Ka Wai Ola - Office of Hawaiian Affairs, Volume 15, Number 1, 1 January 1998 — WKDING OUT INVADERS [ARTICLE+ILLUSTRATION]

WKDING OUT INVADERS

By Paula Durbin ALIEN PLANT invasions are a worldwide eoneem, but nowhere have they reached the magnitude seen in Hawai'i. So it's no surprise that an intemational I cadre of scientists travels around the i state trying to figure out how so mueh of : Hawai'i became overgrown with vegeta- : tion introduced relatively recently

; trom Asia, the continental i United States and Cen-

: tral Amenea. : Among the ; botanists at work A

: are Guillermo : Goldstein from : Argentina, a ; full professor i of botany at : the University : ofHawai'i, i and Zdravko : Bamch of the

; department of envi- ; ronmental studies of

: Simon Bolivar Universi- : ty in Caracas, Venezuela. ; For two years they have been

: studying the proliferation of noxious : weeds - in layman's terms, noxious i means obnoxious — such as the notorious ; mieonia, brought here in the 1950s as an i omamental plant, and a nuisance omi- : nously called Koster's curse. The project : is affiliated with the University of ; Hawai'i Cooperative Park Studies Unit, : directed by Dr. Clifford Smith. j "This invasion phenomenon also is the : story of the Venezuelan savannahs," said ; Baruch. "The plants are brought in j intentionally, for cultivation, or unintenj tionally, on clothes or shoes, for examj ple. If they get loose, they ean be danj gerous. They ean bring changes whieh

are not always for the better - in the native vegetation and in the surrounding environment, including animal life." Hawai'i's remote location might have contributed to the fragility of its plant life. "Hawai'i is the most isolated archipelago in the world," Bamch explained, "the farthest ffom any other land mass. People think that because Hawai'i is tropical, it must have a big variety of plant species, but loeal plant diversity is realtively low." Some species thought _ of as native are not verv

"plastic," meaning they don't have the abilitv

to adjust to differ- , ent environments.

A current theory of ecology holds that alien plants might thrive on nutrients that native plants don't ise. "There are

' places where the natives are very

Y well adapted, very strong and new plants

can't invade," said Goldsfpir> "fnr PYfimnlp in flnw«

where there are few nutrients and the soil is not developed." But in lush areas such as the rain forests, mainland and Asian species do well. Goldstein and Bamch's research has focused on the basic biology of noxious weeds and their use of water, light and nutrients. They have studied these aliens in U.H. greenhouses and in the wild on the Big Island. "The question is why they grow so efficiently that they are capable of replacing native plants," said Goldstein. He and Bamch hope the results of their work will soon assist in decisionmaking on the direction and control of invading plants. ■