|Wetting up farmland for birds and other biodiversity
Defra project BD1323
|Simon Mortimer, Ben Woodcock, Stephanie Harris and Rebecca Kessock-Philip
The decline in recent decades of U.K. farmland birds is well documented and has led to a Public Service Agreement (PSA) to reverse these trends. For many species, we now have relatively good knowledge of how to provide the nesting and food resources needed. However, there are still some knowledge gaps. In particular, there is increasing evidence that many species make use of wet habitats on farmland, but we do not yet know the best way to provide the resources associated with wet habitats to which the birds are responding. Theoretically, increasing the availability of these wet habitats on agricultural lands should benefit populations of BAP and PSA target bird species and other biodiversity. In practice, however, the benefits of such enhancements have been little tested.
This project aims to:
(i) Use a review to develop a mechanistic understanding, at the level of resource delivery, of the causes of these wet habitat associations.
(ii) Quantify the benefits to birds from bunding ditches and creating paired ponds, shallow surface scrapes and waterlogged areas.
(iii) Quantify the agronomic impacts of introducing wet areas to farmland.
(iv) Provide recommendations for provision of wet areas on agri-environment land.
The biodiversity benefits of wet habitats will be assessed in the context of the agronomic costs of creating such habitats, and an evaluation will be made of the suitability of each feature for Entry Level and Higher Tier type agri-environment scheme options.
The project involved the creation of replicate examples of a number of small-scale wet habitat features, chosen to reflect the types of feature that most farmers could create on their land with minimal impact on their agricultural practices of the area under agricultural production. These are:
(a) Measuring the success in delivering open water, bare earth, sward heterogeneity and a diversity of vegetation, as a measure of access to food resources for farmland birds.
(b) Measuring the success in delivering obligate wetland invertebrates, especially those important as a food resource for farmland birds.
(c) Measuring the success in delivering terrestrial invertebrates, especially those important as a food resource for farmland birds.
(d) Measuring the use of wet areas in arable land and intensive grassland by foraging farmland birds.
Assessments of the arable plants (weeds) and invertebrates will be performed along each transect at 2m and 30m from the field boundary. The arable plants are assessed in June, October and February, while invertebrate densities are assessed during the summer period.
Ponds Conservation Trust