Making agricultural landscapes more sustainable for freshwater biodiversity: a case study from southern England.

1. Agriculture is known to have a range of deleterious impacts on freshwater habitats and biota and many countries have introduced measures to attempt to mitigate these impacts through agri-environment initiatives. Despite the protection they provide, water bodies (any discrete body of surface fresh water) in farmland landscapes commonly remain impaired by agriculture. In some areas of the UK there have been calls to halt farming completely, indicating that the measures offered for the widespread protection of aquatic systems, particularly the use of buffer strips, may not be extensive enough to provide sufficient protection for freshwater biota. 2. This study investigated whether existing agri-environment measures for the widespread protection of aquatic habitats could be better deployed to provide a higher level of protection for the aquatic macrophytes and macroinvertebrates of a study area in southern England. 3. Reserve selection procedures were used to reallocate the area of land that could be remunerated under the Environmental Stewardship scheme as buffer strips bordering water bodies, so that a higher level of protection was provided for both the richness and rarity of aquatic species in the study area. 4. Almost 395 ha were available for reallocation in the reserve selection process, which was found to provide a satisfactory level of protection for up to 90% of the surveyed species. 5. The results showed that the agri-environment scheme in England has a great deal of potential to provide more effective protection for the aquatic biodiversity of agricultural landscapes if measures are targeted. Copyright © 2008 John Wiley & Sons, Ltd.