Just south of the parking lot is a small grove of trees. To their east is a cornucopia of newly reclaimed prairie.  In early summer of 2009 the transition between trees and prairie was abrupt and unnatural.  Usually there is a transition zone between plant communities (ecotones).  In prairies we usually see grasses blending into shrubs and bushes and finally trees.  These transition zones are extremely species rich. This transition zone had been cleared long ago by farmers for monocultures.

The Spirit Mound Trust enlisted the assistance of an aspiring Eagle Scout, Andrew McCann, to re-establish some shrubs and small trees: wild plum, buffalo berry and choke cherry.  All three were selected because they were plants used by the Sioux for food. They are common species of wooded and prairie ecosystems on the Great Plains, and they also happen to be plants described by Lewis and Clark. They are surrounded by fencing to protect them from deer and rabbits in winter.

Walking north on the trail and crossing the bridge, you will see a short path to the right along the creek.  Among the 80 species introduced or reintroduced to the Mound in 2009, many are inhabitants of wet areas and were seeded or planted along this trail spur. Trust members and the Andrew anxiously anticipate their emergence in the spring of 2010. We plan a bench alongside the creek where you can sit and contemplate the diversity and beauty of this prairie.

As plant species increase, so do the numbers of prairie-adapted animal species. Rustling among the plants are numerous mammals, birds and insects specialized for life among the grasses, forbs and the reconstituted ecotone.

As you read the following articles you will experience how we have put your membership dollars to work promoting biodiversity.  Plants and seeds were purchased; herbicides, obtained (to use judiciously); signs, posted to identify the plants and other inhabitants of restored prairie. It has been a busy year for Mound volunteers. 

In addition to the volunteer efforts at the Mound, board member Tim Cowman has been doing a great job of managing and improving the web site at www.SpiritMound.org. The site contains historic and natural history information along with previous news letters. Please email comments and suggestions to us at info@spiritmound.org.  If you have special Mound stories you would like to see published in our newsletter, please submit them to us. If you want to help as a volunteer, send us your email address and let us know the type of work you would like to do.

The focus on increasing the diversity of the plant species there, in turn, will increase the success of the prairie community, including the birds, insects and other wildlife. We can hope for a healthier and more sustainable ecosystem that will be closer to what Lewis and Clark experienced on their visit over two hundred years ago.

In 2009 we consulted the species list of plants that are historically native to Clay County and obtained seed to use in over-seeding. The aim was to utilize seed of plants from as nearby as possible, called local ecotype seed, and also seed from similar habitats. Seed was both collected and purchased. For two areas, plants were added.

Plants collected by Lewis and Clark or documented in their journals are called Lewis and Clark plants. While some already grow at the Mound, we are especially interested in re-establishing those that are missing.  This year fifteen of these species of Lewis and Clark Plants have been obtained as either plants or seed: buffalo berry, clammyweed, curly-cup gumweed, cut-leaf ironweed, prairie wild rose, wild plum, aromatic aster, buffalo bean, choke cherry, death camus, Illinois bundleflower, plains coreopsis, prairie turnip, wild licorice and yucca.

The seed of dozens of additional species has also been collected or purchased.  Species represented include plants that naturally would have grown at the Mound but now are either scarce or absent. This will further promote species richness at the Mound and increase the populations of some of the existing Lewis and Clark plants.

To create the best opportunity for success, the challenge is to target specific areas to be sown with appropriate seed, to prepare the areas to be sown, and to properly time the sowing. Special management might later be needed to help the seedlings survive. Don't be surprised if you see some mowed patches on your visits in 2010!

As plants become established (which can take years), additional signs will be made to introduce visitors to these plants. The website will also be updated with individual photos of many of these plants.

Do not expect to see sudden changes at the Mound, but over the next several years, you can expect to observe progress toward a more diverse prairie and an associated increase in butterflies and other species.  Something to anticipate on your future visits!

These new tools seem to be putting popular insect study where the new Peterson Field Guide to Birds put birding in the 1930s.  And it’s true that more visitors to Spirit Mound each year come to see butterflies and insects.  For instance, last June a high school-age young man and his father were on the mound looking for regal fritillary butterflies; other summer visitors told friends that they didn’t make it to the top of the mound because they spent their time looking at insects along the trail.   Jody Moats from the Adams Nature Center had over 40 people attend her monarch-tagging event at the mound this year.

You can visit the bugguide.net site now and search for “Spirit Mound” to see insects photographed there last summer.  If you take an interesting insect photo on Spirit Mound and can post it to the site, please do so; and mention the mound in the location data.

Although usually wingless, ant colonies can produce large numbers of winged individuals during breeding flights in the summer.  This year colonies of two species of ants adapted to prairie habitat were found on prairie remnant areas of the mound.

In April, when there were still patches of snow on the ground, we discovered a large mound of the western thatching ant, Formica obscuripes, in the remnant area west of the summit.  These red and black ants build their large dome-shaped mounds almost entirely of dried plant material, mostly short segments of grass, and they live on scavenged and hunted invertebrates and on the ‘honeydew’ they collect from aphids.  The mound is at least three feet in diameter and two feet high.  Scientific literature says that the mound structure, with various chambers for raising young, can extend three feet underground; one colony can remain active for ten to thirty years.  The remains of an identical, relic mound lies about fifty feet upslope from this one and many other hillocks buried under the grass suggest where other old colonies may have been.

Many smaller mounds of the prairie mound ant, Formica montana, were also found along the north side of Spirit Mound Creek, near the new spur trail.  These are smaller ants found in rich, moderately moist or floodplain prairies.  Their mounds, mainly of soil particles, are very airy and chambered, using the prairie grass stalks, and roots that grow out into the mound, for structural support.  The Trust placed an informational sign near one of these mounds.  Parks Division staff in Pierre, believe it’s probably the only South Dakota state park sign honoring an insect.

Although the ant multitudes are all that we usually see, ant colonies can actually be communities of many different creatures that have evolved various symbiotic relationships.  There was a bumble flower beetle, (Euphoria inda), among the thatching ants this spring.  This species lays its eggs in the colonies and the larvae eat plant material in the mound, apparently unmolested by the ants. A large, colorful carrion beetle, Nicrophorus marginatus, was also near the same mound.  This species has been observed with F. obscuripes before, but apparently the relationship, if any, isn’t known.  And an adult glowworm (Phenogodes sp.) was seen going in and out of an F. montana mound; this genus preys on millipedes, so its association with the ants is a mystery.  (An excellent paper on ants and the tallgrass prairie, by James Trager, can be read at www.npwrc.usgs.gov/resource/insects/ants/.)

           

Finding these ant populations on the Mound helps confirm the value of our remnant areas and reminds us of the wonder of the insect world.  It also reinforces our desire to manage the Spirit Mound Historic Prairie with the immense diversity of prairie invertebrates in mind.

Perhaps 10% of the Spirit Mound site is made up of never-cultivated prairie remnants, primarily pasture areas on the summit or on steep slopes and along the creek that were never cultivated.  The state’s prairie reconstruction efforts generally avoided these areas in order to leave undisturbed what native species remained. 

Remnants are a precious resource for bringing back the original prairie.  They are an ecosystem of plants, animals, insects, fungi, and other organisms, living in a web of interdependence, which is tremendously hard to reproduce.

Unfortunately, almost all of these areas on the mound are degraded by non-native species crowding out the original ones.  The most damaging is smooth brome grass, an aggressive cool-season grass that begins growing early in the year, before the native warm-season grasses and forbs get a chance to start.

One priority of the biodiversity project is to preserve and restore these remnants.  Methods include burning, mowing, grazing, selected use of herbicides and over-seeding.   Controlled burns are the sole responsibility of the Parks Division and will continue to be used as they are able.  The trust is helping with the others.

Although only done in two small areas, tentative conclusions from the test are positive.  The brome was completely absent all year, and a variety of native plants grew robustly in the circles, even though they were stressed or completely missing from the area adjacent to the circles.  Two natives were notable:  hoary puccoon, an early-blooming forb which was clearly not harmed by the herbicide, and rough dropseed, a native grass which grew abundantly in one of the circles, but was invisible in the brome sod that surrounded the circle.

We intend to continue experimenting with herbicide on small areas of brome, including three circles that we treated November 5th, when brome was the only remaining green vegetation.  Besides allowing existing native plants to grow freely, killing the brome creates open ground more conducive to over-seeding, which will be part of our continuing biodiversity project for 2010.