Railway embankments - a refuge areas for food flora, and pollinators in agricultural landscape.
In a modern agricultural landscape the assurance of food resources is a key issue in the maintainance and control of food niche for pollinators. In the present study we evaluated bee forage flora composition and diversity within railway embankments located in the agricultural landscape, SE Poland. We also analysed the abundance of pollinators that use food resources along railway embankments and recognized insect visitors preference for selected plant species. Railway embankments represent valuable refuge areas for bee forage flora (307 species, i.e. 76.1% of total flora) and pollinators (in total 4172 insect visits from 9 taxonomic groups). However, the richness and abundance of bee forage flora significantly differed between types of the railway distinguished by traffic volume. The highest diversity of bee forage flora is noted along the railway with intermediate traffic volume. Approx. 25% and 40% less bee forage species was identified along railways with low and high traffic volume. Likewise, bee forage flora differed considerably between microhabitat types, i.e. top vs. slope vs. bottom of the embankment. Providing support (e.g. mowing) seems to be an important management type in order to strengthen the native bee forage flora particularly on railway embankments along low and high traffic volume tracks. Such activity is crucial to counteract the spread of aggressive non-forage species (e.g. Calamagrostis epigejos, Artemisia vulgaris, Phragmites communis) and invasive species (e.g. Bunias orientalis, Solidago gigantea).