New research compares the biodiversity value of plants classed as ‘injurious weeds’ against those stipulated by DEFRA for pollinator targeted agri-environmental options. The findings show that the abundance and diversity of pollinators visiting weed species are far higher than DEFRA recommended plants.

Dr Nicholas Balfour and Professor Francis Ratnieks compared the biodiversity value of plants classified as ‘injurious weeds’ with those stipulated by the Department for Environment, Food and Rural Affairs (DEFRA) for pollinator targeted agri-environmental options, such as red clover and wild marjoram.

Their findings, published in the Journal of Applied Ecology, show that the abundance and diversity of pollinators visiting weed species are far higher than DEFRA recommended plants.

In the UK, five species of native wildflowers are classified as «injurious» in the 1959 Weeds Act. Three of them are frequently visited by many species of bees and other insects — ragwort (Jacobaea vulgaris) and two thistles (Cirsium arvense, C. vulgare). The other two are docks (Rumex crispus and R. obtusifolius), whose flowers are mainly wind-pollinated.

Dr Balfour and Professor Ratnieks conducted a field study in East Sussex where they quantified and identified insects visiting three of these species — the flowers of ragwort, thistles, and other wildflowers, including those recommended by DEFRA — growing in six pasture or ex-pasture sites.

Their results, which found that pollinators were visiting weed species in higher numbers than DEFRA recommended plants, were mirrored by a subsequent analysis of scientific literature.

Story Source:
Materials provided by University of Sussex. Original written by Stephanie Allen. Note: Content may be edited for style and length.