A cozy campfire for summer days, a warm fireplace for winter evenings– the use of firewood is an "established cultural norm". However, moving firewood from place to place can have devastating consequences, as it can spread forest pests that decimate forests to collectively cost an estimated $4.2 – $14.4 billion per year. In order to better address the problem of people moving firewood and vectoring forest pests, Solano and colleagues examined trends and gaps in the existing literature on firewood and human-mediated forest pest movement in North America. The existing literature demonstrates the risk of firewood movement, but fails to address the level of awareness the public has on such risks, or the level of effectiveness of firewood regulations to prevent forest pest spread.
Natural pathways (i.e., those not aided by humans) include wind, currents (including marine debris), and other forms of natural dispersal that can bring species to a new habitat.
Man-made (or human-mediated) pathways are those which are created or enhanced by human activity. These are characteristically of two types:
- Intentional, which is the result of a deliberate movement of a species by humans outside of its natural range. Examples include the introduction of biological control organisms or the movement of species for the horticultural or pet trade. Intentional introductions as a whole should not be labeled as either good or bad. A specific intentional pathway can only be judged by the positive or negative impact of the specific organisms that are moving along that means.
- Unintentional, which is the inadvertent movement of species as a byproduct of some other human activity. Examples of unintentional pathways are ballast water discharge (e.g. red-tide organisms), pests and diseases in imported plants, firewood, and other agricultural products (e.g. fire ants), the movement of recreational watercraft (e.g. zebra mussels), and the international movement of people (e.g. pathogens). In these and countless other unintentional pathways, the movement of non-native species is an indirect byproduct of human activities.
For our purposes, the term "vector" is viewed as a biological pathway for a disease or parasite (i.e. an organism that transmits pathogens to various hosts) and is not completely synonymous with the much broader definition of a pathway. The Asian citrus psyllid is an example of a vector of the serious citrus greening disease or Huanglongbing.
Examples of ways invasive species spread include:
- Agricultural materials (see Hungry Pests - Agricultural Materials)
- Aquaculture farming
- Ballast water and shipping
- Classroom or science lab; escapes or introductions
- Firewood (see Hungry Pests - Firewood)
- Fishing gear
- Food trade and its packing material
- Fouled hulls of commercial and recreational vessels; boats
- Internet sales (see Hungry Pests - Internet Sales)
- Mail (see Hungry Pests - Mail)
- Moving (see Hungry Pests - Moving and Outdoor Household Items)
- Outdoor gear; hitchhikers on boots, clothes, and camping equipment (see Hungry Pests - Outdoor Gear)
- Passenger baggage (see Hungry Pests - Passenger Baggage)
- Pets; unwanted or escaped
- Plants and plant parts; escaped or disposals (see Hungry Pests - Plants or Plant Parts)
- Recreational vehicles (RVs) (see Hungry Pests - RVs)
Cornell University. New York Invasive Species Research Institute.
USDA. FS. Southern Research Station. CompassLive.
Seeds that float in the air can hitchhike in unusual places – like the air-intake grille of a refrigerated shipping container. A team of researchers from the USDA Forest Service, Arkansas State University, and other organizations recently conducted a study that involved vacuuming seeds from air-intake grilles over two seasons at the Port of Savannah, Georgia. The viability of such seeds is of significant interest to federal regulatory and enforcement agencies, and the project required a shared stewardship approach. Their findings were recently published in the journal Scientific Reports.
Seeds from 30 plant taxa were collected from the air-intake grilles, including seeds of wild sugarcane (Saccharum spontaneum), a grass on the USDA Federal Noxious Weed List. Federal noxious weeds pose immediate, significant threats to agriculture, nursery, and forestry industries. Although a lovely grass and useful in its native range, wild sugarcane has the potential to join cogongrass, stiltgrass, and other nonnative species that have become extremely widespread in the U.S.
New Zealand Ministry for Primary Industries. Biosecurity New Zealand; National Institute of Water and Atmospheric Research.
New Zealand is the first country to implement nationwide regulations to manage risks associated with biofouling on international vessels. The development of this regulation and its implementation can serve as a blue-print for other jurisdictions that are interested in preventing the spread on non-indigenous marine species.
Australian Invasive Species Council.
A new report has identified an international 'bug superhighway' capable of carrying a large variety of environmentally destructive overseas insects into Australia. The study, led by Monash University, rated the environmental harm being caused by 100 of the worst overseas insect species and recommends a string of actions to keep them out of Australia. The most dominant group of invasive insects by far are the hymenopteran insects – ants, bees and wasps – making them the world's most environmentally harmful invasive insect species.
"Our report found that environmentally harmful bugs, beetles, ants and moths are most likely to hitch a ride into Australia along an international bug superhighway made up of imported plants, nursery material and the timber trade," said report author Professor Melodie McGeoch from Monash University. The report identifies the international trade in cut flowers and foliage as a high-risk pathway for more than 70 of the species studied. Invasive Species Council CEO Andrew Cox said this is the first time Australian and international scientists have comprehensively analysed which invasive insects overseas are doing the most environmental harm and could therefore threaten Australia's natural environment if they breach the nation's borders.
USDA. Animal and Plant and Health Inspection Service.
Whether used to heat your home or build a campfire, firewood is a must-have item for millions of Americans. However, firewood also presents a very real threat to the Nation's forests. Invasive species including the Asian longhorned beetle (ALB), the emerald ash borer (EAB), and gypsy moth can be spread into new areas of the country on firewood.
The section below contains highly relevant resources for this subject, organized by source. Or, to display all related content view all resources for Pathways
Council or Task Force
The purpose of pathway risk analysis is to provide scientific analyses and policy recommendations in support of U.S. National Invasive Species Council’s Management Plan. Developed jointly by the Aquatic Nuisance Species Task Force (ANSTF) and National Invasive Species Council (NISC) Prevention Committee via the Pathways Work Team.
Note: This guide only applies to existing unintentional, man-made pathways
Georgia Invasive Species Task Force.
Washington State Recreation and Conservation Office. Washington Invasive Species Council.
International Union for Conservation of Nature.
This report offers recommendations to improve biosecurity measures at U.S. ports, as well as a possible funding mechanism based upon the polluter-pays principle.
Aquatic Invaders in the Marketplace.
The AIM campaign that focuses on providing information and best practices to manage The Organisms in Trade (OIT) pathway. The OIT pathway is one of the main avenues by which non-native aquatic species become established in waterways. Many of the aquatic plants and animals available in the marketplace can negatively impact ecosystems, economies, and public health when introduced to new freshwater habitats. AIM was developed by a collaboration of researchers and outreach specialists led by Illinois-Indiana Sea Grant and the Illinois Natural History Survey.
Ontario's Invading Species Awareness Program (Canada).
Local Government Aquatic Invasive Species Toolkit.
The primary challenge associated with invasive species ecology is management of introduction vectors. This resource illustrates the framework used to describe invasive species pathways and threats, including the primary pathways of introduction as well as the techniques commonly used to manage the threats, and the priorities for protection from threats. The framework includes 10 primary pathways of introduction: Air transportation/cargo, water transportation, land transportation, items used in shipping, travel tourism/relocation, plant pathways-plant trade, food pathways, non-food animal pathways, non-food animal, other aquatic pathways, natural spread, and ecosystem disturbances.