Tuesday, January 25, 2011
Restoring the oak savannas
Several years ago, when Sunwiggy and I had just recently gotten into birding and were still exploring all the "birdable" areas in McLean and surrounding counties, someone told us about Parklands Foundation Merwin Preserve.
So one day we drove up to the North Gate, and saw a flock of northern flickers flying away from us -- I didn't know at the time what they were, and was tantalized by the white circle on their rumps as they quickly disappeared.
We got out of the car and walked into what seemed to be an enchanted glade--tall oaks dotted the landscape, with a park-like expanse of grasses underneath. The air smelled like warm grasses, and the sounds of birdsong filled the air. I have been to a variety of beautiful landscapes over the years, but this one just seemed to beckon us further and further along the trail. It was late in the day and we had little time to explore, but there was something so wonderful about this place, we didn't want to leave. To this day, we don't call it Parklands North Gate -- we say it's "The Beautiful Place."
Later I learned that this marvelous spot of the county is a remnant of a once widespread habitat known as the oak savanna. Savannas once filled a large part of the midwest, and were known by other names such as "oak openings" and "oak barrens" -- a landscape that was neither woods nor prairie. Prairies are open grasslands, and woods have a closed canopy -- think thick tree cover in the summer. Savannas, on the other hand, have from 10% to 60% tree cover, with huge oak and some other species growing so large that they create open areas in between. (The picture above is of me standing by a burr oak, a common component of the savanna habitat here in central Illinois -- although the photo was taken at Funks Grove, which does not have an intact savanna.)
I have been fascinated with oak savannas for several years now (the best on-line resource I have found is out of Wisconsin, the Savanna Oak Foundation -- check it out for great info on restoration, lists of plants and animals, etc.) So the other day when I was at the used book store in Champaign, I was delighted to find a book called Miracle Under the Oaks: The Revival of Nature in America, by William K. Stevens (Pocket Books, 1995), about the restoration of an oak savanna north of Chicago, called Vestal Grove.
The book describes how a 1960s activist, Steve Packard, found a neglected area of the Cook County Forest Preserve and used his experience to create a solid network of volunteers to restore it to its original state. At first, they focused on the surrounding prairie, gathering seeds, planning controlled burns, etc., until he realized that part of the area was something different, something special -- although choked by buckthorn, invasive honeysuckles, and other plants, the remnants of an oak savanna were there.
Packard realized that he had found something rare and worth preserving, but it took some effort to convince others of what was there. Many academic ecologists did not think highly of restoration, and even dismissed the idea of the savanna as a separate habitat -- but Packard continued in his efforts, both in the field and in the library, until he prevailed.
I found the first part of the book to be fascinating -- since I love savannas, I really enjoyed learning about how he discovered exactly what they are, largely by trail and error. His was real labor of love! The middle section discusses other restoration activities around the country. The last section describes several obstacles to this kind of work -- in-fighting amongst the people involved and other political issues, such as the need for controlling deer populations and also placating the animal rights activists who are opposed to harming the deer.
Although the book is fifteen years old now, besides the tale of finding and restoring the savanna, there were many points that I found to be very interesting--such as the idea that conservation is no longer sufficient; if we leave an ecosystem to its own devices, it may be completely degraded by invasive species. Restoration is the wave of the future, trying to approximate what the habitat used to be. Also the idea that one of the obstacles involved is that well-meaning people may have a very simplistic view of "nature," and thus oppose some activities (chopping down trees to free the savannas, sacrificing deer so they won't eat everything in sight as their natural predators are gone, etc.), so education is imperative. Finally, I loved the concept that people can be a natural part of the habitat -- the savanna evolved in concert with many influences, including the native Americans who periodically burned the landscape. Responsible restoration activities can involve humans once again as a natural part of the environment, an idea that I personally welcome.
Since this book was written quite a while ago, I don't know if there is still debate that the oak savanna is a separate ecosystem that needs protecting -- all I can say is that once you experience them, it's hard not to fall in love. In addition to the huge list of plants and insects that love the savanna, many species of birds call it home, including the red-headed woodpecker:
This species is sadly in decline, but they love savanna-like habitats--two places that I can almost always see them are at Parklands and Humiston Woods in Livingston county, which also has a small oak savanna.
Other species that thrive in the semi-open woodlands include American kestrel, red-tailed hawk, northern flicker, eastern bluebird, blue-gray gnatcatchers, blue-winged warblers, cedar waxwings, great-crested flycatchers, indigo buntings, rose-breasted grosbeaks, and eastern wood-pewees and other flycatchers:
If you are looking for a nice savanna to visit, other examples that I have been to are can be found at the Morton Arboretum, Midewin National Tallgrass Prairie, and the Hooper Branch Savanna in Iroquois County.
Finally, with some trepidation (what if it was turned into a subdivision since the book was written??) I looked up the Vestal Grove savanna on the Internet--it appears that it is still flourishing! Maybe this year I'll make a trip to see it.