RA3A PAPER: Native forest plant pathogen ...

Plant-pathogen management in a native forest ecosystem

June 2023

Mainwaring JC, Vink JNA, Gerth ML. 2023. Plant-pathogen management in a native forest ecosystem. Current Biology 33(11): R500-R505.

ABSTRACT

Forest ecosystems all over the world are facing a growing threat from plant-disease outbreaks. As pollution, climate change, and global pathogen movement intensify, so too do the impacts of forest pathogens. In this essay, we examine a case study of the New Zealand kauri tree (Agathis australis) and its oomycete pathogen, Phytophthora agathidicida. We focus on the interactions between the host, pathogen, and environment — the building blocks of the ‘disease triangle’, a framework used by plant pathologists to understand and manage diseases. We delve into why this framework is more challenging to apply to trees than crops, taking into account the differences in reproductive time, level of domestication, and surrounding biodiversity between the host (a long-lived native tree species) and typical crop plants. We also address the difficulties in managing Phytophthora diseases compared to fungal or bacterial pathogens. Furthermore, we explore the complexities of the environmental aspect of the disease triangle. In forest ecosystems, the environment is particularly complex, encompassing diverse macro- and microbiotic influences, forest fragmentation, land use, and climate change. By exploring these complexities, we emphasize the importance of targeting multiple components of the disease triangle simultaneously to make effective management gains. Finally, we highlight the invaluable contribution of indigenous knowledge systems in bringing a holistic approach to managing forest pathogens in Aotearoa New Zealand and beyond.

KEYWORDS

Plant-pathogen management; Native forest ecosystem; Disease triangle; Phytophthora agathidicida; Environmental complexity; Indigenous knowledge systems; Forest fragmentation; Climate change; New Zealand kauri tree; Reproductive time