Invader potential
Encyclopedia
In conservation biology
, invader potential is the qualitative and quantitative measure of a given invasive species
probability to invade a given ecosystem
. Exotic species with high invader potential are ones with high tolerance of different climates, dissolved oxygen content
(for aquatic organisms), high propagule pressure
and species with a large number of individuals introduced. The last factor is called a transport vector, for instance, sea lamprey
s and zebra mussel
s were transported into the Great Lakes
through the vector of ballast water in ships. Transport vector is one of the most important factors, because if a large enough number of individuals are transported to an area that they cannot thrive in, a mutation within that population to thrive in the new ecosystem is more likely.
Most invaders are adapted to disturbed areas, so ecosystems that have been disrupted or roadside ditches are susceptible to invasion.
Climate matching is one of the most common measures of invader potential. Mostly exotic species that have already exhibited invasive traits are studied.
Biotic resistance is a controversial concept in invader potential. Small scale studies have borne the concept of diversity resistance, that diverse ecosystems resist invasions better than less diverse ecosystems. However, evidence on regional scales finds a positive correlation between diversity and number of invasions. The exact interpretation of these studies is unclear.
Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...
, invader potential is the qualitative and quantitative measure of a given invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
probability to invade a given ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
. Exotic species with high invader potential are ones with high tolerance of different climates, dissolved oxygen content
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
(for aquatic organisms), high propagule pressure
Propagule pressure
Propagule pressure is a composite measure of the number of individuals of a species released into a region to which they are not native. It incorporates estimates of the absolute number of individuals involved in any one release event and the number of discrete release events...
and species with a large number of individuals introduced. The last factor is called a transport vector, for instance, sea lamprey
Sea lamprey
The sea lamprey is a parasitic lamprey found on the Atlantic coasts of Europe and North America, in the western Mediterranean Sea, and in the Great Lakes. It is brown, gray, or black on its back and white or gray on the underside and can grow up to 90 cm long. Sea lampreys prey on a wide...
s and zebra mussel
Zebra mussel
The zebra mussel, Dreissena polymorpha, is a small freshwater mussel. This species was originally native to the lakes of southeast Russia being first described in 1769 by a German zoologist Peter Simon Pallas in the Ural, Volga and Dnieper rivers. They are still found nearby, as Pontic and Caspian...
s were transported into the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
through the vector of ballast water in ships. Transport vector is one of the most important factors, because if a large enough number of individuals are transported to an area that they cannot thrive in, a mutation within that population to thrive in the new ecosystem is more likely.
Most invaders are adapted to disturbed areas, so ecosystems that have been disrupted or roadside ditches are susceptible to invasion.
Climate matching is one of the most common measures of invader potential. Mostly exotic species that have already exhibited invasive traits are studied.
Biotic resistance is a controversial concept in invader potential. Small scale studies have borne the concept of diversity resistance, that diverse ecosystems resist invasions better than less diverse ecosystems. However, evidence on regional scales finds a positive correlation between diversity and number of invasions. The exact interpretation of these studies is unclear.