Lily-of-the-Valley as a Menace

The story of a deceptive killer …

… in which a seemingly-irresistible force meets a few possibly-unstoppable stewards.

It’s a drama. Who will win? 

The poisonous killer plant in question is Convalaria majalis. As a deceptively favorite garden plant, it’s called lily-of-the-valley. But stewards of biodiversity call it the death lily, because – under certain conditions in nature – it kills all. 

The photo below shows what this monster looks like – toward the edge of the patch, where some diverse vegetation still survives. In the middle of the patch, we found nothing beside death lily and dirt.

But the next photo zooms in to show why this spot is worth caring about:

Above, you see a purple-leaved plant on the Endangered list – cream vetchling or wood pea (Lathyrus ochroleucus). It deserves life, and, indeed, reproduction and recovery of its once-common woodland status. (Notice the huge stipules visible where one compound leaf meets the main stem. These stipules distinguish the wood pea from some related look-alikes.) This plant, which now survives in few other places in Illinois, inspires the work shown in the next photo, of the same place, but after some handiwork.

Here six stalks of wood pea and a bit of other vegetation stand separated from the lilies. Step one - accomplished. Next we step way back, and you can see how big this patch is: 

We're looking from the north. The south edge of the patch isn’t quite visible here, but if you look closely, you can make out three of the Restore Moraine team, weeding this menace from rare species on that south edge, at the top of the slope where the patch ends. 

These are the heroes yanking out stems that are near the higher quality vegetation. We want to save as much rare vegetation as we can. Stewards from left to right are Eriko, Ryan, Mary, Mills, and Erica.

Then comes step two!

The herbicide glyphosate kills all plants. It’s a last resort for species like this lily that aren’t killed by something less toxic. 

Here the heroes are Ali, Jordan, and Steve. Ali and Jordan are spraying death lily. But remember this photo?

If you look closely, you can see that not only wood pea survives on this rocky slope. Among the many other species we found here are round-lobed hepatica, woodland milkweed, nodding wild onion, northern bedstraw, rue anemone, Carolina vetch (also endangered), and many more. But the major other plant above is that robust grass. 

It's reed canary grass, another killer invasive. If we left it, that grass would quickly fill the entire area we opened up. Fortunately, that one is susceptible to herbicides that kill only grass. So, step three, Steve is spraying the reed canary. It's relatively easy to dispatch that one.

Not so for the death lily. This whole lily colony is one plant, roots connected underground. What will happen to the roots in the area where we pulled out the leafy stems – when we spray the nearby intact vegetation? We don’t know. Has anyone else done this? We expect, from experience with other invasives, that the remains of un-herbicided roots will put up new stems near the endangered wood pea and other surviving natural vegetation. We may continue to pull the weakened new shoots, or perhaps we’ll carefully hand-wipe them with herbicide.  

In the meantime, we’ll also focus on the rest of our priorities here. 

The intrepid Restore Moraine volunteers work in only perhaps 20 acres of the 2,200-acre Moraine Hills State Park. Indeed, within these 20 acres, most of our work has been directed toward a top-priority four acres of rare high-quality oak woodland. Quality areas have shrunken under the stresses of past grazing, invasive species, over-populated deer, and excess shade from lack of fire. The four best quality acres are divided up among five little slopes where much of the ecosystem has somehow miraculously survived and is recovering.

As described by Dr. Wayne Schennum, who studied it for decades, what survives here contains patches of rare high-quality remnant white and bur oak community – not recognized until relatively recently as a high priority for biodiversity conservation.  Like the vast prairie, oak woodlands were once a major natural feature of this state. This park also has bogs and fens and sedge meadows and prairie remnants. It has many rare animal populations that also deserve stewardship. We help some with them, but we mostly try to focus on restoring health to this oak woodland.  

Dr. Schennum, long advocated for “first aid” rescue work for this woodland, mostly by cutting invasive trees. Rare species had been vanishing in the gloom, as he documented. The diverse animals and plants of oak woodlands thrive in dappled sunlight under oaks that are naturally well-spaced by fire.

Friends of Illinois Nature Preserves agreed with Illinois Department of Natural Resources biologist Melissa Grycan that this site should be a priority. With her guidance and support, starting on June 7, 2025, the resulting Restore Moraine stewards have worked every Saturday morning (and some days in between), year round, to do what oak woodlands are increasingly understood to need.

We hadn't tackled the death lily until last week. We've studied the literature and the Internet and asked expert stewards about their experiences. This menace is most vulnerable to herbicide in spring. No other approach controls it, except repeated hand pulling, which is impractical for large populations. We hope to hear from others about varied approaches. This post will be updated as we learn more.

Endnote 1

At Moraine there have been surprises. We’ve found many new populations of Endangered or rare species. All have been injured by excess shade or invasive species. Hundreds of acres of ailing oak woods here need more care. They need regular fire, invasives control, tree thinning, and seeds – which need to be hunted, gathered, prepped, and broadcast into areas where richness has been lost. 

But Moraine isn't the only Preserve with a lack of resources. Most Preserves are suffering. We can't just shift resources here from elsewhere. The Illinois Nature Preserves System needs more staff, contract stewardship, and support for volunteers. But with high-quality woodlands even rarer than prairies, some of us decided that this Nature Preserve was a priority for help by a Friends volunteer community. We're less than a year old here, but off and running. All are invited to come and help, if you're so moved. 

Endnote 2

Compelling account of control at Bluff Spring Fen and Poplar Creek by Kirk Garanflo:

Massive infestations of Lily-of-the-Valley (Convalaria majalis) can be eradicated without hand-pulling and without killing everything with herbicide. Ongoing experiments at both Bluff Spring Fen and Carl R. Hansen Woods have been successful at dramatically reducing this pest in small areas.

For large areas such as shown in the photographs above, use a weed whip (or a metal-bladed brush cutter when woody stems are present) to cut the plants AT GROUND LEVEL during the last weeks of April and the first weeks of May when not much else has emerged. Eliminating leaf structure weakens them for the rest of the year; follow-up is essential thereafter during the spring to attack plants that were missed or that emerged after cutting. As long as the plants are cut below that first leaf axil the plants do not usually then leaf out or flower. This process must be repeated for many years (possibly five) in a row without failure in order to exhaust the energy stored in the roots and eventually kill them. Do not skip a year which will allow new leaves to reinvigorate the roots.

It is necessary to expose the plants free of surrounding plant material. Annual burning to remove old dead material is essential in order to find plants that are hidden among tall, withered foliage.

The use of a weed whip or a brush cutter is far more labor effective than hand pulling for an area larger than a quarter acre. Eventually the infestation will be reduced sufficiently to allow effective hand pulling (even just snapping the plants off at ground level works too) of the odd plants that do survive.

Endnote 3

Experience of Maria Vujic and Stone Hansard at Morton Grove Prairie:

This photo (by Stone) shows where a solid stand of the lily stood last year, indicated by the red line. Where the lily re-emerged this spring is outlined in blue:

It was controlled by multiple sprayings of Glyphosate (4% Aquaneat with Liberate).

This infestation was in an area where the prairie had been shaded out by large cottonwoods (since removed). Prairie seed from nearby was broadcast last fall.

Why did those two patches re-emerge, when this invasive seems completely gone over most of this large area? There are many possibilities. But perfection in one year is not to be expected. The small volunteer crew that assembled to restore this little gem of a Nature Preserve was, at the same time, dealing with massive infestations of sumac, briars, tall goldenrod, buckthorn, and other challenges. We do what we can, and then we follow up. Those blue-outlined patches have been sprayed this spring and will be sprayed again or receive other treatments as needed. 

To see what this area looked like in 2025 prior to treatment, see Maria's photo below:

Acknowledgements

Thanks for review, suggestions, and editing to Lana Fedewa, Jonathan Sabbath, and Eriko Kojima. 

Index to Posts on Birds

Bird Bonanza in 1908

Big bird year at Somme

Birds - habitat restoration for

Birds moving into open woods

Cowbirds

Falcon likes new habitat

Hummingbirds, co-evolution

Hummingbird mating drama

Migrating Birds use of Somme Woods

Migrating Birds use of Somme savanna

Nuthatch Love

Oak Animals and Fire

Prairie restoration for birds

Red-tailed Hawk learns Lesson

Shrub Thicets

Sparrow, "tree" or scrub?

Thrush, Hermit - in winter

Woodcock

Woodcock, Woodhen, and Woodchicks

Woodland restoration for Birds

Woodpeckers, Downy, in love

Yellowthroat

The Discovery of Nature - A Quick History

a DRAFT summary - for a book in progress

Comments welcome

The Discovery of Nature

People and Dates

Some will say that no one discovered it - that people already knew what nature was, since the stone age at least. In that sense, all the animals also "knew" about nature – but scientific discovery is something else. And true understanding of ecosystems is just beginning. 

In the early 1900s, a few people in the Midwest got the ball rolling. Here - unlike most of the temperate world where natural ecosystems had been entirely replaced by croplands, pastures, mines, and cities - small bits of ancient ecosystems survived. More importantly, they survived alongside a rapidly developing culture including universities with at least a few curious scientists who noticed strikingly rich remnant prairies and woodlands that were gone from Eurpoe and farther east (even by the time of Thoreau). These scientists began groping toward new understandings. 

·      In 1899 botanist Henry Cowles at the University of Chicago publishes planet Earth’s first insights into how an ecosystem functions. He focuses on plants that colonize bare sand and describes how much richer such communities become over time. He mentors Victor Shelford, May Theilgaard Watts, and others who would play key roles.  

·      In 1915 animal ecologist Victor Shelford, then a professor at the University of Illinois, launches the Ecological Society of America (ESA) with a mission that includes study and saving the surviving natural ecosystems of the Americas. As the ESA academics vie for grants and professional advancement, the conservation part of that vision gets lost. 

·      Starting in 1916, also building on Cowles, Henry Alan Gleason, a former Illinois farm boy trying to be a plant ecologist, briefly becomes the cutting edge of ecology. Breaking with the conventional simplistic and formulaic approach, he questions some basic principles of the time  – for example, that “succession” is always good … and fire always bad. Conventional scientists shun him. He abandons ecology, his ideas triumphing only decades later. 

·      In the 1940s, Aldo Leopold and colleagues at the University of Wisconsin begin efforts to learn to restore ecosystems. 

·      In 1949, a year after his death, Leopold’s “A Land Ethic” is published – for the first time defining a morality of ecosystem conservation. 

·      In 1951, following Leopold’s earlier recommendations, the State of Wisconsin begins work which will result in a State Board for the Preservation of Scientific Areas – and the first prototype nature preserve system. 

·       Also in 1951, Victor Shelford, still plugging away, enlists George Fell and others to launch The Nature Conservancy, which for decades becomes the unchallenged heavyweight of the ecosystem conservation business, buying quality wildlands.

·       In 1957, May Watts publishes Reading the Landscape – engaging a constituency in ecosystem appreciation. It focuses on the Midwest; later she publishes Reading the Landscape of America and Reading the Landscape of Europe. This is a vision people were hungry for. 

·       In 1959, giving credit to Gleason, John Curtis publishes The Vegetation of Wisconsin, for the first time defining plant communities in scientific detail. 

·       In 1962, Rachel Carson publishes Silent Spring – inspiring world-wide conservation efforts and conveying to many people that the planetary ecosystem is a precious and fragile thing. 

·       In 1963 George Fell launches the Illinois Nature Preserves System, to focus on the small, highest quality areas, that had often been neglected. This updated Nature Preserves vision is sufficiently compelling that in the next two decades, more than half the other states follow suit. 

·       In 1975, Fell hires Jack White to lead the Illinois Natural Areas Inventory – the world’s first comprehensive effort to document a state’s surviving high-quality remnants of nature. Its first challenge: to define what such nature meant. 

·       In 1977, the North Branch Prairie Project becomes a model for public participation in the care of publicly owned natural lands, leading to the Illinois Volunteer Stewardship Network in 1983. 

·       1978 the Natural Areas Association forms (under the guidance of George Fell and Illinois chief botanist John Schwegman). Now national. 

·       In 1979, Gerould Wilhelm publishes an early draft of the Floristic Quality Index – a now widely used system for measuring plant community integrity, health, or quality.  

·       In 1988, the Society for Ecological Restoration is launched under the guidance of Bill Jordan and the University of Wisconsin. Now international. 

·       In 2019, although the Illinois Nature Preserves System has grown to more than 600 preserves with more than 250 owners, the ecological health of many preserves is badly stressed. Though legally protected, biodiversity is being lost. The Friends of Illinois Nature Preserves start work to help rescue these still-threatened gems of nature. Government alone can’t do it. 

Woodland Burn at Moraine Hills - March 21, 2026 - in videos and photos

This was a good burn to learn from. It also did a ton of ecological good for a rare and important site. Such burns don't just happen. It took a lot of good work to get to the photo below:

We started the day with a brief intro and some training (especially for those of us new to burning) as we put on our fire-resistant Nomex clothing: 

The crew consisted of nine Restore Moraine volunteers, some never on a burn before. So we started out with the basics (as shown in the diagrams below) and how to use the tools. The key person here, still in a tee-shirt, is Illinois Natural Heritage Biologist and accredited burn boss Melissa Grycan. For more about how she led and taught, see Endnote 1.) 

The biggest worry of the day was the possibility of the fire escaping into hundreds of acres of adjacent cat-tail marshes, which are also burned on purpose sometimes, but which with today's winds would smoke out nearby roads. Then we drove from the Maintenance Yard to the woodland. 

Here we made specific plans and assignments for the day and divided into two groups, each with a crew chief. But while we're together, the glorious crew deserving credit for the day consists of (from left) Tony Tucker, Jordan Botezatu, Ali Fakhari, Steve Schumacher, Mills Guanci, Eriko Kojima, Lana Fedewa, David Urbansky, Andy Delorenzo, and Melissa Grycan. 

First we walked the entire firebreak - 360 degrees - to double check. Although the break had been "leafblown" and raked a week earlier, winds had scattered leaves across some parts, and the area above (with big cat-tail marsh immediately down wind today) looked like it could use a bit more work. 

Now, at 12:10 PM, Melissa lights the fire in a patch of leaves on which Lana has poured a bit of drip-torch fuel, to get the fire started on this somewhat cool and humid morning. Lana, Melissa, and half the crew will go clockwise around the break, lighting a continuous line of backfire (a fire that backs slowly into the wind). This backfire results in a fuel-free fire break.

David takes the other drip torch and leads the other half of the crew counter-clockwise, lighting a line of fire that will burn uphill through the thin fuel here. Most of the dead leaves have blown off this windswept morainal hillside. 

Here Tony makes sure the fire doesn't cross the break while Steve lights a second line of fire ... to widen the break ... and Eriko coaches Steve.

The goal of the crew in this video is to widen the burned-out break so that the bigger head fire, when it comes, will not be able to jump it. Here two wrinkles emerge. There are many big and little elements in most burns that may need adjustments or compensations. 

The first in this case is that the drip torch isn't working as it should. Burning drops of fuel (mostly diesel but some gasoline, which keeps it ignited) should be falling on the leaves and making a simple line of fire, as on the left. But with this third drip-torch, either too little fuel comes out, or too much. Probably it's clogged.  This torch will probably be replaced by another once Steve checks in with Melissa at the head of the line, but in the meantime, he makes the best of it. 

The second "element" that needs "adjustment" - at least as this observer sees it - is that Steve may be making this second line too far to the right. The video ends before Steve's strip head fire reaches its height, but it may be a little too vigorous for this early in the burn. A strip about two feet back from the backfire (instead of five or so) might have been better. A problem could occur when his little gradually-increasing head fire meets the backfire. At that point, the two fires tend to "jump up" with more vigor, and could send a few burning leaves across the break to start a new head fire where we don't want one. 

In the next video, David is lighting more backfire ... 

... but the camera pans away to show the other crew, in the distance, extending their line of backfire so as to increasingly encircle the burn area with "black" - that is,  safe - no leaves or grass left to burn.

Another interesting component of the above little video is that David (who's never used a drip torch before) listens to a suggestion from Jordan (who's been on one previous burn and used the drip torch once). Melissa's goal on an easy burn like this is to encourage people to listen, learn, observe carefully, and think. Burning needs more people who know what they're doing, and experience is a crucial teacher. Most new people get to use all the tools. On a more challenging burn, more experienced people would do all the most demanding jobs, and the rest would marvel at their skill, and learn even more. 

At this point we saw our only flower of the day. Hepatica. We burned it up. 

How late in the year is too late to burn? There's no easy answer. Last year's hepatica leaves are still green, as they were all winter. (See leaf to the left of the flower.) Theres no time to burn when you don't burn them.  This year's leaves are not up yet. The burn will not hurt the hepatica. It will help it and the many other rare and high-quality species here. 

Most burns take place during the dormant season. Eurasian bluegrasses stay green later in fall and green up earlier in spring than most fire-adapted vegetation. A serious pest, bluegrass is set back by early fall and late spring burns. The weakened bluegrass in some areas here will allow recovery of many species of biodiversity importance. This was a good time for a burn.

In the next video, the counter-clockwise crew is dealing with a dense stand of grass. They go slowly. Jordan extends the line a little farther while Ali sets another little line of fire to widen the break. Then they patiently wait for the fire to die down before they move ahead. 

At one point during this little video, the camera pans right where you can see the smoke of the clockwise crew rising. The next photo shows that crew, carefully working along, at this point lighting a side-fire. The plan unfolds.  

Finally, at 1:25 PM, one final video. An hour and fifteen minutes after we started, the two lines of fire come together, and the head fire burns with the wind. Even though oak woods fire usually has just two or three-foot flames at most (as opposed to 20 or 30-foot flames in a prairie fire), the head fire comes last because even this much of a fire would have been hard to control if we had not burned a wide, fuel-free fire break on the downwind side by backfiring. 

This burn was at Kettle-Moraine Nature Preserve at Moraine Hills State Park, owned and managed by the Illinois Department of Natural Resources, with support of the Friends and the Restore Moraine volunteers. The footpath we used as a firebreak for this modest burn is about a mile long. We burned about 15 acres.

As a result of this excellent and easy work, one of the finest remnant oak woodlands in Illinois (see Endnote 2) will especially thrive and recover this year. As we walk the path, we'll compare the burned with the unburned sides, to observe differences and learn. The Moraine Hills bur and white oak woodlands have been on the path toward the recovery of full health and vitality for some time, and we expect it to make more big strides this year.

Endnote 1. How to Teach and Learn

Leaders like Melissa (and the Friends of Illinois Nature Preserve burn-boss mentors) are always thinking about training new leaders and other effective contributors. An intro, like the one Melissa gave at the start of this burn, seems primarily for those who are new to burning, but it is at least equally important to the ongoing in-service training of others who will become burn leaders in time. Expertise is promoted by hearing principles in various forms, as they apply to different sites and situations. 

After a second or third successful experience in some role, many people can be expected to be asked to mentor others or demonstrate some component of the training to them. People develop expertise: when strip fires may help, how to most effectively operate the water backpack, how to fill the drip torch, what is the best diesel/gasoline ratio under various conditions, how to best protect ourselves and each other from unnecessarily smoke, etc. Such participants gain not only technical expertise but also a cultural sense of the need to, and how to, help newer people learn. 

More fire and more burn leaders are needed. Our staff and volunteer burn capacity is too small, as is demonstrated by the ongoing losses of biodiversity and natural ecosystem quality in Nature Preserves. Many have deteriorated because of lack of ‘burn bosses’ and ‘crew chiefs. (It’s fairly easy to train new volunteers to do much of the needed work. What takes time and skill is training leaders.) 

In some areas, increasing numbers of new burners see themselves as being on the road to leadership in a community of expert stewards and burn practitioners. 

Some burn managers make an effort to have new burners on the team as often as possible. It helps everyone’s learning. This same approach is valuable in restoration generally: having new people join in at workdays week after week keeps things fresh, and everyone continues to learn with an open, questioning mind. When we don't have new people coming on a regular basis, we find, unfortunately, even in the most community-conscious settings, that the approach can become rigid and opinionated. In contrast, welcoming and training new people, and thinking about their questions, encourages all, including veteran participants, to embrace an open culture, continuously wanting to learn new things and improving current best practices. In recent years this growth-focused approach has been a real game changer that may expand capacity exponentially.

Endnote 2: How good is this woodland, and what saved the biodiversity here?

Like most other woodlands in the Midwest, this Moraine Hills Nature Preserve woodland had been damaged through over-grazing by fenced in livestock. Grazing by bison and elk had been very different; they came and went. Cattle, horses, sheep, and pigs were fenced in. Moreover, the numbers of native grazers was kept relatively low by such predators as wolves, mountain lions, bears, and, especially, Native American humans. Fenced in livestock wiped species out.

In parts of this oak woodland Nature Preserve today, little biodiversity is evident beyond the oaks. But miraculous patches here and there, often on steep slopes, are rich with diverse endangered and rare plant species. Other large areas appear to be on the road to recovery thanks to decades of staff and volunteer stewardship. A helpful 1996 evaluation compared this woodland to others in Illinois. Part is reprinted below. There were no very high or high quality (Grades A and B) of this community surviving. This good quality (Grade C remnant) was best of its kind. See the original under references.

Kettle Moraine Woodland, McHenry Co. (grade 

C best of type mesic Quercus rubra-Q.alba

woodland, (282.7 trees/ha, 45.5 m /ha basal area). 

This 30-acre woodland is the best known example

of a Quercus rubra-Q. alba woodland. This

structure apparently developed under post-

settlement fire protection, as the Public Land

Survey notes describe the area as a Quercus alba-

Q. velutina savanna, with 20.5 trees/ha. The site

was maintained by moderate grazing, which

reduced plot species richness but allowed survival

of a comparatively large number of native species.

The herb layer is dominated by Carex

pensylvanica. Fragaria virginiana, Allium

cernuum, Antennaria plantaginifolia, &

Amphicarpa bracteata. However, there are local

populations of prairie species such as Andropogon

scoparius, Heuchera richardsonii, Amorpha

canescens, & Ceanothus americanus, and

woodland species such as Carex hirsutella,

Smilacina stellata, Dodecatheon meadia, &

Hepatica americana. The Illinois endangered

Corallorhiza maculata and Lechea intermedia and

threatened Lathyrus ochroleucus occur in the

woodland. The tract is dedicated Nature Preserve,

and is being managed by prescribed burning.

(Schennum 1984)

References

What is a grade A woodland?

Dr. Wayne Schennum's paper on Moraine Hills woodlands

Bowles and McBride 1996 a still relevant and valuable review of the status of oak savanna and woodland remnants in Illinois

Index to blog posts on oak woodland conservation

Acknowledgements

Burn diagram from Packard and Mutel The Tallgrass Restoration Handbook, courtesy of Island Press.

Eriko Kojima wrote the first draft of Endnote 1. She and Rebeccah Hartz contributed proofing and edits. 

Dense, Dark Forests are a Modern Phenomenon

In much of North America and Europe, the romantic vision of nature has been the deep dark forest. That was largely a boring and unfortunate myth.

Below are artistic palaeo-reconstructions of ecosystem states in Central Europe over the last 23 million years. These illustrations depict typical landscapes and key large herbivores from six time periods. This thinking somewhat parallels recent conservation research and thinking from the Americas. 

The following is a summary of the full article, which can be found here. 

Dense, dark forests in Europe are a modern phenomenon

by Aarhus University

edited by Gaby Clark, reviewed by Robert Egan

For over 20 million years, the landscape of Europe has been a tree-rich mosaic of grasslands, scrubs and more or less open woodlands with an abundance of wildflowers. This is the conclusion of a new and comprehensive study of Europe's vegetation history—a study that suggests modern afforestation runs counter to the continent's long-term ecological trajectory.

Imagine that you are walking through pristine nature in central Europe 100,000—or even a million—years ago. If you picture a dark, dense primeval forest, where sunlight barely reaches the forest floor, then you have taken a wrong turn. Not geographically, but temporally.

But if you picture scattered woodlands combined with colorful flowery meadows, where lots of different birds and butterflies are thriving—you're probably on the right track.

From nature's perspective, the dense forests are a very recent phenomenon.

A new, comprehensive study led by Aarhus University shows that Europe's landscapes over the past more than 20 million years have predominantly been a mosaic: a mixture of grasslands, scrub and woodlands of varying density. Such a light-filled, flower-rich open woodland was shaped by grazing animals.

The study has been published in Biological Conservation.

"The study shows that current reforestation practices are on the wrong track—both here in Denmark, where subsidies are only granted for planting dense forests, and elsewhere in Europe. This will not only be harmful for biodiversity; it will be in direct contradiction to the type of ecosystems that Europe's species have evolved in over millions of years," says Professor Jens-Christian Svenning from the Center for Ecological Dynamics in a Novel Biosphere (ECONOVO), Department of Biology at Aarhus University, senior author of the study.

Svenning adds, that the so-called "closed-forest paradigm" for decades has dominated nature management and our understanding of what is natural: the idea that dense forests with closed canopies were Europe's natural baseline before human intervention.

The new study takes a significant step beyond previous research. Whereas earlier studies have primarily focused on relatively recent periods in the past, the researchers here bring together all available paleoecological evidence covering the entire period from the Miocene epoch (which began around 23 million years ago) to the pre-industrial era.

The researchers reviewed paleoecological studies covering the last 23 million years based on pollen records, plant macrofossils, charcoal particles from ancient fires, stable-isotope analyses of herbivore teeth and bones, fossil insects and mammals, and ancient environmental DNA preserved in sediments.

The conclusion is clear: across this long period, the typical landscape was a dynamic tree- and flower-rich mosaic, where large wild herbivores such as elephants, rhinoceroses, aurochs and bison kept vegetation semi-open and diverse—and this was the case in temperate climates similar to those prevalent in Europe today, as well as in warmer and in cooler climates.

The ecosystems we see in Europe today lack the large wild herbivores that not only shaped landscapes but also sustained its biodiversity for millions of years. The most dramatic shift has largely taken place within the last hundred years, when traditional extensive grazing disappeared from large parts of the landscape.

This suggests that the sharp division between "forest" and "open habitats" that characterizes modern conservation practice is a modern invention.

Implications for afforestation and restoration

The findings have direct implications for nature management and biodiversity across temperate Europe—precisely at a time when forests are being planted in the name of climate mitigation and biodiversity.

If the goal is to restore ecosystems resembling those in which Europe's species evolved and are still adapted to, the study indicates that uniform, dense forests are not the answer.

"Instead, restoration efforts should place greater emphasis on creating and maintaining mosaics of woodland and open habitats—not least through the restoration of natural-living large herbivores," Svenning concludes.

The study thus reinforces growing evidence from earlier research: Europe's past was lighter, more heterogeneous and more strongly shaped by large animals than we have long assumed.

End of article summary.

Comment on the article

A great deal of North American conservation is based on restoring fire to landscapes that were long burned by lightning and Native Americans. Burns go a long way toward restoring landscapes that have much in common with those discussed above. Although not mentioned in the article, burning was also a major factor in Europe until recently. (See Vestal Fire by Stephen Pyne.) The above article reminds us that restoring another major factor, large grazers, is also being being researched as a part of biodiversity conservation in such North America sites as Nachusa Grasslands. But one key factor for both continents is that the "leave nature alone" approach does not work for biodiversity conservation in many areas. 

The Richness of Soil Crusts

These two photos from an excellent post by Dan Carter show a part of the ecosystem that deserves more attention: the communities of lichens, mosses, bacteria, algae, and more that may play an important role in prairies and oak woodlands. Crusts may, for example, help determine which plant species reproduce and which do not. 

In this first photo we see an elaborate lichen and its moss companion on the floor of an oak woodland.

In the second, of a burned prairie in early spring, zoom in to see most of the above-ground crust burned off but starting to re-emerge along with blooming yellow stargrass and Seneca snakeroot among emerging prairie betony, bastard toadflax, prairie violet, some small panic grasses, and many other species characteristic of high quality. 

It would be great if we could make management decisions based on full knowledge of an area's plants, animals, fungi, lichens, micro-organisms, etc. Instead, we make decisions based as much as possible on what we know. Otherwise, brush or other invasives win out, and the rich biodiversity is lost. But let's encourage study, learning, and collaboration.     

We do better and better thanks to many dedicated individuals who take on detailed studies. Thanks to Dan Carter's fine blog for reminding us of the magic of crusts. 

Nine Woodland Seed Mixes (with headers, but blurry)

The lists of species below represent the current planting mixes of summer and fall-blooming species of herbaceous plants as used by the Somme Woods stewards in our work to restore the brush-degraded herb layer of bur and white oak woodlands (here including "open woodlands"  or "closed savannas'. 

Expanded abbreviations for the column headings from left to right are as follows: 

MCS = Open Woodland (Mesic Closed Savanna)

MW = Mesic Woodland

WMCS = Wet-mesic Open Woodland

WMW = Wet-mesic Woodland

WW = Wet Woodland

MCST Mesic Open Woodland Turf Mix

MWT = Mesic Woodland Turf Mix

MCSLO = Mesic Open Woodland Low-pro Mix

MWLO = Mesic Woodland Low-pro Mix

Detailed comments about the differences among these can be found, along with a less blurry version of the list (but without repeated headers) is here.