Invasive Species Flashcards
(31 cards)
1
Q
What is an invasive species?
A
- species that occur outside of their natural range due to human activities
2
Q
Why do most introduced exotic species not become invasive?
A
- unsuitable habitat, too low numbers to become established, ecological controls in place in new habitat to prevent this
3
Q
What is ecological release?
A
- when a species expands its niche within its own habitat into a new habitat where there is little competition for resources, which remain abundant
- sp introduced to islands also experience competitive release
4
Q
What are the four main causes of introductions?
A
- European Colonization
L> settlers released various bird, mammal and fish sp - Agriculture, horticulture, aquaculture
L> ornamentals, agricultural crops, pasture grass, soil stabilizers - Accidental transport
L> ballast water, planes etc - Biological control
L> species introduced to control invasive
5
Q
What are some examples of invasive sp?
A
- zebra mussel in great lakes
- round goby in great lakes
- yellow crazy any on Christmas island
6
Q
What are the impacts of aquaculture on native species?
A
- water pollution
L> via food, drugs/chemicals used to treat fish, fish waste etc - risk of pathogen /parasite transmission between farmed and wild populations
- fish predators can become entangled in nets
- escaped fish , adapted for life in farm, can breed with locals, leading to increases in maladapted genes in wild populations
7
Q
Explain the example of biocontrol for water fen.
A
- introduced to australia from Brazil
- deliberately released weevils to bring moelstra levels down at Lake Moon Darra (looked completely green from overgrowth)
- within one year fen biomass went down to 1 metric ton (use to be 50,000)
8
Q
Provide an example of how native sp can benefit from disturbance.
A
- coyotes
- spreading via human activity
L> creation of acceptable habitat
L> removal of competitors (wolves)
9
Q
Explain genetic swamping within an invasive species concept
A
- genetic swamping is the loss of unique haplotypes within native species through hybridization with closely related introduced species
10
Q
Give an example of genetic swamping
A
- northern crested newt
- threatened
- hybrids with invasive T.carnifex = genetic pollution
- mixed populations now and few that are pure
11
Q
Explain how cats are invasive on islands
A
- feral cat colonizes introduced to many islands
- large impact one endemic species esp birds
- humans often responded to loss of endemics by trying ti kill feral cat colonies with some success
- BUT sometimes this results in indirect effects resulting in a loss of wildlife via species interactions
12
Q
Relationship between rats and cats on islands and indirect species effects?
A
- where cats have been introduced so have rats
- cats will preferentially eat rats
- rats both compete with, and prey on, local wildlife
- reducing feral cat colonies can cause rat populations to increase, which causes larger crash in wildlife than if cats were still present
13
Q
Explain how controlling invasive species occurs and troubles associated.
A
- typically requires altering habitats to favour natives
- customs restrictions prohibiting transport and introduction of exotics
- inspected plants, animal soils, other bio materials being transported to prevent pest and pathogen transmission
- potential biological control programs -> resulted from carefully testing
- controlling typically is costly and difficult
14
Q
Are all invasive sp bad?
A
- no
- context dependent
- european honey bees for ex
- invasive plants that provide for other sp in disturbed habitat etc
15
Q
Explain the situation of climate change in Mount Loa, Hawaii
A
- human activities (burning fossil fuels, deforestation) increase atmospheric CO2
- higher atmospheric CO2 has been linked to past global warming events
- Mount Loa observatory set up to measure CO2 in atmosphere
- Seasonal CO2 variations - effects of PS (spring/summer) and decay (fall) of plants / leaves (largely plants in North)
16
Q
How does CO2 vary with seasons?
A
- CO2 levels peak in April nd lowest in Oct/Nov
- cellular respiration is occurring prior to Oct/Nov, no leaves on most plant so PS isn’t happening, not sequestering carbon
17
Q
Does CO2 have the greatest warming potential?
A
- no but it has the greatest concentration
18
Q
What is climate change velocity?
A
- proportional to distance that has to be traveled across the earth to maintain temperature as climate changes
L> doesn’t look at rain but this also influences velocity
19
Q
What species are at greatest risk to increasing climate change velocity?
A
- species with lower dispersal
L> risk exitniciton if velocity of change too fast for them to keep up
L> may not be able to move up elevations, even if velocity is low
20
Q
What is one potential management solution for poor disperses in the face of increasing climate velocity?
A
assisted migration - could we help them move into suitable habitat? Is this a good idea?
21
Q
What are some examples of range shifts via climate change?
A
- Edith’s Checkerspot Butterfly
- Red foxes
L> moving northward into tundra, outcompete arctic foxes, also sometimes preys on them - Trees
L> tree line shifting northward, advancing treelike into tundra –> spruce trees and shrubs in N Canada now…
L> tree lines shifting upslope in mountain habitats –> Alpine plants moving up Swiss Mountains
22
Q
How is spring arrival determined ?
A
- budbrusts on trees
- arrival of first migrant birds, butterflies
- first flights of insects ending diapause
- ice breakup in lakes and rivers
23
Q
How is climate change influencing seasonality?
A
- spring is arriving early
- fall is occurring later
24
Q
Why do we care about spring moving forward and fall starting later?
A
- growing season
- opening of waterways for travel
- end of harsh winters
25
What is happening with cherry blossoms in Japan?
- earlier bloom time
- bloom advance and acceleration matches fossil fuel brining and acceleration of fossil fuel use
* evidence of climate change
26
Why are longer summers bad?
- insect explosions
- overwintering beetles killed if temps reach -25
- warm winters means beetle pop explosions
- pine beetles are experiencing booms bc of this..killing lots of lodgepole pine
- they also get a longer growing season and can overexploit food supply
27
How does climate change influence invasive species?
- RANGE SHIFTS
| - diseases and pests...like avian malaria, pine blister rust. pine moth etc increase range and moving into new areas
28
Insect explosion examples?
- pine beetle
- mountain pine beetle
- Bark beetle
L> increased temp have caused bark beetle pop to explode and drought in pine forests.
29
How does long summer impact water flow?
- snow pack declining in size and melting earlier due to long summers and short winters
- water flow ins streams and rivers decreases bc it is fed by melting snow in spring, and max flow occurs earlier in season bc spring advanced and less snow build up
- increased drought occur impacting riverine and riparian vegetation, can lead to increased risk of forest fires
- loss of cold water sp at high elevations bc rivers are smaller, warmer and less oxygenated via less water influx
30
What example did we touch on in class for climate change and extinction?
- Monteverde golden toad
- Costa Rican rain forests are hotter and drier, favouring fungal outbreaks, causing skin disease in toads killing them
L> linked to global warming and introduced chytrid fungus
31
The boreal forests in Canada are currently
experiencing a range expansion northward, but are potentially also at risk of being greatly
harmed by climate change.
- can only expand so far
- angiosperms cannot handle severe winters..so as climate change happens they move up and out compete boreal sp
- range expansion of invasive sp (like pine beetles)
- more forest fires , more severe forest fires in the future.
- drought is also an issue...a lot of these sp cannot reproduce successfully without enough water
** all reasons why we are concerned about the boreal forest even though they are getting a range expansion
