Invasive Species Flashcards
What is the driving force behind biodiversity loss?
Human activities
What % of species imported appear in the wild?
10%
What % of species become established?
10%
What % of species become a pest?
10%
What is the rule?
10% rule
Give three examples of the types of invasive species
Predator
Parasite
Parasitoid
Give three more examples of the type of invasive species
Pathogen
Herbivore
Swamping (growing in dense concentrations)
Give an example of an invasive parasite
the isopod that has invaded mud shrimp
How does the isopod affect mud shrimp?
Enters the gill chamber, sucks the blood and destroys the ability to reproduce
Invasive species are an important component of what?
Evolutionary processes
How are most invasive species introduced?
Purposely mediated human introductions as garden plants
Horticultural industry
Farming
Accidental
Do all introductions have negative effects?
No not all
Give an example of how one invasive plant can have a positive impact on native biodiversity
Himalayan Balsam has the ability to offer a valuable nectar source for pollinators in later summer months
In the UK, what percentage of plant species are non-native?
10%
Give an example of the percentage of non-native species found in another country
In New Zealand up to 50% of the plant species are non-native
Give an example of the rate in which a species can invade
Himalayan Balsam was introduced as a garden plant in 1839 and quickly adapted to the environment, reproducing in large numbers (Hedja, 2009).
Give a characteristic of a why an invasive species may be successful
Himalayan Balsam has an ability to literally launch its seeds over a distance of 3-5 meters (Ammer, 2011) and using river habitats to disperse further
How can some native species be vulnerable to invasion?
Some plant species may be specialist in their habitat requirements, and invasive alien species are normally generalist species
What makes a good invasive species?
High productive rate
Broad habitat requirements
Good dispersal
What makes s good habitat for invasion?
Early successional area
Disturbed areas
Why are remote islands good for invasive species?
Low taxonomic diversity
Empty niche space
No predators
Define invaders
A species from somewhere else
Define Weed or pest
A species that someone would like to remove
Give an example of two stowaways
Black rat and house mice
Give an example of an invasive mammal in the UK
The Rabbit
Where are rabbits native?
The Iberian peninsular
Are rabbits invasive in their native range? And if not, what are their characteristics
Never a pest, smaller and mature earlier
Lower reproduction rate
When were rabbits introduced into the UK?
12th Century
How did rabbits evolve?
They became more hardy and prolific
How did agriculture help rabbits?
Winter crops facilitated their establishment
Give an example of an invader that has impacted the rabbit invader
Mixamatosis
What is mixamotosis?
It’s a virus spread through insect transmission
What impact can Himalayan balsam have on river banks?
It can outcompete native plant communities by competing for space, light and nutrients and during winter can result in the erosion of river banks
Give an example of an invasive duck in the UK
The Ruddy Duck!
When was the ruddy duck introduced?
1948
How many breeding pairs of Ruddy Duck were introduced? And in what year?
Three breeding pairs in 1948
What was the population of Ruddy Duck by 1992?
3500
What percentage did the ruddy ducks population increase each year?
15%
What happened as the Ruddy Duck spread through Europe and Iceland?
It hybridized
What is the name of the duck species that the Ruddy Duck interbred with in Europe?
The endangered white headed duck
Give an example of an invasive pathogen
Ash dieback
What factor can increase invasive species and why?
Climate change can increase invasive species spread by creating suitable conditions for invasive species to colonise
Give an example of the impact an invasive species can have on native plant communities and pollination
Himalayan Balsam can disrupt native plant-pollinator relationships resulting in a reduction in genetic diversity (Truscott et al., 2008)
How can some species be introduced accidently?
Some species can be introduced accidently by transport (I.e. seeds stuck on car tyres).
Give an example on the extent of a species introduction from one plant
Japanese knotweed established itself from one individual plant and spreads through rhizomes. It outcompetes and destructs habitats
How can some species of invasive plants facilitate their survival?
Dispersal methods and mutualistic bonds with pollinators
Give an example of how invasive plants can have a positive effect on pollinators?
It can provide a nectar source, and increase their geographical range
Explain how Himalayan Balsam can be hardy in terms of its seeds?
Its seeds can last up to 18 months allowing it to easily recolonize
Why else may Himalayan Balsam be popular with native pollinators?
It’s brightly coloured and attractive petals (purple and blue).
