Biodiversity of ditches on intensively managed farmland

Apart from studies of fens and grazing marshes, biodiversity data from ditches are exceptionally scarce for lowland farmed landscapes in the UK. The small, often seasonal, drainage ditches which surround many grassland and arable fields have largely been overlooked, with most agri-environment research and policy initiatives on intensively farmed land focusing on field margins and hedgerows. However, their ubiquity and the fact that they are surrounded by intensively managed land mean that such ditches are potentially highly valuable reservoirs for biodiversity in their own right and that they can provide crucial resources for other farmland taxa. Furthermore, as linear features which form a network of habitat across much lowland farmland, ditches potentially have an important function in enhancing landscape permeability, and aiding species dispersal.

This two year project will conduct a landscape-scale survey of ditches and their biodiversity across the Upper Thames Tributaries area. We aim to answer the following questions:
•    How important are ditches for biodiversity within intensively farmed landscapes?
•    How does the degree of connectedness/isolation of ditches within a landscape affect their biodiversity?
•    How do ditches compare to other linear habitats such as hedgerows and field margins in terms of their importance for biodiversity, and does spatial combination of these habitats enhance their biodiversity?
•    How does ditch management affect biodiversity?  

This work is funded by the Esmée Fairbairn Trust.