COURTESY PHOTO
On the Big Island Mark Nadybal recently pulled down a 12-foot- Miconia tree. A UH professor says a system he helped develop would have prevented the plant from entering Hawaii.
Plant screening WAILUKU >> State and federal researchers have completed a study that proposes a new way of screening plants to determine if they should be imported into Hawaii.
reviews mixed
Backers say a plan will keep out pests,
but critics say no new laws are neededBy Gary T. Kubota
gkubota@starbulletin.comBut some horticulturists are worried the new system may also restrict trade of imported plants and add to the cost of government.
Those in favor of a new system point out that the state already spends millions of dollars each year to control alien plants that have been allowed into the islands.
One of the major plant pests is Miconia calvescens, which has destroyed about 70 percent of the Tahitian rain forest and is now threatening native forests on Maui and the Big Island.
The $100,000 study, funded by state and federal forestry agencies, was developed in light of criticism about the screening system for imported plants in Hawaii.
The Hawaii system currently rejects plants that are on the state Department of Agriculture's list of noxious weeds. But critics note the list, developed to protect the sugar cane and pineapple industries from noxious weeds, has only about 80 plants. They say a number of plants harmful to the native forests are not on the list.
Critics also say putting a plant on the noxious-weed list takes several years, during which time an alien plant can establish itself in Hawaii.
The proposed system would have a list of plant species approved for importation into Hawaii. If the plant is not on the list, it would have to undergo a scientific review based on a scoring system that determines its likelihood of being a major pest.
University of Hawaii professor Curtis Daehler, one of the researchers, said the new system is a modified version of the weed risk assessment system that has been used for several years in Australia and New Zealand.
Daehler said the system would score a plant's potential for becoming a pest in Hawaii based on researched responses to 49 questions.
He said researchers would look at a number of variables, including its ability to produce seeds and grow at different elevations.
A plant such as Miconia that produces millions of seeds a year and has the ability to grow at a broad range of elevations would generally receive a high score that would prevent it from entering Hawaii, he said.
In contrast, a plant like the plumeria with limited number of seeds and ability to grow only in warm weather would score low as an invasive species, researchers said.
Daehler said the study scored about 200 plants and found that some plants currently in Hawaii might become major pests, such as Darwin black wattle and Australian cheesewood.
The study advised officials to keep a careful watch on these potentially invasive species in Hawaii and perhaps look for substitute plants whenever landscaping an area.
To check the scoring system, researchers compared the results drawn from the screening system with assessments from 18 botanists and weed scientists.
Daehler said the rating system correctly identified 95 percent of the major pests, as judged by experts.
He said among species rated as nonpests by experts, 84 percent were given the same rating by the system.
Daehler and U.S. Forestry Service research ecologist Julie Denslow said they are working with plant growers in Hawaii to develop a voluntary system of controlling importation of plants.
Under the system, growers would check the list from the study before importing a plant.
Lelan Nishek, acting president of the Kauai Landscape Industry Council, said he feels the state should focus on educating the growers and the public at large before considering any legislation.
"Hopefully, it can be self-policing. We don't need more laws to do this and do that," he said.
Randy Bartlett, chairman of the Maui Invasive Species Committee, said he feels the system should be made mandatory and that the state Legislature needs to enact a law requiring it.
"It's not going to work on a voluntary basis," Bartlett said. "Unless the Legislature forces the state Department of Agriculture to mandate it, I don't think the Department of Agriculture is going to force people to do it."
Bartlett said Australia and New Zealand tried a voluntary system and eventually had to enact a mandatory screening process.
State forestry Administrator Michael Buck said he feels the state eventually will have to adopt the new system as a requirement either through regulation or by law.
But Buck said a balance has to be struck to protect the environment while at the same time allowing trade.
For a more detailed description for the system, including results for 178 species in Hawaii, Daehler has a Web site at www.botany.hawaii.edu/faculty/daehler/wra.
U.S. Forestry Service
Department of Agriculture
