Invasive species „But the cardoon (Cynara cardunculus) has a far wider range.: it now occurs in...
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Transcript of Invasive species „But the cardoon (Cynara cardunculus) has a far wider range.: it now occurs in...
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.
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)
Some well known examples
Colorado Potato beetle Gipsy moth
First introduced to Europe in 1877
First record in Poland 1960First introduced into North America in 1868
Has about 650 different host plants
During outbreaks causes major damages in softwood forests
Tiger mosquito Nil perch
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)
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.
Marenzelleria viridisEichhornia crassipes
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
Harmonia axyridis
First observations of the Asian Lady beetle 2001: Belgium2002: Germany, Netherlands2004: UK, France2007: Scandinavia, Poland2009: Whole of Poland
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.
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.
Number of
native species Number of
invasive species
New Zealand (plants) 1790 1570
Hawaii (plants) 956 861
Hawaii (all species) 17591 4465
Tristan de Cunha (plants) 70 97
Campbell Islands (plants) 128 81
South Georgia (plants) 26 54
Southern Africa (freshwater fish) 176 52
California (freshwater fish) 83 52
Berlin (plants) 839 593
Woody perennials (Southern Australia) 2230 188
Europe (spiders) 3500 80
Great Britain (trees) 35 1700
How many species are invasive?
Data from McNeely J. A. (1999), Kobelt and Nentwig (2008), Caley et al. 2008, and Sukopp (1990)
Air cargo39%
Miscella-neous
2%Mails3%
Baggage40%
Ship cargo16%
How do alien species come to Hawaii?
25% of all Hawaiian species are alien
Human activities
Disturbance
Changing environmental
conditions
Changing land management
Changing land use
Changing of ecosystem functioning
Invading species
Habitat fragmentation
Increasing opportunities for invaders
A conceptual model of invading species
What makes a species invasive?
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
Marcel Rejmanek (1946-
DNA contents of 148 Californian angiosperms (from Knight et al. 2005)
What habitats are susceptible to invasions?
• Early to mid-successional habitats
• Mesic environments and open water
• Disturbed habitats
• Fragmented habitats
Phylogenetic distance from the resident species
„...floras gain by naturalization, proportionally with the number of native genera and species, far more in new genera than in new species”
Charles Darwin 1959: The Evolution of Species by Means of Natural Selection
Number of European
species NOT naturalized in
California
Number of European species
naturalized in California
2
Poaceae shared genera 466 43 <0.0001European genera 257 69
Asteraceae shared genera 681 22 <0.0001European genera 762 66
Brassicaceae shared genera 230 12 <0.05European genera 342 36
The analysis of plant species introduced to California shows that significantly more species of European genera were naturalized
than of shared genera.
(from Rejmanek 1999)
Time lags
Trees
Time lag
(years) Shrubs
Time lag
(years)
Robinia pseudoaacia 152 Mahonia acuifolium 38
Acer negundo 183 Syringa vulgans 124
Prunus serotina 29 Symphoricarpus albus 65
Aesculus hippocastanum 124 Philadelphus coronarius 183
Quercus rubra 114 Lycium barbarum 70
Ailanthus altissima 122 Cornus stolonifera 76
Populus canadensis 165 Lonicera tatarica 94
Prunus mahaleb 54 Ribes aureum 61
Laburnum anagryroides 198 Colutea arborescens 265
Salix intermedia 112 Cornus alba 84
From introduction to spreading might pass a long time.
Observed time lags from intyroduction to sprading in various trees and shrubs in the area of Berlin and Brandenburg (Kowarik 1995)
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
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