Policies
Approaches to solving the invasives
problem
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When deciding how to prevent exotic plants from becoming invasive pests, policymakers must decide on the strategy that will balance the costs of invasions with the benefits of new plant introductions, on both a regional and national scale. This decision of "which species to import and release are ultimately cultural and political choices – choices about the kind of world in which we want to live" (OTA 1993), meaning that the strategy used to address the invasive plant problem must take our cultural desires for conservation and economic prosperity into account. Regulation
Controlling current invasive plants
Current plant invasions need to be controlled through so that they do not spread to new areas, and, when feasible, eradicated or removed to reduce their impact on presently invaded sites. Controlling new spread is done through a combination of regional legislation and local land management. Briefly, management techniques use monitoring, biological control, physical removal, inspection of vectors (in natural areas, these are often unsuspecting cars, boats, and humans) (see Luken and Thieret 1997, Assessment and management of plant invasions). When targeting spreading populations, it is considered more effective to eliminate small, outlying populations rather than the large, main population, according to Moody and Drake's (1988) model of nascent foci. Regional legislation is appropriate when plants are already established within the country and are only invasive on a regional level - as most are. In this case, state and county noxious weed lists are often used, though they have the similar drawbacks to the Federal Noxious Weed list: the lists are often not complete and listing is not done in a preventative manner. The Rhode Island Department of Environmental Management (RIDEM), for instance, administers the Rhode Island Seed Law. It prohibits four plants and restricts nine, none of which are sold in the nursery trade. RIDEM acknowledges at least 10 more plants which are of concern that are not addressed – almost all of which are widely invasive horticultural plants, most notably Lythrum salicaria, purple loosestrife (Martin 2000, presentation, see Muth and Hamburg 1998). RIDEM is not even considering listing species on a preventative basis. Preventing new invasions
Preventing new introductions of harmful species is the first line of defense. When prevention fails - for technical or political reasons - rapid response is essential. Eradication of harmful nonindigenous species is often technically feasible but complicated, costly, and subject to public opposition. (OTA 1993) If a new houseplant is potentially invasive in Florida, but cannot possibly survive out of doors elsewhere, should it be allowed into the country? The answer that provides the most cautious solution is to prohibit its import entirely. If the plant ends up in the country it could easily be deliberately or inadvertently introduced to Florida. However, it could also be a valuable houseplant that removes indoor air pollutants or simply turns a good profit. Another issue is with plants that are being imported to the United States to fuel the market for new and unusual landscaping plants or innovative food and fiber crops. According to the estimates done by Eduardo Rapaport, discussed by Reichard and White (2000) there are at least 1000, and perhaps as many as 22,000, invasive weed species that have yet to move around the world and that are likely to become problems in the future. This estimate points to the need for regulations preventing the entry of new invasive plants. Nonindigenous plants enter the United States through a number of pathways, both intentional and unintentional. The majority of invasive woody plants were originally introduced intentionally for horticultural or agricultural purposes (Reichard and Campbell 1996), and about 50% of all invasive plants were introduced for horticultural purposes (Randall and Marinelli 1996). Controlling horticulturally introduced invasive plants is quite important and will make large strides in controlling the spread of invasives throughout the United States. Horticultural plants are generally introduced by botanic gardens these days, though some nurseries do their own introductions through plant explorations and trade with foreign nurseries (Klinkenbourg 1999). Historically, invasive plants have spread throughout the country through the commercial seed trade (Mack 1991, Mack 1990). Strategy 1: Prohibit all new introductions
The most effective way of regulating invasive plant introductions would be to ban the import of nonindigenous and non-naturalized species altogether. This would follow the Precautionary Principle, which dictates that when the consequences of a rare event are large, the safest path should be taken and the risky activity should not be permitted at all (Plater et al 1998). In the case of plant introductions, invasions are relatively rare – somewhere between 0.2% (Lowe 1998) and 15% (the rate of invasion by any organism, OTA 1993) of all introduced plants will become invasive pests. However, the consequences are high because new invasives may threaten biodiversity, ecosystem stability, human health, food production, recreation, and the economy negatively (see Ecosystem Impacts and Economic Impacts sections). Banning all new introductions, however, is not appropriate because of the many economic, agricultural, and environmental advantages of them. Prohibiting new imports would mean not only prohibiting potentially popular and profitable horticultural plants, and thus potentially cutting back on the nursery industry’s profits, it could also mean prohibiting potentially valuable food, fiber, and ecological restoration plants. Seed collecting by arboretum and botanic gardens is one way the world’s botanists are attempting to preserve biodiversity – but a ban on new imports would severely hinder that endeavor. A slightly more permissive, but similar strategy would permit only plants that have demonstrated that they are harmless, called a "clean list" approach (Reichard 1997b). To qualify for the "clean list", plants would be tested which would be laborious, time consuming, and expensive. Strategy 2: Prohibiting proven invasive
species
Forming effective policies for prevention then must rely on the knowledge of a plant’s potential to be invasive. An important consideration with prohibition of new nonindigenous plants is that while it may be the most cautious and perhaps effective strategy, it would also be politically difficult to implement. The American Nursery and Landscape Association (ANLA) lobbies on behalf of the nursery industry and is willing to make compromises to prevent invasions, but it also is opposed to "regulatory overkill" and "extremism" - two terms used by Craig Regelbrugge, ANLA's director of regulatory affairs and grower services, in the "Invasives Roundtable" (1999). In order to strike a balance between all-out prohibition and maintaining the benefits of new introductions, policies must be formed that use the knowledge of a plants' invasive potential to decide whether it should be permitted to enter the country. The current importation regulation is called the Federal Noxious Weed Act (7 USC 2801-2814), which prohibits plants according to whether they are nonindigenous and may be harmful to crops, "useful plants", agriculture, fish and wildlife, navigation, or public health.
While the legislation itself does not intend to restrict itself to only currently invasive plants, its listing process is so cumbersome that only 96 of the 750 plants that qualify under the definition are actually listed, and these 96 are generally current agricultural pests with economic – not environmental impacts (OTA 1993). The list has no preventative merits, most plants on it are already so widespread that they are beyond control (Reichard 1997). However, because the list does consist of widespread plants, it is easy to say that they are conclusively invasive. Proof of invasiveness is a common theme among the nursery trade – they do not want plants considered invasive, and therefore restricted, unless there is scientific proof behind the categorization. Unfortunately, waiting as long as the FNWA effectively requires to determine whether a plant is a proven invader and worth including on the list means allowing the plant to invade. This makes the FNWA entirely reactive and ineffective at prevention. This regulatory technique is not successful at preventing new invasions and it is limited in its success of preventing the spread of current invasive plants to new parts of the United States because of its poor enforcement. Section 4 of the FNWA requires a permit for moving listed species between states, but the Animal Plant Health Inspection Service (APHIS), who administers the FNWA only applies this when there’s a quarantine imposed – which had happened only once in the 18 years before the OTA report (OTA 1993). Because unlisted weeds can be legally imported (OTA 1993), potential invasive plants can easily enter the country, no matter how much is known about their invasibility. The requirement of proof could be tightened so that plants aren't proving their invasiveness in natural settings, but are tested for invasiveness by experts. Scientific proof would convince the nursery industry that the plant is worth regulating, but it is a time consuming, expensive strategy (Reichard 1997b). Strategy 3: Prohibiting potentially
invasive species
Improvements must be made on the FNWA in order to prevent the 1,000-22,000 potentially harmful nonindigenous plants that will enter the country in the future. There must be a system that mixes prevention and caution with permissiveness of harmless plants. Determining potential invasiveness has been an undertaking of ANLA and the Horticultural Research Institute as well as Sarah Reichard, a horticultural ecologist at University of Washington. The decision tree that Reichard (1997) has created uses common traits of invasive plants (see Iplant Characteristics) to predict whether new introductions are likely to invade. Most regulatory approaches to nonindigenous species importation and release use variations of "clean" (allowed) or "dirty" (prohibited) lists of species or groups (OTA 1993). The FNWA uses a short "dirty" list to prevent importation of invasives. Reichard's decision tree uses both clean and dirty strategies because it examines each plant for invasability and then places the plant on either the clean, the dirty, or a "to be tested" grey list. The advantageous aspect of the decision tree is that it does not require thorough, long-term studies to be done of every new import, just some brief research in horticultural journals to determine the plant's traits. The "to be tested" plants will be quarantined for at least five years, but most plants would not need to undergo testing. When Reichard (1997) ran her model on 87 non-invading woody species, 46% were accepted, 18% were rejected, and 36% needed further testing, showing that the model is cautious, but false-negatives are more tolerable than false positives (only 2/204 invaders fell under the "clean" category). Jurisdiction
One problem with forming regulations concerning invasive plants is deciding the level of government that should be responsible for the issue (see Reichard and White). Because the United States is so large and environmentally heterogeneous, very few plants become invasive throughout the entire country. This means creating lists of "banned" plants can be very problematic. If Norway Maple (Acer platanoides) is becoming a dominant feature of forests around the urban Northeast to the detriment of native species, should it be banned in Texas, where it’s never been a problem (Keith Warren 1999, in Invasives Roundtable)? The common answer to this question is that plants that are already established in the United States should be monitored and regulated at the local or regional level. State regulations, in the west where states are large enough, and regional agreements in the East, are best suited to preventing the spread of invasives already in the States. However, state legislation, as discussed above, is rarely comprehensive and usually only addresses agricultural pests (OTA 1993). Importation legislation does not address the regional invasiveness of most plants. What is "clean" or "dirty" in one part of the US is not necessarily so elsewhere. Regulation of importation, however, makes the most sense when it is dealt with on a Federal level because of the Interstate Commerce Clause, which states that Federal government has jurisdiction over interstate commerce in order to prevent inconsistencies between states. However, preventing new invasions should allow for some compromise - newly imported potential invaders should not be allowed to spread to the region where they might be invasive and the best way to prevent this is by preventing their introduction to any part of the country. Noninvasive exotic plants could still be imported, but only after they had passed the decision tree screening. Currently, the Animal Plant Health Inspection Service (APHIS, a division of the Department of Agriculture) and 19 other Federal Agencies work on invasive species introductions or controls (OTA 1993). Agencies are poorly coordinated in their efforts and often issue conflicting mandates. In fact, Federal Agencies – specifically the Soil Conservation Service often promote the use of invasive nonindigenous plants for erosion control or groundcovers (OTA 1993). APHIS's implementation of noxious weed control and prevention traditionally has overlooked nonagricultural pests, and introduced species are usually assumed to be harmless unless they are proven otherwise. However, its risk assessments are much more rigorous than the ones performed by other agencies (OTA 1993). APHIS is the agency in charge of monitoring importation of live organisms, but its resources and the authority granted to it by the FNWA do not allow it to effectively prevent new introductions from being invasive. Exotic Pest Plant Councils (EPPCs) are one way regional invasions are being addresses. The EPPCs, located in the Pacific Northwest, California, the Southeast (including Florida EPPC and Tennessee EPPC), the Mid-Atlantic region and New England. They are nonprofit groups meant to coordinate the many different invasive plant efforts in the absence of a strong national effort. Their mission is to raise awareness, promote research into effective control methods, promote cooperative effective national control programs, provide forums for interested parties, and prevent duplication of efforts (Campbell 1997, CalEPPC 1999). Pending Legislation
The Federal government has recognized its need for more comprehensive
legislation. Currently, there is a bill pending in both the US House
and Senate that refines the Federal
Noxious Weed Act (7
USC 2801-2814 According to Jayney Bracket (phone conversation, February 2000), an assistant of Larry Craig, the Idaho Senator who sponsored Senate Bill 910, the Noxious Weed Coordination and Plant Protection Act may be passed in June of 2000, provided that it is not overshadowed by more controversial measures. It is a piece of legislation that has been in the works for more than ten years and is the result of a long series of compromises between the nursery industry, Federal agents, and conservation interests. Changes to the legislation, according to Bracket, would mean changes in support for the legislation and more difficulty in passing it. As it stands now (May 2000), neither bill has moved out of committee since the Spring of 1999, shortly after they were introduced (see http://thomas.loc.gov for the bills' current statuses). Because the bills are both relatively uncontroversial (all 50 states' departments of agriculture agree with them), they should pass easily once the legislatures attend to them. Once the controversial sections of the bill is ironed out, the senate bill will be simply passed unanimously by getting senators to sign it, rather than put up for a more time consuming vote. According to Bracket, the one controversy about the bill has been voiced
by Senator Akaka of Hawaii
who feels that the bill will not provide enough protection for some
states – particularly Hawaii, where 946/2690 plants are nonindigenous species
and about 800 natives are endangered (Pimentel 1999), controlling invasives is of great concern.
The bill creates Federal preemption of state invasive plant laws, such
that states cannot create barriers to trade that would be beyond those
of the Federal government (see section
305 of S910). This would fix the nursery industry's complaints of
inconsistency between states, but would also make it impossible for
states to impose any rules beyond those of the Federal government concerning
importation and introduction, and would only allow states to go beyond
Federal regulation concerning interstate commerce if the states are
able to provide "thorough scientific data or a thorough risk assessment".
This safeguard against inconsistency is understandable, but may go too
far, especially in the case of Hawaii, where there are unique ecosystems
that are invadable by different species than the other 49 states, such
that Federal rules applying to importation of particular plants invasive
in Hawaii would restrict plants that would
have little chance of invading on the continent. Depending on how the US Department
of Agriculture views the bill if it is passed, Federal rules could be
far too lenient to adequately protect Hawaii or other states. Historically,
implementation of the legislation regulating invasive plants has not
been thorough or effective (OTA
1993), especially provided that there have been inadequate funds devoted
to the issue. States interested in protecting their biodiversity have
reason to doubt S910
and HR1504. The other controversy concerning this pending legislation is with Title IV which is simply the codification of President Clinton's Executive order on Exotic Plants from February 1999. In the Senate version of the bill, Title IV has been stricken altogether. Executive Order 13112 was issued on February 3, 1999; it established an Invasive Species Council who would set forth guidelines for Federal agencies to prevent the spread of invasive species, which it (and Title IV of the Act) define as "an alien species whose introduction does or is likely to cause economic harm or environmental harm or harm to human health." According to Bracket, detractors from Title IV felt that this definition was too inclusive and basically equated alien species with invasive species. The omission of Title IV, Bracket implied, increased the support of the bill, but means that the senate version is no longer identical to the house version, so the differences will need to be resolved before the Noxious Weed Coordination and Plant Protection Act can be codified.
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Links
US Code: http://uscode.house.gov/do wnload.htm Federal Noxious Weed Act, 7 USC 2801-2814; Federal Seed Act 7 USC 1551-1611 Animal Plant Health Inspection Service – Federal Noxious Weed list Four fronts of effort for controlling invasive species, by The Nature Conservancy |
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