Long-term changes in the extent of heather moorland in upland Britain and Ireland: palaeoecological evidence for the importance of grazing
1993
Stevenson, A.C. | Thompson, D.B.A.
On the basis of pollen analysis of ²¹⁰Pb-dated lake and loch sediment cores from across upland Britain and Ireland we show that heather cover has declined in c. 90% of sites over the last 200 years. Our analysis covers the time from AD 1400 to the present with a resolution of decades. Major losses commenced during the seventeenth to nineteenth centuries, and were greatest in regions with high grazing pressures from sheep. Subsequently, extensive afforestation from the 1920s has caused further significant losses of Calluna moorland. Adverse effects due to acidic deposition and eutrophication, described already in continental heathlands, remain to be demonstrated on upland heather moorland in Britain.
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