Document: MON-3-99-149

Vegetation management in Galapagos and Hawaii Archipelagos.

SORIA, M.C.* and M.R.GARDENER

Charles Darwin Research Station, Galapagos 01-3891 Ecuador ¹

Abstract:
Two isolated island ecosystems, Galapagos and Hawaii, have both been severely affected by introduced plants. Hawaii has approximately 4600 introduced plants with 86 classified as serious pests in native ecosystems. The number of native and endemic plants recorded for Hawaii and Galapagos are 1130 and 560 respectively. A larger proportion of these plants are threatened by habitat degradation in Hawaii than in Galapagos. The aim of this paper is to compare invasive weed problems in both archipelagos and discuss management practices. The most invasive weeds can be grouped into four different life forms: 1) Trees such as Psidium guajava, Syzygium jambos and Cinchona pubescens are invasive in Galapagos and Psidium cattleianum, Myrica faya, Acacia sp. in Hawaii; 2) Shrubs like Lantana camara and Rubus sp. are noxious weeds in both archipelagos; 3) Climbers such as Passiflora sp. in both archipelagos and; 4) grasses such as Melinis minutiflora, Panicum maximum and Pennisetum purpureum in Galapagos are aggresive. In Hawaii Pennisetum clandestinum, P.setaceum, M. minutiflora are troublesome. Manual and chemical control methods are used in both archipelagos whereas bio-control has been trialled only in Hawaii. Manual method have been successful in controlling small area whereas a combination of manual and chemical methods have been employed for large scale control. In Galapagos many new chemicals methods have been recently developed and possibilities for bio-control need to be investigated.

Keywords: invasive

This abstract is being presented at: 9:15 AM in session:
Oral Session #60: Forest Restoration.