transcript
- Invasive Species Toma Drashkov Alexandra Panusheva Yana
Stoyanova 10/6
http://news.stanford.edu/news/2007/may2/gifs/plants_swordfern.jpg
- General Information
- A species occurring in a result of human activity, accidentally
or intentionally
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- Animals, plants, microorganisms, pathogens
- It goes beyond its accepted normal distribution
- They are non-native (alien) to the given area
- Always harmful to an ecosystem in a way
- Threatens environmental, agricultural resources
- Have a major impact on environment, threatens biodiversity and
reduces other species abundance and diversity [1]
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- more information
- Highly competitive, adaptive and successful at reproducing
- Lack of predators is the main reason for their success
- Sometimes invasive species were introduced to control other
such species
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- An example is the domestic cat
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- introduced in order to control
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- rodents but it can spread diseases
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- to wildlife and humans and
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- for the disappearance of some birds
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- species -> is considered an
http://www.des.ucdavis.edu/faculty/Springborn/Large-Zebra-Mussel--US%20FWS.jpg
- Methods of introduction of invasive species
- accident into areas where
- These species are not checked by natural controls and this
results in their spreading through waterways
- They also destroy already brittle native species and ecosystems
[3]
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- After the introduction
- The best thing to be done after a noticed introduction is the
invasive specie to be removed
- The processes are dependent on the type of specie : mowing,
cutting, spraying [5]
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http://upload.wikimedia.org/wikipedia/commons/thumb/b/b1/Secateur_ouvert.jpg/250px-Secateur_ouvert.jpg
- From Economic Point of View
- Invasive species are the second-leading threat to menaced
species ( the first threat is the habitat destruction):
- -> Because of invasive species many freshwater fishes in
America (40 North) became extinct over the past hundred years
[1]
http://www.riverfriends.org/Portals/0/phraus.jpg
- what else for economics?
- Alien invasive species can
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- Introduce new diseases to areas where people live
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- Disrupt cultural landscape
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- We dont want Weliko Tarnovo destroyed
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- Decrease the value of land and water
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- Make people loose their production
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- Stop the work of big factories
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- People loosing their jobs [2]
http://irkatur.com/bg//7/veliko-tarnovo.jpg
- Ecological Problems
- Invasive species can be considered as on of the causes for
biodiversity loss.
- There is a hypothesis that alien species who are dominant can
cause some modifications of the habitat of the native ones
- => loss of native species [4]
http://webecoist.com/wp-content/uploads/2009/12/Invasive_1a.jpg
- some other eco problems
- They affect the ecosystems in many ways
- They may compete directly for food and free environment or
indirectly by changing their food web or space where they live
- They may kill or cross (interbreed) with native species
[6]
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- Are they only harmful?
- Invasive species may act positively because species with
limited resources and environment may be dependent on them (most of
the times this occurs in islands because of the isolation and lack
of defenses there)
- According to some researches the invasive species are balancing
between drivers of community changes and only passengers, because
they serve in both positive and negative way
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- They are problems in parks,
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- roads and complicate restoration
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- Also their removal may have
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- negative consequences or their
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- use in restoration is desirable
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- Sometimes; or other organisms
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- Are all Alien Species Invasive?
- Non-native species come from somewhere else and they are not
natural to the ecosystem they have been introduced to , which makes
them invasive
- M ay be harmless and beneficial in their natural surroundings
(surroundings before they migrated) , but they can totally destroy
different environments.
- If there is no predator control there can be an invasive alien
species offspring boom
- Consequently, n ot all non-native species are invasive and
harmful.
-
- Invasive are only those that invade a certain environment
[1]
- An examples of invasive species
- Moved from South Africa to America in 1884 because the flower
was beautiful
- These flowers grow very rapidly and took almost all resources
of the surrounding environment
- They grow over everything they pass including trees and
houses
http://farm1.static.flickr.com/222/447088277_1efd5696e4.jpg
- Another example of invasive specie
- Introduced to Angel Island in San Francisco bay from the
mainland in 1900s
- They ate most of the food on the area
- to eat everything they see
- The deer started to destroy
- forests and this cost a lot of
- money to the community [3]
http://accad.osu.edu/womenandtech/2009/researchpages/images/white_tailed_deer_buck2.jpg
- Works Cited
- J.Gunsch, "What are Invasive Species?". wiseGEEK. June 6, 2010
.
- "Invasive Non-Native Species". Eco-Pros. June 6, 2010 .
- Invasive Species - Examples Of Invasions June 6, 2010
http://science.jrank.org/pages/3669/Invasive-Species-Examples-invasions.html
- (64), In Scopus. "ScienceDirect - Trends in Ecology &
Evolution : Are Invasive Species the Drivers of Ecological Change?"
ScienceDirect - Home . Web. 13 June 2010. .
- "Removing Invasive Species." Google . Web. 13 June 2010. .
- "NatureServe: Invasive Species." NatureServe Homepage: A
Network Connecting Science with Conservation. Web. 13 June 2010.
.