Author
Ben Gooden
ben.gooden@csiro.au
CSIRO
Canberra
Coauthors
Isabel Zeil-Rolfe, CSIRO, Canberra, Australia
Gavin Hunter, CSIRO, Canberra, Australia
Louise Morin, CSIRO, Canberra, Australia
Abstract
Biological control research often focuses on agent efficacy, yet the pathways of native ecosystem recovery remain unclear. Our work shows that increases in native species richness alone are insufficient to benchmark recovery. Instead, we advocate for tracking compositional change towards native reference states, revealing that recovery trajectories are highly context-dependent. We illustrate this with a multi-year, multi-collaborator case study on the biocontrol of wandering trad (Tradescantia fluminensis) in eastern Australia. Following establishment of the foliar pathogen Kordyana brasiliensis, we observed rapid and sustained declines in wandering trad (up to 80 % reduction in weed volume within 5 years), with some plots achieving near-complete suppression. These declines were linked to high pathogen infection and influenced by climate. Importantly, trad reduction was associated with significant increases in native species richness, while secondary invasion by alien plants remained limited. However, the magnitude and speed of native recovery varied with site conditions, and compositional shifts towards reference communities were context-dependent. Our findings highlight the need for context-aware, multi-metric monitoring to truly evaluate biocontrol success for ecosystem restoration, and the value of collaborative, long-term research.
keywords
Restoration monitoring
Community composition
Secondary invasion
Climate variability
Pathogen impact
Highlights
Biocontrol of wandering trad boosts native richness, recovery rate varies with context
Richness alone can’t benchmark recovery, compositional change to reference is essential
Multi-metric, context-aware monitoring is vital for evaluating restoration success