Prevention strategies are not perfect and may only interrupt a percentage of weed introductions. Long-term protection of weed-free rangelands relies on continuous monitoring to detect and remove invasions as they establish. This is critical, as small weed populations can spread quickly. Successful detection of new weeds in WPAs includes the following steps:
- Establish high- and low-risk sites based on invasion susceptibility.
- Design early detection surveys based on the invading plant and the invasion risk of each site.
- Survey and re-survey sites based on an optimal frequency of re-surveillance.
- Develop a mapping process to record new invasions and document weed-free areas (see “Early Detection Surveys” below).
- Develop passive monitoring networks consisting of user groups that access remote areas (see “Early Detection Surveys” below).