I am Sibylla Brown. I was born in Germany in 1940. In 1946 my father, a German Operation Overcast scientist, was brought to the U.S. My family followed him to the U.S. in 1947, settling in Cedar Rapids Iowa in 1950. I married my husband, Bill in 1962. Bill practiced dentistry in Des Moines for over 40 years. In 1993 we sold our house in Des Moines and moved to a 200 acre farm in Decatur County, Iowa. Except for a small vineyard we had no plans to farm our land. But we did want to take care of it, particularly the overgrown oak and hickory woodlands. We began timber stand improvement in 1993. When we learned our land was actually a rare oak savanna remnant we implemented prescribed fire. These posts share how we restored the rare oak savanna on our 200 acres, what is happening in our lives, and what we are thinking.
Long considered a weed of roadsides, farm fields, and waste areas I’ve never had much respect for Asclepias syriaca, common milkweed. Until last week, that is, when Ray Moranz, a post doctoral researcher who studies the effects of invasive species and prescribed fire on soil invertebrates brought two very special guests to Timberhill: Dr. Ernest Williams and Dr. Lincoln P. Brower. Having studied the eastern North American population for 60 years Dr. Brower is considered to be the world’s leading expert on monarch butterflies. He and Dr. Williams have co-authored several papers about monarch population trends, particularly the decline of Monarchs overwintering in the Oyamel fir forests west of Mexico City. Threatened by the illegal logging in their winter habitat and loss of milkweed species that monarch larvae require in their breeding habitat I wasn’t aware of how serious the situation had become. In 2013 the number of monarchs overwintering in Mexico had declined by 95%. From 60 million in 2012 to only 3 million in 2013.
In order to gain a deeper knowledge of prairie ecology and its native milkweed flora, Dr. Brower and Dr. Williams spent four days in the Midwest. According to Ray ‘they want to publish something on the plight/future of milkweed flora in the agricultural landscapes of the Midwest.” Research has shown that as many as 92% of monarchs that overwinter in Mexico “had fed as larvae on the Common Milkweed.” Before european settlement 29 milkweed species were distributed throughout the prairies and woodlands east of the Rocky Mountains. As the prairies gave way to the plow and the forests were logged off the more conservative milkweed species were replaced by common milkweed. Now it is the primary monarch larval food source. Before the use of genetically modified glyphosate resistant seeds this plant was often found in corn and soybean fields. Since the adoption of GM crops in 1999 common milkweed has been rapidly disappearing from farm fields. It is also declining in roadside ditches. Now the distance that a monarch has to travel before finding a milkweed on which to deposit her seeds greatly reduces the species’s fecundity. Although the Timberhill plant list includes 7 milkweed species we have found that it is on common and marsh milkweeds that monarchs prefer to lay their eggs. I don’t know about the rest of you, but I’m going to sow seeds of these species in roadsides around Timberhill. I’ll also give seeds to neighbors and urge them sow milkweeds on their properties.
When John and Sharon Orvis retired they didn’t flee to Florida (even though they owned land there) or to a tax haven state in the southwest. They stayed in Iowa and retired to 310 acres of prairie and oak-hickory woodland near Lineville, Iowa on the Missouri-Iowa border. Theirs was not the kind of Iowa farmland most people envision. Instead of acres of flat, productive soil their land consisted of sharply dissected overgrown oak and hickory woodlands and prairie overlooking the Weldon River. Beginning in 1998 they hacked and burned their way through the tangles of honey locust, multiflora rose, and honeysuckle to restore the prairie and oak-hickory woodland ecosystem presumed lost by years of abuse and neglect since European settlement.
Before the plow, thirty million acres of open oak woodlands formed the transition between the eastern deciduous forest and the tallgrass prairie. This landscape of widely spaced oak trees that spread over an understory of wildflowers, sedges, and grasses stretched from Minnesota and Wisconsin south to the Texas Hill country in a shifting mosaic of prairie, wetland, woodland, and savanna. It was a broad transition zone that varied due to the frequency and intensity of fire and drought. After European settlement, what wasn’t converted to farmland became dense forest. It is now considered a globally endangered ecosystem.
Despite a history of heavy grazing followed by years of neglect the Orvis land has responded well beyond what anyone thought possible. When I first visited their site the soil in their woodlands was so tightly packed that I thought the seeds were locked in. But fire and timber stand improvement were the keys to unlocking the seed bank. The widely crowned oaks now spread their branches freely over a ground layer of grasses, sedges, and wildflowers. But John and Sharon have restored not only the plants. All of the elements that comprised this habitat have been restored. Savanna restoration has created a mosaic of habitats for a heterogeneity of bird species including red-headed and pileated woodpeckers and neo-tropical migrants. Residual conservative plants now thriving include false hellebore, yellow false foxglove, and purple milkweed. Wildflower bloom continues in the woodland understory from early spring until fall frost when the growing season climaxes with elm-leaved goldenrod, woodland sunflower, and blue aster bloom. During a visit last week Bill and I saw coral and Edwards’ hairstreaks, silver spotted and cloudy wing skippers, all habitat sensitive butterflies nectaring on common and butterfly milkweeds. Ectomycorrhizal fungi including species of Amanita, Russula, and golden chanterelles fruiting in the woodland indicate restoration of the hydrology and the underground mycelial network. On our walk through the open woodlands we even flushed a wild turkey incubating nine eggs. The previous week, John told us, fifteen bobwhite quail chicks had hatched. Most important fire and timber stand improvement have restored the oak regeneration with young oaks scattered throughout the property.
Our visit was on the day before John’s 75th birthday. We asked him what he was going to do to celebrate. “Sit on the porch and listen to the bobolinks” he replied. John knows how to celebrate.
It was Amy Robertson of Promise City, Iowa who first recognized the restoration potential of the southern Iowa and northern Missouri counties. She proposed that the southern tier of Iowa and northern Missouri counties be turned into a national park. An entrepreneur, she invested every spare dollar in Wayne and Appanoose County farmland. Besides seven farms in southern Iowa she also purchased land from Texas relatives. Oil found on that land made her a rich woman. After her death in 1992 she left 10 million dollars to Simpson College, her alma mater.
Miss Robertson well knew that the topography and second-rate soil of this region make for poor crop land. But she also knew that’s what saved remnants of the presettlement habitat from being extirpated. Although not as a national park her vision is now being fulfilled. Private landowners supported by conservation organizations including US Fish and Wildlife, National Wild Turkey Federation, Quail Foundation, Iowa DNR, Missouri Dept. of Conservation, and The Nature Conservancy, are restoring unplowed woodlands throughout the region.
Several of these organizations were represented at a landowners’ workshop Bill and I attended at Turkey Hills Farm (Putnam County, MO) on June 14. Mark Williams, the landowner, had purchased this 830 acre woodland to be used as a hunting preserve. However, the abundant population of wild turkey and deer have declined significantly since Williams purchased the property in 1983. So he consulted Missouri private lands biologist John Murphy. Murphy explained that the wild game had declined because the woodland had become severely overstocked and proposed a management program of timber stand improvement and prescribed burns.
Now, only three years after implementation of this program the results are amazing. Prescribed fire and sunlight penetrating the newly opened oak woodland have stimulated a highly diverse community of conservative plants. Not only did I see large populations of leadplant, wild quinine, blazing star, and violet and slender bush clovers, but there were several four-leaved milkweeds, Asclepias quadrifolia, a plant found only in high quality savanna remnants.
The southern Iowa-northern Missouri restorations now include 2000 acres being restored in northern Missouri, private lands restoration in Davis and Appanoose counties to the north, almost 3000 acres of SIOSA sponsored oak savanna restoration in south central Iowa, the Grand River Grasslands in Ringold County, Iowa, and TNC’s Dunn Ranch in Missouri. Private landowners have also been recruited surrounding the last two sites.
In his 1958 dissertation “The Flora of South Central Iowa” Theodore Van Bruggen described Wirth-Springer Woods as “sandy open woods.” It was one of 100 different ecological habitats he included in his floristic survey of south central Iowa. Located in Decatur Township, 3 miles northwest of Decatur City this 38 acre timber preserve was donated to Decatur County by Mary Louise Springer and her sister in 1991. It is bordered by 198th Street on the north and a hunting preserve to the east. A road that services the hunting preserve forms the west and south boundaries. Van Bruggen’s dissertation listed characteristic or common native plants of each community. When he surveyed Wirth-Springer Woods Van Bruggen in 1957 he found conservative plants typical of remnant oak and hickory woodlands in southern Iowa. They included Leadplant, New Jersey tea, Rough blazing star, Sky-blue aster, Rockrose, Prairie alum root, Lousewort, and June grass. When Bill and I visited the site last week we were unable to find any of them.
Instead of widely spaced oaks and hickories spreading their branches over a ground layer of sedges, grasses, and wildflowers we found a closed-in woodland where very little sunlight could reach the ground layer. A woody understory of Prickly ash, Coralberry, and Poison ivy was blocking the sunlight. The only savanna forbs we found were Pointed tick trefoil, Bedstraw, and Early horse gentian. Progression erosion north and south of a ravine that dissects the property is also a problem. However, the occasional patches of pen sedge and scattered bottlebrush grass we found were indicative of high potential for restoration. To quote Gerould Wilhelm, “These upland sedges once formed the matrix within which hundreds of other species grew, each with different growing and flowering periods, different vegetative morphologies, and different decomposition relationships.” (Wilhelm, “The Arboretum’s East Woods: Are They Forever?”)
Annual dormant season fire would restore that matrix. In the above photo of a woodland that has had over 10 annual dormant season burns fire has controlled the woody underbrush and stimulated the forbs and sedges. Various sedges, Elm leaved goldenrod, Violet bush clover, and Fragile fern are among the plants now found in the understory.
Combining timber stand improvement with prescribed fire further increases the plant diversity. For example, Leadplant, Lousewort, Rough blazing star and Purple twayblade orchid have become well established on this thinned and burned hillside. There is even a small clump of Four-leaved milkweed, a rare plant found only in dry, open woods.
We have become so accustomed to dark, dense woodlands that few of us realize what we have lost. Or that much of what we have lost can be restored.
Decatur County is on the Iowa-Missouri border, seventy miles south of Des Moines, halfway between the Missouri and Mississippi Rivers in the Southern Iowa Drift Plain. In the half a million years since the last glaciers retreated from south central Iowa the upland glacial plain has undergone extensive erosion into a drainage pattern that looks like the branches of a tree. Ephemeral flow paths, creeks, and rivers have dissected the landscape into steeply rolling hills and valleys that branch off the ridgelines. These rolling to hilly uplands make up almost two-thirds (64.7%) of the county. Although many were subject to heavy grazing most were too steep to plow and wildflowers, native grasses, and sedges, remnants of pre-settlement plant diversity have survived years of neglect and degradation. Now landowners are restoring the overgrown oak woodlands and prairies in this sharply dissected landscape. John and Sharon Orvis were among the first to meet this challenge.
The Orvis’s purchased 310 acres in Section 14 and 15 of Morgan Township in 1996. Their purchase consisted of 47 acres of cropland along the Weldon River, a 27 acre CRP field with native grasses and forbs, and overgrown pastures and savanna remnants. In 1998 they began restoring the land with annual burns of the CRP field. In 2001, working with district forester Randy Goerndt, they implemented timber stand improvement in the overstocked oak and hickory woodlands. Working through 10 acres at a time, John thinned most of the timber himself. In 2004 he and Sharon introduced prescribed burns into the woodlands. Since then they have expanded their annual burns to include the entire property.
According to the original General Land Office survey notes compiled in 1847 the surveyor did not note a single tree when he walked west between Sections 14 and 23 (the Orvis property south east boundary) of Morgan Township. Were he to walk that line now he would be very busy noting all the trees. However, he did note two white oaks near the quarter section post: “White oak 14’ south 5.2 feet, 4 feet diameter” and “White oak 11’ north 25 feet, 531/2 inches diameter.” We found a white oak very near that point.
The early history of Section 14, Morgan Township can be pieced together from several records. “Family Maps of Decatur County, Iowa” which maps owners of original land patents records two 40 acre parcels sold in 1855 and 1856 on what is now Orvis land. But there is no indication either landowner occupied his acreage. The earliest tombstone burial in Elm Cemetary just south of the Orvis property line was on November 5, 1849. Donated by the McMurtrey brothers who settled in Morgan Township in 1854, the cemetery was named after the elm trees nearby. The 1894 plat map of Morgan Township lists H & M Engle as owners of 346 acres, most of which is now the Orvis farm. The earliest Elm Cemetery Engle family burial in was in 1862. Therefore one can assume that they occupied the land before 1894. They farmed the bottom ground along the Weldon River and pastured the upland meadows and woodlands. The land continued to be grazed by successive landowners until it could no longer support cattle. In 1974 grazing ceased. After that only 75 acres continued to be farmed and honey locust, honeysuckle, red cedar, and multiflora rose invaded the pastures and woodlands. By the time the Orvis’s purchased this farm one could not walk through the property without a machete.
In his article “The Arboretum’s East Woods: Are They Forever?” Gerould Wilhelm discusses the “unbroken genealogy” of presettlement native woodlands. “In these woods lies an unbroken genealogy; indeed, they represent a community which for ten thousand years has adapted itself to this part of the globe.” Native “pollinators and soil microorganisms and their inherent stability, facilitate population gene flow necessary for the long-term survival of our native flora.” It will take many more years of management to determine the extent to which the genetic memory of the oak savanna community on the Orvis farm can recover from the rapid changes that have occurred after European settlement. But their dedication and hard work have already restored many sedges and native wildflowers. On a recent visit Bill and I marveled at the huge drifts of Delphnium tricorne, dwarf larkspur, blooming in the thinned and burned open woodland.