Friday, October 22, 2010

Field Evaluations

As I go around evaluating potential projects for the coming winter season, I check out recently completed projects to see if I achieved my desired goal. Usually I’m satisfied to some degree with what I see. My greatest lament always seems to be that I didn’t get more accomplished. I’m always certain that I could have squeezed in another day or two of work, but if I go back and review my notes I invariably find that I managed to use every hour not committed to my job and family or prohibited by bad weather. This is one of the fields I did maintenance on last year to remove encroaching woody vegetation.

After 25 years, this evolving prairie is looking great. When I began my work here, there wasn’t a lot of practical information on how a typical landowner would manage a large area of prairie. I was pretty much told that I would need to regularly burn the fields to maintain open grassland. As a private landowner and a workforce of one, I didn’t have the resources to safely burn these fields, so I set about to discover techniques that I could use to turn my fields into the best possible prairies. The fact that the photos show grassland instead of forest is evidence that it is possible to keep encroaching woody species under control.

By design, there are a few places where trees grow in the field. Diseases have eliminated Flowering Dogwoods from the woodlands, so I maintain areas of dogwoods in the fields. The small trees are spaced far enough apart to allow sunlight to maintain grassland right up next to the trunks.

Much of the prairie flora and fauna has close associations with oaks, so I have left several oak trees scattered throughout the grassland. However, most of the field is kept open and free of any vegetation taller than the grasses.

The fields won’t need any work for a few years, so I’ll be concentrating on improving the transition zone between the fields and the woodland. This is a prime area for the appearance of invasive species. Berry eating birds tend to use these edges as travel lanes or for escape cover, which results in a lot of seeds being dropped. Improving the edges for use by transition zone plant species will also make it easier to find and eliminate invasive species.

There are a few isolated spots in the field that I will still need to work on. This is where I cut and killed a large Autumn Olive last year. Getting rid of one big Autumn Olive invariably leaves you with many little Autumn Olives. Some of the new growth comes from surviving root growth from the old bush. Other sprouts are from seed dropped in the vicinity of the bush. It makes sense that birds spending a lot of time eating seeds in the bush will poop out a lot of seeds in that same area. The new seedlings are generally within the canopy area of the original bush and I’m wondering if my clearing efforts make the environment more suitable for germinating Autumn Olive seeds. I’ve never viewed any of my work with a feeling of completion, but I’m happy if I can see just a little progress each year.


  1. Personally I think you have done a marvelous job Steve.

  2. It is amazing what you have accomplished.

    I did have a question about the autumn olive. Are they considered to be undesirable plants, and if so, why?

  3. Hi Roberta. Autumn Olive is indeed an undesirable non-native invasive species in this area. It was originally planted with the purpose of providing food and shelter for huntable wildlife. The abundance of fruit and tangle of branches served very well for this purpose.

    When originally planted, the thought that this plant might spread naturally was not a serious consideration. Trials showed that the seed was nearly impossible to germinate. What no one considered was the fact that traveling through a bird's gut scarified the seed and made it ready to grow. Autumn Olive suddenly started showing up all across the landscape.

    Autumn Olive is an aggressive plant that can easily form a monoculture in a field. Leaves develop early and remain on the plant late in the season. Plants beneath the Autumn Olive canopy die for lack of sunlight. An infestation of this plant can destroy stands of native vegetation as well as agricultural grasslands. Woodlands are not immune to invasion and can also lose their ground cover to Autumn Olive.

    Autumn Olive did achieve its intended purpose. Certain game animals benefited by the food and cover provided. Unfortunately, the plant spread so well that it became impossible for hunters to penetrate the fields full of tangled, thorny Autumn Olive. Game animal populations even declined because Autumn Olive destroyed the other habitat components needed for the animal's survival.

    Many bird species feed on the berries and some insects nectar at the flowers, but for the most part, native animal species do not benefit from the presence of Autumn Olive. Resistence to pests was one of the things evaluated when selecting this plant for use. Pests were primarily defined as any non target animal that would feed on the plant. If you search the branches and foliage of Autumn Olive, you don't find the communities of insects that you would expect to find on native species. As Autumn Olive spreads, insect diversity declines.

    Multiflora Rose and Bush Honeysuckle share stories almost identical to that of Autumn Olive. Other invasive non-native plants pose the same threats. The invasive plants have not evolved with these native ecosystems and the space they occupy is not much more than a dead zone in the landscape.