Comparison of Invasive Plant Management Treatments including Prescribed Burn on Populations of Daphne laureola at Canadian Forces Ammunition Base, Rocky Point, Metchosin, B.C.

Abstract

The Department of National Defence and other European settlers have suppressed natural and cultural fire at Rocky Point in Metchosin since the 1850s. Suppression of natural fire regimes harms Garry oak ecosystems and allows for invasive species such as Daphne laureola to overrun native vegetation. Established communities of Daphne laureola are barriers to the restoration of Garry oak ecosystems. A prescribed fire program has been ongoing at CFAD Rocky Point since 2017, with the intentions of managing invasive species, reducing fuel loads, and promoting native seed establishment. The efficacy of this program for invasive management had previously not been monitored. The goal of this study was to evaluate prescribed fire as a management treatment for Daphne laureola. Daphne laureola plants were counted before and after invasive management treatment at four sites within the planned burn area. Three of the sites were unable to burn, so additional treatment methods were applied to Daphne Laureola. One site was a control, receiving no treatment, the other treatments were manual removal and weed torch. Daphne Laureola at the sites were recounted the following spring to determine how many plants survived. The prescribed fire treatment was just as effective as the standard manual removal treatment for Daphne Laureola. Based on the comparison of results from various treatments, the needs of the land managers and additional parties involved, the ecosystems present at the site, and the constraints of access to the site, prescribed burn is the recommended invasive management technique for controlling Daphne Laureola at CFAD Rocky Point. The prescribed burn program is likely to be successful in managing Daphne laureola populations if continued, and additional management techniques are used on an as-needed basis.