The alpine zone supports some of Scotland’s most natural habitats. Complex topography interacts with snow cover and climate to create gradients in water availability and temperature, resulting in a mosaic of plant communities variously dominated by dwarf-shrubs, grasses, or mosses.
Above and below-ground biodiversity and ecosystem functioning are closely linked, and we expect above-ground variability to be reflected below-ground, but our knowledge of alpine soil biodiversity and functioning is poor. As alpine systems are increasingly affected by climate change, we need to better understand how these complex systems work, to enable us to predict the impacts on biodiversity and the ecosystem services they provide.
StageWork in Progress
The alpine zone (the area above the tree line) comprises a complex mosaic of plant communities resulting from variability in key factors such as water availability, snow-lie duration, temperature, and wind speed. Alpine plant communities vary markedly in their functional composition (e.g., dwarf shrub heaths vs grasslands vs moss-dominated communities) and this variability is likely to be reflected below-ground, in terms of soil biodiversity and functional attributes (carbon stock, nutrient stocks, nutrient cycling, and decomposition). However, to date we have not explored the variability in alpine soils at fine scales and our knowledge of the variation in soil biodiversity and function across mosaics of alpine plant communities is very limited.
Figure: The Ben Avon plateau in the Cairngorm mountains showing the mosaic of snowbed, grassland, dwarf-shrub heath, and moss-dominated plant communities.
(Photograph by Dr Andrea Britton)
Scotland’s climate is changing. The last 40 years have seen significant changes in seasonal air temperatures, amounts of precipitation, and the timing and duration of snow cover. Alpine habitats are also subjected to nitrogen pollution in rainfall and impacts arising from human land use. These, and future changes, are altering the composition and distribution of plant communities across the landscape. Plant community composition and soil biodiversity are tightly linked so, as plant distributions change, we expect this to impact belowground biodiversity, soil function and ecosystem services. The purpose of this research is to develop a greater understanding of soil biodiversity and function across alpine vegetation mosaics to enable us to better predict these impacts.
The Ben Avon plateau, lying within the Cairngorms National Park, comprises the largest contiguous area of alpine vegetation in the UK.
We sampled vegetation and soils at 99 locations distributed across the seven main vegetation types on the mountain, covering 650m to 1171m elevation. At each location we described the plant community and took soil samples from which we extracted DNA to characterize soil biodiversity. Recent advances in DNA sequencing technology allow us to detect the full diversity of fungi, bacteria and other microorganisms present in soil by extracting and sequencing their DNA. Detecting soil organisms would be impossible on this scale using traditional observational methods, and these techniques are revolutionizing our understanding of below ground biodiversity. We also measured carbon and nutrient stocks above- and below-ground and made assessments of decomposition rates, plant nutrient availability, soil temperature, and moisture.