slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Invasive species PowerPoint Presentation
Download Presentation
Invasive species

Loading in 2 Seconds...

play fullscreen
1 / 18

Invasive species - PowerPoint PPT Presentation


  • 152 Views
  • Uploaded on

Invasive species.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Invasive species


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Invasive species

„But the cardoon (Cynara cardunculus) has a far wider range.: it now occurs in these latitudes on both sides of the Cordillera across the continent. I saw it in unfrequented spots in Chile, Entre Rios, and Banda oriental. In the latter country alone, very many (probably several hundred) square miles are covered with one mass of these prickly plants, and are impenetrable by man or beast. Over the undulating plains, where these great beds occur, nothing else can live. Before their introduction, however, I apprehend the surface supported as in other parts a rank herbage. I doubt whether any case is on record of an invasion of so grand scale of one plant over the aborigines”

Charles Darwin 1839: Voyage of the Beagle.

slide2

What are invasive species?

  • Invasive species are those that
  • were accidently introduced into new habitats by man (alien species)
  • were intentionally introduced into new habitats by man for commercial purposes
  • were intentionally introduced into new habitats by man for biological control
  • greatly extended their natural home ranges towards new areas for instance due to climate change or human activities (roads, tunnels)
slide3

Some well known examples

Gipsy moth

Colorado Potato beetle

First introduced to Europe in 1877

First record in Poland 1960

First introduced into North America in 1868

Has about 650 different host plants

During outbreaks causes major damages in softwood forests

slide4

Tiger mosquito

Nil perch

The Asian species was first reported from Houston texas in 1985

Now established in Brazil, Europe, and New Zealand

Vectors of yellow and dengue fever, as well as encephalitis

Changing cimate will promote the spread towards northern countries

First occurrence in mainland France in 2006. Now recorded from Belgium, Italy, France, Balkan region. First deadly infection of Chikungunya feaver in Italy 2007.

Introduced into the great Est African lakes during the 1950s and 1960s to improve fishering.

Caused dramatic changes in faunal and floral composition

Caused algal blooms and eutrophication

Caused the extinction of more than 200 native fish species (2/3 of all species)

slide5

Eichhornia crassipes

Marenzelleria viridis

Introduced into China from South America in the 1930s as an ornamental plant, to provide liestock food and to control air pollution

Caused reduction of lake areas and let to the extinction of about 30 fish species

Reduced lake areas caused climate changes and changes in water cycling

The flatworm was introduced via ship ballast water (first records 1979)

In the vistula lagoon it has become the dominant species constituting up to 97% of the total biomass of the bottom- living macrofauna

slide6

Harmonia axyridis

In the USA unsuccessfully used as aphid predator in biological control programs since 1916.

Sudden spread in USA since 1980.

Major impact on natural communities of aphid predators due to its high reproduction rate.

First observations of the Asian Lady beetle 2001: Belgium

2002: Germany, Netherlands2004: UK, France

2007: Scandinavia, Poland

2009: Whole of Poland

slide7

Unknown harvestman (Opilionida) species

First observed in the Netherlands (2007)

In 2008 massive invasion along the Rhine river up to Switzerland

Species are up to 18 cm in diameter.

They occur in large colonize of up to several hundred individuals.

They show colonial movements.

slide11

How many species are invasive?

Data from McNeely J. A. (1999), Kobelt and Nentwig (2008), Caley et al. 2008, and Sukopp (1990)

slide12

How do alien species come to Hawaii?

25% of all Hawaiian species are alien

slide13

A conceptual model of invading species

Humanactivities

Disturbance

Invadingspecies

Changing land use

Habitat fragmentation

Changing of ecosystemfunctioning

Changingenvironmentalconditions

Changing land management

Increasingopportunities for invaders

slide14

What makes a species invasive?

Marcel Rejmanek (1946-

  • Charcteristics of invasie species
  • r-strategists
  • have high dispersal ability
  • have small genome sizes
  • are habitat or feeding generalists
  • self pollinators (plants)
  • have long flowering periods (plants)
  • have a high proportion of leaf area (grasses)
  • have small seed sizes (in woody plants)
  • occupy often disturbed sites

DNA contents of 148 Californian angiosperms (from Knight et al. 2005)

slide15

What habitats are susceptible to invasions?

  • Early to mid-successionalhabitats
  • Mesicenvironments and openwater
  • Disturbedhabitats
  • Fragmentedhabitats
slide16

Phylogenetic distance from the resident species

„...florasgain by naturalization, proportionallywiththenumber of nativegenera and species, far moreinnewgenerathaninnewspecies”

Charles Darwin 1959: TheEvolution of Species by Means of Natural Selection

Theanalysis of plant speciesintroduced to California showsthatsignificantlymorespecies of Europeangenerawerenaturalizedthan of sharedgenera.

(fromRejmanek 1999)

slide17

Time lags

Fromintroduction to spreadingmight pass a long time.

Observed time lagsfromintyroduction to spradinginvarioustrees and shrubsinthearea of Berlin and Brandenburg (Kowarik 1995)

slide18

Today’s reading

Invasive species: http://en.wikipedia.org/wiki/Invasive_species

Invasive species database: http://www.issg.org/database/welcome/

A different opinion: http://www.nytimes.com/2008/09/09/science/09inva.html