The great juniper hunt

Among its dependants is the juniper carpet moth which feeds on the juniper shrub and is itself rare.

Juniper is under threat across the South of England and the environmental charity Plantlife has launched the Great Juniper Hunt as part of a plan to reverse the decline.

Tim Wilkins, species recovery co-ordinator for Plantlife, gave a talk at a recent meeting in Oxford of the Rare Plants Group of the Ashmolean Natural History Society. He spoke about the hunt during which people are being asked to supply details of any juniper they know of.

One such plant remains in the garden of a private house in the very north of Oxfordshire, and the present owner has been sharing in the conservation work by Plantlife and other groups. His tree, from which cuttings have been taken, is regarded as the last survivor of bushes from the former common at Juniper Hill.

The reasons for the decline of this plant are still being researched, but they include the lack of suitable habitat — pockets of bare ground are essential for germination.

Another is the reduction in fertile seed. Without a good ratio of both male and female bushes there is limited pollination. Uncontrolled grazing, such as by rabbits, can lead to the destruction of seedlings and young bushes.

Climate is another factor, as the seeds need three winters of sufficiently low temperatures to germinate, and the only recent very cold one was this year Although juniper is a long-lived shrub, typically 100 years or more, many of the remaining populations are already old and there is severe lack of young seedlings to replace them.

Juniper is an important part of our ancient landscape and culture: it was one of the first trees to colonise Britain after the last Ice Age. The loss during the last 100 years is so severe that it could disappear altogether. “Without action now, juniper faces extinction across much of lowland England by 2060,” said Mr Wilkins.

Action is being taken. More than 30 project sites have been chosen for a range of conservation measures, including large-scale pilot management and experimental seedling shelters. Where colonies have all but died out, the numbers are being bolstered through the propagation of cuttings.

Other measures, on sites in the Chilterns, include removing 15 to 20 centimetres of the top layer of soil which contains the seed of competing species, at a series of trial plots.

Another is to surround existing bushes with the protection of a low hedge or a barrier of prickly scrub, to deter grazing.

“These all help to give us a bit of breathing space, in our work to stop the genetic loss,” said Julia Carey, a member of the countryside conservation team.

For future provision, cuttings and berries are being planted at a specialist nursery, to be returned to their original site when they are strongly-growing seedlings, so maintaining the original genetic material.

The berries are small cones, as juniper is a conifer. They contain six fused scales, each scale being a single seed, and have a coating which ripens to a blue-black colour.

As it was once a common shrub in Britain, juniper was valued as a source of firewood and as a building material, and the berries as a flavouring for food and drink and for their medicinal qualities.

They flavoured meat dishes and, as well as flavouring gin, gave it its name, which is derived from either the French or Dutch words for juniper, genièvre or jenever.

Medicinally, the spraying of vaporised oils of juniper was found to be effective in preventing airborne infection in hospital wards during the 1918 Spanish ‘flu epidemic.

People who contribute to the survey will be able to recognise the juniper bushes by their evergreen foliage composed of small prickly needles; seen close-to, these needles have a broad white line running along the upper side.

It is most often found on chalk downland, limestone grassland, in mixed scrub, in young, but not dense, woodland, and along ancient trackways or paths.

Distinction is made between the wild population and those that may have been deliberate plantings, such as along a roadside or in a particular formation. Junipers in gardens are not part of the survey, as they may be a different variety from that found in the wild.

As well as the number, age and condition of the bushes, detail on habitat is very important.

“The special conditions thought to be necessary for juniper seeds to germinate are also beneficial to a host of other wild plants, many of which are also under threat,” said Mr Wilkins.

“By focusing on the habitat, our new project aims to help many of these other species too.”

Reference to boundary features also adds to the picture, with records of nearby hedges, ditches and trackways.

So also does the aspect of the site, and whether it is on level or sloping ground, and its use, such as for pasture or plantation.

An interesting question to be considered is the link between juniper and ancient land features, such as hill forts and earthworks.

“There seems to be some significance to features such as hill forts and earthworks. There seems to be significant association between them and it could be useful for us to find out to what extent this is so,” said Mr Wilkins. “It could be quite illuminating.”

The Great Juniper Hunt will run until the end of October 2010. Survey forms can be downloaded from Plantlife’s website, www.plantlife.org.uk, or requested from its offices, on 01722 342730.