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Indicator 1.2.4 - Distribution of selected forest-associated species supporting indicator 
The increased global movement of people and commodities has led to a breakdown in the major biogeographical barriers that have historically separated floras and faunas from distinct continents. This mixing has resulted in many aggressive species becoming widely distributed across the globe, or in the establishment of very high local densities. Despite increased detection efforts at ports of entry, the frequency of introductions and the number of alien species continue to increase. Invasive alien species are the second most significant threat to biodiversity after habitat loss and modification. Alien species typically have no natural enemies to suppress them in their newly invaded areas. They may displace native species by outcompeting them for resources or through browsing, parasitism, or disease, leading to the reduction or eventual elimination of native species or populations of species. Wood packaging and dunnage used in the transportation of a wide array of products have been identified as a major pathway for the introduction of alien forestassociated species. To address this threat, an international standard has been developed. The standard requires countries to ensure that all solid wood used for packing is pest-free. Although a complete list of alien species has not yet been assembled for Canada, preliminary estimates indicate that alien species total 27% of all vascular plants, 24 birds, 26 mammals, 2 reptiles, 4 amphibians, and 55 freshwater fish (Government of Canada 2004). The Canadian Forest Service is compiling a list of invasive and alien forest-associated species. For early detection and control of invasive species, it is essential to have trained and qualified taxonomists to determine which species are alien. The European brown spruce longhorn beetle, for example, was in Canada for nearly 10 years before it was detected because it was originally identified as a related native species (see case study). Monitoring to determine presence and distribution is another key component in understanding the threat and addressing the impact of invasive and alien species in Canadian forests. The establishment of numerous alien species, including insects, microorganisms, plants, and animals has resulted in devastating effects on forest health, loss of biodiversity, and losses to commercial forest products and other forest values. Introduced pathogens have had the most severe economic and environmental impacts on Canada's forest of any group of alien species (Hendrickson 2002). For example, the impact of chestnut blight and Dutch elm disease has led to the disappearance of American chestnut and American elm as significant components of the deciduous forests of southeastern Canada. The loss of these trees has had repercussions on the wildlife that depend on them and on society because of their cultural and economic significance. More than 1500 species of terrestrial arthropods (of which more than 200 feed on woody plants) have been introduced into Canada (D. Langor, NRCan, Northern Forestry Centre, Edmonton, AB, personal communication, 2004). Many of these species cause economically significant damage to Canada's forests, while others likely have important, but yet unmeasured, effects on biological diversity of native fauna and flora. Canadian quarantine regulations governing forest pests and diseases are covered by the Plant Protection Act, administered by the Canadian Food Inspection Agency (CFIA). Table 1.2d describes some of the insect and fungal species currently regulated by the CFIA. Case studies on three of these recently introduced insects follow. Table 1.2d Selected invasive alien insects and fungi regulated by the CFIA.
Alien invasive plant species can outcompete some native flora for resources such as light and nutrients, displacing them from these areas. Many invasive species will colonize primarily disturbed areas and early seral stages. For example, in the Garry oak ecosystems of British Columbia, where urbanization and agricultural development have resulted in substantial habitat loss and degradation, numerous invasive, alien plant species such as English ivy and Scotch broom now threaten species at risk. These include rare flora such as the threatened yellow montane violet and the endangered Howell's triteleia, and species that depend on them such as the endangered Taylor's checkerspot (CWS 2004d, e and COSEWIC 2003). Table 1.2e is a list of selected invasive alien plant species associated with Canadian forest ecosystems or tree species. In response to the threat that invasive alien species pose to the sustainability of forests, some provinces have integrated means to address this issue into their legislation2 such as British Columbia's Weed Control Act, Plant Protection Act, Forest Practices Code of British Columbia Act, and Forest and Range Practices Act; Ontario's Plant Diseases Act, Weed Control Act, and Crown Forest Sustainability Act; Quebec's Forest Act and Plant Protection Act; and Nova Scotia's Weed Control Act. In addition to its legislation, British Columbia created the Plant Protection Advisory Council to address plant health and plant quarantine issues of concern. In 2004, the Invasive Plant Council of British Columbia was created to provide a forum for coordination for invasive alien plant managers across the province. Its five committees pursue issues of funding, legislation, inventory, technology, research, and communication. In 2004, Alberta launched the Alberta Invasive Plants Strategy and created the Alberta Invasive Plants Council (http://www.invasiveplants.ab.ca/) to help protect Alberta's ecosystems from invasive plants by providing information about them and to foster cooperation among stakeholders. Invasive alien species are a global concern and must be tackled globally. Although it might not be possible to stop global change, eradicate all species that are currently invasive, or prevent future invasions, the key to solving this problem is to strengthen the underpinning science surrounding the success of invasive species and the types of future changes we can anticipate. The development of effective policy, inspection, and eradication or control programs is critical to prevent the introduction and spread of new invasive species. The International Forestry Quarantine Research Group, established in 2003, is fostering multidisciplinary approaches to solving some of these issues. The federal, provincial, and territorial governments, led by Environment Canada, are addressing the threat of alien invasive species in a recently developed national strategy found at http://www.cbin.ec.gc.ca/primers/ias/documents/Final_IAS_Strategic_Plan_smaller_e.pdf. CASE STUDY 1. Emerald ash borer (Agrilus planipennis)The emerald ash borer (EAB), native to eastern Asia, was first discovered in North America in 2002. As an adult, this beetle is metallic green-blue with a narrow and finely sculptured body. EAB is capable of attacking all true ashes, including white, red, green, and black ash species native to Canada. Since its discovery in North America, EAB has been reported in two counties in Ontario and in Michigan and Ohio. To date, an estimated 100 000-200 000 ash trees in Canada are believed to be infected and likely to die, while over seven million ash trees have now died in the neighboring United States as a result of EAB. The beetle is suspected to have entered Canada in wood-packaging material. EAB larvae bore through the bark of their hosts to feed on the vascular tissue and sapwood creating tunnels. At the end of pupation (the inactive stage between larvae and adult development), the newly developed adults emerge from the bark and begin to feed on the leaves of the host. Severely attacked trees die when their vascular systems are no longer capable of transporting water and nutrients effectively. EAB are capable of traveling up to several kilometres in search of a new host (CFIA 2004a). Left unregulated, EAB could spread throughout most of eastern North America, devastating ash populations across its range. In 2002, with the collaboration of an international science and advisory panel of experts, an aggressive campaign was established to prevent the spread of EAB. Movement of firewood of all tree species and movement of any ash forest product (including nursery stocks, lumber, and debris) from the infected county was restricted. In addition, an Ash Free Zone was established along the border of the infected area to reduce the future risk of spread of EAB. However, EAB has been confirmed outside of the Ash Free Zone, in zones where infected trees were promptly destroyed and the surrounding area was effectively quarantined. Regardless of these occurrences beyond the Ash Free Zone, the campaign has so far been considered successful in slowing the rate of spread of EAB in Canada (CFIA 2004a). For additional information, see http://www.inspection.gc.ca/english/plaveg/protect/pestrava/ashfre/agrplae.shtml. Table 1.2e Selected alien plant species associated with forests in Canada CASE STUDY 2. Brown spruce longhorn beetle (Tetropium fuscum)The brown spruce longhorn beetle (BSLB), native to Europe, was positively identified in 1999 in Point Pleasant Park, Halifax, Nova Scotia (CFIA 2003). BSLB could have arrived as early as 1990, as samples collected from this time mistakenly identified BSLB as a related native species (T. cinnamopterum). This invasive forest insect is also suspected to have arrived in woodpackaging material. Within the park, the insect has infested mainly red spruce but is capable of attacking all spruce species native to Canada, other softwood species such as firs, pines, and larches, and occasionally hardwood species. The beetle typically attacks damaged or unhealthy trees but has also been known to attack healthy trees during population outbreaks that can last up to a decade. Larval stages of BSLB cause the most significant damage to their host as they feed on the vascular tissue of the trunk; this feeding disrupts the transport of nutrients in the tree and can lead to delayed growth and sometimes mortality. A multiagency and multidisciplinary task force is testing detection, identification, biological control, and phytosanitary treatment methods for the elimination of BSLB (CFS 2004). Since 2000, the CFIA placed Point Pleasant Park and the surrounding Halifax area under federal quarantine; approximately 6000 spruce trees identified as infested by BSLB were removed and destroyed. CASE STUDY 3. Asian long-horned beetle (Anoplophora glabripennis)The Asian long-horned beetle (ALHB), otherwise known as the starry sky beetle, is a forest pest native to Asia that was introduced to North America in 1996 in Brooklyn and Amityville, New York. In 1998, it was reported in Chicago, Illinois. It is again believed to have arrived in wood-packaging material. This shiny bluish-black beetle with long antennae and numerous white spots on its body may be easily confused with several native species. ALHB attacks unhealthy and healthy hardwood tree species alike, including birch, elm, hackberry, horsechestnut, maple, mountain ash, poplar, and willow. Like the emerald ash borer and the brown spruce longhorn beetle, this species does the most damage in its larval stage, as it bores into the trunk of its host and severely disrupts the tree's nutrient flow, causing slow growth and eventually death. Fortunately, it has not been reported in Canadian forests, but in 2003 was discovered in Canada in an industrial park. ALHB is currently being quarantined and eradicated in all North American locations. By April 2004, the CFIA had removed up to 15 000 host trees as part of an ALHB eradication plan. If this species were to spread into Canadian forests, it could significantly affect forest biodiversity as well as Canada's hardwood supply worth $11 billion annually in wood products, and a sugar maple industry worth $100 million (CFIA 2004b). 2 For a more complete list of the Canadian legislation related to invasive alien species, consult the Proposed Action Plan for Invasive Alien Terrestrial Plants and Plant Pests at http://www.cbin.ec.gc.ca/primers/ias/documents/plants_e.pdf | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||