Evaluating reintroduction methods for the Gulf of Saint Lawrence aster (Symphyotrichum laurentianum) on Prince Edward Island

Abstract

The Gulf of St. Lawrence aster (SLA; Symphyotrichum laurentianum (Fernald) G.L. Nesom) is an annual plant species endemic to the Gulf of St. Lawrence region. Owing to the dynamic nature of the environment that the SLA inhabits, severe and major threats to both the aster and its habitat exist. The Committee on the Status of Endangered Wildlife in Canada listed the species as threatened in Canada in 2004. This status was assigned based on the species' limited distribution, fluctuating population size, and continued pressures on its habitat. Surveys have revealed that both site and population numbers have been further and drastically reduced on Prince Edward Island. In 2007, only one populated site of 482 individuals remained. It is possible that this species has been extirpated from Prince Edward Island. Recovery of this species on Prince Edward Island is feasible. Promising results related to seeding and the transplantation of greenhouse-grown seedlings at four in situ sites demonstrated that SLA plantlets have the potential to serve as seed stock to re-establish populations. Over the 2 years of the transplantation experiment, the pooled overall survivorship was 52.8%. Specific site manipulations that were tested may also increase the potential survivorship of the transplants and facilitate second-generation germination.