A new study from Murdoch University reveals how an invasive plant pathogen cascades through an ecosystem to harm native Australian mammals. Phytophthora dieback, a soil-borne fungus introduced from overseas, degrades jarrah forests in Western Australia by killing understory plants. This destruction reduces habitat quality for quendas, small marsupials that dig extensively through leaf litter and soil to forage.
Researchers led by scientists at Murdoch University documented that quendas decrease their digging activity in degraded forest patches where Phytophthora dieback has taken hold. The disease essentially strips away the vegetation layer that quendas depend on for both shelter and food sources. With fewer plants present, quendas face reduced foraging opportunities and spend less time excavating the soil.
The study, titled "Exotic Plant Pathogen Reduces Habitat and Foraging Activities of a Digging Mammal," appeared in the journal Austral Ecology. The findings demonstrate an indirect ecological pathway through which introduced pathogens harm wildlife, extending beyond direct predation or disease transmission. Instead, the pathogen alters physical habitat structure, triggering behavioral changes in dependent species.
This mechanism has broader conservation implications for jarrah forest ecosystems, which support numerous endemic and vulnerable species. Quendas themselves face conservation challenges, making them sensitive indicators of forest health. The research underscores how a single invasive pathogen can ripple through multiple trophic levels, affecting everything from plant communities to animal behavior.
The study adds to growing evidence that controlling invasive Phytophthora dieback remains critical for maintaining Western Australia's unique forest biodiversity. Current management focuses on hygiene protocols and quarantine measures to prevent further spread. Understanding the full ecological consequences of this pathogen helps prioritize conservation resources and informs landscape management strategies for protecting both habitat structure and native fauna.