What is a Grade A woodland?

Ignorance kills. New priorities needed. A new tool shows promise.

 

Rare species are important. Rare ecosystems are immeasurably more important. But they’re often ignored (and therefore lost) because conservationists have not yet developed sufficiently practical and effective tools needed to save them. 

 

Perhaps the first point to make in this post is that there seem top be no Grade A woodlands left. All are degraded. Some may be able to recover high quality with good stewardship.

Serious biodiversity conservation began when we first understood that the last high-quality prairies were vanishing. (How important to an ecosystem is "high quality" - and how is it defined? See Endnote 1.) Savanna conservation emerged later, out of what we were learning from the prairies. 

 

Still, nobody much noticed the oak woods. Common? Boring? Obviously ‘disturbed’ (at a time when ‘disturbed’ meant ‘degraded’). To some, the woods seemed to be benefitting from 'natural succession’ – which was seen as a ‘good’ or ‘beneficial’ process, leading inexorably to something ‘better’ (beech-maple forest). Those people were wrong. The deep-shade-tolerant flora of the maple forest do not return because they'd not been there. The result of increasing shade is not the rich flora and fauna of a forest; the result is degraded woodland, low diversity, and ecological ill health.  

Higher quality woodlands have been losing their species at the rate of 2 or 3% per year. At least, that’s what was happening to the few sites that have been carefully monitored. A few percent may not at first seem like much, but those losses continued to add up. In the 1980s, some of us advocated that oak woodlands, long protected from the ‘destructive’ impacts of fire, actually needed to burn. With trials and careful monitoring, in time a consensus emerged that fire had positive impacts and more and more woodlands gradually benefitted, somewhat. Yet few or no “very high quality” oak woods were being found and celebrated, and the gradual species losses even in Nature Preserves mostly continued. 

A degraded woodland under restoration. Some would say that no truly Grade A oak woodlands survive in the tallgrass region. For photos of one of the best, see here. 

As for this post, all the photos come from an attempt to restore quality to Vestal Grove. In the photo above, the herb flora is rich and compact but still has a long way to go in comparison with a top quality remnant. The very old trees are bur oaks showing spreading limbs – or the 'amputee stumps' of such limbs. The 'middle age' trees are mostly red oaks and hickories without lower limbs. As trees continue to be thinned and overall light is increased, perhaps we'll see more bur oak reproduction with persistent spreading "woodland grown" limbs on their lower or mid-height trunks. 

One trillium blooms with wood betony, golden Alexanders, and rue anemone. Other species visible include cut-leaved toothwort and starry campion. The tree trunk belongs to one of the many shagbark hickories. It shows fire damage at the bottom. Many woodlands today have excess numbers of red oaks and hickories, as those species reproduce more readily in fire-starved habitats.  

In 2016, a “wake-up call” made a big impact and indeed led to the “new tool” featured in this post. Dan Carter was part of a crew that evaluated an obscure site for a boat launch. Were there “environmental impacts” that needed to be avoided or mitigated? The Wisconsin Department of Natural Resources (DNR) was proposing an improved road, parking spots, handicapped access, and other facilities at Army Lake.

 

The road was to reach the water through an oak woodland which turned out to be “jaw-droppingly intact” – indeed, apparently the highest-quality remnant in southeastern Wisconsin and perhaps in the whole state. (There’s apparently nothing of comparably high quality in northern Illinois.) As requested, that survey team (employed by the Southeastern Wisconsin Regional Planning Commission) checked and found one Endangered species, forked aster (Eurybia furcata) and some wetlands. The write-up called for avoiding or mitigating any loss of those plants and or wetlands. (Why were those two categories thought to be deserving of special care? See Endnote 2.) 

 

The survey team's report identified Army Lake's rare woodland as the site’s most important feature. 

The other concerns paled in comparison with the importance of the remnant oak ecosystem. The Nature Conservancy's ranking shows high-quality oak woodland as “G-1” – globally endangered. (How is quality determined? See Endnote 3.) 

Sadly, the ecosystem didn’t seem to count. The one Endangered plant species and the peripheral wetlands both were recognized as meriting care. But no protocol then existed to authoritatively identify the incomparably more important woodland community as a priority. It didn't fit into any official category of concern. 

 

As it stood then, Army Lake Woods included ¾ acres of very high quality, ½ acre of good quality (very restorable) and in between about ¼ acre of badly disturbed land (ultimately restorable and therefore potentially invaluable to the long term sustainability of such a gem). Thus, we had here a prospective restored globally-endangered woodland of 1.5 acres. But it was not to be. 

 

Official channels function in mysterious ways. Sometimes they succeed in their intended goals. In this case, they did not. Some of the old oaks were cut, and about ¼ acre of the very high-quality natural area was bulldozed. It was a painful loss to Carter. This defeat established a clarity in the minds of Carter and others. The system wasn’t working. 

An important principle is: Never waste a major loss. Transform failure into a ‘teachable moment’ and inspiration for needed change. Carter reported on the disaster and, at their invitation, teamed up with Wisconsin DNR conservation biologists Amy Staffen and Matt Zine (along with Wisconsin Nature Conservancy regional land steward Brian Miner and others) to create the new official and authoritative “Monitoring Protocol for Assessing Baseline Condition and Restoration Progress in Oak Woodland.” See Endnote 4.

 

This inventory and monitoring tool could have a long-term impact. Wisconsin and Illinois (among leading states in natural areas conservation) have been weak in evaluating woodland sites (See Endnote 3.) If this tool is a step in the right direction, it will be for two principal reasons. It could help us recognize what remnants most merit conservation. And it could help us determine whether sites under management are stable, improving, or declining. 

Currently, such evaluations are made for most preserves on the basis of one person’s judgment. Often the judge is the person responsible for management, and of course it can be challenging to declare your professional efforts a failure, even if the reason is lack of resources. Also, the one-person’s-judgment process has no transparency. Government doesn’t work well in areas that no one reviews. Funding for conservation comes only with public backing. Volunteer citizen scientists, advocates, and stewards can be crucial ... if they’re empowered … and if they empower themselves.  

 

Biodiversity conservation is popular in the abstract, but it needs more public understanding and support. One way to get that is through more transparency and public participation. The new tool does not deliver automatic protection for sites like Army Lake, but it can aid our evaluations of high-quality and restorable oak woodlands, an important next step. 

Endnotes

 

Endnote 1. How important is "high quality" and how is it defined?

The future of life on Earth depends on its ecosystems. As we (to some extent necessarily) manipulate and simplify, we may one day desperately need the planet's once most common and now rare species. Certainly, we need their rare genes for agriculture, medicine, and industry, but we also may need some to restore an out-of-balance planet that has begun staggering toward poisonous rain, loss of oxygen, or insanely high temperatures. Ecosystems maintain balance, powered by the sun.  

Natural areas conservation was inspired in part by Grade A prairies. They are so rich. The INAI showed that only 1/100^th of 1% of the original prairie survived as high quality. We cannot perceive all the components that constitute ecosystem quality or integrity or health. They certainly include all the interdependent plants, animals, fungi, bacteria, soils and all manner of soil biota. 

 

In the past, conservationists slowly began to realize that ecosystems lose biodiversity in response to over-grazing, plowing, draining, the elimination of predators, and other changes that helped us for some purposes. Aldo Leopold, while employed by the U.S. government to eliminate the threat of wolves, learned that "the mountain fears its deer." As Leopold succeeded and the deer massively increased, many plant and other animal species dropped out. No one at that time checked on how the fungi and bacteria were doing.    

 

Indeed, our overall understanding of the ecosystem is still primitive. But those gorgeous, intact, rich prairies made some people think, and act. A Grade A prairie typically has 20 or more plant species per ¼ square meter - and most of those plants are rare conservatives. A typical degraded prairie may average five common species per ¼ square meter. Conservative plant diversity is believed to be a good indicator of ecosystem health. The hope is that, if a remnant is big enough to sustain them, the other biota will be there too. 

What does "Grade A" mean? The definition changes. The Illinois Natural Areas Inventory defined: 

"Grade A - Very High Quality" as "Relatively stable or undisturbed" and 

"Grade B - High Quality" as "Late successional or lightly disturbed" 

with the more detailed explanations including language like Grade A: "does not show the effects of disturbance by humans" and Grade B: "not disturbed so heavily that the original structure and composition was destroyed." 

But in recent decades it's become increasingly clear how profoundly Native American humans - through fires, hunting, etc. - influenced the "original" nature that Europe-derived science studied. How far back should we consider that "origin" to go. For most of the richest tallgrass area, the ecosystems began to assemble only 12,000 or so years ago when the most recent glacier retreated. But, bless them, scientists have also demonstrated that many of the species and relationships go back hundreds of thousands to millions of years. They can move and re-assemble over time if given the chance. 

So how should "high quality" now be defined? Perhaps the definition could now be: 

A high quality remnant ecosystem is one that has most of its biota surviving in the structure and richness that assembled over thousands of years. 

Perhaps no rich Grade A savannas or woodlands survive. Very few come even close to the plant diversity of the best prairies, but some of the best do. Perhaps high-quality woodlands can be restored from the healthiest remnants?

(Note on soils: The INAI community classification separated areas by soil type. Sand prairies, savannas, and forests are considered separately from those on good soil, which have sometimes been referred to as "black soil savannas" or "rich-soil savannas." But the INAI just called those "savannas." Thus you have to read carefully to determine whether Illinois' savanna remnant heritage amounted to 11.2 acres (INAI Technical Report numbers for dry-mesic and mesic savanna in Table 6) or 1,300 acres (Technical Report's introduction). The difference reflected the much greater survival of sand savannas, as sand areas have not been as intensively used for agriculture and are less vulnerable to many invasive species. The potential for confusion on woodlands is even greater, as the 1978 Inventory did not distinguish between forests and woodlands. For some details of the 2011 revision of the Inventory, see here.)   

 

 

Endnote 2 Who started this?

Much conservation as we now understand it goes back to Silent Spring by Rachel Carson in 1962. Summarizing its impact, historian Jill Lepore credits Silent Spring with launching “environmentalism” as a global force and in the U.S. provoking the efforts that resulted in Clean Air Act (1963), the Wilderness Act (1964), the National Environmental Policy Act (1969), the Environmental Protection Agency (1970), the Clean Water and the Endangered Species Acts (both in 1972). Thus there is now widespread recognition of the importance of  wetlands and endangered species.      

 

Rachel Carson and Jill Lepore “have a way with words.” They’re both worth studying for that reason alone. Lepore praised Silent Spring by saying that, in the history of the planet, books with that much global impact could be counted on the fingers of one hand. Actually, the way Lepore put it reflected Carson’s many previous books, all of which reflected her love of the ocean, its tide pools, and biota. Thus, Lepore actually wrote: “The number of books that have done as much good in the world can be counted on the arms of a starfish.” (from “The Deadline” by Jill Lepore, 2023.)

Endnote 3. How do we Evaluate and Monitor ecosystems?

 

It’s relatively easy to measure Endangered Species numbers and the boundaries of wetlands. But for high quality ecosystems? Some details can be measured. But the vast universe of species and the interrelationships that make up ecosystems are for the foreseeable future beyond our grasp. So we need indicators.

 

Up until now, most people, if they measure or evaluate natural communities at all, use one of two methods: the Natural Areas Inventory method or various Floristic QuaIity methods. Both have advantages and disadvantages. 

 

The Inventory approach was developed in Illinois through the work of John (Jack) White and others in the 1970s (see Endnote 5). Their judgements were based on "lack of disturbance" and richness of conservative species. The resulting Illinois Natural Areas Inventory taught us how to recognize ecosystem remnants and where they were, leading to the acquisition of most of the best ones.  

 

This approach did great on prairies but found little in the way of black-soil savannas. Curtis in 1959 in Wisconsin (under the name Oak Openings) had found savanna to be the most common ecosystem type in the southwestern half of his state. Oak openings were found to have covered an astounding 5.5M acres,  with forests at 3.8M acres, and prairies at 1.5M acres. (These figures for “approximate original area” lump mesic and dry-mesic for forests and prairies, as Curtis lumped mesic and dry-mesic for savannas on rich soil as “oak openings.”) Savannas had been major habitats in Illinois as well, but remnants had been degrading even more quickly than prairies. Indeed, none were surviving with conservative diversity equivalent with what the best prairies exhibited. Had they once had it? As we learned, we began “saving” and “restoring” savanna as best we could. When developing global priorities in the 1980s, The Nature Conservancy gave savannas the highest priority, G1, Globally Endangered.

 

Neither Curtis nor the Inventory recognized mesic oak woodland as a community separate from mesic maple forest. They seem to have been blinded by “succession” theory. Oak woodlands weren’t seen as hallowed eternal nature; they were considered a temporary state, recovering from disturbance, on the way to maple forest. 

 

Yet as biodiversity conservation was studied, we began to recognize that the species of oak woodland were being lost. Species don't evolve over night. Woodlands (like savannas) are ancient communities that depend for their integrity on regular ‘disturbance’ by fire. Some of this history is discussed in Endnote 3. 

 

The Illinois Natural Areas Inventory focused too much on lack of disturbance and, for long term use, depended too much on judgment. Different “experts” had different judgments. Once the highly-trained original team had gone on to other jobs, their work was difficult to replicate.

The Wisconsin approach suffered from their system's Curtis-based approach, which did not recognize the significance of mesic woodlands.  The Coarse-level Monitoring Protocol (2023) presented (and linked to) in Endnote 4 is a new approach that could help conservation practice catch up with the evolving science, in the context of  a less-individual-judgment-based system. 

 

The Floristic Quality approach was developed by Gerould Wilhelm in 1977 for a study of the vegetation of Kane County, Illinois. It became highly influential when it was expanded to cover parts of four states in Plants of the Chicago Region (1994). It had the advantage that all competent experts would arrive at the same results. It had the disadvantage that experts did argue about what those results meant. Summaries of this method and references are here, here, here, and here. 

Wood betony grows in both woodlands and prairies. In the prairie it tends to be yellow. In woodlands, limited experience suggests that it's often reddish. Millions of years of co-evolution with hummingbirds have resulted in some species evolving red flowers. (For more on that, see here.) Much less-obvious genetic richness may be hemorrhaging from oak woodlands as animal, plant, fungal, bacterial, and other species drop out. Small sites of high quality have better potential for sustainability if nearby land can be restored to sufficient quality to support those species that need it.

Endnote 4. The new protocol.

The new woodland protocol will be posted in the Wisconsin DNR website. It's currently posted in full here. For comparison with an officially posted protocol for savanna, look here. For a criticism of this sort of approach, see Endnote 6. 

For some excerpts of the new woodland protocol, see below:

Endnote 5. 

Perhaps we would take our leadership responsibilities and opportunities more seriously if we were to reflect on how greatly our region contributed to the origination of "ecosystem conservation" and "natural areas" stewardship. Henry Chandler Cowles (U. of Chicago) launched ecosystem study in the early 1900s. His student May Theilgaard Watts (Morton Arboretum etc.) wrote the books that raised constituency for it from 1957 to 1975. John C. Curtis (U. of Wisconsin) in 1959 scientifically defined the region's ecosystem types. John (Jack) White (Univ. of Illinois etc.) supervised the Earth's first Natural Areas Inventory in the 1970s. For more see Some History of Biodiversity Conservation.

Endnote 6.

One "peer reviewer" of the draft of this post wrote:

I have to be honest, I don’t really like these checklist scoring sheet type approaches. The scoring calculation seems just as arbitrary and any other approach, and they try and force things into categories too much. 

I understand their appeal (as you’ve outlined), but they aren’t my cup of tea because I have seen so many bad ones that are limited in their utility and are untested and uncalibrated with actual data. They often work in the limited context from which they were created, but when you take them to another site, they don’t apply as well. They are often created, and barely get used, ending up in the dust bins of history.  

But Floristic Quality as an approach remains widely used and increasingly so --- in large part because it is so simple and easy to use. But, it too is not well calibrated with actual data.  And its limitations and strengths aren’t well flushed out.

A few more photos and comments are below: 

The rather dense grass in the top half of this photo is awned wood grass (Brachyelytrum sp.). Perhaps it's so dense that the Coarse Metric would give this area a lower rating. Then again, this grass is not even on the Metric's list of woodland species. Is it naturally more characteristic of maple forest?  The same questions could be asked about large-flowered trillium, big leaf aster, and some of the other species mentioned here. No one really knows the appropriate status of most species in the tallgrass region's oak woodlands. The Metric is based on field knowledge and judgment. It and other methods should improve as we continue to learn more from remnant and restored areas. 

Above, the densest species is big-leaf aster (in bloom). This area in recent years had been increasingly rank with woodland sunflower and dewberry - "Native Indicators of Degradation in Oak Woodland" according to the new Wisconsin protocol. Scything them led to increases in more conservative flora including big-leaf aster (in bloom), zigzag goldenrod, awned wood grass and many others. Will such "facilitated diversity recovery" in time be adequate to control the sunflowers, briars, and other "thugs"? Work and time will tell. It is truly so very much fun to learn how to be good stewards of biodiversity. 

At Somme we have evaluated restoration results using both judgment and FQI. We have experienced such FQI positives as increasing site FQI and mean C, transect FQI and mean C, and average quadrat FQI and mean C. All those measures have consistently improved. Yet we’re far from confident that all proceeds well. Part of the “improvement” may be that woodland sunflower (C = 5) is massively replacing tall goldenrod (C=1). In the early stages, no problem. But over time, there are some indications that this sunflower will shade out (or allopathically reduce or eliminate) many species that had seemed secure. Our four-decades-long experiment definitely seems still in an early stage. 

John Taft pointed out (personal communication) that our species per quadrat and FQI numbers were still rather low compared to a site in southern Illinois that he had been sampling. But that site was substantially drier, more intact, and on much poorer soils, so it was not altogether comparable.

In restoration, different species respond differently to different approaches. Rue anemone (in bloom above) did not establish from our seeding. It was restored only through transplants from quality areas being bulldozed for housing developments. Individual transplants sat there, not reproducing, for decades - but now bloom in some areas by the hundreds. Most species came well from broadcast seed, but some, like big leaf aster, had minor success until more quality developed. Now it thrives in many areas after decades of existence as tiny, scattered leaves here and there. 

Some parts of Vestal Grove have developed a rich spring flora. Prominent above are wild leek, bellwort, and trillium. Will they be reduced as summer-blooming species increase? If so, people may miss the massed flowers of spring flora here. (Notice that there are few spring flora species on the Wisconsin list of woodland indicator species.) But there'll be plenty of rich spring flora elsewhere, for example under maple. 

We considered this area well on the way until, influenced by the new protocol, we noticed that the only trees in this area were hickories, red oaks, and hop hornbeams. A fine woodland may have such areas and such species. But good management should result in bur oaks reproducing here. This recovering ecosystem will probably see its original oaks reproducing and coming to dominate, soon, or decades from now. Our goals are very long term. 

Acknowledgements 

 

Thanks for helpful comments and edits from Greg Spyreas, Dan Carter, Matt Evans, Fran Harty, Rebeccah Hartz, and Eriko Kojima.