How quickly do flower strips in cities help the local bees?

Image of roadside flowers.

(ScienceDaily/Pensoft Publishers) Many cities are introducing green areas to protect their fauna. Among such measures are flower strips, which provide support to flower-visiting insects. According to the first quantitative assessment of the speed and distance over which urban flower strips attract wild bees, scientists from the University of Munich found that one-year-old flower strips attracted a third of the 232 species recorded from Munich since 1997.