One of the pleasures of going out with the Wiltshire Botanical Society (WBS) this year was in seeing Juniper, Juniperus communis, growing in the wild. Juniper is a native shrub or small tree in Britain. It became established in Britain after the last glacial period. Unfortunately, its future faces multiple threats.
Male and Female
Juniper a member of the Cupressaceae or Cypress family. It is dioecious. This means that it has separate male and female trees, as illustrated by the photos in this blog. The species is wind-pollinated. Male trees have cylindrical cones that shed pollen on the wind. Female trees produce berry-like cones. These are called galbuli or strobili. The blue-black fruit can take 2-3 years to mature. As a result, you may see fruits of varying ages on the same tree. Of course, the Christmas connection is that these berries are used to make gin for one of the nation’s favourite tipples: Gin and Tonic (G&T).
Juniper is a priority species on the UK’s Biodiversity Action Plan (BAP). It is an important habitat indicator. It tends to grow on largely acid soils in Scotland and the North of England and on calcareous soils in Southern England. UK populations are in decline in the face of multiple threats. Overgrazing and undergrazing both pose threats. Excessive browsing prevents the establishment of seedlings. Where there is too little or no grazing activity, Juniper is crowded or shaded out by encroaching scrub. Juniper is a resilient shrub, but it does not respond well to wildfires which could increase with climate change. Phytophthora austrocedri, a fungus-like pathogen, is an additional concern as it can cause dieback or death in a matter of a year or two.
Plantlife is actively engaged in a conservation project to save this tree that has been with us for 10,000 years. Efforts are directed at saving the special lowland Juniper habitats in Wiltshire and Oxfordshire. Fifty percent of the historic range has already been lost. The loss of Juniper also endangers over 100 invertebrates and fungi. Many are exclusively dependent on Juniper for their survival.
As you drink your G&T sourced from Mediterranean berries this Christmas, spare a thought for, and raise a toast to the survival of British Juniper.
© Karen Andrews
References and Further Reading
- Botanical Society of Britain and Ireland (?): Axiophytes.
- Plantlife (2022): Juniper, Juniperus communis.
- Plantlife (?): Juniper, Juniperus communis. Species Fact Sheet.
- Plantlife (2022): Saving England’s Lowland Juniper.
- Forest Research (2022): Phytophthora austrocedri disease of juniper and cypress.
- Milner, Edward (2011): Trees of Britain and Ireland. Natural History Museum.
- Thomas, P. A. & El-Barghathi, M. & Polwart, A. (2007): Biological Flora of the British Isles: Juniperus communis L. Journal of Ecology. Vol. 95, Issue 6, pp.1404-1440. 18 October 2007. British Ecological Society.
- Thorogood, Chris & Hiscock, Simon (2020): The botany of gin. Bodleian Library, University of Oxford.
- Walker, Kim & Nesbitt, Mark (2019): Just the Tonic. A Natural History of Tonic Water. Royal Botanic Gardens, Kew. (Chapter 7. The Rise, Fall and Rise Again of the Gin and Tonic. pp 109-121).
- Ward, Lena K. & Shellswell, C.H. (2017): Looking after Juniper. Ecology, Conservation and Folklore. Plantlife, Salisbury.
- Woodland Trust (2022): Juniper (Juniperus communis). British Trees.
- Woodland Trust (2022): Phytophthora austrocedri.
Karen does not seek or receive any commercial interest or advantage from this blog. She is not promoting any business venture. She simply loves to share fascinating facts about plants. These pages illustrate her love of plants, botany, biodiversity, gardens and creative expression. There is always so much to learn about plant diversity. This blog is designed as a showcase for photography, commentary on plants and wildlife, gardens and other places visited, horticulture and related topics. Viewpoints are her own, not those of her employer.