Early detection of invasive plant species monitoring plan: Pacific Island Network

Ainsworth, Alison; Gross, Jacob; Simon, Melissa; Jacobi, James; Loh, Rhonda; Harrison, Sky; Berkowitz, Paul; Yoshioka, Joan; Starr, Forrest; Starr, Kim; Loope, Lloyd

This document describes the plan for early detection of incipient invasive plant species within the national parks in the Pacific Island Network (PACN). Oceanic islands are extremely vulnerable to invasion by non-native plant species from continents because of their evolution in relative isolation and in the absence of some of the forces shaping continental organisms. As a result, ecologically disruptive or invasive species are able to completely displace native vegetation and alter ecosystem processes. Non-native plant invasions can also lead to significant economic and cultural costs. By targeting invasions at initial stages, significant costs may be reduced or avoided in the long-term. The PACN early detection program involves 1) repeated early detection field surveys along park dispersal corridors (e.g., roads, trails, fence lines) including other high-risk sites (e.g., parking lots), 2) maintaining a database (NPSpecies) consisting of all species documented in each park, and 3) the development of educational materials such as identification cards and calendars designed to increase park staff invasive species awareness and reporting capability. Field crews knowledgeable of the native flora, will survey sections of corridors and high-risk invasion sites in the parks in order to document non-native plants that are new to the area, or of interest to the park. Documentation will include GPS points, photos of the species encountered, and associated attributes related to the species’ age, abundance, and distribution. Field survey effort will also be documented by GPS. Field surveys under this plan emphasize dispersal corridors and other high-risk sites as these are important areas for non-native plant species transport via humans and animals. Additionally, frequent disturbance along these corridors provides sites for non-native plant species establishment. Information on incipient species found during surveys is communicated with park management to facilitate rapid response efforts. This is a long-term program that uses repeated survey efforts to detect and report new invasive or suspect plants before they become widespread. The timeline and budget developed for this plan are assumed to be on a three-year cycle with field surveys conducted by the Pacific Island Inventory and Management Program. Although a three-year cycle is considered ideal, PACN does not currently have the resources to regularly implement this plan and it will require either an increase in base funding or reduction of other monitoring work to implement it as described. Surveys may also be conducted by PACN, park staff, or contractors opportunistically, as done for the four reported pilot studies in this plan. In all four of these studies, new non-native plant species were identified, locations were provided to park managers, and control efforts were instituted, exhibiting the value of any early detection surveys even when conducted on an opportunistic and sporadic basis. After each field season, the project lead will summarize the information and survey data from that year in a report. Reporting will 1) categorize, map, and describe the incipient species detected during the survey, 2) summarize species attributes (e.g., species richness, life form, reproductive status), 3) explore potential trends related to location of detections (i.e., frequency of detections relative to distance from trailheads and/or populated areas), 4) provide updated status of species identified during previous sampling events (i.e., species now considered widespread and not included in survey), and 5) summarize overall survey effort (e.g., worker hours, distance surveyed, time required to identify unknown species). When paired with rapid response, early detection of invasive species along corridors is a cost-effective way of addressing plant species before they cause long-term damage to park resources and other areas of conservation value.

Early detection of invasive plant species monitoring plan: Pacific Island Network

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