Weeds at the Early Stage of Invasion (WESI)

Invasive species management, including weed management, is an integral component of any landscape or reserve scale conservation program.  The benefits of a preventative and early intervention approach has been adopted in many parts of the world with great success.

About the WESI Project

The WESI Project was created to promote these benefits and enable us, with Parks Victoria public land managers, to adopt this approach.

WESI focuses on high risk invasive species that threaten biodiversity when they are at the early stage of invasion. Together we look after public land across Victoria.

WESI is funded through the Weeds and Pests on Public Land Program.

Weed management including eradication

Weed activities fall into four broad categories: prevention, eradication, containment and asset-based protection.

Better understanding of these different management approaches, means public land managers can make informed decisions, invest resources wisely, and have better biodiversity outcomes.

Eradication is the elimination of every single individual (including propagules e.g. seeds and buds) of a species from a defined area in which recolonisation is unlikely to occur.

What is 'at the early stage of invasion'?

Weeds, at the early stage of invasion (early invaders), are plants that have naturalised and started to spread.

Naturalised plants are non-indigenous species that sustain self-replacing populations for several life cycles without (or despite) human intervention

When spread has just begun, such plants are not at all widespread and are generally encountered only by chance, unless specifically targeted by search efforts.

Co-ordinated management intervention, i.e. eradication or containment, is at its most feasible for plants at this stage of invasion, owing to their highly restricted distributions.

The WESI project has developed a decision making framework that guides public land managers through the process of dealing with invasive plants at the early stage of invasion. The following six guides describe the components of the framework. By using all the guides in the series, public land managers can improve their decision making. The guide series provides step-by-step information to plan and undertake work.

Tools

Regularly searching for weeds at the early stage of invasion is a good way to prevent the next widespread weed.

We have created this guide to assist you when searching for and detecting weeds at the early stage of invasion. It also contains information on how to organise a search, and where and what to look for.

Looking for weeds: search and detect guide  (PDF, 1.6 MB)
Looking for weeds: search and detect guide (Accessible) (DOCX, 275.9 KB)

As we travel around our local patch, we become familiar with the common weeds. Occasionally, something new or unfamiliar catches our eye. This guide has been designed to assist in finding out what an unfamiliar plant is. It may be a weed at the early stage of invasion in your area.

Looking for weeds: name and notify guide (PDF, 1.1 MB)
Looking for weeds: name and notify guide (Accessible) (DOCX, 213.7 KB)

If you have found an unusual weed and worked out what it is, you will need to establish if it has potential to be a future problem. .  The follow guide can assist you to assess the risk. Managing for weeds: assess the risk guide 

Managing for weeds: assess the risk guide 

The Victorian environmental weed risk database contains risk ratings from a number of sources. When weeds do not have a risk rating, an environmental weed risk screen can be carried out (summarised in the guide above).

The development of the risk screen is described in this report:

Environmental weed risk screen for Victoria: Background and development (PDF, 1.1 MB)
Environmental weed risk screen for Victoria: Background and development (Accessible) (DOCX, 246.2 KB)

Once you have identified a high risk weed, you need to find out how far the infestation has spread. Knowing this information will provide clarity on the scale and task ahead for managing the infestation.

Looking for weeds: delimiting survey guide (PDF, 1.4 MB)
Looking for weeds: delimiting survey guide (Accessible) (DOCX, 240.2 KB)

You should establish if you need to eradicate the weed, contain it, control it sufficiently to protect the biodiversity values, or monitor it?

The following guide has been designed to assist you to make these decisions.

Managing for weeds: decide the response guide (PDF, 950.2 KB)
Managing for weeds: decide the response guide (Accessible) (DOCX, 219.6 KB)

If eradicating a weed is a feasible aim (removing it completely from your patch), having a plan improves your chances of success. This guide will assist you to plan and carry out eradication works.

Managing for weeds: eradication response guide  (PDF, 1.1 MB)
Managing for weeds: eradication response guide (Accessible) (DOCX, 262.1 KB)