Lecture 2: Are Invasions a Unique Form of Global Change? Flashcards Preview

Ecology of Species Invasions > Lecture 2: Are Invasions a Unique Form of Global Change? > Flashcards

Flashcards in Lecture 2: Are Invasions a Unique Form of Global Change? Deck (41)
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1
Q

What are the two main opposing views of human-assisted invasions

A
  1. Modern invasions are nothing new

2. Modern invasions are an unprecedented global change

2
Q

Describe the opposing view that modern invasions are nothing new.

A
  • the magnitude and impacts of human assisted invasions are similar to those in the fossil record.
  • basically arguing that they are nothing new and the the earth has experienced them, sometimes with waves of many sp and often independent single sp colonization event. Highlighting this is true for extinctions, such that many prehuman extinction and invasion events were of at least comparable magnitude to current ones.
  • TRUTH THOUGH: BUT BUT BUT the combination of the rate and magnitude, as well as the distances and agency involved, that separates human driven invasions form self perpetuated colonization events. Invasive sp are a pervasive and major component of HUMAN INDUCED global change.
3
Q

Describe the other opposing view that modern invasions are an unprecedented global change.

A
  • current mass invasion event is unique in scale and impact.
  • there is evidence of invasions in geographical past but these events were episodic, differing greatly from human assisted invasions in spatial and temporal scales and the number + diversity of organisms involved in LONG distance dispersal.
  • should be viewed as global change
  • BUT prehistoric invasions are important for examining and learning about species area effects, evolutionary effects, biotic resistance and impacts of novel functional groups introduced to naive biota. BUT regardless they only provide a limited insight to synergistic effects of invasions and other environmental stresses, the effect of propagule pressure, global homogenization -> which all characterize the present situation.
4
Q

What are the four propositions of why invasions are global change.

A
  1. invasions are occurring at unprecedented rates and spatial scales
  2. Virtually all of these are the result of human activities
  3. They are eroding the distinctiveness of biogeographic realms
  4. This phenomenon is a unique form of global change
5
Q

Explain natural invasion (range expansion) !

A
  • invasion without direct human influence
  • usually involves movement along corridors
  • sequential, small-scale movements
  • predictable
6
Q

Explain human-assisted invasion!

A
  • movement across barriers
  • often involves long-distance jumps
  • difficult to predict
    • barrier (geographic or physiological)
7
Q

List species colonizing the great lakes by point caspian species

A
  • 145 alien species have invaded the great lakes
  • through ballast water and canal
  • ruffle, zebra mussel, quagga mussel, rud, round goby, tube nose goby, New Zealand mudsnail, Blueback herring, amphipod, water flea,
  • two key traits for ballast water transport = planktonic larvae and parthenogenetic reproduction
  • ability to tolerate a broad salinity tolerance
  • theorized that as the cumulative number of attempted and successful introductions increases, each perturbing the system and potentially facilitating one another, the recipient community becomes more easily invaded over time. Especially when invaders co evolved together
8
Q

Explain the quagga mussel turning up in western US control plan

A
  • plan to use chlorine or copper sulphate to kill any mussels or larvae in the 386km long canal. Luckily quagga mussels prefer deeper, cooler water
  • Introduced to great lake, then moved out west.
  • Attaches to boats
  • Can live out of water for awhile
  • Enough moved to start a reproducing pop
  • If they don’t establish the first time we provide introduction chances many times before a successful establishment occurs (lots of boat use).
9
Q

Explain alewife invasion of great lakes

A

the alewife seems to have entered the Great Lakes at about the time of canal building in the late 19th century. Perhaps using the Erie as a mode of transportation, the alewife range increased greatly as they entered the Great Lakes and from there became established in all five lakes; cold temperatures in the winter have been known to kill off large populations periodically, but typically the alewife can survive most winter temperatures even in the northern parts of Lake Superior. These introduced populations have forsaken the second part of the anadromous life cycle, and do not return to the sea as adults. Instead, they spend the entirety of their life in fresh water. There are also a number of separate isolated inland populations in Virginia, Kentucky and Tennessee.

    • eerie canal is what allowed them to overcome the Niagara falls geographic barrier
  • natural range: the alewife used to be a purely anadromous species, breeding in freshwater rivers but returning to the ocean to complete their life cycle. They were typically found from Newfoundland to the Carolinas, preferring depths of approximately 150 to 350 ft off the coast, and spawning populations were found among the tributaries at a maximum of about 100 miles inland.
  • Herring like fish
  • Alewife
  • Can be invasive but we didn’t realize until mid 20th century
  • Native range was clear until recently
  • Knew it was atlantic drainage but how far west we were not sure
  • Nat range = includes lake Ontario
  • This sp was able to get into the rest of the great lakes with welland canal bypassing niagra falls (natural barrier) along with lamprey
  • And it just exploded in these other lakes
  • Green line east – now native range
  • Red = non native range
  • Not 100% not native to great lakes bc it is probably native to lake Ontario
  • Eastern rivers all the way west to lake Ontario = nat range bc niagra was a barrier
  • SO technically native to part of the great lakes but not all
  • Spatial reference is important
  • Doesn’t mean it is not less of a problem though
  • Natural dispersal barrier = Niagara Falls;
10
Q

Explain the occurrence of natural invasions on human time scales and the spatial scales they happen in

A
  • they are rare on human time scales
  • usually occur over small spatial scales
  • VS human assisted invasions which occur in higher freq over larger spatial scales
11
Q

How do natural invasions occur?

A
  • creation of dispersal corridors ex through glacial retreat, continental drift or chance events to bypass a geographic barrier
  • the removal of a physiological barrier e.g. a thermal barrier shifting over time
12
Q

Explain natural invasion of opossum shrimp (Mysis relicta)

A
  • original natural range was in around quebec, ontario up into NWT
  • Wisconsin ice maximum moved them out to Kootenay lake and Waterton lake – two places that previously they would have had no way to get to.
  • Glacial melt water allowed opossum shrimp to expand their range and due to glacial retreat, they were refugees in the areas they were stranded.
  • Distribution reflects the boundary line of the glacial retreat
  • Planktonic shrimp
  • Adapt for cold water
  • Occurs outside of green line bc we moved it bc we thought fish would like to eat it
  • We have a natural range reflecting dispersal range in evo past from glacial melt water and retreat for dispersal and adaptation
  • We have a distribution outside of it due to human interference
13
Q

Collared dove?

A
  • expanded it’s range across Europe, naturally
  • it’s not a migratory bird
  • it is strongly dispersive
  • Successful natural invader
  • Historically confined to turkey and central asia
  • It took off from there
  • Spread in early 1900s
  • NW across Europe and invaded UK
  • Last ten years it spread across the atlantic and reached western Canada
  • Completely on its own
  • Driving forces behind it are from human influence
  • Changing climate and agriculture increased its success rate
  • But its dispersal was via natural mechanisms
14
Q

Examples of natural disasters expanding the range of a sp?

A
  • exotic weed
  • introduced to a lake by hurricane francis
  • floodwater swept weed fragments from one reservoir to the next
  • iguanas being dispersed overwater via hurricane. Hurricane luis and Marilyn through lesser Antilles, Caribbean
    L> this occurred by floating on debris
15
Q

Describe an example of a prehistoric mass invasion

A
  • The Great American Faunal Exchange
  • 3 million years ago, N and S America became connected via panamanian land bridge
  • mammals moved north ( armadillos, anteaters, opossum, porcupines) and south ( bears, racoons, weasels)
16
Q

What are Wallace’s Biogeographic realms?

A
  1. Nearctic
  2. Neotropical
  3. Ethiopian
  4. Palaearctic
  5. Oriental
  6. Australasian
    • broad division of the world’s land masses into realms that organisms have been evolving in relative isolation over long periods of time separated by oceans, deserts, mountains etc making barriers of migration
    • these realms are characterized by the evolutionary history of the organisms they contain
  • Each continent has it’s own characteristic flora and fauna reflecting unique evol opportunities. Evolving in relative isolation allowing distinctive flora and fauna. Barriers preventing/limiting genetic material exchanging across the barriers ; reproductive isolation
  • THIS all changed 1000 years ago through colonialism
  • We’ve eroded the distinctiveness in these regions
17
Q

What is the overall trend of aquatic invasions?

A
  • there has been a steady increase/exponential in the cumulative number of invaders in the great lake, san fran bay, baltic sea and mediterranean sea.
18
Q

Compare species per year in various regions between modern and prehistoric

A
  • basically in general the number of species per year ending up in new regions is extremely higher vs prehistoric times
19
Q

Explain natural invasion rates estimated from genetic divergence

A
  • fresh water cladocerans dispersing between europe and N america, modern rate is 50,000 times higher
  • Inverts and fishes dispersing from W Pacific to E Pacific, 8000,000 times higher
20
Q

Contrast % of non native organisms in different geographic regions

A
  • higher percentages on islands vs continents
21
Q

Explain the GLOBAL invasion of the argentine ant, L. humile.

A
  • human aided in movement
22
Q

Explain the GLOBAL invasion of the Asian tiger mosquito

A
    • vector for human viruses
  • major vector
  • In various areas it couldn’t get without human help
23
Q

What’s the deal with New Zealand ?

A
  • it’s an island
  • Europeans suck bc a TON OF INTRODUCED EURO MAMMALS
  • le whoops
  • remote geographically
  • 35 European mammals there, arrived with human help
  • 12 British birds that came with human help
  • over 150 years
  • some placed on purpose for hunting like deer, some accidentally like some rodents
24
Q

Do human migrations promote invasions?

A
  • HELL YAS.
  • measles
  • small pop
  • europe to central and south america via Spain
  • rodents, microbes (encounter humans with no immunity to them)
  • enhanced colonization of South America bc biological invasion caused many deaths
  • ecologic imperialism
  • other sp help facilitate or resist European expansion
25
Q

Explain tourism trend

A
  • international tourist arrivals are expected to reach 1.8 billion by 2030
  • steady rise
26
Q

Why is globalization a big issue with invasions?

A
  • FUCKING ALL THE CONNECTIONS

- between boat traffic and aviation we have taken away almost any geographic barrier

27
Q

What up with SARS (Acute Respiratory Syndrome)

A
  • originated in Hong Kong
  • > 250 cases and 41 deaths in Canada
  • > 8400 cases, ~920 deaths worldwide (Sept 2003)
  • has spread to 300 countries
28
Q

Why is the Antarctic increasingly at risk for biological invasions?

A
  • increased tourism
  • increased presence of scientists
  • INCREASED PRESENCE OF PEOPLE
  • largely associated with the movement of people and cargo in connection with industrial, national scientific program and tourism
  • they have both direct and indirect effects on species poor antarctic systems like with biodiversity loss and changes to ecosystem process
  • Also with climate change , increasing the range of species
  • antarctic tourism has been on a steady rise
  • 200 non native sp invaded
  • half are plants
  • coastal areas of Antarctic= shipping traffic
  • the rest? Ecotourism
  • people move sp around even on their clothes etc
  • tourism has gone up in Antarctic
  • Emperor penguin have suffered from salmonella
  • No part of the planet is free from invasion
29
Q

How many introduced exotic species are in the sub-antarctic islands?

A
  • Plants= 108spp
  • Inverts = 72 spp
  • Vertebrates = 16spp
30
Q

Explain the trend in international trend.

A
  • since 1950 it has been increasing
31
Q

Explain the relationship btwn trade activity and spider introductions.

A
  • volume of global imports from manufacturers, mining products and agricultural products have increased with time ALONG with the number of introduced alien spiders
32
Q

Why is economic development accelerating biological invasions in china?

A
  • there is a positive correlation between total GDP and number of new introduced invasive species
  • probably bc with economic growth, there is more trade occurring etc
33
Q

Describe the composition of ballast water.

A
  • 1 litre contains”
  • hundreds of zooplankton, thousands of phytoplankton, millions of bacteria and billions of virus particles.
  • > 5000 sp are carried in ocean vessels
  • ** 3-10 billion tonnes of water is moved annually.
34
Q

Contrast natural (prehistoric) vs human assisted invasions for freq of long distance dispersal events

A
  • Natural invasions = very low

- human assisted = very high

35
Q

Contrast natural (prehistoric) vs human assisted invasions for invasions between biogeographic realms

A
  • natural = rare

- human= common

36
Q

Contrast natural (prehistoric) vs human assisted invasions for number of species transported per event

A
  • natural invasions: small., except during biotic interchange
  • human assisted: potentially very large
37
Q

Contrast natural (prehistoric) vs human assisted invasions for favoured species

A
  • Natural: those with natural dispersal abilities

- Human assisted: human commensals

38
Q

Contrast natural (prehistoric) vs human assisted invasions for mass colonization

A

Natural invasions: episodic, regional

- Human assisted: global, on going

39
Q

Contrast natural (prehistoric) vs human assisted invasions for variation in mechanisms and routes of dispersal

A
  • natural invasions: small

- Human assisted:Extremely large

40
Q

Contrast natural (prehistoric) vs human assisted invasions for potential for synergies with other stressors

A
  • natural invasions : low

- human assisted: very high

41
Q

List forms of global change.

A
  1. Overharvesting
  2. Nitrogen Pollution
  3. Climate Change
  4. Human assisted invasion
  5. Landscape alteration
  6. Stratospheric ozone depletion