Definitions

Definitions

Alien species.  Means, with respect to a particular ecosystem,
any species, including its seeds, eggs, spores, or other biological
material capable of propagating that species, that is not native to
that ecosystem.

Anthropogenic disturbance.  Human-induced disturbance (e.g., mowing) or human-induced changes in natural disturbance regime (e.g., changing the frequency, extent, or severity of fires).

Benefits.  Advantages or profits derived as a result of an action (e.g. social or economic benefits from a proposed introduction).

Casual alien species. 
Alien species that may flourish and even reproduce occasionally in an area, but which do not form self-replacing populations, and which rely on repeated introductions for their persistence

Code of conduct.  A formalised code of best practice to address (in the context of this report) existing or potential problems from the introduction of non-native species. Codes of conduct may be voluntary or involuntary.

Conservation introduction.  The deliberate release for conservation purposes of individuals of a species or race outside of the native range

Control.  Means, as appropriate, eradicating, suppressing,
reducing, or managing invasive species populations, preventing spread
of invasive species from areas where they are present, and taking steps
such as restoration of native species and habitats to reduce the
effects of invasive species and to prevent further invasions.

Discrete sites.  Disjunct habitat-types or fragments of habitats
at least 1 mile apart that support invasive plant populations that
likely arose by separate long-distance dispersal mechanisms.

Disturbance.  Mechanisms that limit biomass by causing its partial or total destruction.

Domesticated or cultivated species.
  Means species in which the evolutionary process has been influenced by humans to meet their needs.

Ecosystem.  Means a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Eradication.  The extirpation of the entire population of an alien species in a managed area; eliminating the IAS {invasive alien species} completely from a defined area by a time limited campaign.

Feral.  An organism which has been kept in domestication, captivity (animals) or cultivation (plants) but which, after escape or release, now lives in the wild state. This also applies to descendants of such released or escaped organisms.

Formal Risk Benefit Analysis.  Detailed economic studies of impact and  management costs and commercial value for present and future infestations.

Indigenous species.  A species or lower taxon living within its natural range (past or present) including the area which it can reach and occupy using its natural dispersal systems
Invasive non-native species. A non-native species whose introduction and/or spread threatens biological diversity. This is interpreted broadly to include threats to the entire ecosystem including human interests (e.g. including threats to public health and financial damage)

Introduction.  Means the intentional or unintentional escape,
release, dissemination, or placement of a species into an ecosystem as
a result of human activity.

Invasive plant.  Means an alien plant whose introduction does or is likely to cause economic or environmental harm or harm to human health.

Isolated. Present in small disjointed patches within an ecological region.

Localize.  Found to be prevalent in a localized area within an ecological region.

Long-term alterations in ecosystem processes. 
Examples of ecosystem processes that could be altered: erosion and sedimentation rates; land elevation; water channels; water-holding capacity; water-table depth; surface flow patterns; rates of nutrient mineralization or immobilization; soil or water chemistry; and type, frequency, intensity, or duration of disturbance

Minimal impact or risk.
  A change in an environmental attribute that will have, or is predicted to have, little or no consequence to the environment.

Native or indigenous species
.  Is one that occurs in a particular place (e.g., habitat and ecosystem) as a result of natural forces, exclusive of human actions. Species native to the US and other parts of North America are generally recognized as those occurring on the continent prior to European settlement.

Natural areas.  Areas with native plant communities supporting native plant and animal species with long undisturbed soil systems and hydrological regimes relatively intact.

Naturalized.  A non-native species or race which, after escape or release, has become established in the wild in self-maintained populations.

Non-native.  (Alien, exotic, non-indigenous) species are those that exist at a site as a result of direct, indirect, accidental or intentional human actions. This term can be used to describe a species introduced to the US from another country or continent as well as a US native species that has been introduced to a part of the US outside of its known natural range.

Noxious weed.  Any plant or plant product that can directly or indirectly injure or cause damage to crops (including nursery stock or plant products), livestock, poultry, or other interests of agriculture, irrigation, navigation, the natural resources of the United States, the public health, or the environment.

Qualitative risk assessment.  An assessment where the conclusions on the likelihood of the outcome or the magnitude of the consequences are expressed in qualitative terms such as high, medium, low or negligible.

Risk.
  The probability of a negative or undesirable event occurring; the likelihood of the occurrence and the magnitude of the consequences of an adverse event; a measure of the probability of harm and the severity of impact of a hazard.

Risk analysis.  The assessment of the consequences of the introduction and of the likelihood of establishment of an alien species using science-based information (i.e., risk assessment), and (2) to the identification of measures that can be implemented to reduce or manage these risks (i.e. risk management), taking into account socio-economic and cultural considerations.

Risk management.
  The process of selection and implementation of options to reduce, to an acceptably low level, the risk of negative impact of introductions or transfers of aquatic organisms; the process of identifying, evaluating, selecting and implementing alternative measures for reducing risk.

Spatial gaps.
  The ability of a species to disperse away from existing occurrences.

Species.  Means a group of organisms all of which have a high
degree of physical and genetic similarity, generally interbreed only
among themselves, and show persistent differences from members of
allied groups of organisms.

Stakeholders.  Means, but is not limited to, State, tribal, and
local government agencies, academic institutions, the scientific
community, nongovernmental entities including environmental,
agricultural, and conservation organizations, trade groups, commercial
interests, and private landowners.

Unintentional introduction.  An unintended introduction made as a result of a species utilising humans or human delivery systems as vectors for dispersal outside its natural range.

Vector.  Any living or non-living carrier that transports living organisms intentionally or unintentionally.

Syndicate content