Glen Finglas grazing

Studies of grazing impacts on biodiversity at Glen Finglas

The character of the Scottish upland landscape is shaped by domestic livestock grazing. The James Hutton Institute and collaborators have been conducting a grazing experiment at the Woodland Trust’s Glen Finglas estate, in the southern Highlands, since 2002. Here we study the varied impacts of sheep and cattle grazing on upland grassland biodiversity within a series of enclosures in which sheep and cow numbers are carefully controlled.

Project aim

Detailed monitoring of plants, invertebrates and birds is carried out regularly. We investigate how species and communities respond to different grazing treatments and how responses at lower levels of the food chain affect those higher up. This experimental platform provides an invaluable resource for a wide range of scientists.  As well as the core monitoring carried out, further biological and environmental processes studied have ranged from population cycling in voles through carbon storage properties of vegetation under different grazing regimes to determinants of the sex ratio of pipit chicks.

We have summarised the results as syntheses for policy and for stakeholders. A more general summary is available on the SEFARI website.

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.

Principle investigator

Prof. Robin Pakeman
Plant Ecologist

Project Publications

For further details of these publications, click the first author’s name (where activated) to send them an email.

Scientific Papers