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Project Topic
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The intensification of agriculture and herbicide use has led to the degradation of farmland ecosystems, with significant loss of farmland terrestrial and freshwater biodiversity and services. Herbicide use within fields has reduced farmland plant (weed) abundance and diversity, destroying these refuge and food resources relied upon by birds, pollinators and natural enemy arthropods. Herbicides have selected for some noxious weeds, damaging to crops, leading to an arms race with more herbicide being used to combat weeds that do relatively well in conditions of herbicide use. This is compounded by agricultural intensification at landscape scales that has led to the loss of semi-natural floral habitat surrounding fields, including areas of meadow, margins, hedgerows and woods that provided overwintering, oviposition and alternative food resources for biodiversity. This lost semi-natural habitat is also no longer able to intercept herbicides, applied in field, leading to an increase in the run-off of these and other pesticides into water courses adjacent to farmland fields where they significantly impact the ecological quality and diversity (ecological status) of freshwaters, within farmland and downstream. In the FRESHH project, we hypothesise that we can reduce herbicide usage by adopting the ecosystem service of weed seed regulation by carabid beetles. Restoration of semi-natural habitat in and around fields, via beetle banks, margins or hedgerows, would increase carabid abundance and diversity by conservation, through the provision of food and refuge resources. These restored habitats could also intercept some of the herbicides that are still applied, preventing run-off into freshwaters. Semi-natural habitat restoration in farmland would therefore have multiple, synergistic effects, playing a role not only in the conservation of carabids and of terrestrial and freshwater biodiversity, but also in the release (rewilding) of weed communities to more natural abundance and diversity within farmland with lower herbicide selection pressure. This FRESHH approach is dependent on the acceptability to farmers of the adoption of carabids, in place of herbicides, and of the installation of semi-natural habitat. FRESHH explicitly uses a transdisciplinary approach, at the interface of socio-economics, ecology and agronomy, to balance our concerns for farmland terrestrial and freshwater ecosystems and farmer needs for weed control. Co-development with farmers will produce acceptable management to restore semi-natural habitat, to foster carabid beetle regulation of the weed seedbank and to reduce impacts on freshwaters through direct herbicide input reduction and greater interception of herbicide runoff.
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