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Click here to go back Details of this species in Raoul Is. Status: Alien Invasiveness: Invasive Occurrence: Present/controlled Source: West, 2002 Arrival Date: Introduction: Species Notes for this Location: Psidium guajava is relatively widespread on Raoul Island, and grows in the greatest concentrations along the slopes near the hostel. Seeds are dispersed by birds. Management Notes for this Location: This species has been subject to an eradication programme on Raoul Island since 1972, and is ranked Category A(i) - known to have the potential to significantly alter the vegetation of Raoul Island. Raoul Island has been divided into 13 weeding blocks for the purpose of controlling and eradicating alien plants since 1972, which make up 64% of the vascular plant flora on Raoul Island. These are divided into active plots which are searched at least twice a year, and null plots which are searched at least once every two years. Grid searching is used to examine the areas with easier access, while steep cliffs are searched using binoculars or a telescope. This is carried out when plants such as Caesalpinia decapetala are in flower (June-November). Aerial surveillance is carried out periodically which has been useful in identifying flowering trees such as Senna septemtrionalis, mature vines of Passiflora edulis or trees of Olea europaea ssp. cuspidata. The initial knockdown phase involved for most species the cutting of mature individuals and painting of stumps with herbicides, or scattering herbicide granules around them. Blanket spraying was used to treat dense, inaccessible infestations. Subsequent searches involve the removal of any seedlings or young plants found. If a mature plant is found, the fruit is removed for burning, the stem is cut and herbicide applied. Information regarding the eradication programme is stored on an Access database. Psidium guajava can resprout vigorously from cut stumps, and may require many applications of herbicide. Less than 100 individuals have been removed since 1997, and all have been removed from Denham Bay. The importation of alien plants to Raoul Island is prohibited. Location Notes: Last Modified: 30/12/2005 3:01:58 p.m.