Invasive Species Flashcards
have are the two things that have led to dramatic increase in invasive species translocations?
Human movement and international trade
Trade volume is now the strongest predictor of alien species introductions, especially for floras and faunas of island ecosystems (Hulme, 2009; van Kleunen et al., 2015).
what are the two major historical ‘invasion booms’
End of the Middle Ages
Industrial Revolution (Hulme, 2009)
- Today, the Era of Globalisation has intensified the magnitude and diversity of invasions.
what are the two pathways of species invasions?
Intentional introductions (e.g. agriculture, ornamentals)
Unintentional pathways: contaminants, stowaways, and corridors (Hulme, 2009)
what are the traits of successful invaders?
Large litter sizes
Frequent reproduction
Long reproductive lifespans
High propagule pressure (Capellini et al., 2015)
Introduction bias: humans more likely to introduce species with traits that favor establishment and spread (Capellini et al., 2015).
what are two examples of invasives that have led to ecosystem modification?
Water hyacinth: blocks waterways, worsens disease spread, reduces water quality.
Spartina anglica (English cordgrass): converts mudflats to saltmarsh, altering bird habitats.
what are 3 examples of invasive predators and their effects
Nile perch: led to extinction of up to 200 cichlid species in Lake Victoria.
Harlequin ladybird: outcompetes native ladybirds.
Invasive predators like rats dramatically reduce seabird populations, lowering nutrient transport from sea to land and even reducing coral reef productivity (Wilson, 2018).
What are 2 examples of apparent competition with invasives and disease?
Grey squirrels introduced squirrelpox virus, devastating red squirrel populations.
American crayfish brought crayfish plague, wiping out native white-clawed crayfish
What recovery of a species is leading to the reversal of grey squirrel invasion impacts
However, pine marten recovery has begun to reverse this by preying on grey squirrels (Twining, 2022).
how are islands more vulnerable to invasives? what are the impacts of rats as an example?
Islands are especially vulnerable due to evolution in predator-free environments.
300+ bird species impacted by invasive predators like rats and cats.
On rat-free islands, seabird density and nutrient flow to adjacent reefs is dramatically higher (Wilson, 2018).
what is the world undergoing?
biotic homogenisation: widespread generalists replace local endemics, reducing both taxonomic and phylogenetic diversity (McKinney & Lockwood, 1999).
what are the winners and losers in terms of competition in ecosystems? what % of birds, mammals and plant species are the winners and invade?
Winners: Generalist, fast-growing, disturbance-tolerant species (often invasive).
Losers: Specialists, endemics, species with narrow niches or slow life histories.
Only 2% of bird, 1% of mammal, and 2% of plant species are successful invaders, yet they dominate disturbed ecosystems (McKinney & Lockwood, 1999).
what is the trend in future invasions with trade?
Trade is a primary driver of new invasions (Levine & D’Antonio, 2003).
As trade increases, the rate of new species introductions per shipment declines, but cumulative introductions still rise (Levine & D’Antonio, 2003).
what are the methods for prevention and modelling of invasives?
Pathway risk assessment is now central to invasive species management (Hulme, 2009).
- By bringing together spatial data on climate suitability, habitat availability and points of entry, as well a demographic models that include species dispersal (both natural and human-mediated) and measures of propagule pressure, it is possible to generate risk maps highlighting potential invasion hotspots that can inform prevention strategies.
The GloNAF database provides a foundation for understanding plant naturalization patterns, helping to track biodiversity changes, and inform management efforts for controlling invasive species. By examining phylogenetic relationships between native and naturalized species, researchers can gain insights into the ecological impacts and risks associated with these plant invasions (Kleunen et al. , 2015).
How can predation resoration for biocontrol work?
Invasive species are often naïve to native predators—they lack evolved defenses, increasing their vulnerability (Twining, 2022).
Restoring native vertebrate predators (e.g., pine martens, wolves) can suppress invasive species across landscapes (Twining, 2022).
