Yearly Essay on Buckthorn
…on the fertile Corn Belt soils, all our oaks are headed for oblivion, except where ecological restoration or other intentional management protects them
The Tallgrass Restoration Handbook
Edited by Stephen Packard and
Cornelia F. Mutel
Which situation is worse? Top or bottom photo?
Actually, they are both terrible. Both sites guarantee the demise of our oak trees, because neither situation allows baby oak trees to sprout and grow.
In the top picture, shade from the buckthorn prevents the acorns that fall from the oak trees from sprouting; In the lower picture herbicides and the lawn mower prevent germination.
The top picture is from Kane County Burnidge Forest Preserve; the bottom one is on private property–what business is it of mine, what one does with one’s own property?
Trees, especially our native oak trees, benefit all of us, not just the owner of the tree.
Let me count the ways:
Trees provide shade, not only in ones own yard, but also on hard surfaces that will otherwise absorb heat and create heat islands that affect everyone.
Provide food and habitat
Sink carbon and make oxygen
I’ll address the choked savanna/woodland today.
Clearing Invasives from Savannas and Woodlands
By Mid-November, in the Chicago region, most of the leaves have fallen from the trees. Except–what is that shrubby, choking undergrowth that’s still hanging unto its dirty green foliage in the understory of our oak savannas and woodlands? You know the answer–it’s Common Buckthorn (Rhombus cathartica), an alien imported from Europe in the late 1800’s. Buckthorn leafs out early and abcisses late, not allowing sunlight to reach the ground level. The excessive shade keeps oak trees from reproducing, guaranteeing their eventual demise. It also keeps native wildflowers from sprouting and growing on the woodland floor. Without an herbaceous carpet, the soil will soon erode away. In addition, trees rely on the deep fibrous roots of herbaceous plants to keep them adequately hydrated.
Project Quercus of McHenry County Land Conservancy says that “these beloved trees are under stress, and if nothing changes, they may be largely gone from the local landscape within 20 years.” 20 years!
And even more bad news:
“New scientific studies reveal Midwestern frogs decline, mammal populations altered by invasive plant.” May 1st, 2013. http://phys.org/news/2013-05-scientific-reveal-midwestern-frogs-decline.html
Amur and Tatarian Honeysuckles (Lonicera maackii and L. tartarica) are other alien shrubs equally harmful to our oak savannas. Honeysuckles flower prettily in May, but their aggressive weediness soon chokes out native plants. “It would be difficult to exaggerate the weedy potential of this shrub,” say Floyd Swink and Gerould Wilhelm of the Amur Honeysuckle in Plants of the Chicago Region.
Still more aliens choking our woods and savannas are European Highbush Cranberry (Viburnum opulus), Multiflora Rose (Rosa multiflora), Autumn Olive (Elaeangnus umbellata), and Oriental Bittersweet (Celastrus orbiculatus). And lately, the popular Burning Bush (Euonymus alatus) and Japanese Barberry (Berberis thunbergii) have become invasive in our oak woodlands, as well.
Many of these shrubs were brought to this country because their berries would feed wildlife. Why anyone thought native plants weren’t adequate to feed native animals is a mystery. Here is a paragraph I found in a website this morning called Forager’s Harvest. “The autumn-olive was lauded as a virtual miracle forty years ago; it was intentionally planted by the same government agencies that are now villainizing it and spending millions trying to eradicate it. Latham (1963, p. 19) expressed the prevailing attitude when he said, “These shrubs add beauty to narrow field corners, roadsides, [etc.]—with no evident danger of becoming a pest by spreading onto pastures or well-kept places.” Latham then lived in Ann Arbor, Michigan—around which, today, the autumn-olive is the most prevalent shrub, having choked out most native species. I wonder how many of the current ideas espoused by today’s natural resource managers will be laughed at in a generation. (I can name a few.)”
And here is Swink and Wilhelm’s description of Autumn Olive in Plants of the Chicago Region:
“Introduced from Asia. Commonly planted as an ornamental and in ”wildlife areas” as a forage plant, this species was unknown as a spontaneous element in the Chicago region flora until the late 1970’s. By the late 1980’s it had become nearly ubiquitous in degraded open woods, railroad rights-of-way, and unmowed meadows.”
Prior to European settlement, the grasses in the savannas burned, just as they did in the prairies, keeping woody plants from taking hold. But the suppression of fire, plus the introduction of the aggressive alien shrubs, mentioned above, has spelled ruin for our oak savannas and woodlands.
What to do? Late fall and winter are the perfect time to cut out the brush that is choking our savannas and woodlands. Cut the shrubs to the ground and paint the stump with Brush-Be-Gone or Garlon. If you don’t want to use chemicals, you can cover the stump with black plastic and, given time, it will die. Or you can girdle the tree trunk by removing a section of the bark encircling the tree. Best time to do this is early spring before the tree leafs out.
And then follow up with a yearly autumnal burn.
Woodland at Morton Arboretum that has had a controlled burn every fall since 1989. Cardinal Flower (Lobelia cardinalis) is in bloom.
Burnidge Forest Preserve after controlled burn 11/2/08
One can use the branches from the Buckthorn to make a fence as did this homeowner.
A yearly burn is necessary, says Dr. Wilhelm. In my area, Bluff Spring Fen and Trout Park, both Illinois Nature Preserves, are burned yearly by the stewards that result in almost pristine natural areas. On the other hand, it is my understanding that our Kane County Forest Preserves are burned on a 3 year rotating schedule. Better than not burning at all, but after 3 years, the areas that were burned have grown back–either from re-sprouting or from all those berries scattered by birds.
Please read the following:
Founded by William & Sibylla Brown in 1993, Timberhill Oak Savanna comprises 200 acres of woodlands, prairie openings and wetlands in Decatur County, Iowa.
This is written by Sibylla Brown
“One of the most harmful things modern man has done to birds has been his attempt to exclude fire from fire-type pine forests. Within a few years most forests choke up with brush, lose their prairie-like vegetation, and can no longer support birds dependent on periodic burning for their food supply and proper cover.” (Herbert Stoddard, 1963)
The above quote can also be applied to Midwest oak and hickory woodlands. Without fire they become overstocked species poor habitats. This results in lower reproduction and even displacement of some species.
Bill and I began burning our woodlands in 1995. We began in small units, gradually increasing the size of our burns as we became more experienced in managing controlled burns. Since 2003 we have burned the entire restoration each year. These annual burns are spotty leaving a patchwork of burned and unburned ground. They are much less destructive than less frequent burns because there is less fuel. Instead of parboiling and scorching the ground as periodic burns do they scud over the ground leaving the rhizome layer intact.
Without any seeding the number of vascular plants has increased almost 500%. Not only has fire increased soil fertility by releasing nutrients into the soil, but is has stimulated plants from the seed bank. These plants harbor an abundant insect population for breeding and brood rearing. Fire has also lowered soil acidity stimulating legumes such as cream wild indigo, lead plant, white prairie clover, tick trefoil, and bush clovers which provide high quality protein for quail, wild turkey, and other birds.
The increased diversity and abundance of butterfly nectar sources has been remarkable, especially in our West Creek unit. In 2005 when we began restoration there I could find only 2 butterfly milkweed plants. Last summer I counted 40. Later in the season numerous swamp milkweeds and rough blazing stars continue to provide nectar into fall. From first bloom to fall frost various hairstreaks, fritillaries, skippers, and other butterfly genera are abundant on these nectar plants. (Our annual dormant season fires have the least impact on the invertebrates. We have documented many fire sensitive species at Timberhill.)
To read the entire post click above on Why We Burn
So how do we rid our Forest Preserves and other natural areas of the buckthorn scourge??
Annual thinning and burning is the only way.
Who will do it?
There are many companies that will do this–for pay, of course.
Who will pay for it?
Let’s bring back the CCC, the Civilian Conservation Corps, and send them out into our Forest Preserves to eradicate Buckthorn and other invasive shrubs, trees, and vines. This could be funded by the Federal or State government and would provide jobs.
What if the Forest Preserve parking lots were gated and $1.00 per car were charged?
Tyler Creek Forest Preserve next to where I used to live is right across the street from Judson University. What if Judson offered degrees in Environmental Restoration that required every student enrolled in the program to donate X number of hours to restoring government owned native areas? What if all colleges and universities did this?
What about privately owned property, particularly townhouse developments?
Make a clean up event into a party–I have a friend who has a brush/tree removal party every New Year’s Day. Begin work in the morning, throw the branches into bonfires, finish up with a lunch of homemade soups, breads, and desserts.
Rommy Lopat wrote on this issue this morning in the Weedpatch Gazette–here is the link:
While the title refers to Ornamental Pear, she discusses the Buckthorn problem in more detail, especially in terms of banning them by law–which I am certainly all for. Click on the title to read the rest of her article.
What are your ideas? Let’ s have a conversation.
Next: Buckthorn gives us privacy–with what will we replace it?