PDF《Invasive plant species on Kosrae,》

4 Momordica charantia (bitter-melon), a member of the cucumber family, is a climbing vine and its fruit can be the host for fruit flies. It is present on Pohnpei, Chuuk and Guam. Passiflora foetida is present on Kosrae, but several invasive members of this invasive genus are absent, including: ? Passiflora mollissima (banana poka), a smothering vine that is a problem in Hawai'

i and New Zealand. ? Passiflora suberosa (wild passionfruit, devil'

s pumpkin or indigo berry). ? Passiflora laurifolia, Passiflora ligularis, Passiflora maliformis, Passiflora quadrangularis and Passiflora rubra. Passiflora quadrangularis is present on Pohnpei. Piper auritum (eared pepper, locally called false sakau ), recently introduced to Pohnpei. This species suckers profusely and produces many small seeds that are spread by birds, rodents and bats. An attempt is being made to eradicate it on Pohnpei. It was introduced into Pohnpei as a new form of sakau, but is worthless in this regard. Pithecellobium dulce (Madras thorn), on all the other major Micronesian islands but apparently not yet present on Kosrae. Psidium cattleianum (strawberry guava), a small tree that forms dense thickets, is a major problem species in Hawai'

i, Tahiti and elsewhere. It is present on Pohnpei and thus is a serious threat to Kosrae. Spathodea campanulata (African tulip tree), a commonly planted ornamental present on Pohnpei, Chuuk and Guam. This tree has become a major problem in Fiji, the Hawaiian Islands and some other places. It was not seen on Kosrae and it would be good to exclude it from the island. Tibouchina herbacea (glorybush or cane ti), another species that is a major problem in Hawai'

i. The best indicator that a species might be invasive is the fact that it is invasive elsewhere. However, each island ecosystem is unique, and invasiveness cannot be predicted with certainty. A good strategy is to be extremely cautious and exclude these and other species known to be invasive or weedy elsewhere (although an even better strategy, now being adopted by countries such as Australia and New Zealand, is to exclude all species not shown by risk analysis to be of negligible risk). Known problem species that have the potential to cause problems in tropical island ecosystems and are not yet present on Kosrae are listed in Appendix 2, Table 1. These species should be excluded through plant quarantine and, if establishment is detected, promptly evaluated for eradication. In addition, species that are present in Guam, Pohnpei and Hawai'

i but are not present on Kosrae are listed in Appendix 3. There is high risk of introduction of these species because of air and ship traffic between these points and Kosrae.

5 2. Species that are invasive elsewhere and are likewise invasive or have the potential to become so on Kosrae Some known invasive plants that are causing trouble in similar ecosystems have been introduced into Kosrae (Appendix 2, Table 2). Some of them are already causing problems while others are not. Some are cultivated plants that have not (yet) escaped and their potential for causing damage is so far unknown. However, one of the best predictors of invasiveness is the behavior of the species elsewhere, and these are known troublemakers. Adenanthera pavonina (the coral bean tree), invasive in secondary forests and already widespread on Kosrae. Chromolaena odorata (Siam weed), a highly invasive pan-tropical weed. It will likely become even more widespread over time. Biological controls are available that are effective in open areas, less so in shaded stands. On Kosrae it is likely to follow new developments such as roads. Clerodendrum quadriloculare is suspicious because it appears to have the ability to invade intact or relatively intact n........