Vegetation dynamics and livestock performance in system-scale studies of sheep and cattle grazing on degraded upland wet heath
This study is summarised as evidence for the following.
Change type of livestockAction Link
Change type of livestock
A replicated, controlled, before-and-after study in 2001-2006 in degraded wet heath in Northumberland, UK (Critchley et al. 2008) found that grazing with both cattle and sheep, as opposed to just grazing with sheep, reduced purple moor grass Molinia caerulea cover, had mixed effects on cover of common heather Calluna vulgaris, and had no effect on the cover of four other plant species. Cover of Molinia caerulea declined after the introduction of cattle into areas grazed by sheep (before: 12-13%, after: 15-19%), but increased in areas that were only grazed by sheep (before: 29-13%, after: 20-19%). Common heather cover declined in one of two areas grazed by sheep and cattle (before: 20%, after: 13%), but one of two areas saw no significant change over time (before: 14%, after 12%). Common heather cover declined in areas grazed by only sheep (before: 12-21%, after: 8-18%). The cover of common sedge Carex nigra, rush species Juncus spp., hare's-tail cottongrass Eriophorum vaginatum, and mat grass Nardus stricta did not change significantly over time in areas that were grazed by sheep and cows (before: 2-11%, after: 3-14%). The heathland was split into four areas by fencing, two of which were stocked with both sheep and cattle, and two of which were stocked only with sheep. The entire area was grazed by sheep from 1995 and cows were introduced in 2003. Vegetation cover was recorded in one hundred and ninety six 1 m2 quadrats in July–August 2001, and 2003-2006.