Predicting native plant succession through woody weeds in New Zealand
- Author
- Wotton DM, McAlpine KG
- Year
- 2013
- Journal / Source
- DOC Research & Development Series
- Publisher / Organisation
- Department of Conservation
- Number
- 336
- Pages
- 32 pp
- Keywords
- marram, gorse
- Summary
- It is widely known that gorse (Ulex europaeus) eventually disappears from many areas in New Zealand where native forest is regenerating, but what about the numerous other woody weed species that dominate large areas of the landscape in New Zealand? Are any of them similarly susceptible to competition from native plants in the long term? Very little successional information has been published to date for most of these other species, so the answer to this question remains largely unknown. The aim of this work in progress is to begin to explore options for making general predictions about when and where native succession is likely to replace woody weeds. This information could allow weed managers to achieve conservation goals at significantly reduced cost. We searched the literature for studies about native succession through woody weeds and surveyed Department of Conservation weed managers to discover their understanding, beliefs and behaviour around this issue. We summarise the weed and site attributes that are likely to have the most influence over successional outcomes, and propose a number of options for predicting those outcomes. In general, quantitative data on native plant succession through woody weeds in New Zealand are scarce. For a handful of species it has been shown that native succession will replace the weed population under certain environmental conditions, but it is not known whether this will also occur with most other weed species. Despite these uncertainties, weed managers do make decisions about the likelihood of weeds being replaced by native succession. This study is the initial stage of a research project that will endeavour to reduce uncertainty and allow better decision-making around which woody weed species do and do not require active control in New Zealand.