Evaluation of community structure and dynamics in certain widespread types of upland grazings in Scotland
Nardus and Molinia dominant grasslands (Nardetum and Holinietura respectively) cover large areas of the rough grazings of Scotland. There has been a general view that, in many cases, these two grasslands were derived from heathland as a result of a deflected succession caused mainly by heavy grazing and over-frequent burning. From the point of view of economics, the change from heathland to Nardetum or Molinietum is considered as a 'loss' since the former type supplies greater grazing value, all the year round, to sheep, cattle, deer and grouse. Both Nardus and Molinia can exist in a wide range of habitats, constituting several communities which, though dominated by one of them, are distinct in their composition, structure and dynamics. This study aimed to understand the processes and mechanisms (including management) that cause these patterns and to assess the possibility of re-introducing Calluna either by sowing seeds or, if the seeds are already present in the substratum, the treatment/s that encourage them to germinate and the seedlings to establish. The study also includes a review of the autecology of Nardus and Molinia and observations on their phenology and interactions with other species as affected by various grazing regimes.