Bill Durston is almost sold out of Australian tree ferns at his Leilani Nursery in Waimanalo. The fern, which closely resembles native hapu`u, is a popular tropical landscape plant. While it’s made up a big chunk of his farm’s revenue in the past, he won’t restock once he sells out, he says.
The Australian tree fern is one of seven invasive plant species that Durston, as a member of the O`ahu Nursery Growers Association, has agreed not to sell anymore. As part of a Code of Conduct the association members signed late last year, they will no longer sell Australian tree fern, rubbervine, smokebush, glorybush, butterfly bush, mule’s foot fern, and Pampas grass. They have also agreed to use a tool called the Hawai`i Pacific Weed Risk Assessment (WRA, for short) to screen new plants for invasiveness before they import or market them, and to work with and support researchers at the University of Hawai`i’s College of Tropical Agriculture and Human Resources to develop sterile plant varieties of popular invasive ornamentals.
The association, which is made up of about seven nurseries, including some of the largest in the state, has recognized that certain nursery species pose a threat to Hawai`i’s environment, says ONGA member and Nature’s Plants nursery owner Ken Welter, who adds that the move is also good public relations. (The nursery industry has been linked in the press to many of the major environmental pests in Hawai`i, including the coqui frog, the wiliwili gall wasp, and `ohi`a rust.)
ONGA — which includes Waihale Products; Charles Nii Nursery, Inc.; R & S Nii Nursery; Olomana Tropicals; Koguchi Orchids; and Leilani Nursery, Inc. – is the first group of nurserymen in the state to adopt a code of conduct regarding the sale of invasive plants.
For years, local scientists and government-related agencies have been trying to coax the landscape, nursery, and horticulture industries (through public meetings, panel discussions, etc.) into joining in the fight against the spread of invasive species in Hawai`i, with little obvious success.
Mindy Wilkinson, coordinator for the state’s Hawai`i Invasive Species Council, which provides millions of dollars each year to various control and prevention projects, says that of the $19 million spent on conservation-related invasive species control each year, some $15 million is spent on invasive plant-related issues, including roughly $1.5 million for rapid responses to plant invasions by various island invasive species committees. Because research has found that 91 percent of these plants were intentionally introduced by local plant growers, many feel that the cooperation of these “green” industries is crucial to winning that fight.
The way Durston tells it, it wasn’t that hard to get ONGA to join the cause: Christy Martin, public information officer for the state’s Coordinating Group on Alien Pest Species, asked him to be the first nursery owner to adopt a code of conduct. He raised the idea with his fellow ONGA members, and they decided to do it.
In truth, getting nurseries or landscapers to go along with efforts to reduce the sale of invasives has been far from easy.
In December 2001 and again in April 2005, at annual meetings of the Landscape Industry Council of Hawai`i, participants discussed the issue of invasive plants, the landscape industry’s role in controlling their spread, and pros and cons of developing a code of conduct, among other things. And although the Landscape Industry Council of Hawai`i has posted several examples of codes of conduct on its website, it has not endorsed one.
“It takes a lot of massaging,” says Teresa Trueman-Madriaga, who heads the state Department of Land and Natural Resources’ Kaulunani Urban Forestry Grant Program, which is where much of today’s effort to control plant sales got its start.
Many in Hawai`i have heard about the state’s struggle to control miconia (an introduced landscape plant that has taken over and devastated 75 percent of Tahiti’s forests) or how the state spent millions of dollars clearing “the green monster,” Salvinia molesta, from the surface of O`ahu’s Lake Wilson. But it wasn’t until a few years ago that the state had the ability to accurately determine whether or not a plant species posed a threat to Hawai`i’s ecosystems.
With funding from the USDA Forest Service and state Division of Forestry and Wildlife, the Hawai`i-Pacific Weed Risk Assessment, adapted from Australian and New Zealand models by University of Hawai`i professor Curt Daehler and Forest Service botanist Julie Denslow, was created to fill that gap. Trueman-Madriaga says that a few years ago, in the course of evaluating tree-planting grant proposals for the Kaulunani program, “We decided we should know what’s invasive [before giving
money to people to plant trees]…The Weed Risk Assessment (WRA) was created for that.”
While today the Kaulunani program uses the WRA in its grant evaluation process, the WRA has not been widely embraced by the private sector.
Daehler’s graduate students have run some 500 non-native species in Hawai`i through the WRA and assigned each plant a score denoting how likely it is to become invasive. All of this information has been posted on the web at [url=http://www.botany.hawaii.edu/faculty/daehler/WRA/full_table_d.asp]www.botany.hawaii.edu/faculty/daehler/WRA/full_table_d.asp[/url]
At the same time, CGAPS and DOFWAR’s Carter Smith have held meetings and workshops with the landscape industry on invasive species and the WRA across the state.
Despite the effort and the fact that the WRA has no regulatory authority, Denslow says the industry remains hesitant to use it.
“We’re providing risk assessments. We post it [on the web]. Anyone can consult that and instruct their landscaper [what not to use]. For the nursery industry, that’s a de facto regulation. They’re seeing it as a threat from that position, a first step toward regulation,” she says.
“All of them need to understand they need to adopt a code of conduct. We’re really trying to help them understand what’s invasive,” says Trueman-Madriaga. “ONGA has been the only one to adopt one…It was really a milestone,” she says, especially since there’s little incentive for the industry to change.
“Landscape architects use certain plants because they work. A replacement palette hasn’t come up yet….No landscape architect wants to put in plants and six months later they all die,” she says.
In the case of ONGA, Durston says the species it chose to stop selling represent those that are not widespread and are controllable.
Martin says she consulted with The Nature Conservancy, the state, and others to determine which plants they would recommend banning – plants that were not big sellers yet, but we’re being pulled out of the forest by those agencies.
“No sense having a plant [on the banned list] that’s in everyone’s yard. So it has to be practical,”
Durston says. Just as important, he adds, “It can’t put us out of business.”
While Australian tree fern has always been a big seller, Durston says, “There’s plenty of other things to take its place.”
Updating the state Department of Agriculture’s Noxious Weed list is “another piece of the puzzle,” says HISC’s Wilkinson.
Two of ONGA’s “no-sell” plants, glorybush and Pampas grass, are on the list, which has been another target of conservationists wanting to control the spread of invasive species. Plants on the list are generally not sold, but DOA rules do not prohibit their sale, only their introduction and movement to areas designated as relatively free of those plants.
“At times when noxious weeds had been offered for sale, we had asked the seller to discontinue and explained the reasons. We have not encountered any sellers who chose to continue selling the plants as the sellers did not want to be known as those who sell noxious weeds,” DOA Noxious Weed Specialist Becky Azama wrote in an email to Environment Hawai`i.
The problem many see with the list is that except for the legislative addition of Salvinia molesta, Salvinia minima, and Pistia straiotes in 2003, it hasn’t been updated since 1992, despite many efforts to do so. There are 79 species on the noxious weed list, which does not include 23 species that have been documented to cause significant ecological or economic harm in Hawai`i and are listed on the WRA website.
HISC’s Wilkinson says she submitted a list of proposed additions to the DOA three years ago and was told that her list was being evaluated. Despite a fairly constant stream of similar requests from agency folk and others, she says, nothing has been brought to the Board of Agriculture for approval, in part, because the DOA’s Noxious Weed Specialist position had been vacant.
Earlier this year, the Maui Invasive Species Committee submitted a list of 36 species that it believes should be added to the noxious weed list. The list includes longtime MISC targets as well as species the MISC is working to control under a U.S. Fish and Wildlife Service-funded eradicable species project.
“What we’ve been doing has been putting out fires – the little fire ant, the coqui frog,” Azama says, alluding to her department’s recent effort to add the coqui frog to the DOA’s list of pest species (see page 2).
While she admits that her department hasn’t focused much effort on updating the weed list with an eye to protecting native ecosystems, she says “things have kind of evolved in the last 10 years to be more focused on environmental issues [rather than just agricultural ones]. There’s room for change.”
And with increasing awareness of the need to control invasive species, CGAPS, HISC, Denslow and others see the WRA being a vital tool for updating the noxious weed list, for the “green” industries,and the general public.
“There’s been a continual expression of support [from the DOA] on the development of the weed risk assessment…not so much that this would add species to the noxious weed list, but would provide information to the committee involved in developing the list. There is a fact-finding exercise involved in adding species to the noxious weed list, and that background research is a hurdle when they’re short staffed,” says Denslow.
Martin notes that it’s been very difficult to update the noxious weed list (For a plant to be added, it must meet specific criteria regarding reproduction, growth, detrimental effects, control and distribution). And although it was created to give the DOA the ability to control invasive species that are here, it doesn’t aid in prevention.
“What we would like to work towards is preemptively screening new introductions to the state, to run it through the system well before it’s ever brought to market. We’re a long, long ways from that,” Wilkinson says.
Denslow says that no one knows what plants are being brought into the state.
Martin says that because the WRA has proven to be 80 percent reliable in predicting the invasiveness of a species, “One of the things we’d like to see is its application to plants that are not here, new imports. There are thousands of plants in the world. It’s legal to bring in plants that are not on the noxious plant list.”
She says that while the O`ahu Nursery Growers Association has agreed to submit plants they’re thinking of bringing in to the WRA program (now housed at Lyon Arboretum), none had been submitted as of press time.
“This is a very new process,” she says. She adds that the Landscape Industry Council of Hawai`i will revisit the code of conduct issue at its conference to be held at the Waikiki Marriott April 20 and 21, and that Boyd Ready, the council’s new president, seems to want the same things she does, “to protect Hawai`i from invasive species.”
— Teresa Dawson
Volume 16, Number 10 April 2006