The Status of Juniperus communis ssp. nana (dwarf juniper) communities at six sites in north and north-west Scotland

Summary

Sites with semi-natural vegetation containing Juniperus species are becoming scarce in Britain. The prostrate subspecies Juniperus communis nana (dwarf juniper) occurs in remote areas with a cool oceanic climate, in the NVC community H15 (Calluna vulgaris-Juniperus communis ssp. nana). Evidence suggests that dwarf juniper is considerably less widely distributed than in the past, and the subspecies is absent from large areas of seemingly suitable habitat in north-west Scotland. Dwarf juniper communities were compared at altitudes ranging from sea level to c. 600 m. Sites ranged in area from 0.15–2.0 km² and showed few signs of management. The physiognomy of individual plants and plant density varied within and between sites. The communities appear to be at risk because of a lack of seedling recruitment and from possible impacts of grazing or burning. Environmental change and nitrogen deposition may also affect the dynamics of dwarf juniper populations.