Invasion species

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Invasion species

• Sapozhnikova Elena

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Invasions are processes of the penetration of
alien species into ecosystems located outside
their natural areas and their impact to the
native communities.

• Invasions can be caused by
• natural migrations of organisms by climatic
  changes and fluctuations of population abundance
• introduction of the economically useful organisms
  
• accidental drift with ballast water, agricultural
  products etc

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The types of invasion species influences on
native species

• alien species can essentially change habitat of
  indigenous species
• invasion species can become superior competitors,
  predators or pathogens for native species and
  promote their replace

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G. fasciatus is successful invader from Lake
Baikal.
1989
1989
1986
1986
1988
1988
1986
1986
1969
1977
1969
1973
1964
1968
1967
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The main factors, which promoted replacement of
Gammarus lacustris by Gmelinoides fasciatus in
Lake Ladoga

• G. fasciatus is superior competitor for food
• G. fasciatus has shorter generation time and
  higher productivity
• G. fasciatus has a higher ability to avoid the
  fish predation

Gmelinoides fasciatus
Gammarus lacustris
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The ways of invasion prevention

• careful studying of the influence of alien
  species on native species at all levels
• toughening of the customs inspections
• informing of the population about possible danger

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Thank you for your attention!