Factors influencing moth assemblages in woodland fragments on farmland: implications for woodland management and creation schemes

Abstract

As a consequence of long-term deforestation, woodland cover has been drastically reduced in the United Kingdom. The remaining woodland consists mainly of small, highly fragmented woodland patches within farmland. A number of agri-environment schemes aim to increase the amount and quality of woodland on agricultural land, but there is limited information on associations between moths and woodland characteristics which can be used to produce practical recommendations for woodland creation and management. We studied micro- and macromoth communities in woodland patches within farmland to assess the effects of woodland vegetation character and patch configuration. In addition, we measured the influence of the surrounding landscape to assess the potential importance of a landscape-scale management approach for moth conservation. In general, high tree species diversity and a high proportion of native tree species were related to higher moth abundance and species richness; there was a negative impact of grazing. Moth abundance and richness were higher in large woodland patches located close to other woodlands. Woodlands of compact shapes (with proportionally less edge exposed to the surrounding matrix) had higher numbers of 'woodland species', which were associated with woodland core habitat. Small woodland patches can potentially maintain relatively high moth abundance and richness, depending on their shape and proximity to other woodlands. Woodland extent was the most important landscape parameter influencing moths, mostly at relatively small spatial scales (less than or equal to 500m); macromoth ‘woodland species' were influenced by woodland extent at larger spatial scales (less than or equal to 1500m) and are more likely to benefit from a landscape-scale management approach. Our results have important implications for the design and management of woodland patches of high conservation value within agricultural land.