Wetland habitat creation and mitigation of water pollution from field drains: use of buffer strip pools within an arable landscape.

Abstract

The impact of diffuse agricultural pollution on water is of concern because it causes eutrophication and increases water treatment costs. Riparian buffer strips may reduce soil and phosphorus movement to water but are not sufficiently effective where land is contoured or drained. Filtering of drain or ditch water through buffer strip pools may provide a better solution. We investigate phosphorous concentrations in field drain water and assess the value of two shallow pool sequences for wildlife and nutrient management in a Leicestershire clay catchment. Phosphorus in drains frequently exceeded concentrations likely to trigger eutrophication. Concentrations were lower in pools than in their supplying ditch or drain. Pools supported 9-18 macrophyte species and 24-52 aquatic macroinvertebrate species (excluding Diptera), including six nationally scarce Colepoptera. The results imply that: 1) buffer strip ponds can help to reduce transport of P to watercourses in arable catchments, and 2) a range of freshwater plant and invertebrate species can benefit from buffer strip pools.