UK: The first in-depth study of a rare juniper
25.03.11
Scientists in Cornwall have accurately mapped the population of a rare juniper subspecies confined to the Lizard peninsular, Juniperus communis ssp. hemisphaerica, for the first time, and produced a management plan for its ongoing conservation.
Gew Graze on the Lizard peninsula is the only known site for the rare Juniper
Dr Alistair Griffiths and Rosemary McClenaghan of the Eden Project, in partnership with local experts, succeeded in mapping the very rare plant, which was previously thought to be limited to 10 individuals. Despite having a much larger range in the past plants were only found on one historic site - Gew Graze - but because two new plants were found in June 2010 by Andy McVeigh and Julia Carey the total number has been revised upwards. However, positively identifying individual plants proved rather problematic as Dr Griffiths explains: "Probably only a detailed genetic study will accurately identify how many individuals there are on the cliffs of the Lizard or if indeed hemisphaerica is a distinct sub species."
Two new plants were discovered on this rocky slope in 2010
Another mystery solved by the team was of uncovering the fate of some plants re-introduced to Mullion Cliff's National Nature Reserve in 1982 by Bristol University. Apparently the plants were destroyed sometime in the 1980s when a flare shot during a lifeboat demonstration on Mullion Regatta Day landed in the middle of the plants and set fire to the coastal grasslands. A second introduction was attempted by Bristol University, however no consultation with English Nature (now Natural England) was carried out and, instead, the plants were taken to Poltesco National Trust Volunteer House garden. These specimens are no longer in the garden meaning not a single example of the university's fated reintroduction programme can be located...
But Bristol's progeny aren't the only plants to have suffered at the hands of fire. In 1959 Erica vagans and Ulex europaeus bushes were accidentally burned and the fire
stopped short by only a few centimetres from juniper plants on the Lizard. There also used to be several plants on the Rill between Kynance and Gew Graze and a single upright bush at Kynance Gate - all of which are thought to have met flamey ends.
Other causes of decline in the population seem to point to cattle damage and lack of natural regeneration. Highland cattle were introduced to the cliffs of the Lizard to keep control of the scrub, while allowing the extraordinary local flora to flourish. Although Gew Graze has been grazed since 1939 unfortunately the Highland cattle took a fancy to the rarity, which led to English Nature putting electric fences around all the plants in 2003.
This extensive study of the extant plants led to some significant breakthroughs in the conservation of the taxon. Because of the historic evidence of fire damage it is recommended that fire management techniques are employed on Gew Graze, while simultaneously carrying out annual management on the surrounding scrub. By keeping the areas of ground adjacent to the plants free of gorse and heather there should be less chance of fire damage and it should also improve the chances for any seedlings in the locale.
The project team inspecting a Juniper enclosure
Arguably the most significant development is that all wild plants now have a clone growing in the Eden Project nursery and a propagation protocol has been produced. Cuttings will be taken in five yearly intervals from each wild plant and
three plants of each individual wild plant will be maintained ex situ. The five year
collection time period is suggested to reduce the risks of genetic shifts in both the
wild and the ex situ plants.
The Juniper clones are being grown at the Eden Project nursery
As well as looking after the existing plants propagated individuals from Gew Graze will be planted on old historical sites, under the guidance of Natural England and Plantlife, and with the agreement of landowners and receptor sites should be appropriately managed for the survival and natural regeneration of the juniper. Naturally the team are hoping for better luck that the Bristol University project!
Download the full report (pdf)
Related links:
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