Margaret Stanley

1. Margaret Stanley Manaaki Whenua – Landcare Research Mt Albert, Auckland stanleym@landcareresearch.co.nz

2. Weed Management What are the goals of weed management? Keep ‘to improve the ecological state of the site’ in mind rather than ‘to control weeds’

3. If you remove a weed, something must grow in its place = often another weed e.g. tradescantia selaginella Replacement Weeds Disturbance promotes weed invasion. Weeds are usually faster at colonising bare ground than natives. Method of Least Disturbance (MOLD) = use the weed control method that causes the least disturbance. MOLD principles allows for the surrounding vegetation to replace the weed.

4. Weed Management Programmes • Weed-led control: • one weed species is controlled throughout the site • usually when there are very small infestations of a very invasive weed   • Site-led control: • all weed species are controlled throughout the site • less chance of replacement weeds invading • at least control all the weeds that have the same growth form/habitat and might be competing with each other (e.g. groundcovers and low-growing shrubs – tradescantia, watsonia, arum lily, etc.)

5. Vines can invade intact forest and overtop the canopy (eg. mothplant, smilax, climbing asparagus, blue morning glory, etc.) Shade tolerant species – weeds that won’t disappear when your canopy is closed (eg. sycamore, acmena/monkey apple, figs) Woody weeds in wetlands – weeds that can overtop low-growing wetland plants (eg. alder, grey willow) Weed Management Programmes Prioritise – which weed?

6. core Weed Management Programmes • Satellite vs core infestations: • always control the smallest infestations (satellite infestations) first and work towards the largest (core) infestations. Satellite infestations have the greater potential to become bigger, faster. Controlling all the small satellite infestations is the best way to contain the weed.

7. core Weed Management Programmes • Satellite vs core infestations: • always control the smallest infestations (satellite infestations) first and work towards the largest (core) infestations. Satellite infestations have the greater potential to become bigger, faster. Controlling all the small satellite infestations is the best way to contain the weed.

8. BUT – when in doubt, control small, satellite infestations first!! Know your weed! • some weed species fruit prolifically only when on edges of forest remnants (ie. more light). Start control of these species from the edges and work in (e.g. wild ginger). • advice for weeds with re-sprouting fragments is start upstream and work down (e.g. tradescantia and willow) • try to control weeds before the fruit/set seed. If this is not possible, try to remove flowers/fruit (without spreading them!!)

9. Follow-up control It is critical to follow-up any weed control with surveillance and control of seedlings and ‘the bits you missed’ Removal of mature plants often results in a flush of seed germination Follow-up surveillance and control must be done regularly and persistently – you must be in for the long haul!!

10. Mapping weeds, systematically recording weed density and distribution, re-mapping and recording over time Monitoring Monitoring shouldn’t be an afterthought! • Recording this data gives you: • changing trends in weed infestations • an ability to alter weed management strategies • some measure of success - evaluation of weed control • an ability to detect new invasions rapidly and eradicate the small infestation before it gets too big!! Surveillance for new/small infestations is critical

11. e.g. • stop nutrient runoff into site • maintain natural water flows • get canopy closure: reduce light • tracks: keep narrow & well-shaded and/or dense shrubs on borders Site Management Why is this site weedy? Why are conditions favourable? Light? Water? Nutrients? Disturbance (bare ground)? How can we change site conditions to exclude weeds or reduce their density/impact?

12. Weed Hygiene Be aware that you could be spreading weeds within your restoration site!!! e.g. fragments and seeds on clothes and boots • try to maintain some sort of hygiene regime – don’t undo all the hard work!! • check with council on best ways to dispose of particular weeds

13. Weedy Advice Regional councils - fact sheets on all the common weeds in your region: contain info on the weed and the best ways of controlling them (manual, chemical, biological). DOC’s Weed Manager - info on conservation weeds and the best ways of controlling them (manual, chemical, biological). Weedbusters - get the local community more involved

14. Weeds Education Website www.landcareresearch.co.nz/education/weeds Weeds in New Zealand! Home Information Resources Teacher Resources Activities Glossary • books • posters • videos • websites • people • wordfind • crossword • match quotes • curriculum links • unit plans • learning experiences • assessment • worksheets • facts • impacts • ecology • control

15. Tradescantia – Brazil (native range) Tradescantia – NZ A Biocontrol programme for tradescantia has started…..