Invasion basics and human vectors of dispersal Flashcards
(11 cards)
1
Q
species invasion definition
A
spread and establishment of a self-sustaining population into a region beyond its natural historic range
2
Q
Traits of natural invasions
A
- small scale
- movement along corridors
- rare on human time frame
- predictable
3
Q
Traits of human invasions
A
- movement across barriers
- long distance jumps
- many species per event
- difficult to predict
4
Q
Tens rule
A
10% of species are able to establish, 10% of these species are invasive.
5
Q
The 4 barriers to species invasions
A
- Geographic barriers
- Physiological barriers
- Demographic barriers
- Biotic resistance
6
Q
Intentional release of species that break geographic barriers - ways this happens
A
- wildlife stocking
- biocontrol
- cultured organisms
- pet release
7
Q
Unintentional release of species that break geographic barriers
A
- attach to animal or human imports
- escape from cultures
- fishing and boating
- container traffic
- canals
8
Q
cryptogenic species
A
species whose origin we are unsure of - this means we underestimate rates of species invasions
9
Q
Physical factors contributing to species surviving ballast
A
- Increase ship traffic (more trips, shorter trips)
- Better ship design (larger ballast tank, move faster)
- Opening of Panama and suez canal (warmer, faster)
- Better water quality in harbours (more spp in harbour)
- Estuarine water in ports
10
Q
Biological traits for success of species in ballast
A
- Planktonic life stage
- Broad temperature and salinity tolerance
- Tolerance for anoxic conditions
- Can feed in the dark
- Preference for cryptic habitats
- Can withstand starvation
- Ability to delay metamorphosis
- Ability to encyst - form a resting stage
11
Q
What explains the tens rule?
A
- Survival and abundance
- Species are often introduced to unsuitable habitats
- Species are often introduced in too small of a number
- Species are often introduced to places from which they cannot easily spread
