Common juniper ‘in a pickle’

Juniper populations in the UK have declined significantly over the past forty years, making juniper the subject of a UK Biodiversity Action Plan and a Species Action Plan

News from Forest Research: November 2009

Purple plump juniper berries

Early results from seed research indicate new ways to boost struggling populations.

The decline in juniper populations is mainly due to a lack of natural regeneration, which is attributed to poor seed quality and a shortage of suitable micro-sites for germination and establishment. Nursery production offers a means of bolstering these declining juniper populations, but propagation is still difficult as juniper produces a large proportion of empty seeds, which makes nursery production inefficient and thereby expensive.

Last year, a joint project was started with Frances Graham of the Yorkshire Dales National Park Authority focusing on three juniper populations. This research aims to understand the reproductive biology of juniper, to improve seed lot quality by effective processing (to remove empty seeds) and to improve seed performance by adequate pre-treatment (to break dormancy).

Early results show that seed quality varies significantly between the three populations, with the proportion of empty seeds ranging from 0–96%. Results also show that properly processed and pre-treated seeds from the ‘best’ population germinate relatively rapidly, with up to 70% germinating within 40 weeks. Further research is underway to ‘scale-up’ processing and fine-tune pre-treatment of juniper seeds.

It is hoped that this research will be a significant step towards the successful regeneration of juniper populations in the UK.

For more information contact Shelagh McCartan.


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This and other news stories can be found in the November 2009 issue of FR News, our online newsletter.