Individual study: Effect of grazing management on hay meadow vegetation at Bowberhead and Piper Hole Meadows SSSI, Cumbria, England
Smith R.S. & Rushton S.P. (1994) The effects of grazing management on the vegetation of mesotrophic (meadow) grassland in Northern England. Journal of Applied Ecology, 31, 13-24
Hay meadows in the Yorkshire Dales and the North Pennines (northern England) are often grazed with sheep or cattle outside the 2-3 month period when a hay or silage crop is grown. An experiment was conducted to examine the effects of grazing management on the flora in one such hay meadow, Undergate Meadow (part of Bowberhead and Piper Hole Meadows Site of Special Scientific Interest) in Cumbria, northwest England.
Study site: The vegetation in the meadow prior to the grazing experiment was classified as a ‘northern’ meadow - a Geranium sylvaticum (wood crane's-bill)-Anthoxanthum odoratum (sweet vernal) meadow, Bromus hordaceus (soft brome) subcommunity (UK National Vegetation Classification).
Grazing treatments: The lower portion of the meadow (approx. 1.5 ha) was divided into three blocks of visually homogeneous vegetation of similar species composition with livestock excluded by fencing as necessary. Four 2 m² exclosures were randomly positioned in each block (12 in total) to prevent grazing in various periods of the year throughout the duration of the experiment; 1987 (after the haycut) to 1991. The four treatments (one in each of the three blocks) were:
i) no grazing;
ii) no grazing from time of hay cut to 1st January i.e. a spring grazing treatment;
iii) no grazing from 1st January to time of hay cut i.e. an autumn grazing treatment;
iv) control plots in which the normal grazing regime was followed from the time of hay cut until grazers removed for the growth of the following year’s hay crop.
Forty nine vascular plant species were recorded, those occurring in 80% or more of sample quadrats were the grasses: common bent-grass Agrostis capillaris, sweet vernal Anthoxanthum odoratum, soft brome Bromus hordaceus, cock's-foot Dactylis glomerata, red fescue Festuca rubra, perennial rye-grass Lolium perenne, rough meadow-grass Poa trivialis; and herbs: meadow buttercup Ranunculus acris, common sorrel Rumex acetosa, great burnet Sanguisorba officinalis and dandelion Taraxacum officinale.
Frequent species (60-79% of quadrats) were: daisy Bellis perennis, meadow fescue Festuca pratensis, yorkshire fog Holcus lanatus and ribwort plantain Plantago lanceolata.
By 1991 each grazing treatment had altered the plant species composition. The most extreme response was elicited in the plots ungrazed for 4 years, with the greatest reduction in species richness resulting in a distinct species group dominated by five grasses: Bromus hordaceus, F.rubra, meadow foxtail Alopecurus pratensis, D.glomerata and H.lanatus.
Varying the timing of grazing between autumn and spring favoured different species groups. Autumn grazing favoured the grasses A.odoratum, L.perenne, P.trivialis and crested dog's-tail Cynosurus cristatus. Spring grazing favoured the herbs wood cranes'-bill Geranium sylvaticum, melancholy thistle Cirsium (heterophyllum) helenoides and great burnet Sanguisorba officinalis.
The changes in plant composition were primarily of the relative abundance of species rather than species loss.
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