Definition and Impact of Invasive Species
– Invasive species harm their new environment by overpopulating it.
– They cause ecological, environmental, and economic damage.
– Native species can also become harmful after human alterations to their food web.
– Invasive species have become a serious global threat since the 20th century.
– Human-facilitated introductions have increased the rate and scale of invasion.
Examples of Invasive Plant and Animal Species
– Examples of invasive plant species include kudzu vine, Andean pampas grass, English ivy, Japanese knotweed, and yellow starthistle.
– Examples of invasive animal species include New Zealand mud snails, water fleas (such as Daphnia), feral pigs, European rabbits, and grey squirrels.
Terminology and Research in Invasion Biology
– Alien or naturalized species are not native but established.
– Invasive species are poorly defined and subjective.
– Invasive species can include plants, animals, fungi, and microbes.
– Some include native species that have invaded human habitats.
– The definition of native species can be controversial.
– The study of invasive species is mainly done in ecology and geography.
– Charles Elton’s book influenced the study of invasive species.
– Research on invasive species has grown substantially since the 1990s.
– Field observational studies have focused mostly on terrestrial plants.
– The lack of standard terminology is a problem in invasive species research.
Impact of Invasive Species on Diversity
– Small-scale studies show a negative relationship between diversity and invasion.
– Large-scale studies show a positive relationship between diversity and invasion.
– Invasives capitalize on increased resource availability and weaker species interactions.
– Vertebrate invaders, like the brown tree snake, have a significant impact on native populations.
– Flightless birds on islands are vulnerable to introduced predators.
– Invasive insects, plants, and hoofed animals threaten native plants and animals in Hawaii.
– Dogs, rats, cats, rabbits, and other exotic species heavily impact native wildlife in New Zealand.
– Man-made disturbances, like logging, create spaces for non-native species to establish in Madagascar.
Traits and Control of Invasive Species
– Invasive species have specific traits that allow them to outcompete native species.
– Traits include fast growth, rapid reproduction, high dispersal ability, and phenotype plasticity.
– Invasive species tolerate a wide range of environmental conditions and can live off various food types.
– Association with humans and prior successful invasions are common traits.
– Controlling hull fouling and ballast water are important measures to prevent the spread of invasive species.
– Invasive species can modify abiotic factors, influence soil processes, and physically modify habitats.
– Rapid adaptive evolution and genetic pollution are factors influencing the success of invasive species. Source: https://en.wikipedia.org/wiki/Invasive_species
