Farming and Wildlife Programme

APPROACH

Farming and wildlife research

WildCRU’s research focuses on revealing how agricultural systems and wildlife interact. The scale of our studies has varied from microcosmic to entire landscapes, individuals to populations, and covered plants, invertebrates, birds, and mammals. The over-arching purpose is to fortify the evidence base for managing outcomes, including careful consideration of the implications for agricultural development for natural habitats, biodiversity, and the provision of essential ecosystem services. Our flexible, interdisciplinary approach is a consistently effective strategy to tackle the most pressing challenges facing farmers, conservationists, and policy makers today.

Our work is summarised in two major academic volumes, Wildlife Conservation on Farmland, which synthesize the results of WildCRU’s agro-ecology studies over the last 25 years. Some examples from our studies are below.

Field margins and invertebrate biodiversity

Farmland invertebrates are vital for healthy ecosystem functioning, but many groups have declined due to agricultural intensification. Arable field margins potentially can increase food resources, provide refuges for invertebrates and buffer them from pesticides and farm operations. We undertook a series of field and farm-scale experiments which showed the ways in which arable field margins are established and managed affect their invertebrate assemblages. For example, field margin swards established by sowing with a grass and wildflower seed mixture attracted more butterflies than naturally regenerated swards. In the short term, larger and more species-rich invertebrate assemblages were fostered on unmanaged margins than on those managed by cutting. The results suggest that blanket management approaches for invertebrates at the farm scale are not optimal. A farmed landscape with a diversity of habitats will provide for the different ecological requirements of invertebrate populations in the characteristically unstable environment of arable systems.

Small mammals on lowland farmland

Increasingly intensive agricultural management since the 1940s has corresponded with a severe decline in the habitats used by small mammals on farmland. There have also been changes in habitat quality, including declines in invertebrate and plant foods. Although a lack of long-term monitoring hampers our understanding of small mammal population trends on farmland, our research suggests a range of ways in which to encourage their abundance and diversity, including measures to promote plant and invertebrate diversity in and around crops, such as field margins and conservation headlands, and hedgerow restoration and management.

Organic farming and biodiversity

Organic farming is a low intensity system, offering benefits to biodiversity. Using two paired-farm studies, we explored the responses of different taxonomic groups to organic farming. In the first, smaller-scale, study, positive impacts of organic farming on butterflies and spiders were found. In the second, large-scale, study of eighty-nine farm pairs across England, organic farming was mainly associated with positive effects on biodiversity, although there was substantial variation in the size of effects among taxonomic groups surveyed, which included plants, spiders, bats and birds. The largest and most consistent (positive) effects were for plants. The results highlight the importance of developing strategies for managing farmland at the landscape scale for most effective conservation of biodiversity.

Moths on farmland

Landscape-scale conservation of farmland moths is urgently needed because of their alarming rates of decline. We have undertaken several experiments that involved light-trapping of macro-moths on intensively farmed land, at both the field and landscape scale, in lowland England.  We have shown that hedgerow trees and wide field margins locally enhance macro-moth diversity. Our research has demonstrated and explained why relatively larger gains for farmland moths are to be obtained from a landscape-scale provision of these features. The establishment of both hedgerow trees and wide margins are management options that are easily integrated within national agri-environment schemes. These features could help to reverse negative trends for farmland biodiversity if they are implemented over sufficiently large areas, and managed appropriately, providing a dense network of key habitat resources.

Freshwater biodiversity

Freshwater resources are of vital importance but the biodiversity of freshwater systems in agricultural land can be negatively affected by agricultural activities. We studied how land use surrounding streams and rivers at the entire catchment scale can affect the quality of freshwaters, as measured by macroinvertebrate indices. We also looked at how adjacent land use and management affected the water quality and biological communities of agricultural ditches. We found that increasing woodland close to riverbanks and managing hedges next to ditches, could have beneficial effects on the water quality and biodiversity of freshwater on agricultural land.

Water vole conservation

The water vole Arvicola amphibious provides a vivid illustration of the process of conservation research, from the initial discovery that a species is declining, through diagnostic research into the causes, then development and testing of solutions, to the production and implementation of a strategy for the species’ recovery. In doing so, the following questions are relevant: How did it come to light that the species was a conservation concern? What evidence was required, and how was that evidence accumulated? How were the causes of the decline diagnosed? How were the remedies devised, tested and implemented? Is society prepared to foot the bill, both financially and ethically, to enact the conservation actions required? Twenty years of WildCRU research have aimed to address these questions for the water vole.