16 - Invasive Species

Question 1

why aren’t polar bears in antarctica?

Answer 1

dispersal barrier

Question 2

what prevents species from dispersing globally?

Answer 2

geographical barriers such as oceans, mountains, deserts, lg lakes

Question 3

who is the “father of biogeography”?

Answer 3

Alfred Russel Wallace

Question 4

what did alfred do

Answer 4

outline 6 global biodiversity realms

each divided by geographical barriers

Question 5

what global biodiversity realms are we talking about in this class?

Answer 5

nearctic

palaearctic

Question 6

define invasive species

Answer 6

Species that is exotic and a considered to be a threat

Question 7

species are being spread at _____ times greater rate than natural dispersal bc of humans

Answer 7

50, 000

Question 8

define exotic species

Answer 8

from another part of the world

Question 9

define introduced species

Answer 9

implies introduction but not a threat

Question 10

define alien species

Answer 10

implies introduction to a particular ecosystem

Question 11

define invasive species

Answer 11

exotic AND a threat to native species

Question 12

define non-native species

Answer 12

species introduced by humans and includes those that naturally invade as a result of human-caused envr changes

Question 13

list the 5 steps in the classical mode of invasion

Answer 13

regional species pool
biogeographic filter
physiological filter
biotic filter
local assemblage

Question 14

what 3 factors are needed for establishment?

Answer 14

dispersal across barriers
colonization in acceptable numbers
successful reproduction

Question 15

at what step does human introductions interfere?

Answer 15

biogeographic filter

Question 16

list two introduced species discussed in class

Answer 16

european starling

crested mynah

Question 17

what allows invaders to invade?

Answer 17

broad environmental tolerance

local adaptation

Question 18

Evolution of Increased Competitive Ability Hyp

Answer 18

1. usually a lag period between the time of introduction and point its considered invasive
2. invasive plants seem to be more virulent in introduced habitats compared to native habitats

Question 19

under identical growing conditions, species will produce ____ biomass in area where its been introduced vs native

Answer 19

more

Question 20

invasive species will exhibit ___ herbivore defense rates in introduced range

Answer 20

lower

Question 21

___ fitness when it becomes invasive than at time of intro

Answer 21

greater

Question 22

example of non-native plant in MB talked about in class

Answer 22

purple loosestrife

Question 23

Describe the “enemy release” hyp

Answer 23

species in native range are suppressed by natural enemies.
when in new area, alien species often arrive as seeds so they have escaped from their enemies and are no longer affected by biotic constraints

Question 24

T/F invasives accumulante pathogens @ faster rate

Answer 24

False

bc they escape harmful pathogens when invading foreign territory

Question 25

virus vs fungi as pathogens

Answer 25

viruses are much more easily transported and have a broader range of hosts than fungi

Question 26

pros and cons of escape from biotic constraints hyp

Answer 26

pros: intuitively clear, strong evidence in many cases, underlying concept for biological control cons: assume: native specialist enemies left behind, host swiping doesn't occur. other stuff

Question 27

two hypotheses for what makes a species invasive

Answer 27

Enemy release | Biodiversity hyp

Question 28

Explain the biodiversity hypothesis | what is this for?

Answer 28

what makes a species invaisve high biodiversity - high community stability TF stable communities are not invaded

Question 29

T/F invaders do better with increased native diversity

Answer 29

False

Question 30

how does vulnerability to invasive species change WITHIN ecosystems and AMONG ecosystems

Answer 30

within = more species, less invasable among = more diverse systems, more vulnerable

Question 31

T/F native species diversity generally decrease with increasing latitude

Answer 31

True

Question 32

T/F non-native species diversity generally decreases with increasing latitude

Answer 32

IDK - little understanding of status of invasive species in the boreal forest

Question 33

why is there little understanding of the status of invasive species in the boreal?

Answer 33

extreme climate, low biodiversity, poor resource availability are hostile to introduced spp much of the forest is undisturbed - reducing susceptibility researchers aren't looking

Question 34

why is boreal forest resistant to invasion by exotic plants?

Answer 34

- most invasive plants are weedy and those don't do well in boreal conditions (low light, low nutrients, low ph) - native species with higher recruitment, survival and growth - distance from seed source populations - low anthropogenic dist - non-vascular plants are large component of the plant community

Question 35

__ % of non-native plant species were deliberately introduced to canada

Answer 35

58%

Question 36

list modes of entry of non-native species into canada

Answer 36

- ballast of sailing ships - dung/fur of domestic animals - ornamental trees & shrubs - airplanes and ships - untreated solid wood packing materials

Question 37

methods of deliberate introductions

Answer 37

- silk production - ornamentals - forage/food crops - research - biological control - improving soil conditions

Question 38

how are humans aiding in the movement of established non-native species in the boreal?

Answer 38

- commercial transport of goods - hitchiking on humans/means of transportation/pets - abandonment of bait in natural areas (worms) - creation of disturbed habitats that promote dispersal

Question 39

2 examples of mammals that humans have increased the geographical range of intentionally

Answer 39

moose on newfoundland wtd to antipasti island in self of st lawrence

Question 40

non-native biota of the boreal zone mostly associated with disturbed ________ habitats

Answer 40

anthropogenic habitats

Question 41

at what level of disturbance is diversity highest for native and end exotic species?

Answer 41

native: intermediate disturbance hyp exotic: higher with greater anthropogenic disturbance

Question 42

T/F management of non-native species is most commonly initiated when the species is considered to have a negative effect on commercial-economic interests

Answer 42

T

Question 43

4 diseases from non-native species

Answer 43

west nile virus dutch elm disease infectious salmon anemia chronic wasting disease

Question 44

T/F plants and inverts make up the most invaders in the great lakes

Answer 44

T

Question 45

what is the most significant invasion vector in the st lawrence seaway? why?

Answer 45

ships | ballast water

Question 46

3 ways to determine where the invasive species originated

Answer 46

track vector look @ pathways of airlines/ships assess genetic composition of pop's in introduced areas and source areas

Question 47

most invaders began in ____

Answer 47

northern black sea region | ~Eastern Europe

Question 48

list some aquatic invasive species

Answer 48

fishhook flea spiny waterflea zebra mussels

Question 49

greatest threat to biodiversity of native zooplankton communities on canadian shield since acid rain

Answer 49

spiny waterflea

Question 50

what can be done for invasive species?

Answer 50

provincial, federal and international cooperation - strategies address the threat - ballast water regulations - laws passed in 2006 greatly reducing aquatic species invasions to the great lakes