Sand dunes are important habitats which support a wide variety of flora and fauna. Dunes are under threat from issues such as climate change and scrub encroachmnent. This project examined the impact of conservation grazing by domestic cattle (Bos primigenius) as a management tool for maintaining designated dune systems in 'favourable condition' by reducing scrub cover and generating a species rich sward, whilst accounting for the potentially confounding effect of grazing by naturally occurring wild European rabbits (Oryctolagus cuniculus). GIS analysis of dunes in Northern Ireland suggested that they underwent substantial temporal change from the 1950s to 2010 with loss of open areas of bare sand replaced by increased areas of grassland but most notably scrub and woodland. A factorial experimental approach revealed that grazing by domestic stock reduced vegetation height and biomass whilst controlling the coverage of scrub species such as Ulex europacus (Gorse). Rabbit grazing had 2.6 times the effect of cattle grazing on sward height maintaining a well cropped sward. Rabbit abundance on dunes exhibited significant spatiotemporal variation that fluctuated by orders of magnitude making their impact difficult to predict. Seasonal grazing by cattle had no effect on plant community composition but year round grazing by rabbits skewed plant composition towards unpalatable species, particularly in close proximity to their warrens creating spatial variation in plant community structure. Input of nutrients via the deposition of dung by cattle and rabbits had no discernible· effect on soil pH or nutrient flow including nitrogen, carbon or other trace elements. A review of studies that examined scrub control techniques suggested that effective scrub management is best when using mechanical or manual clearance followed by the immediate application of herbicides with on-going grazing to prevent re-establishment. Recommendations are made for further research and management of designated sand dunes sites throughout Northern Ireland.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:676515 |
| Date | January 2014 |
| Creators | Herron, L. E. |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0015 seconds