Plant 269

Juniperus bermudiana L. (Cupressaceae)

Bermuda red cedar

Juniperus bermudiana is endemic to Bermuda. It grows naturally in shallow, calcareous soils on hillsides, along coastlines and marshes, where it once formed stands with estimated densities as high as 1,200 trees per hectare. A pioneer tree species of open land, with few competitors until the mid-twentieth century, Juniperus bermudiana thrived because of newly cleared land and quickly became a monoculture forest after the initial removal of the more diverse pre-colonial forest.

Bermuda is one of the most densely populated, isolated oceanic islands in the world, with an average population density of 12 people per hectare and one third of the country being urban. In addition, approximately 20% of Bermuda's land area is now paved with roads, parking lots, industrial centres and buildings.

Because of habitat conversion, Juniperus bermudiana was heavily exploited for building houses and sustaining a thriving ship building industry until about 1900. It was also used for furniture making, fence posts and coffins.

In more recent times, Juniperus bermudiana has been assessed as critically endangered, due to defoliation and subsequent mortality caused by two scale insects, oyster-shell scale (Lepidosaphes newsteadi) and juniper scale (Carulaspis visci), which were introduced from California, USA in the 1940s. In the absence of natural biological controls or notable genetic traits for resistance, Juniperus bermudiana suffered greatly, with its population being reduced by 95% between 1946 and 1956. Over the last 30 years however, the population has started to recover because of natural resistance and intensive conservation efforts. With the potential to supplement restoration programmes, Juniperus bermudiana is cultivated in gardens outside of Bermuda. The largest plantings have taken place on the Atlantic Islands of St Helena and Ascension, where seed was introduced during the mid-nineteenth century to establish timber tree plantations.

Closely related to Juniperus virginiana of eastern North America, Juniperus bermudiana forms a tree up to 15 metres tall, with a slender trunk. Its bark is greyish brown, thin and flaky, peeling in long narrow strips. A narrow and conical crown initially, the crown becomes broad and rounded, often broader than tall. A notable feature of the tree's foliage is that there are both juvenile and mature leaves on the same plant; leaves in the juvenile phase are a brighter green than the dark green of the mature shoots. 'Fruits' ripen in September and October. Despite the vastly reduced adult population, seed germination rates, where the habitat allows, are relatively high.

Further reading

Adams RP 2014. Junipers of the world: the genus Juniperus. Trafford.

Farjon A and Filer DF 2013. An atlas of the world's conifers. Brill.

Ben Jones