Microhabitats of planted sea wall strips used by pollinators and Orthoptera

Abstract

As part of an Urban Buzz scheme, strips of teasel (Dipsacusfullonum) and greater knapweed (Centaureascabiosa) have been established along a sea wall flood defense in the UK to provide a corridor of flower-rich habitat for pollinators such as bees and butterflies. The cutting of tall grassland and planting of dicotyledons also created a suitable short sward environment (c. 30 cm height) for Orthoptera nymphs in the establishment year (2018). However, by 2019, the grassland in the pollinator strips was taller (c. 75 cm) and suboptimal for grasshoppers; in contrast to Roesel’s bush-cricket (Roeselianaroeselii), which inhabited the taller vegetation in greater abundance. The progression to established grassland with flowering D.fullonum saw the pollinator strips attract significantly higher numbers of bees and butterflies than the floristically poor control strips. This small-scale study illustrates that pollinator strips can have multi-functional benefits for ecosystems beyond pollination, with Orthoptera of tall grassland (R.roeselii) likely to persist alongside planted wildflowers.