Report to the Kingdom of Tonga on Invasive Plant species of environmental concern

Résumé

The Kingdom of Tonga requested assistance from the US Department of Agriculture. Forest Service,Institute of Pacific Islands Forestry, to conduct a survey of invasive plant species of environmental concern, similar to surveys previously conducted in Micronesia. American Samoa and Niue. The survey was carried out from 5-20 July 2001. The islands of Tongatapu. ‘Eua, Vava'u, Ha'ano, Lifiika, Foa and ‘Uilia were surveyed. The latter four islands are in the Ha'apai group of islands. The survey of Ha'ano was not as thorough as we would have liked because stormy weather forced us to return to Lifnka. The objectives, as with previous surveys, were to: (1) identify plant species that are presently causing problems to natural and semi-natural ecosystems; (2) identify species that, even though they are not presently a major problem, could spread more widely or are known to be problem species elsewhere: (3) confirm the absence of species that are a problem elsewhere and if introduced to Tonga, could be a threat there: and (4) make appropriate recommendations.