The sudden ignition of a brightly lit wildfire on the horizon sparks immediate actions and budgeted resources. After all, the loud, crackling, hot flames are hard to ignore as they advance toward communities. So how should we respond to the silent, but significant, threat of invasive plants that appear pretty and harmless along the highways and farmer’s fields, in public parks and backyard gardens of British Columbia?
Despite their attractive appearance, invasive plants are one of the five most significant causes of biodiversity loss and change to ecosystem functions, as reported by the Millennium Ecosystem Assessment. They carry potential negative impacts to the economy, environment, and society; therefore, preventative planning and careful budgeting are required.
To date there is no established annual budget in BC to control invasive plants. Once established, the environmental impacts of invasive plants can be as significant as those caused by wildfire, and are often irreversible.
Recent studies on the economic impacts of invasive plants in BC have staggering results. A 2006 survey showed that approximately $7 million was spent on invasive plant management activities in BC that year (IPCBC Economic Impacts Baseline Report #6). Results of the 2009 Economic Impacts of Invasive Plants in BC (Report #12) analysis indicate that without intervention, the economic damage caused by each invasive plant in the study was estimated to range from $1 to 20 million dollars in 2008, increasing to between $5 and 60 million by 2020 (based on 2006 Canadian dollars). The total expected damages, in the absence of any management, were estimated to be a minimum of $65 million in 2008, rising to $139 million by 2020. These values are likely underestimates as economic data were not available for all potential impacts.
The above projections indicate enormous economic losses and severe environmental damage in the decade ahead, which may be worsened by climate change. Thus, a consistent province-wide invasive plant management budget is needed. Current funding is a result of improved awareness about invasive plants in BC and partnerships between the provincial government, key stakeholders, and the Invasive Plant Council of BC. Some of these funds have been dedicated to undertaking comprehensive economic impacts research.
To date, the majority of research reports assessing the economic impacts of invasive plants in BC have focused on the agriculture sector. Crop losses alone cost BC farmers and ranchers over $50 million annually due to invasive plant species, like knapweed, that infest rangelands and reduce forage quality, states the BC Ministry of Agriculture and Lands. Several million dollars more are spent annually to control invasive plants through herbicide and cultivation.
In addition to impacts on agricultural and range resources, invasive plants can impact forestry operations by competing with seedlings for light, nutrients, and water; and recreation opportunities by puncturing tires, obstructing trails, and reducing aesthetics. These environmental impacts lead to costly restoration of recreational trails, re-planting of tree seedlings, as well as reduction in value of personal and commercial property.
The impacts of invasive plants to all natural resource sectors of the economy are being felt across the nation. The Canadian Food Inspection Agency (CFIA) estimates that of the 485 invasive plant species in Canada, invasive plants in crops and pastures alone cost approximately $2.2 billion every year. The CFIA classifies 94 invasive species as agricultural or forest pests and estimates that these regulated species cost the Canadian economy $7.5 billion annually.
In the Prairie provinces, canola yield losses and treatment for Canada thistle (Cirsium arvense) cost an estimated $320 million per year (CFIA). In Manitoba, leafy spurge (Euphorbia esula) infests 340,000 acres of land, costing an estimated $19 million per year in protection of grazing land, public land, and right-of-ways.
Furthermore, a United States study reports that the invasion of leafy spurge in four northern states has resulted in annual losses of US $129 million, equivalent to approximately 1,433 jobs. According to the CFIA, the total cost of preventative measures, control programs, and lost production due to invasive species is estimated to exceed $137 billion a year in the US.
Invasive plants have no boundaries, and their introduction to an environment may threaten the survival of native species, and can also prompt trading partners to impose restrictions, causing further economic losses.
A US study conducted by the Center for Aquatic Conservation at the University of Notre Dame and University of Wyoming suggests invasive species transferred in ship ballasts may be costing the Great Lakes region more than $200 million a year in losses to commercial fishing, sport fishing, and the area's water supply.
On a larger scale, invasive species reduce the effectiveness of development investments by choking irrigation canals, fouling industrial pipelines, and impeding hydroelectric facilities. Invasive species therefore contribute to social instability and economic hardship, placing constraints on sustainable development, economic growth, poverty alleviation and food security, says the Global Invasive Species Programme (GISP).
The Secretariat of the Convention on Biological Diversity concurs, saying that invasive species can exacerbate poverty and threaten sustainable development through their impact on agriculture, forestry, fisheries, human health, and biodiversity, which is often a basis of livelihoods of people in developing countries. The alien aquatic plant, water hyacinth (Elchhornia crassipes), for instance, costs an estimated US $100 million a year on issues related to water use in developing countries.
Despite the growing evidence of the economic impacts caused by invasive species, the level of awareness amongst decision-makers is still relatively low, says the GISP. The economic impact of many invasive species is poorly documented because of the difficulty in assessing impacts to habitats, such as forests, rangelands, aquatic, wetland, and riparian sites. A conservative estimate by the GISP puts the global cost of tackling invasive species at $1.4 trillion each year, 5% of the global economy.
Ironically, most introductions of invasive species are based on economic motivations, but are seldom preceded by cost-benefit analysis that discusses societal and ecological consequences, states the BC Ministry of Environment. It is rarely those responsible for introducing an invasive species, either intentionally or accidentally, who pay for resulting damages. Instead, consumers, other resource users, and tax-payers bear most of the burden.
Without greater intervention and an appropriate budget, the cost of controlling invasive plants will increase exponentially over time. These “invaders” have the capacity to permanently alter ecosystems, reduce property values, impact natural resource sectors of the economy, and in the worst cases, cause the extinction of native species. They are silently and rapidly impacting the landscape with the same swiftness and destruction as a wildfire, but without the bells and whistles to sound the alarm.
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