Quiz 6 and 7

Question 1

According to Hoopes & Hall, which of the following is true about a non-native species that has a lag time between establishment and impacts? (select all that are correct)
The species invades a narrow habitat range
The species is a selective invader
The species is a twin invader

Answer 1

The species is a twin invader

Question 2

Which of the following can affect the impacts of a non-native species? (select all the are correct)
Characteristics of the non-native species
Ecological interactions between the non-native and native species
Characteristics of the environment
History of the non-native species, biotic environment, and abiotic environment

Answer 2

all

Question 3

How did Theile improve the Parker-Lonsdale Ecological Currency Model of non-native species impacts. (select all that are correct)
Accounted for spatial variation in impacts across the non-native species range
Included both economic impacts and ecological impacts measured separately
Only included suitable habitat within the range in estimating the area of invasion

Answer 3

Accounted for spatial variation in impacts across the non-native species range

Only included suitable habitat within the range in estimating the area of invasion

Question 4

The spongy moth is an invasive forest pest in the United States. In the eastern part of its US
range, the spongy moth has periodic outbreaks where it defoliates large areas of forest, and its
range expansion is around 5-10 km per year. In the western part of the spongy moth range, it
does not reach outbreak densities, but has a rapid rate of range expansion of 20 km per year.
Based on what you learned in Lectures 11a&b, does this pattern make sense?

Answer 4

This fits with the finding that invasive species spread is not related to impacts.

Question 5

Do you think Littorina littorea is more of a selective invader or a twin invader. Explain your
reasoning.

Answer 5

Littorina littorea remained undetect for centuries in the Northern Atlantic Ocean. This is more
consistent with a twin invader, which can remain hidden for long periods of time before
increasing in abundance and having impacts.

Question 6

Among the non-native species that you have learned about in this class, can you think of a
species that fits the following…
a) A density impact curve I

b) A density impact curve II or linear

c) A density impact curve IV

Answer 6

a- Morella faya can invade the lava fields in Hawaii and immediately begin increasing the
nitrogen content, which in turn will allow other non-native species to invade the lava fields.

b- The area of disturbance caused by feral pigs is proportional to the density of the feral pigs;
thus, the curve is likely near linear.

c- Zebra mussels in the Great Lakes probably had little impacts until their abundance because
so high that that they covered native mussels and clogged water flow pipes in the lakes.

Question 6

Among the 6 types of theories about invasive species impacts, select the type that best fits each
of the below examples. (Evolutionary-based, niche-based, Abundance, propagule pressure, Community structure hypotheses, Changing Environments (Dynamic Equilibrium Model), Additive and synergistic effects)

a) Spotted knapweed

b) Brazilian pepper produces many seeds with a high success of germination.

c) The Nile perch in Lake Victoria

d) Morella faya in Hawaii

e) The crazy ants on Christmas Island

Answer 6

a) Spotted knapweed
Evolutionary-based and niche-based
b) Brazilian pepper produces many seeds with a high success of germination.
Abundance and propagule pressure
c) The Nile perch in Lake Victoria
Community structure hypotheses
d) Morella faya in Hawaii
Changing Environments (Dynamic Equilibrium Model)
e) The crazy ants on Christmas Island
Additive and synergistic effects

Question 7

What are the advantages to using a) economic currency vs. b) ecological currency to quantify
impacts of an invasive species?

Answer 7

Economic currency is a clear impact that easily understandable across disciplines. However,
estimating economic currency for some invasive species impacts is difficult and subjective.
Ecological currency is easier to quantify for many ecological effects of invasive species, but can
be difficult for non-experts to understand.

Question 8

Where does Kevin Heffernan work?
University of Virginia
VCU
Governor’s Office
Natural Heritage

Answer 8

Natural Heritage

Question 9

What are impacts of two-horned trapa in Virginia? (select all that are correct)
Shades out native submergent vegetation
Shades out terrestrial vegetation at lake edges
Invades highway edges
Affects boating in Virginia waters

Answer 9

Shades out native submergent vegetation

Affects boating in Virginia waters

Question 10

What was the estimated annual economic cost of invasive species in the United States in 2005?
$120 billion
$12 million
$240 million
$2.4 billion

Answer 10

$120 billion

Question 11

What are the two components of risk? (select the TWO that are correct)

Probability of survival
Probability of an event occurring
Consequences if an event occurs
Rate of species accumulation

Answer 11

Probability of an event occurring

Consequences if an event occurs

Question 12

What are some causes of statistical issues that can reduce predictive value of invasive species risk? (select all that are correct)

Stage-specific risk assessment
Dangers of extrapolation
Spurious correlations

Answer 12

Dangers of extrapolation
Spurious correlations

Question 13

Which of the following allow invasive species management to focus on high risk transports? (select all that are correct)

Ecological niche modeling
Airport climatic matching
Identifying taxonomic groups that are particularly invasive
Identifying global hotspots for invasive species

Answer 13

all

Question 14

You want to predict the potential world non-native range of a plant that is native to the
eastern United States. You investigate climatic factors that are associated with the plant
and find that the in the US the plan lives in climates with average summer temperatures
that do not exceed 30 degrees Celsius. Provide alternative explanations for this finding –
one where summer temperature is a causal factor and other where summer
temperature is a spurious correlation.

What may be a way to distinguish between the two scenarios?

Answer 14

• Causal: Summer temperatures may be too hot for the plant, for example, if evaporation
  is too high that it causes desiccation.
• Spurious Correlation: The plant may be able to survive at hotter temperatures, but is
  out-competed by a congeneric species in this hotter part of its range.

Doing a more comprehensive study such as ecological niche modeling. In this case, the
modeling should include biotic factors such as the presence/absence of congeneric
species.

Question 15

Name two reasons why managing a non-native species in the early stages of invasion is
preferred.

Answer 15

• Managing species in the early stages of invasion will avoid most or all of the impacts of
  the species.
• Managing species in the early stages of invasion can i) prevent arrival or establishment
  or ii) result in extirpation of the species in the non-native area, which is much less
  expensive than continual management after the species has spread

Question 16

You are an inspection agent for APHIS at Dulles Airport. A cargo flight is arriving in Washington
DC from Norway. Do you expect this flight to be a high priority for inspection for non-native
species? Why or why not?

Answer 16

The cargo isn’t high priority for inspection because the climates in Washington DC and Norway
do not match. Only perhaps the very northeastern part of the US around main may be a region
of concern, but that isn’t enough to raise the risk level to high

Question 17

In your role as an inspection agent for APHIS, you are working at the Port of Baltimore. A ship
arrives from Spain, a high risk donor of invasive species in the United States. APHIS is terribly
understaffed and it is your job alone to inspect the cargo. It is impossible to inspect it all, so you
must decide what to inspect. You look over the manifest and see three shipments of ornamental
plants: i) tropical orchids, ii) palm seedlings, iii) water lilies, and iv) a mix of flowering plant seeds
from a grassland region of Europe. You only have the ability to inspect two of these shipments.
Which two do you choose and why?

Answer 17

While all of these could potentially be invasive or be incidentally carrying seeds or other life
stages of invasives, I am most concerned about the water lily shipment and the mix of flowering
plant seeds from grasslands. Water lilies are aquatic plants, and we know that aquatic and
subaquatic plants tend to have a greater likelihood of being invasive than other plants. Similarly,
the mix of flowering plant seeds is likely to have grass seed mixed in, and we know that grasses
are a major group of invasive species worldwide.

Question 18

What is the ‘niche conservatism hypothesis’?
The niche that a species occupies in its non-native range will be broader that the niche it occupies in its native range.
The niche that a species occupies in its non-native range will be different than the niche it occupies in its native range.
The niche that a species occupies in its non-native range will be similar to the niche it occupies in its native range.

Answer 18

The niche that a species occupies in its non-native range will be similar to the niche it occupies in its native range.

Question 19

What is COUE? (select all that are correct)
A method that is more robust and introduces less bias than other methods used to test the ‘niche conservatism hypothesis’.
A method for quantifying the similarity of native and nonnative ranges for a species
A unified terminology representing Centroid shift, Overlap, Unfilling, and Expansion when comparing native and nonnative ranges.

Answer 19

all

Question 20

What taxonomic group had the greatest similarity in niche space between native and non-native regions?
Terrestrial Endotherms
Plants
Aquatic Species
Terrestrial Ectotherms

Answer 20

Plants

Question 21

Define the following terms (and which is typically larger than the other).
a. Fundamental niche

b. Realized niche

Answer 21

a- The entire set of abiotic conditions under which a species can live and reproduce.

b- The realized niche is the set of conditions which a species can live and reproduce after
considering biotic interactions.

Question 22

a. What method did the authors use to test the ‘niche conservatism hypothesis?

b. What are advantages of this method?

Answer 22

a- The COUE scheme, which considers multiple ways ranges may be similar (or differ)
based on Centroid shift, Overlap, Unfilling, and Expansion.

b- The COUE scheme 1) has the convenience and robustness of ordination approaches (i.e.,
where many factors are effectively combined to create a few manageable factors), 2)
overcomes biases due to differences in spatial resolution of data and/or sampling effort,
3) is useful for linking the continuous process of niche shifts to binary conclusions (i.e.,
conserved or not conserved).

Answer 23

Preadaptation to similar climates:
Species introduced to climates resembling their native range are more likely to thrive, reducing the need for niche shifts in new environments.

Limited genetic diversity in introduced populations:
Invasive species often come from specific native lineages, representing only part of their native climatic niche. Random introductions can limit genetic mixing, preventing niche expansion in new areas. (diosyncratic (specific random) species introductions

Question 24

How does increased propagule pressure likely affect niche similarity between native and non-
native ranges?

Answer 24

• Greater propagule pressure is probably related to higher niche similarity because more of the
  genetic variation of the non-native species will have been introduced to a great range of the
  non-native habitat.

Question 25

Which of the following should be considered when designing a program to manage invasive species? (select all that are correct)

Public education of the invasive species, impacts, and management program
The economic costs/benefits
Optimal methods to control or eradicate the invasive species

Answer 25

all

Question 26

What did Shea et al. (2005) recommend for biocontrol of the nodding thistle in Australia and New Zealand?
The thistle weevil would be the most effective biocontrol agent
The most effective biocontrol agent would be determined by the demography of the nodding thistle in each geographic region
Neither biocontrol agent would be effective
The root-crown weevil would be the most effective biocontrol agent

Answer 26

The most effective biocontrol agent would be determined by the demography of the nodding thistle in each geographic region

Question 27

What was the most cost effective action to deal with the reduction in water for the city of Cape Town, South Africa due to invasive woody plants?
Build water treatment plants to reuse sewage
Build desalinization plants
Build a dam(s) to store water in reservoirs
Manual removal of the invasive species

Answer 27

Manual removal of the invasive species

Question 28

What are two ways to reduce the cost of eradication/management of non-native species?

Answer 28

Early detection and early action when the non-native range is small.

Create a management plan that will optimize efforts of eradication/management on a cost basis

Question 29

Describe the methods used by Odom et al. (2003) to determine whether management of Scotch
broom would have a net benefit.

Answer 29

With the model they evaluated real life policy scenarios to assess cost/benefits. In the
optimization analysis, the authors incorporated costs of the management (control) options, and
the economic losses to recreational use and biodiversity by the Scotch broom. They found that
implementing Scotch broom control measures would have a net benefit of approximately $21
(Australian) per hectare.

Question 30

What options were considered for dealing with water shortage caused by invasive woody
species in Cape Town? What method was the most economical? What other benefit did the
‘best’ solution provide?

Answer 30

They considered 1) physical removal of non-native woody plants, 2) building desalinization
plants, 3) dam construction, and 4) treatment and reuse of sewage. They found that the physical
removal of non-native woody plants was the most economical. A side benefit of the woody plant
removal was employment for disadvantaged workers

Question 31

What is a major reason why eradication of the painted apple moth in New Zealand was a
success, but eradication of the light brown apple moth in California was a failure?

Answer 31

In New Zealand, the management program allocated substantial resources toward public
education before protests could control the narrative and (potential) spread untruths and
rumors.
In California, the public education campaign for painted apple moth came too late, which let the
protests control the narrative, and untruths and rumors take hold. At that point, it was too late
to change the narrative.

Question 32

Describe three examples of unintended consequences of invasive species management.

Answer 32

i) Eradication of feral cats on Macquarie Island (a world heritage site), allowed a
population explosion of non-native rabbits.
ii) The removal of feral goats and pigs in the Northern Mariana Islands allowed a
previously undetected non-native vine to spread across the island in high densities.
iii) Removal of the invasive Spartina grass in San Francisco Bay also removed habitat for
the native clapper rail.

Question 33

How might climate change benefit non-native sea squirts in the North Atlantic Ocean? (select all that are correct)
Warming waters would create a phenological shift in recruitment (reproduction) to earlier in the Spring, which may give an advantage over native sea squirts.
Warming waters would eliminate predators of the non-native sea squirts.
The collapse of the Gulf Stream would result in cooler waters, which the non-native sea squirts prefer.

Answer 33

Warming waters would create a phenological shift in recruitment (reproduction) to earlier in the Spring, which may give an advantage over native sea squirts.

Question 34

Which of the following would be a benefit of using invasive species as biofuels? (select all that are correct)
Could help offset costs of invasive species management.
Some invasive species have characteristics that make them more attractive for biofuels programs than the typical plants corn and soybean.

Answer 34

both

Question 35

According to the lecture, which stage(s) of invasion may be affected by the opening up of arctic trade routes (select all that are correct)
Arrival
Spread
Impact
Establishment

Answer 35

Arrival
Establishment

Question 36

Explain how warming Arctic waters may change patterns of non-native species arrival?

Answer 36

Ice melt will open existing shipping rounds for longer each year, and open a new shipping route
called the northwest passage. This will significantly shorten the travel time that invasive species
will arrive and broaden the season in which non-native species can arrive. This allow a more and
a broader species pool of non-native species to arrive in better physiological condition. This
would result in higher propagule pressure, which is predicted to increase the probability of
establishment of more species.

Question 37

What are two ways that a changing climate could increase establishment of non-native species?

Answer 37

• Allow more non-native species to be a part of the species pool of potential invaders.
• Altering the native climate may have negative effects on the native biotic community,
  which in turn could lower biotic resistance to invasion.

Question 38

What are ways that climate change could affect the pattern of non-native species spread?

Answer 38

• Warming temperatures could allow spread to historically cooler climates – typically to
  higher latitudes and higher elevations. Also, could cause range retractions in the
  historically warming parts of the invasive range due to exceeding maximum
  temperatures. Similarly, changes in precipitation could affect species ranges, maybe
  interactively with temperature.
• Warming could increase reproductive opportunities by increasing the growing season
  and increasing the number of generations per year, each of which would typically
  increase population growth rate, which is a component of spread.
• Also, could increase the time available for a non-native species to disperse.

Question 39

What are pros and cons of using invasive species as biofuels?

Answer 39

Pros:
* Sustainable energy source
* Economic compensation which reducing impacts of an invasive species.
Cons
* Biofuels are not as efficient as fossil fuels in the conversion to energy
* Could encourage spread of invasive species, e.g., farming

Question 40

Which of the following are potential consequences of climate change for invasive species as identified by Hellmann et al.?

Decrease in invasibility of native habitat
A general reduction in risks of invasive species
Altered transport and introduction methods
Establishment of new invasive species
A general increase in invasive specie adaptiveness to non-native habitat
Altered distributions of existing invasive species
Altered impacts of existing invasive species
Altered effectiveness of control strategies
Reduced invasibility of regions in high latitudes
Disproportionate increase in invasibility of marine habitats

Answer 40

Altered distributions of existing invasive species
Altered impacts of existing invasive species
Altered effectiveness of control strategies
Altered transport and introduction methods
Establishment of new invasive species

Question 41

Native and non-native species both respond to a changing climate. So what reasons do
Hellmann et al. give for considering climate change effects to native and invasive species
separately?

Answer 41

• Invasive species are typically abundant, while native species are often rare.
• Invasive species often have broader climatic tolerances.
• Invasive species often have traits that allow for rapid range shifts.
• Invasive and native species are managed differently – with different outcome goals –
  resulting in opposite sets of concerns regarding the effects of climate change
  Dr. Johnson would also say that because native have an evolutionary history with the native
  biotic community, while non-native species do not, this may result in differing responses to a
  changing climate.

Question 42

What is the “Invasion Pathway”, which the authors used as a framework to assess the effects of
climate change on invasive species?

Answer 42

In this class we learned the Invasion Pathway under a different name – The Stages of Invasion –
albeit with some variation in definitions of the stages

Question 43

Give an example (empirical or hypothetical) for each of the 5 consequences of climate change
for invasive species.
a. Altered transport of invasive species

b. Altered climatic constraints on invasive species

c. Altered distributions of existing invasive species

d. Altered impacts of existing invasive species

e. Altered effectiveness of management strategies

Answer 43

a. The opening of sea ice around the north pole opens shorter routes and for longer seasons,
potentially allowing more species to arrive in better physiological condition.

b. Warming climate could allow colonization/ establishment by an arriving species that was previously unable to invade a certain region. A hypothetical example in the paper is an
invasive species of mussel in South Africa that could become invasive in Antarctica as ocean
waters warm.

c. Similar to (b), but in this process existing invasive species would expand their current non-
native range as a climate changes. For example, the sea squirts (ascidians) expansion on the
U.S. Pacific coast.

d. Increased water limitation due to drought-inducing climate change in the Southwestern U.S.
may increase the perceived impacts of the invasive plant Tamarix, which is known for its
ability to take water from soils.

e. Climate change may increase or decrease the effectiveness of current management
strategies. If warming reduces or eliminates the freeze-inducing dieback of some invasive
species, current management strategies may not meet current goals. In contrast, sea level
rise could hypothetically work to the advantage of efforts to manage invasive coastal plant
species, such as Spartina on the Pacific Coast and Phragmites on the East Coast of the U.S.

Question 44

qq: The founder effect will be greater when…
A low number of individuals are introduced
b. The introduced individuals are all unrelated
c. The population growth rate of the introduced population is high
d. All answers are correct

Answer 44

low number of individuals are introduced

Question 45

qq: How did geographic variation in the non-native fly Drosophila subobscura mimic geographic variation in the fly’s native range?
a. Populations in colder climates evolved shorter generation times
b. Populations in colder climates evolved larger wings
c. Populations in Los Angeles (but not San Francisco) became cryptic species
d. All answers are correct

Answer 45

Populations in colder climates evolved larger wings

Question 46

qq: Which of the following will increase genetic drift in a small population, for example, of a nonnative species?
a. Unequal sex ratios
b. Social mating systems where only a small proportion of individuals reproduce
c. Random factors
d. All answers are correct

Answer 46

d. All answers are correct

Question 47

qq: Which of the following is an example of a non-native predator that caused mass extinction in a native community?
Feral sheep
Brown trout
Rainbow trout
Nile perch

Answer 47

Nile perch

Question 48

qq: Which of the following is an example of a non-native competitor that had an impact on a native ecosystem?
a. Morella faya
b. Spotted knapweed
С. Rosy wolf snail
d. Pacific rat

Answer 48

Morella faya

Question 49

qq: What does a larger size distribution of tuataras on islands shared with Pacific rats tell us about the impacts of the rats on tuatara populations?
a. The rats are killing competitors of tuataras, allowing them to grow larger.
b. The tuataras feed in the rats, allowing them to grow larger.
C. The rats and tuataras form social packs that allow them to more efficiently hunt for
prey.
d. The rats are killing the tuatara eggs and young tuataras, which removed all young from the population and prevents reproduction of tuataras.

Answer 49

d. The rats are killing the tuatara eggs and young tuataras, which removed all young from the population and prevents reproduction of tuataras.

Question 50

qq: How does hybrid vigor impact the native species?
Causes introgression of non-native genes into the native population.
Gives the non-native species a competitive advantage.
Reduces the competitive ability of a native species.
Reduces the competitive advantage of the hybrid.

Answer 50

Reduces the competitive ability of a native species.

Question 51

qq:Which of the following statements about the non-native brown anole in Florida is true?
a. The Florida population has a higher genetic diversity than populations on any of the native Caribbean Islands because of multiple introductions to Florida.
b. The Florida population has a low genetic diversity due to the bottleneck effect.
c. The Florida population has a high genetic diversity due to rapid evolution of the nonnative population.
d. The Florida population has a low genetic diversity because it was only introduced into Florida one time.

Answer 51

The Florida population has a higher genetic diversity than populations on any of the native Caribbean Islands because of multiple introductions to Florida.

Question 52

qq: A species of marsh grass is introduced into a non-native region. The nonnative marsh grass doesn’t invade, but when it crosses with a native marsh grass, the offspring become highly invasive. What is the name for this phenomenon?

Bottleneck effect
Founder effect
Ecosystem impacts
Hybrid vigor

Answer 52

hybrid vigor

Question 53

qq: According to Borden & Flory, how could evolution in urban environments enhance species invasion?
a. By altering traits that are beneficial under urban conditions, which could then promote spread into non-native urban areas.
b. By altering traits that could promote spread; for example, the ability to disperse in highly fragmented habitats.
c. By altering traits that provide invaders with a head-start in adapting to future global conditions.
d. All answers are correct

Answer 53

d. All answers are correct