Juniper Survey of Perth and Kinross, 2010
The survey was commissioned to monitor the condition of juniper outside designated Juniper Wood SSSIs. In particular the health of populations and regeneration were looked at. More than 7500 bushes were monitored at 96 sites. Of these sites, 22 had more than 50 bushes, the number generally considered to constitute a viable population (FCS 2009). Only one site over 350 m had more than 50 bushes.
The majority of sites had some healthy bushes with vigorous green growth. Diseased bushes were not a prominent feature at any site. An abnormally high number of dead bushes were found on Lurgan Hill. Bushes were doing poorly at several sites because of shading, browsing damage by deer, mechanical damage from rubbing or snow damage.
The majority of bushes were mature (2084 bushes) or overmature (4121 vigorous bushes, 581 moribund or dead bushes). Young bushes were found at only 20 sites and seedlings at 7. Sites with seedlings had a complete age range of bushes present with a good source of berries nearby. On most sites with regeneration, young bushes and seedlings were found in low numbers in suitable habitats with low competition from other species, such as small areas with short vegetation or rocky bare soil. Regeneration was good at two sites and outstanding at one site, Shillinghill, where mixed grassy heath (NVC M15, U4) was grazed very short by cattle and sheep to about 5 cm but grazing pressures did not seriously impact on the young juniper.
There was a good source of berries at 39 sites. Many overmature bushes had abundant berries. There was no regeneration at most sites as no suitable habitat was available for germination and growth of young seedlings. Where seedlings were found the vegetation was less than 10 cm. At most sites the vegetation surrounding bushes was more than 20 cm tall, often thick tussocky grasses or tall bracken preventing seedling establishment. Shading from bracken makes regeneration very unlikely on many hill pasture sites below 350 m.