Recruitment failure of keystone trees in Phytophthora infested forest

Invasive plant pathogens cause considerable forest loss worldwide. However, little is known about how tree populations recover post‐invasion. In Western Australia, Phytophthora cinnamomi ‘dieback’ affects jarrah ( Eucalyptus marginata ), with historical records of mass deaths in this keystone tree species due to infestation, resulting in permanent loss of standing forest. Historical observations of marri ( Corymbia calophylla ), a co‐dominant keystone jarrah forest tree, suggest it is resistant to P. cinnamomi . Impacts of P. cinnamomi on the population dynamics of jarrah and marri are unknown. We recorded densities and stem diameters of jarrah and marri in a peri‐urban forest to examine their population demographics in >60‐year‐old P. cinnamomi infestations compared with adjacent non‐infested forest. While seedling (