Individual study: Impact of change in start date of grazing on limestone grassland communities, Deep Dale, Derbyshire, UK
Costley J. (2013) Impact of change in start date of grazing on limestone grassland communities, Deep Dale, Derbyshire, UK. Conservation Evidence, 10, 77-79
Deep Dale is situated within the carboniferous limestone area of the Peak District National Park. The study site occupies an area of 36 hectares, representing the south-eastern slopes of the dale. During the period from 1950 to 1996, the site was grazed by cattle, traditionally from the beginning of May each year. Then, from 1997 to 2012, the grazing start date was delayed to the beginning of July in order to comply with the requirements of agri-environment schemes. Repeat surveys indicate that this change in start date appears to have resulted in few pronounced changes to the vegetation. Some areas of grassland on shallow soils (conforming to National Vegetation Community CG2d) have become more herb-rich with an increase in abundance of kidney vetch Anthyllis vulneraria, common milkwort Polygala vulgaris, devilsbit scabious Succisa pratensis and autumn gentian Gentianella amarella. However, it appears that these changes are mainly associated with areas grazed preferentially (first) by livestock, whilst in an area of CG2d grazed later, fewer positive indicator species have shown an increase in their abundance and there are early signs of a decline in condition, including a decrease in the abundance of fairy flax Linum catharticum and an increase in the abundance of bryophytes. Most significantly, areas of acid U4c grassland have shown a notable increase in the abundance of hawthorn Crataegus monogyna seedlings, and in the abundance of wavy hair-grass Deschampsia flexuosa.