Weeds growing together may interact and change each other’s impacts on native species. This project focuses on the interactions between woolly nightshade (Solanum mauritianum), brush wattle (Paraserianthes lopthantha), and tree privet (Ligustrum lucidum) and assesses the types of impacts they have on native plants when they co-occur.
The field research aims to understand patterns of weed co-occurrence by surveying the plants growing with each of the three target weeds compared to those growing under native species in Auckland restoration plantings. Shade house experiments will test the impacts of the weeds on mānuka (Leptospermum scoparium) depending on the different combinations of weed species they are growing alongside and then test how mānuka are affected by the removal of different weed species.
Why This Matters
Currently, most weed research is based on single weed species impacts and management. However, managers are dealing with multiple species at sites. This project will guide managers as to which weeds should be prioritised for removal based on how they interact with co-occurring weeds rather than based solely on the risks they pose as an individual weed.
The research will also serve to fill a gap in our knowledge around the prevalence of different types of interactions that weeds have with native species and each other (positive, neutral, and negative).
- Identify weed co-occurrence patterns in the field.
- Measure the impacts of multiple weed species on each other and on native plants.
- Detect differences in impacts and recovery based on removal priority