birds, calling frogs, butterflies, dragonflies, and others. The Field Museum wisely proposed or agreed to sponsor a monitoring program for mushrooms. We learned to dry them for proper study and sent hundreds of specimens to the specialist who identified them. He reported that every site that submitted mushrooms included rare species – and that the rare ones were pretty much different from site to site. This should not surprise us. There are vastly more species of fungi than there are plants.  

There are no species of fungi recognized as endangered in Illinois. The federal endangered list includes fungi only in the form of two species of lichens. Globally, the IUCN lists just one fungus as endangered. The reason is lack of knowledge. We conservationists need to do better.  

Fungi, like animals and bacteria, are both crucially important to ecosystems and much more difficult than plants to monitor. Many mushrooms show their heads above ground to reproduce only briefly and only every few years. In between times, it’s hard to know what’s happening. Yet, they’re crucial to conserving whole, functioning ecosystems.  

Sadly, the Field Museum’s volunteer fungus monitoring lasted only until the staff responsible for the program left the museum, as professionals do. The monitoring then withered. It was too bad.  
In 2020, Merlin Sheldrake, 34 years old, published a world-significant book in a world-changing field: Entangled Life: how fungi make our worlds, change our minds, and shape our futures. Perhaps someone who reads it would take on the challenge of leading some conservation efforts on fungi in woodlands we work to restore? It’s needed, and it’s not happening. 

Ongoing research about the relationships among animal, plants, and fungi raise unsettling questions. Much that’s basic is not known. Life is more than we thought. As Sheldrake put it:  

“Fungi … make the world look different. … I have tried to find ways to enjoy the ambiguities that fungi present, but it’s not always easy to be comfortable in the space created by open questions. Agoraphobia can set in. It’s tempting to hide in small rooms built from quick answers.”  

We agree. We struggle to “leave questions open” while rescuing ecosystem patients from passing away. We believe in and try to have a “reverence for life” toward the diversity of nature. We have faith that future generations will better understand life on Earth, live within it richly and wisely.

Here's an example from Sheldrake, citing poorly-funded, bootstrappingly-carried-out research by Suzanne Simard and other pioneers in this new field. It compelling suggests how human culture and economy could better work with biodiversity:  

As part of the self-regulating complexity of a healthy system: a) fungus networks actively farm bacteria of general use to the ecosystem while, b) they pass chemical messages among trees, grasses, and wildflowers, c) alerting plants to an aphid attack on one plant so that, d) many connected plants release pheromones that attract the parasitic wasps that, e) reduce the populations of those aphids, benefiting all.  

It took millions of years to evolve such interconnections – which include alleles possibly of great value to the Earth’s future – supposing optimistically that our species someday develops a non-pathological relationship with the rest of life on this planet – even a symbiotic one? But for now, biodiversity survives tenuously. Do we really want to let it just slip away? To save ecosystem tottering on the brink, we can’t wait for all the research that would be helpful. We conservationists need to use judgment, make decisions, and do the best we can. 

The challenge and the adventure are hard to match. We find we make our best discoveries and do our best work when we recognize how much we don’t know, and strive for new understandings, while we make best use of what we do know.  

Endnote 4. Restraint vs. Initiative 

Some people believe that the best management is the least. Such beliefs are hypotheses that can be tested. Various management regimes should be monitored and compared. In some cases, for comparison, high-quality sites should be managed by fire and invasives control only. Biodiversity recovery and sustainability at such sites should be compared with more ambitiously managed sites. Current assertions about minimal care are more like religious doctrine than like science. 

There should not be a “one size fits all” approach to management for biodiversity conservation. We don’t know enough. And more importantly 1) sites are varied and 2) we can’t evaluate alternate methods unless we add up years of faithfully using one approach per site, measuring results, and comparing them with sites differently managed. 

Endnote 5: Who are the people writing this?  

Christos Economou, professionally, is a PhD research chemist looking for novel medicines to treat human diseases. After years of anguished reading about the global decline of biodiversity, a few years ago he was lucky enough to fall in with the North Branch Restoration Project’s Somme Woods team – and felt empowered that he might be able to do something about it. Now working on his “second PhD,” he spends a lot of his free time studying tallgrass nature, seeking out treatments for ecosystem diseases as a Somme Woods zone steward, and supporting newer stewards with Friends of Illinois Nature Preserves.

Matt Evans as a grad student studied historic oak distribution for Chicago Wilderness. Professionally, he is manager of McDonald Woods, a rich remnant at the Chicago Botanic Garden. He credits his collaborative work as a Somme zone steward with "at least as much" significant conservation and restoration learning as he benefitted from in academics. 

Eriko Kojima loved plants from her childhood in Yokohama and San Diego. After receiving a degree at the University of California and working as a landscape architect in Chicago, she was disappointed in what she could contribute and switched careers. Later, as a veteran Japanese-English conference interpreter, she discovered the ecosystem restoration mission and community at Somme. Since 2015, with the encouragement of husband and daughter, she has gradually cut back on her conference jobs to contribute as a volunteer steward and teacher at "more than full time" by professional standards.

Stephen Packard was Director of Science and Stewardship for the Illinois Nature Conservancy for 15 years and then did similar work directing Audubon Chicago Wilderness for 15 years. He considers it to have been a great privilege to work with and learn from many of the global experts on this stuff during that time, including expert volunteers. A great part of what he learned that informs this post was as a volunteer doing restoration in most of his “spare” time between 1977 and 2023. 


The writers of this post acknowledge the importance of discussions with and experiments by the zone stewards of the Somme preserves as explored in "field seminars" like the one shown above. 

References 

The pathetic photo of spring flora that begins this post came from Horticulture Magazine. Does anyone want to contribute a better one? Woods with only spring ephemerals left are common - and superficially beautiful. 

A companion post in this blog that discusses the history and theory of oak ecosytems conservation.

Panzer, Ron et al. Prevalence of Remnant Dependence Among the Prairie- and Savanna-inhabiting Insects of the Chicago Region. Natural Areas Journal. 15(2),1995. 

Sheldrake, Merlin. Entangled Life: how fungi make our worlds, change our minds, and shape our futures. 2020 

Wilhelm, Gerould and Laura Rericha, Timberhill Savanna - Assessment of Landscape Management. April, 2007 

Attempted "Myth-Busting" - https://woodsandprairie.blogspot.com/2021/07/hypotheses-or-myths.html 

From Bill Kleiman and colleagues: https://grasslandrestorationnetwork.org/2023/02/16/oak-woods-management-a-short-list-of-descriptions-of-how-and-why-we-manage-oak-woods-with-fire-and-thinning/

https://woodsandprairie.blogspot.com/2022/06/wisconsin-discovery-may-raise-standards.html

Acknowledgements

The drawings in this post are by Paul Nelson from Packard and Mutel's Tallgrass Restoration Handbook.

Wednesday, May 10, 2023

A Steward Reviews What He’s Learned

by Don Osmond 

Don Osmund has worked at and enjoyed natural areas stewardship for 27 years (at MacArthur Woods in Lake County, IL and Military Ridge Prairie Heritage Area near Madison, WI). He wrote to ask a question about a post here. We responded in part with a question. Here is Don’s insightful response.

Your question made me realize that I never sat down to formally review what I learned, so I took some time to do that. My stewardship focused on invasive control rather than overall site restoration.

Prioritization

Considering the lack of resources & the magnitude of the task, I learned that prioritization is everything. Now I divide sites into parcels that are prioritized by potential for successful restoration. Within those parcels I prioritize the invasive species by the magnitude of its effect on native diversity as well as projecting how successful my efforts are likely to be for the number of years I intend to work there. If contractors are available, I avoid tasks that are more suitable for crews. This method ensures I’m focused on the overall goal of diversity enhancement, allows me to handle multiple species at any point in the growing season & avoids burnout by keeping goals realistic.

MacArthur Woods - Lake County Forest Preserves

Attachment

I no longer get too personally attached to a site, task or the state of the natural world. Attachment created blinders that sometimes interfered with proper priorities. For example, I spent too much time on rare species until the ecologist gently & correctly encouraged me to focus on the entire habitat. It’s easy to get into a mindset that anything less than a pristine ecosystem is a failure. Initially I felt an urgency to fix the entire nature preserve before it’s too late, which led to viewing restoration as a war instead of a relationship. Which led to burnout. It may be more realistic to accept disturbance & change as natural, which implies we don’t need to burn ourselves out reshaping the world within a lifetime. We only need to shift the trajectory on a given piece of land towards more resilience against whatever the future brings. 

Persistence

I went to a lecture by Jack White & when asked how he was able to pull off the Illinois Natural Areas Inventory, he replied that persistence is the key. I applied that to invasives, telling myself if I’m more persistent than the weeds are, good things will happen.

The human aspect of restoration

Hiking in beautiful places is enjoyable, but since it’s mostly a sensory experience, it doesn’t provide the deeper satisfaction of restoration, which is primarily about relationship. Restoration shows us that nature isn’t always wonderfully harmonious & it isn’t always about survival of the fittest. There are times when self-centeredness is best for the individual & ecosystem, times when selflessness & cooperation are best & times for somewhere in between. Applying this to our lives, since we have the potential for self-awareness, it might be possible to know moment to moment where we are & where we should be on that selfish/selfless spectrum, so that we benefit ourselves & our community simultaneously.

Gear & techniques

I wasted a lot of time & abused my body using ineffective gear, so it would be great to have a moderated living document on the web for restoration gear, tools & clothing, with input from volunteers, contractors & managing agencies.

Physical training

To feel good at the end of a 7 hour day of brush cutting or weed pulling, perform daily abdominal exercises like sit-ups, boat poses & leg raises. It may take 6 months to feel the difference.

Invasive species time commitment

Reasonable suppression of most invasives takes at least 3 years of commitment (usually more) without missing a year. Some weeds will take >7 years.

Invasives like to socialize

One invasive often harbors or masks another so after controlling one weed, be prepared to control other weeds in the same location next season. For example, clearing a brush clone in a prairie can result in a Solidago or clover explosion the next year.

Creeping charley

At MacArthur, it displaces natives in northern flatwoods & is very hard to control.

Tall goldenrod (Solidago altissima)

I watched this invade from an old field into an 80-90% canopy woodland that had a weak forb/sedge layer and estimated 20-40% bare ground in the form of vegetation gaps. Solidago developed & expanded in this environment & after a few years of monitoring, it appeared to be permanent. It didn’t invade micro-habitats with decent sedge coverage. Since it was invading large areas & Lake County Forest Preserve District was planning canopy thinning, I used Transline & it worked very well as long as every stem was sprayed. Control was maintained 4 years after application. Transline is persistent & controls most composites so careful site evaluation is needed before use.
Tall goldenrod after spraying
Left half - sprayed previous year
Right half - just after spraying in September

Garlic Mustard - initial approach
This was a real journey because in the 1990’s, MacArthur Woods was degraded enough to allow GM to spread throughout the preserve. My goal to control it in most of the 500 acres meant supplementing hand pulling with fall herbiciding of monocultures & spring herbiciding of small patches. The latter creates dead zones but they revegetated quickly so my thinking was as long as I could hit it every year, exhausting the seedbank was more important than temporary dead spots. By 2012 I was controlling 804 GPS waypoints every year but by that time, most had only a handful of plants & monocultures were eliminated.


After 7 consecutive years of mechanical & chemical control plus occasional burns, many of the 78 patches I monitored still had small numbers of 2nd year plants. This doesn’t necessarily mean >7 year seed viability since missed plants or pulling too early are alternative explanations, but studies show >10 year viability is likely.

Ground layer condition where garlic mustard persists

Garlic Mustard - spring timing

For 3 years I monitored 60 locations during herbicide application in the 1st 10 days of May, then revisited a few weeks later to see what was missed. I omitted locations where missed plants due to human error were likely, such as in heavy vegetation or plants near a tree. Results: Locations with search areas >30’ diameter had more missed plants than smaller areas, confirming human error as a contributor. The most missed plants occurred in the year when I herbicided before they were in full bloom & the least missed plants was in the year when I sprayed a bit after full bloom. That observation included small patches where missed plants were unlikely, so I suspect not all plants had emerged when I sprayed before full bloom. I also noted at 10 revisited locations, there were 2nd year GM plants on the edge of the previously sprayed patch, raising the possibility that release from self-allelopathy caused rapid growth.

Garlic Mustard - new approach #1

Start scouting sunny areas on 4/20 (in northeastern Illinois) with the goal to start chemical control when most plants are in full bloom, but before siliques are present. Switch to shady areas when plants in those areas reach the same bloom stage. Control can begin earlier if there is enough time before seed drop to revisit those early patches. Scattered patches are prioritized over monocultures & waypoints with larger search areas are prioritized because blooming plants are easier to find. My data suggests this single visit method should result in 60-70% of small patches having 0 or 1 missed plants, assuming an experienced, focused worker.

Garlic Mustard - new research leads to new approach #2

Ecology Letters 24:327 (Residence Time Determines Invasiveness and Performance of Garlic Mustard (Alliaria petiolata) in North America by Blossey etal) has caused me to change strategy. It may be better to leave established monocultures alone, where the development of a natural biocontrol is more likely, and instead go after scattered smaller populations & ones that threaten high quality remnants. For moderate size patches, cutting at ground level or very targeted herbiciding is favored over hand pulling, because pulling disturbs potential soil biocontrols & creates optimum conditions for further invasion. For sites with good competition, it may be better to not control GM at all. For sites where it’s unlikely that decent competition will occur, perhaps reassess the desire for GM control by considering ecosystem quality & if resources are better used for other tasks or on another site. I view GM control as a temporary measure to buy time until robust native competition (or potentially a natural biocontrol) is established.











Tuesday, April 25, 2023

Good Questions about How to Burn

from Drew Harry of Madison Audubon's Faville Grove Sanctuary in Wisconsin

 

Caveat

 

This caveat may be boring. But it’s important. No one knows the “right” answers to ecosystem “prescription” questions. That’s partly because this “science” or “medicine” or “physical therapy for the ecosystem” is relatively new. It’s partly because every site and natural community is different. It’s partly because the way we learn is for many of us to try differing approaches, keep records, and compare. And yet – we have responsibility for “life and death decisions” about irreplaceable remnant ecosystems. We have to decide and act.


Q and A  


Q: I'm wondering how you all handle raking around trees before woodland or savanna burns.

 

A: The answers differ from area to area and from tree to tree. But a central principle is that we hope the fire will kill many trees. Too much tree shade is the greatest threat to oak woodland biodiversity. Bur oak and white oak woodlands are two of the mid-continent’s most endangered or threatened ecosystems. The threat to them is not too much fire … but the lack of it. 

 

Most woodland burns, while "top-killing" buckthorns and some other small trees, do not reach temperatures hot enough to damage most trees, including the ones that merit control. 

In a bur oak woodland, excess shade from invading tree species of many kinds kills off the lower oak limbs (leading to rot) and prevents reproduction (as oaks need more light than the invaders). Many bur oak woodlands have had no bur oak reproduction for over one hundred years. Although it doesn't often happen, we'd hope our burns would be hot enough to kill most other trees. In the past a natural bur oak woodland was often mostly bur oak - with a few other tree species here and there. But in the decades without fire, those other species have grown so numerous and dense as to become a kind of ecosystem pathology. We invest a lot of stewardship energy in sawing them down and burning them in bonfires to let in enough light for bur oak reproduction and for the welfare of all the other plants and animals of the now-rare bur oak woodland ecosystem. To the extent that fire will do some of this work, so much the better. 


In this degraded oak woodland, the biggest, oldest trees are bur and white oaks. Neither have reproduced in recent decades. Aside from a few red oaks, the principal new trees are invading maples. For biodiversity conservation, we would hope for fire intense enough to kill most of those maples and restore enough light for reproduction of the bur and white oaks. 


Only a bit less threatened, white oak woodlands in our experience have much less fuel and much tamer fires. But the principle is similar. Especially in areas of good soil, invasive maples, basswoods, cherries, elms, red oaks, and other trees have already become too dense to allow white oak reproduction. As we cull many of them by saw, girdling, and fire, literally hundreds of species of rare plants and animals are able to return as light levels increase. 

 

This hickory has been scarred by fire four times. 

On the second such occasion, the heat almost girdled the entire circumference, which would have killed the tree (about 30 years old, at that time). But after each fire, enough phloem and cambium remained that the tree recovered. This year, following 50+ years of survival, it succumbed to our saw and that purple herbicide. Hickories are good. But this woods had far too many of them.  

 

Leaf litter fires and the resulting scarring of trees are parts of nature, and the process favors bur and white oak trees which are keystone species to two of our most endangered ecosystems.

 

We also protect many young bur and white oaks and some shrub thickets by raking and backfiring. We only slowly became conscious of the fact that we needed to protect bur oaks at Somme Prairie Grove if we were to see reproduction of actual trees. All the young oaks in open areas, because of burning since 1980, were re-sprout bushes. 

 

Do you let headfires run through the leaf litter, or patiently wait for the backburn?

 

We burn with headfires as much as we can. They’re hotter and do more of the work that we want fires to do. Other people give good reasons for preferring backfires. It would be great to have long term studies comparing the two approaches. But as a default position, if we’re emulating nature, most land burned by headfires, as they moved the fastest and covered most ground. 

 

How do you handle the prairie/savanna margin? Do you let a hot fire run into the savanna?

 

Yes. In such situations we follow the principal “Let the fire decide.” In our experiences, we haven’t found “too hot” fires to be a problem. On one site where I work, we had an artificial situation where dense prairie grass grew right up to the edge of planted white oaks, then perhaps 20” DBH. The fires over the years killed most of those mature oaks. And yet, the site was former bur oak savanna. We were happy to see the planted white oaks retreat and the burs advance. Possibly, it once was the natural order of things for bur oaks to abut the prairies. White oaks seem to have grown in somewhat more protected areas, indeed protected in part by the reduced fire under the bur oaks between them and the prairie.  

 

Fire in the open grassland typically has flames many times longer than fire in the woods. 


The tree on the left is a Hill's oak (in the area shown above). Given its thin bark, much of the lower part of this tree has been killed by the previous fire. On the right is a young bur, with much thicker bark, little impacted by the burn. Over years of burning, this bur oak may outcompete the Hill's on this open grassland edge. 

 

And do you change your actions based on humidity, temperature, wind etc.?

 

A good answer here might take a whole book. So perhaps, for now: Yes, certainly, in so many ways. 


Do you still burn when spring ephemerals and other spring flowers are blooming? The leaves never seem to dry out by the time hepaticas and bloodroot start blooming, but they never seem to fall and dry out before snow in late fall/early winter either. 

 

Yes. We sometimes burn plants that are evergreen - or stay green late in fall - or green up early in spring. Last year's evergreen leaves are not the ones that will do the main photosynthesis in the new year. Those species that are part of the oak woodland ecosystem, which are all or most species that we find there, come right back. The spring flora is precious … thought-provoking … refreshing … especially coming, as it does, after the barrenness of winter. It’s emotionally hard to hurt that spring flora. 

 

As you point out, Drew, it’s similar in the fall. Many species are now so rare and precious that it’s emotionally difficult to burn gentians and asters while they're in flower. But fire-adapted plants roll with the punches. It’s good for the oak woods ecosystem to get a good burn and ultimately good for spring and fall species too.  If they must skip a year of seed production, that’s a small price to pay for overall health of the ecosystem they depend on. 


That being said, it's possible repeated late spring burns when wildflowers are up may lead to declines in some of those species – though I’m not aware if anyone has truly studied that. Increased competition from recovering summer and fall species may also conceivably decrease some spring species that have profited from lack of such competition. There’s much to learn.

How do you handle downed wood?

 

With such an excess of dying trees (from ash and elm disease as well as from fire), there can be unnatural amounts of fallen trunks and large branches. We mostly hope it catches fire and burns up. Some managers carefully rake around dead wood … and then extinguish the logs that catch fire anyway. But that means they must take the time to do that same work year after year – meaning less time for work that’s much more important to both safety and the ecosystem. 


In some areas we see thick accumulations of unburned decaying smaller sticks, bark, twigs, nut shells, and other litter. Ray Schulenberg from the Morton Arboretum observed that such rotting woody material acidified the soil or otherwise negatively impacted soil chemistry. We continue to hope that fires will be hot enough to burn that up.


We pull logs and dense branches away from oak trunks (both old trees and reproduction, if any) to the extent that we find time for it.  

A low-intensity leaf fire can kindle a much hotter wood fire where a downed log lies close to a tree trunk.  This dead log against a red oak trunk led to a fire that damaged the red oak (and continues to consume the downed log days later). Protecting the young white oaks (pale barked trees in the middle distance) was a priority here. It we'd had time, we would have moved a section of such a trunk that was up against a white oak. It did not concern us that this red oak trunk was damaged. Indeed, for biodiversity conservation purposes, we are culling red oaks in this area.


Fire between this trunk and log badly burned this bur oak trunk years ago and re-burned a part of it recently. In a woods or savanna with little bur oak reproduction, if we saw it ahead of time, we would have cut and moved the part of the log away from the tree. 


How does the size of a unit affect the care you're giving to individual trees?

 

Here I can’t resist invoking one of my favorite burns. At Nachusa Grassland we burned a circle around about 400 acres of prairie, savanna, and woodland on a spring day. We had no prepared firebreaks, as we knew where natural firebreaks occurred and where elsewhere we needed to go slow with special care. During the burn, Wilson’s snipe winnowed over the wetland and wild turkeys gobbled in the woods, while surrounded by flames. Ducks landed in the ponds during the burn, perhaps expecting the fires to drive tasty insects to them. In the evening, now with 360 degrees of burned firebreaks, woodcock performed their mating rituals as the fire burned up all it wanted within that circle, wandering idly in some places, then flaming dramatically in others, until well after dark. That was decades ago, before any of us had heard of Nomex flame-retardant clothing. We used no vehicles – just legs, arms, flappers, backpack sprayers, and rakes instead of drip-torches. 

 

Yes, large burns are different. We typically don’t have time to worry about details within the burn. The fire decides. 

 

Because they nest on the ground in early in spring, we often burn up woodhen’s nests. We are sorry. If we run across a nest by chance, we rake around it and spray water over the area, and we have seen such nests survive. But some are burned. The woodcocks will nest again.  


Is this bad for woodcocks? Our fires restore such good woodcock habitat that our bird reports regularly get skeptical questioning from Ebird. Woodcocks have in recent years spread out of the savanna and into the now-more-open and thriving oak woodlands. Belatedly we now understand why they’re called “woodcocks.” 


Taking the long view, oak woodland restoration has been very good to birds. But you have to break some eggs to restore good habitat for all. 

 

Drew's questions and this post refer back to this burn report.


Additional References:

https://woodsandprairie.blogspot.com/2023/03/discovering-oak-ecosystems-history-and.html

https://woodsandprairie.blogspot.com/2022/03/why-fire-is-needed.html

https://vestalgrove.blogspot.com/2014/11/unexpected-big-ass-forest-fire.html

http://woodsandprairie.blogspot.com/2018/04/dont-hurt-woodcocks.html

https://ruffedgrousesociety.org/woodcock-facts/

 

Acknowledgements

Thanks to Drew Harry of Madison Audubon Society for good questions and discussion.

Thanks for proofing and edits to Christos Economou and Eriko Kojima. 


Monday, April 10, 2023

How we Burned a Nature Preserve: details from April 8, 2023

 Burning Kishwaukee Fen Nature Preserve in Lakewood, McHenry County.

The burn itself, like most burns, was inspiring, especially at its height. But a lot more interesting is the process that makes the burn safe and effective. 

First we gather and review the plan:

That plan was prepared this time by Illinois Nature Preserves staff John Nelson. As shown on John's map, with a wind from the southwest, our first job would be to start at A and carefully complete a backfire to B. 

We study the map and divide responsibilities. 
We study the map and ask questions.

Our target, before we start, is shown above. A-B is in the foreground: a degraded, early-stage prairie restoration with not much fuel. In the background are the fens and sedge meadows, with lots of fuel. 

Today's "burn boss" John Nelson ignites the fire. On the north, our fire break is the little stream, part of the Kishwaukee River headwaters, that the site is named after. 

Next, John spreads that backfire along the upwind side of the break. So the fire burns toward the break and then goes out - or is put out by the crew. We make sure the fire doesn't cross the break and race away as a headfire. That task was made easier by the fact that we first wetted the break with water (see hose). But we still have to be keep an eye on the fire so that it doesn't find a way to sneak across. Because this backfire burns back into the wind very slowly, due to light fuel, John does two more strips. We want to make sure that the burned area is plenty wide enough that the fire will not jump it when the large flame-lengths of the head fire come this way - with the wind.  

Once the fire has consumed the fuel in a strip all the way to the green grass of the golf course, that break is complete. And yet, Amy stays on this corner to keep an eye on the backfire until the end of the burn. 

Now, as that first backfire spreads back from the east edge of the burn, we start a second backfire through heavier fuel along the bank of the creek that marks the north edge of the burn. 

At some points, where the fuel was wet and burned poorly, we made a number of strips ... until there was a complete burn wide enough to protect the other side of the creek from the headfire when it roared north. 

Some areas were more challenging, as downed trees made passage difficult.

We treated such areas with special care. 

Other areas were impossible. There was no practical way to keep the fire from jumping the creek in such a place. At this point we reminded ourselves that an important objective before the next burn would be to clear those downed invading trees away from the firebreak. But for today, with a bit more effort, we moved the break back to a deer path.

Here, with a bit of care, the backfire was kept well away from the woody, grassy tangle that could allow it to cross the creek.

This was the hardest work we had to do. But it was not all that challenging. We moved slowly. Some of the crew were relatively new to fire control, and we all learned more by doing. 

And now, we've reached point D on the plan. For a refresher, see below.
Once we've finished break C - D (through heavy fuel) and burned the little there was to burn through a bit of brush and to the golf course, we're done with most of our work.

This west break was easy and quick to burn in, because a break line through the dense fuel had been mowed and raked last fall (and because a hose reached most of it, so we could wet down patches that looked iffy). 

At this point, the headfire is lit.

Here, the fire doesn't reach the edge of the golf course, because it stops at the no-fuel area where we've been cutting the buckthorn (and collecting stray golf balls). 

In a few minutes, fire does the brush-control work that - if fire is withheld for too long - takes us days or weeks. Fire keeps the grassland healthy, and a healthy grassland resists invasion by brush. 

Then, within secure firebreaks, the flames wander around for some time, going out where areas are too wet or have little fuel, and flaming high where the fuel is dense. In the foreground here, former prairie had been covered with brush so dense that nothing else grew. This small brush had been cut and the trees girdled, so natural prairie can be restored to this important fen watershed. 

In the drone video below by David Martin, we can see fire behavior after the breaks are complete and the headfire has been lit. In this video, it's impressive how the short flames of the slow-moving backfire compare to headfire flames, which reach many times higher, burn hotter, and move faster.




At this point we noticed that one of the raised fens had entirely escaped the burn. The sedge meadow that surrounded it was wet and had little fuel, as last year we had sprayed out the invasive Reed Canary Grass that had been thick there. But it was the fens that were the priority to enrich by burning, so Ben Davies hiked back down with the drip torch and touched it off. 

Here, at the top of the high hanging fen, springs pour out of the moraine. Parts didn't burn simply because of the character of the fen. Those unburned areas we were happy to leave naturally unburned. 

At the end, we gathered for an "after action review." Was the burn as hot as we hoped? A fall burn might have been preferred. In spring wetlands tend to have a lot of standing water (with snow-melt and all), so this burn may have been less effective in deterring some weeds and top-killing some brush. Fall burns once roared across the landscape for miles. The ecosystem may be adapted to those hotter burns. But maybe the bison and elk had removed a lot of the vegetation, so the burns would have been less hot?  Today's burn certainly served the critical role of returning nutrients to the soil and providing other imperfectly-understood benefits. Burned high-quality wetlands retain their quality better when burned over the years. One certain benefit will be in the ease to controlling invasive Reed Canary Grass, without the duff obscuring new growth.  

This burn was especially smooth and quick because the team had so many effective volunteers (two Illinois staff people and nine volunteers). John Nelson expressed appreciation that Friends volunteers recruited the volunteer team, made the arrangements with local officials, prepared fire breaks, and brought most of the tools. John's responsibilities cover more than 100 sites; he can do only so much for each. Many sites go unburned, sadly. At some sites, trained, certified, expert volunteers do the entire burn without staff. Athena, Justin, and the rest of the Friends of the Plank Road Prairies would burn those prairies the next day. Conservation needs more trained burn leaders and crew across the state. Public relations is also important. The golf course was busy, and one of Amy's jobs was to talk with golfers as they came by and answer their questions. 

Honor Roll

People Deserving Recognition

For preparations: Rebeccah Hartz, Eriko Kojima, Amy Doll, and John Nelson

Burn boss for the day: John Nelson

Crew: John Nelson (Illinois Nature Preserves Commission), Patti West (Kish volunteer), Ben Davies (Boone County Conservation District and Kish volunteer), Kent Beernink (Kish Volunteer), Sadie Dainko (Kane County Forest Preserves and Kish volunteer), Rebeccah Hartz (Kish and Somme Woods volunteer), Amy Doll (Friends of Illinois Nature Preserves director and Kish volunteer), Dave Griffith (IDNR), Ellie Krall (Shaw Woods and Prairie volunteer), Athena Knisley (Plank Road Prairie volunteer), Justin Hunger (Plank Road Prairie volunteer), and drone videographer David Martin (friend of Amy).  

And from the Village of Lakewood, which owns this preserve, thanks to Jean Heckman (Village Administrator) for facilitating the many administrative details that assure understanding and avoid snafus at many levels. She has been so responsive and easy to work since the first time that Friends of Illinois Nature Preserves organized a burn here.

And The Beat Goes On!

True to form, Friends of Kishwaukee Fen had their regular work party the very next day. That was just a crew of six; some of us couldn't do two days in a row. But there was work to do.
There were 12 brush piles waiting to be burned, a process now very safe, with all the nearby fuel burned out. We did them all.

At break we snacked.

And discussed: the news of the day, all manner of happinesses for ourselves and families, and of course, the fen.

Then some of us did a bit more planning and set our next priorities.

Life is good. 

Acknowledgements

Thanks to Amy Doll, Rebeccah Hartz, and Eriko Kojima for edits and proofing.
Thanks to David Martin for the drone video.

Resources

For good diagrams of how to burn (and other details), see: