Scrubby woodland comprising of juniper bushes is associated with a variety of soil types, though typically acidic and supporting heather, cowberry, bilberry, wavy hair-grass, ferns and mosses. It has many important and characteristic invertebrates, including the Juniper Pug and Juniper Carpet moths. It is also important as a food source for many birds, notably the song thrush and fieldfare.

Juniper scrub is largely confined to the east-central Highlands of Scotland, particularly in the Cairngorm and Monadhliath ranges. More isolated stands of juniper scrub occur in southern Scotland, Northumberland, the Pennines and Lake District.

Although it is not rare in the UK and is still locally common in many areas, it is now extinct in many sites in the south as a result of agricultural change such as ploughing of scrubland, or planting with trees. Stands in northern England and Scotland have suffered decline as any new young bushes are lost due to heavy grazing. A lack of grazing can also have a detrimental effect and where sheep grazing has been abandoned, juniper sites have been lost due to natural succession by birch or other scrub species. Other than loss of suitable habitat, lack of regeneration is considered to be the greatest long-term threat to juniper in the UK. The "Atlas of British Flora" of 1990 records a serious continuing decline in juniper in central, eastern and northern England, and parts of Scotland, since 1930.

Juniper scrub is a priority for conservation because it is an increasingly scarce and fragmented habitat in Durham as well as nationally. Surveys in 1973 and 1994 have shown a complete loss of 12 juniper sites (24%) and a decline in overall bush numbers of 36%. Juniper habitats are dominated by old bushes of >50 years old, with young natural regeneration being very rare. If this trend continues without active conservation management, this habitat is likely to be lost in Durham within 50-60 years. The problems, highlighted in the 1994 survey, are recognised and a few sites enjoy conservation designations. Other than Teesdale's National Nature Reserve, 7 sites are in SSSI's and 12 form parts of County Wildlife Sites.

Juniper scrub occurs today mainly in the North Pennines Natural Area in the west of Durham, invariably on unimproved pasture or moorland above 300m. A notable exception is the Magnesian limestone sea cliffs at Blackhall Rocks with a few isolated bushes. The total area of this habitat in the county is approximately 115ha, split between 26 colonies. Around 100ha of this total occurs in the Upper Teesdale NNR, counted as one site, A further 17 sites, consisting of very scattered or isolated bushes, contain as few as 1 or 2 bushes.

Heavy grazing. The losses in this habitat are due overwhelmingly to grazing pressures from increases in sheep numbers, and to a lesser extent cattle, and in rabbit populations. Heavy grazing opens up dense stands of juniper, gradually fragmenting colonies into an open, park-like community of scattered shrubs. Regeneration does not occur and the population gradually dies out. In some cases in the past juniper bushes have been removed to provide better grazing. Over time, shrubs get older and become less able to reproduce; seed viability reduces from 80% in young stands to 5% in older populations.

The loss of traditional management. Between 1600 and 1900 land-use in the uplands of the Durham area fluctuated between farming and small-scale mining, depending on the economic climate of the time. The periodic breaks from farming would have allowed juniper to regenerate. Up until the 20th century juniper was used as fuel, in building walls and as bases for haystacks. The removal of juniper for these uses created bare areas that provided ideal conditions for the germination of seed. The fluctuating grazing levels would have allowed these seedlings to establish and mature.

Development of woodland. Where grazing is very low or absent, in some cases natural succession to woodland has taken place and the maturing trees shade out the juniper.

Regular burning carried out as part of grouse moor moorland management. This has resulted in the loss of several small juniper scrub colonies.

Management. Management and regeneration of juniper is complex and many of the techniques are somewhat experimental.

Encouragement of regeneration. Regeneration of juniper scrub from seed is a difficult process. Juniper establishes only very slowly; it may be 20 years before a seedling reaches one metre in height. Slow-growing seedlings tend to be outcompeted by other vegetation. Controlled burning may be used to create a surface that will remain open for a long period, allowing more time for juniper to become established.

Planting of seedlings. An approach currently being used in the area by English Nature and Durham County Council is to grow on juniper artificially in nurseries and then planting it out at sites. This approach is being used whilst investigations continue into more natural methods of regeneration. Growing seedlings from both seed and cuttings has been tried; the seed has provided a better source of material and growth rates are more vigorous. Seed or cuttings from each site are kept separately to retain the genetic integrity of individual populations. Seedlings are usually about 2 years old (10-20cm high) when planted out. Preparatory work on site includes removal of any gorse (by cutting and treating with herbicide) and cutting and removing vegetation.

Control of grazing. Seedlings require protection from browsing for a significant period. Plots should be ideally in small enclosures of about 20m square and protected with rabbit-proof fencing. Small enclosures are easy to maintain in a rabbit-proof condition. Seedlings are also protected with tree guards or netting. If the site is grazed then stock-proof fencing is also necessary.

Planting other suitable species. The characteristic ground flora of juniper scrub can be encouraged by sowing seed or planting seedlings of acid grassland species, heather, rowan, bilberry and crowberry from suitable nearby locations.

Barrett J. (1997) "Regenerating juniper" Enact (English Nature's magazine) Vol. 5 No. 1

Clifton S.J., Ranner D. S. and Ward L.K. (1995) "The conservation of juniper in Northumbria" English Nature Research Report No. 152

Dunn T.C. (1965) "The juniper in Co. Durham" Vasculum Vol. 50 p.23-24

Gilbert O.L. (1980) "Juniper in Upper Teesdale" Journal of Applied Ecology Vol. 68 p.1013-1024

Ranner D.S. (1994) "Juniperus communis - its history, current status and future conservation, with particular reference to County Durham" Unpublished HND dissertation, Newton Rigg College, Penrith

Rodwell J.S. (ed.) (1991) "British plant communities. Vol. 1. Woodlands and scrub" Cambridge University Press: Cambridge