Likely and potential biodiversity impacts associated with infection of Bilberry

Damage caused by Phytophthora @ Forestry CommissionThe biodiversity impact of Phytophthora infection is potentially extremely high.  Infected bilberry suffers very extensive dieback.  Over 60% of 10km grid squares in the UK contain native bilberry, and in many areas bilberry forms a dominant component of the vegetation.  Heathlands, acid woodlands and uplands will be particularly affected.  If other native species, in particular heather, were to become infected then potential impacts could be even more widespread.


Seven of the Annex I Habitats Directive habitats contain bilberry as a major component of the vegetation.  A large number of SSSIs contain heathland types as interest features, and the loss of bilberry would lead these features to be assessed as unfavourable.  A considerable number of species are directly or indirectly dependent on bilberry.  The Phytophagous Insect Data Bank lists 113 species as feeding on bilberry, bearberry and heather.  42 appear to be entirely or mainly associated with the ericaceous shrubs known to be highly susceptible, and three of these are BAP species (Small Dark Yellow Underwing Anarta cordigera; Northern Dart Xestia alpicola and Argent & Sable Rheumaptera hastata - all moths).  Two more another moth, the Scotch Burnet Zygaena exulansand the possibly extinct shield bug Elasmucha ferrugata) have British Red Data Book statuses.  Indirect relationships with bilberry include that of the BAP butterfly, the heath fritillary Melitaea athalia at some sites.


A number of ecosystem services would be likely to be impacted by the loss of a dominant habitat component such as bilberry or heather.  Recreational services would be particularly affected.  Additionally, soil stability and hence water quality could be affected, as well as primary production, nutrient cycling and food provision.


JNCC has carried out predictive distribution modeling of Rhododendron and Bilberry to help predict the impact of Phytophthora infection.