The Tennessee Valley Chapter of Wild Ones is hosting a Native Plant and Natural Landscaping Symposium March 9, 2013, in Chattanooga. For more information and to register, visit their Web site.
TN-EPPC’s Cost of Invasive Exotic Plants in Tennessee Research Results
Alix Pfennigwerth, our Research Intern, led a project to help TN-EPPC estimate the cost of invasive plant management to the state. She developed the survey protocol and gathered data on how much federal and state agencies, non-profit organizations, and private landowners spend on managing invasive plant species in the state of Tennessee.
Why estimate cost?
While many non-native plants serve as viable commodities in the nursery and landscaping trade, many of these plant species, such as English ivy, privet, and periwinkle cultivars, may become invasive in our state’s landscape, crowding out native plant diversity and turning an aesthetic landscape into a management nightmare. In 2011, the TN-EPPC board sought a grant from the Southeast Exotic Pest Plant Council to fund a study of the direct economic impacts of invasive plants in the state of Tennessee to help address this conflict between economic viability and economic cost.
Invasive plants cost the state of Tennessee at least $2.6 million annually
This figure represents the minimum amount of money spent in our state on invasive plant-targeted control (biological, chemical, and mechanical), mapping, and outreach. We know this is a conservative estimate of the total cost of invasive plants to the state because this study takes into account only one side of the equation: the direct costs. In addition to these direct impacts, invasive plants have quite a large indirect economic impact. Invasive plants influence ecosystem services and land value by decreasing native plant diversity, crowding out wildlife habitat, degrading wildland recreation potential, and lowering property values.
Estimating the total economic impact of invasive plants is extremely difficult. Federal and academic researchers have attempted to place a monetary value on total cost of damages caused by invasive plants on a national scale. Estimates range from $603 million to $25 billion annually ($603 million, Office of Technology Assessment 1993; $25 billion, Pimentel et al. 2005). In 2008, The California Invasive Plant Council estimated that invasive plants cost their state roughly $82 million annually (Brusati 2009). The U.S. Office of General Accounting (2002) recognized that many economic analyses focus on the impacts of invasive species on “commercial activities” such as agriculture, forestry, and fisheries, rather than on the impact on “natural area ecosystems.” We thus chose to focus primarily on the cost of invasive plants on managed natural lands.
How we estimated cost
While studies mentioned above utilize large-scale information analyses to develop national estimates of invasive species impacts, we gathered our data by surveying land managers across the state that work with invasive plant species to some extent. We gathered information from federal agencies (i.e. National Park Service, US Fish and Wildlife Service), state agencies (i.e. TN Wildlife Resources Agencies, TN Department of Environment and Conservation), nonprofits (i.e. nature centers and advocacy groups), and private commercial property managers. Tallying the total expenditures on invasive plants of a given agency is often not as easy as reading a budget line; in fact, most agencies are not required to explicitly track spending on invasive plant management. Because of this, we asked land managers to provide their best estimate of expenditures on a yearly basis.
We sent our survey to nearly 200 agencies and organizations working in Tennessee. Our resulting figure of $2.6 million in expenditures represents the responses received in the survey and is detailed in the fact sheet below. Other invasive plant organizations interested in conducting a similar study, may download a “how-to” handbook on developing and implementing a cost assessment survey.
|TN-EPPC Invasive Costs Fact Sheet Summary|
|How to Develop and Implement a Cost-Assessment Survey|
A report of the 2012 Purple Loosestrife inventory project along the Nolichucky River in East Tennessee is available. Click Nolichucky Inventory to download a copy.
Invasive Plant Control, Inc., is hosting a free series of invasive species management webinars. To gain access to the schedule, visit their website and click on the IPC Web Solutions icon to view the calendar of upcoming webinars with their respective dates and times. More information about each topic can be viewed by clicking on the title. Upcoming discussions include weed wash systems, post invasive-removal planning, and native alternatives for invasive ornamentals.
USFS Native Plant Policy
This USFS link connects to the newly published USDA Forest Service Native Plant Materials Policy, A Strategic Framework, September 2012.
US Forest Service Invasive Management Directive
The US Forest Service has just published a “national-level direction on the management of invasive species across aquatic and terrestrial areas of the National Forest System.” According to US Forest Service Chief Tom Tidwell, “Invasive species cost the American public an estimated $138 billion each year. They deplete water supplies, destroy recreation opportunities and damage landscapes across the country. We are taking this bold approach to better protect our nation’s forest and water resources from the threat of invasive species.” The Forest Service has had an invasive species program, but this policy “adds new requirements for agency-wide integration of invasive species prevention, early detection and rapid response, control, restoration, and collaborative activities across all National Forest System lands.” This will allow them to “more effectively manage invasive species in the context of environmental issues such as adaptation to climate change, increasing wildfire risk, watershed restoration, fragmentation of habitats, loss of biodiversity, and human health concerns,” says USDA Undersecretary Harris Sherman. Download the new Forest Service Invasive Species Management Policy.
TN-EPPC’s Potentials List
TN-EPPC is assembling a list of potentially invasive nonnative plants not currently recognized in Tennessee. We encourage people to report any sightings of Elaeagnus multiflora, Ficaria verna, Youngia japonica, and Paederia foetida to EDDMapS. These species will be examined for addition to TN-EPPC’s Invasive Exotic Pest Plant List at the next revision. Contact us with any additional species recommendations for the Potential Invasive Species Watch List on our Initiatives page.
Japanese Chaff Flower Watch
Flood waters can spread invasive species. Plants such as Achyranthes japonica, Japanese chaff flower, could move downstream from its current center of infestation in Kentucky & West Virginia. Mississippi Embayment states, including West Tennessee, are asked to be on alert for occurrences of this plant in bottomland forests and along riparian corridors. Detailed plant information and photos are available by clicking on the plant name in the adjacent Alert box.
Download the Wildland Weeds Insert of TN-EPPC’s Revised Plant List
|TN-EPPC Plant List from Wildland Weeds|
TN-EPPC in Tennessee
Our mission is to improve public awareness of the serious threats invasive pest plants pose to natural areas and provide solutions to manage those threats. TN-EPPC is a chapter member of the Southeast Exotic Pest Plant Council and the national organization, National Association of Exotic Pest Plant Councils.
Become a Member of TN-EPPC.
Wildland Weeds Available Online
Wildland Weeds, the official quarterly publication of the Florida and Southeast Exotic Pest Plant Councils and all affiliated chapters, is now available online, including all back issues dating to 1997. Articles cover current research, invasive plant biology, ecology and control methodology, taxonomy, impacts of exotic pest plants, and case studies. Wildland Weeds Library