Relationships between vegetation and pollinator communities in established meadows in agricultural landscape

Abstract

Privately owned agricultural easements in Caroline County, MD were seeded with a native forb and grass mix with the intention of creating beneficial pollinator habitat. The purposes of this survey were to (1) evaluate the success of this seeding event, (2) describe the vegetation and pollinator (bee) communities during peak bloom, and (3) to make recommendations for future restoration actions. (1) Sixteen out of nineteen plants being found within the meadows, and all meadows were dominated by planted native species. Four out of five sites established as meadows. (2) There were no uniform patterns among sites for either taxa. Planted species Chamaecrista fasciculata, Monarda fistulosa, and Rudbeckia hirta were top wildflowers in terms of community composition. These flowers complement each other in bloom period and nutritional resources for bees. There were no significant differences in bee abundance and richness between meadows, but bee richness and bee abundance were significantly positively correlated. All sites neglected spring blooming wildflowers and the bee community reflected this oversight. Andrena and Megachile, common bees of late spring and early summer, were found in very low abundances. (3) Phenologically comprehensive and more diverse seed mixes, which also happen to be less expensive, are suggested. The 'Showy Northeast Native Wildflower & Grass Mix' and 'Mesic to Dry Pollinator Seed Mix' offered by Ernst Conservation Seeds Inc. (as of 2019) are more phenologically and structurally balanced and have greater variety of flower color and plant family. No dramatic changes to current best management practices are required, but with the cost savings on seed mixes there may be opportunities for more selective weed treatment and support for plants of high value that are challenging to cultivate. As invasive species abundance was low, treatment of weeds should be conservative. Corridors and edge care for spring ephemerals and milkweeds will encourage successful establishment of these high-priority pollinator resources.