Juniper in Upper Teesdale

SUMMARY (1) About 100 ha of juniper scrub occur in Upper Teesdale, much of it close to farms. It is most common on uneven ground associated with the Whin Sill but there is little relation to soil type or topography. (2) In most cases the assemblage of plants is not distinctive, but one area is floristically similar to the sub-alpine fern-rich juniper scrub which occurs at high altitude in the Scottish Highlands; it is a further example of a community occurring in Teesdale well south of its normal range and at a low altitude. (3) Both even-aged and mixed-aged stands occur, and populations are long-lived compared to those on the chalk. There is almost no replacement of bushes, though heavily grazed juniper seedlings up to 20 yr old are common away from the main stands. Few have managed to reach bush size during the last 70 yr. (4) Past land-uses, particularly those associated with the 'dual economy' of mining and farming, which resulted in a fluctuating grazing regime, probably produced suitable conditions for the spread of juniper during the nineteenth century. (5) Juniper may be naturally migratory. There are no immediate grounds for concern over the survival of the juniper scrub, which should occupy approximately the same sites for at least another 100 yr, but experiments designed to encourage regeneration should be started. Burning seems the most promising treatment.