Phytophthora austrocedri is now endemic in the UK, further threatening juniper (Juniperus communis s. l.): a keystone species already undergoing long-term population declines. With little existing knowledge about the specific host-pathogen-environment interaction and few resources dedicated to disease detection, where should conservation effort for this keystone species be prioritised?

Our results show that management for juniper - such as grazing regulation, scrub clearance and creation of sites for natural regeneration - should be prioritised for stands growing in drier microsites. Disturbance of soil in wetter microsites should also be controlled, to maximise the resilience of existing juniper populations and limit disease spread.