Culardoch

The Culardoch experiment is used to study the impact of nitrogen deposition, climate change, grazing and burning on the biodiversity and functioning of alpine heathland. The experiment is situated in the eastern Cairngorm mountains of Scotland at an altitude of 750 m above sea level. The vegetation is alpine Calluna vulgaris dominated heath, which is short in stature due to the high level of exposure, and supports a rich lichen community.

Despite their remoteness and often pristine appearance, alpine ecosystems in the UK are subject to a variety of human influences. Grazing by domestic stock and burning management on adjacent grouse moors can have strong local impacts, while air pollution and deposition of nitrogen and sulphur in rainfall (acid rain) and climate change have more subtle and wide ranging impacts. Alpine ecosystems may be especially vulnerable to these impacts since alpine plant and microbial communities are adapted to conditions of low nutrient availability and a harsh climate. Alpine plant species are often slow growing and sensitive to physical disturbance. Under conditions of increasing nutrient availability and a warming climate they may be unable to compete with species spreading up from lower altitudes. Due to the close relationships between plant communities, soil microbes and ecosystem processes such as nutrient cycling, changes in the plant community could be expected to have wider consequences for the functioning of these ecosystems.

Experimental manipulations at the Culardoch site began in 1999, with burning, grazing and nitrogen additions (0, 10, 20 & 50 kg N ha^-1 y^-1 above background). In 2004, a climate change (warming and drying) treatment was added using open top chambers. Nitrogen additions ceased after 2010 and the experiment is now used to study the rates of recovery of the plant community and ecosystem processes.

Data collection has included studies of treatment impacts on plant community composition, dwarf-shrub growth and flowering, soil and water chemistry, decomposition processes and fungal community composition. Outputs from the project are listed below. Since 2003 the James Hutton Institute has also maintained an automatic weather station at the Culardoch site.

The Culardoch experiment is listed on the Ecological Continuity Trust's register of long-term ecological research sites in the UK. If you would like to know more about research at the Culardoch site, please contact Dr. Andrea Britton.

Publications:

• Hesling, E. (2013) Arctic-alpine mycorrhizal fungi in Scotland: the ecology of unexplored fungal communities and threats to their survival. PhD thesis, University of Aberdeen.
• Phoenix, G.K.; Emmett, B.A.;Britton, A.J.; Caporn, S.J.M.; Dise, N.B.; Helliwell, R.C.; Jones, L.; Leake J.R.; Leith, I.D.; Sheppard, L.J.; Sowerby, A.; Pilkington, M.G.; Ashmore, M.R.; Power, S.A. (2012) Impacts of atmospheric nitrogen deposition: responses of multiple plant and soil parameters across contrasting ecosystems in long term field experiments. Global Change Biology, 18, 1197-1215.
• Papanikolaou, N.; Britton, A.J.; Helliwell, R.C.; Johnson, D. (2010) Nitrogen deposition, vegetation burning and climate warming act independently on microbial community structure and enzyme activity associated with decomposing litter in low-alpine heath. Global Change Biology, 16, 3120-3132.
• Helliwell, R.C.; Britton, A.J.; Gibbs, S.; Fisher, J.M.; Potts, J.M. (2010) Interactive effects of nitrogen deposition, land management and weather on soil solution chemistry in a Scottish low-alpine heath. Ecosystems, 13, 696-711.
• Papanikolaou, N.D. (2008) Response of alpine heathland soils to environmental change and land management. PhD thesis, University of Aberdeen.
• Britton, A.J.; Helliwell, R.C.; Fisher, J.M.; Gibbs, S. (2008) Interactive effects of nitrogen deposition and fire on plant and soil chemistry in an alpine heathland. Environmental Pollution 156, 409-416.
• Britton, A.J. and Fisher, J.M. (2008) Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management. Environmental Pollution 153, 564-573.
• Britton, A.J. and Fisher, J.M. (2007) Interactive effects of nitrogen deposition, fire and grazing on diversity and composition of low-apine prostrate Calluna vulgaris heathland. Journal of Applied Ecology 44, 125-135.