When the blooms have faded and the plants are mowed, the cuttings are left on the ground to serve as mulch. There is a concern over endangerment to the insects attracted by the flowering plants when they get mown down.
Are such wildflower strips a kind of ecological trap? Biologist Dr. Heiko Schmied of the University of Bonn Institute for Crop Science and Resource Conservation, also active at the Rhineland Cultural Landscape Foundation, has studied this very question. As part of the Buzzing Rhineland project, he and a team of scientists collected and analyzed data over a six-year period.
They planted fifty 50 kilometers of wildflower border strips using high-quality seeds from the region and documented the resulting biodiversity of wild bees and butterflies; the strips were seeded at differing times for staggered observation. It was found that even narrow wildflower strips planted alongside conventionally utilized land that get mulched every year are not an ‘ecological trap’ or otherwise unfavorable as a habitat, having instead a beneficial effect regarding the biodiversity of wild bees and butterflies.
“Wildflower strips are a very important element in efforts to promote insect biodiversity within the agricultural landscape,” summarizes Dr. Schmied. Major difference between strips were observed in terms of quality however.