A comparison of green lanes and field margins as bumblebee habitat in an arable landscape

There have been major changes in agricultural practice over the past 50 years. The increasing efficiency of arable production has led to larger field sizes with the associated removal of many hedgerow field boundaries. This, together with high input farming practices, has had a deleterious effect on the quality of the rural landscape as a wildlife habitat. This study focuses on green lanes, that is, trackways bounded on both sides by hedgerows, and the adjacent field margins of arable crops and examines each habitat to determine their relative resource value to bumblebees. The vegetation communities within 15 green lane sites and those of the adjacent field margins were recorded, and subsequent analysis showed that species richness was significantly higher within the green lanes. Bee numbers were recorded at each site during 10 visits, both along the inside of green lane hedges and the outside of the opposite hedge on the field margins of the arable crops. At each visit the flower abundance of 10 plant groups was recorded for each habitat type. The results show that bumblebee abundance was significantly higher within the green lane habitat than on the field margins and that this difference was directly related to the abundance of flowers within the habitat.