Globalisation has led to the biological homoginisation of communities, with a relatively few dominant species of alien plants widely introduced around the world. The ability of these plants to establish, support productive ecosystems, and/or naturalise and spread is often contingent on fungi, which either support (e.g., mutualists) or restrict (e.g., pathogens) plant growth. This is particularly evident in island ecosystems, such as New Zealand, where alien plant species form around 90% of the total current flora. Using both sporocarp surveys and molecular methods we have analyzed the fungal associations of a wide range of introduced tree species in New Zealand.
The results show an overwhelming predominance of alien fungi associating with a range alien plants, but also support other mechanisms of maintaining symbiosis. Fungi associating with alien plants form a broad interconnected network, while native plant-fungal associations tend towards a more modular network. We also find some evidence of increased functional stochasticity and loss of functional diversity following introduction. Better understanding of interactions between alien plants and fungi may be key to management of both plant and fungal invasions.