A SHRUB once commonly associated with gin production is in need of a tonic as it faces extinction.

Although UK distillers no longer depend on home-grown juniper berries to produce the much-loved spirit, and instead rely on imports from Eastern Europe, unless preventative action is taken now, the juniper bush could be extinct by 2060.

There is no single cause for juniper decline, but loss of seedling habitat through under-grazing and the development of dense grassland and scrub, is a widespread problem and a fungus-like disease, Phytophthora austrocedrae, appears to be spreading through shrubs nationwide.

More than a quarter of the vast juniper population at Moor House - Upper Teesdale National Nature Reserve, in County Durham – the largest juniper wood in England - was severely affected by the disease in 2012, which was first positively identified at the site in autumn 2011.

Experts believe the shrubs were affected prior to the official diagnosis, but there was no test available.

Plants get infected at their roots and the disease travels up to ground level, causing the shrub to die.

Martin Furness, reserve manager at Upper Teesdale, said: “We suspect the disease was around before then, but that was when scientists were able to say officially what it was.

“Before that, nobody could tell us what the problem was.

“There is no treatment for it. When we see bushes that have the disease we cut them down and burn them.

“The process is designed to try and slow and halt the spread but obviously it is not a cure.”

Martin said there were other factors contributing to the decline of juniper, including climate change, atmospheric nitrogen, pollution and changing land use.

During lead-mining times, when cattle and horses grazed on the uplands, they would break through the matt of grasses and allow seeds to be released into an area where they could germinate more effectively.

Nowadays, sheep and rabbits are found in such areas and both species graze so close to the ground that they are eating young seedlings when they are soft and nutritious, therefore preventing new ones from coming through and developing.

Martin added: “Several factors have come together which are impacting to make the overall situation less favourable for juniper.

“It is up to us to see what could be done to preserve this very important habitat.

“There could be other things going on that we will never know about, especially when there is more than one factor involved.”

He urged people walking along the Pennine Way which goes through the site to use foot-washing facilities located at the sections passing through the junipers to help prevent the spread of the fungal disease, which is water-borne and can be carried through damp soil.

He said: “We are working hard to cut out the plants which have got the disease and burn them and we would ask people who are walking through the site to wash their boots before and after being in the area.

“One of the reasons the disease can spread is through mud on people’s boots so that is one thing that the general public can do to help.”

Walkers are also asked to stick to public footpaths and adhere to notices along the route.

Seeds from some of the juniper berries have been sent to a national seed bank to be kept in long-term cold storage.

If kept in the right conditions, they could be revived in hundreds of years.

Justina Simpson, from wildlife charity Plantlife, said: “Juniper is in real trouble.

“It has steadily declined over the last few decades and many counties in southern England have lost over 60 per cent of their juniper populations.

“Without action now, juniper faces extinction across much of lowland England by 2060.”

More than 90 species of insect and fungus either partially or wholly depend on the shrub so the more it declines the more threatened they become.

The special conditions juniper seeds need in order to germinate also benefit a host of wild flowers, some of which are also facing extinction.

The potential disappearance of Juniper would also represent a cultural and historical loss.

Its fragrant wood was traditionally used on fires because it burned well and smoulders with little smoke, and was therefore the preferred fuel for illegal whisky stills.

It was also a useful if unlikely burglar deterrent - the prickly boughs were once used as a substitute for barbed wire.

Juniper has a long medicinal history, too.

The small amount of juniper berries still harvested in the UK are now typically used to add flavour to game dishes such as venison.