Interactions between livestock systems and biodiversity in South-East Ireland

Botanical and arthropod surveys at field level, and bird counts within field boundaries were undertaken on the same random sample of 50 grass-based farms in SE Ireland. Additional data relating to farm system, farm-level nutrient inputs, stocking rates, and participation (or otherwise) in the Irish Rural Environment Protection Scheme (REPS) were collated. Generalized linear models (GLM) showed that farm system was a predominant influence explaining observed biological diversity. Both sward plant and arthropod diversity were greater on non-dairy (drystock) farms, but total arthropod abundance was greater on dairy farm swards. Both the breeding bird abundance and species richness were significantly greater in field boundaries on dairy, compared with non-dairy farms. These insights have relevance to the debate regarding the most effective use of public expenditure on agri-environment policy, and suggest that such incentive schemes need to become more clearly customised to realise the conservation potential of different farming systems.