By KEVIN WALKER
Michigan Correspondent
 
EAST LANSING, Mich. — Researchers at Michigan State University continue to try to piece together the puzzle of how to maximize the benefits of native plant and animal species to help producers produce more, as well as higher quality, product.

Their latest effort is a paper titled “Maximizing arthropod-mediated eco-system services in agricultural landscapes: The role of native plants,” published in the May issue of Frontiers in Ecology and the Environment.

Despite its forbidding title, the article is basically part of an attempt to help producers use native plants that will encourage the growth of beneficial insects and other creatures, which the researchers refer to generally as “beneficial arthropods.” Such arthropods include, for example, the syrphid fly, soldier beetle and leaf-cutter bee.

While it’s known that the use of native plants around crops, especially those that need pollinating, is helpful, what isn’t as clear to the researchers is how such benefits may be maximized.
“In terms of practical recommendations to farmers, there is quite strong evidence from studies around the world that addition of resource habitats has positive benefits on the abundance of natural enemies and pollinators,” said Doug Landis, a professor of entomology at MSU and one of the paper’s authors. “There is less consensus on how far those benefits extend into fields. At this point we are being conservative in terms of making specific recommendations.”

The review paper states most research into beneficial plants has focused on a few that are easy to grow, with readily available seed, such as Queen Anne’s Lace. The problem with these is that most are not native to the region in which they are being used and many are annuals or biennials. Some are considered invasive to the area.
“An alternative that can avoid some of these problems is to use plants native to the area under investigation and to use perennials where possible,” the paper states.

In 2004-05 the researchers evaluated the suitability of plants native to Michigan by determining the abundance of beneficial arthropods on 43 species of native perennials, along with five non-native flowering annuals, which are often recommended for use in agricultural landscapes. From this list they discovered 26 of the native perennials to be the most beneficial at nurturing populations of beneficial arthropods. Those plants can be found via the website listed at the end of this article.

The authors acknowledge the disadvantages of using these perennials – they are more expensive and not as readily available as the more common non-native annuals, although the authors state since the perennials come back year after year, the added expense could be amortized.

They also said the price should come down if these plants become more popular. Also, perennials take longer to become established. The authors clearly believe the native perennials are superior, despite the drawbacks.

“(T)hese (native) plants were frequently associated with a greater abundance of beneficial arthropods than were non-native species. Native bees were also more abundant on these plants species, and there was an increase in the number and diversity of native bees at the flowers through the growing season, as flower size and temperatures increased. These results provide compelling reasons to continue the search for native resource plants in other regions …” the paper states, in part.

According to Landis, the effectiveness of native flowering plants in an agricultural landscape depends on many factors. He said for a landscape to be successful at pest control, pollination and the other desired agricultural services, about 20 percent of that landscape needs to be nonagricultural.

To view the list of native perennials found to be most beneficial, go online to www.nativeplants.msu.edu