Glen Finglas - experimental design
The experiment involves 24 grazing enclosures, measuring 3.3 ha each. There are four grazing treatments with six replicates of each. These are positioned in three blocks of two replicates each, located in different parts of the estate and approximately 5 km from each other.
The grazing treatments are:
I – nine sheep per enclosure
II – three sheep per enclosure
III – two sheep per enclosure with, for four weeks in autumn, two cows each with a suckling calf
IV – ungrazed
Treatment I is regarded as high-intensity grazing. Treatments II and III are each low-intensity grazing regimes and are approximately equivalent in terms of livestock units (a measure of offtake). The sheep used are Blackface and Swaledale/Blackface cross hogs (one year old ewes) and the cows are Luing and Luing/Simmental crosses. Livestock are in the plots from April to December each year except for during essential farming practices such as dipping, shearing and tupping.
Baseline data on plants, invertebrates and breeding birds were collected within the plot areas but before the erection of the fences in 2002. Grazing treatments have been applied from 2003 onwards.