The Biology and Dynamics of Biological invasions

1. The Biology and Dynamics of Biological invasions Megan Van Der Bank 2401402 Department of Biodiversity and Conservation Biology, University of the Western Cape http://www.benettontalk.com/biodiversity.jpg

2. Introduction Invasive Argentinean ants in the Fynbos Biome Weeds in Australian rangelands The Black striped mussel in Australia Acacia mearnsii in South Africa The Cane Toad (Bufo marinus) in Australia The invasive Red deer (Cervus elaphus) The Chinese Mitten Crab (Eriocheir sinensis) Invasive Red mangroves and pickleweed in Hawaiian wetlands The local and global effects of invasive species on biodiversity References Index

3. Introduction • Presently, alien species are one of the biggest threats to biodiversity, only second to habitat destruction • Globalization has increase mobility of biota • Intentional introductions (McNeely. 2001) • Accidental introduction (Chapin et al. 2000) • Alien species become naturalized • Outcompete native species for natural resources (Chapin et al. 2000) and prey on indigenous species • These invasive species lack natural enemies, which gives them a competitive edge • Many become pests

4. Invasive Argentinean ants in the Fynbos Biome Invasive Iridomyrmex humilis displace native ants Slower to discover seeds of myrmecochorous Mimetes cucullatus; seeds are moved shorter distances; fail to store seeds below soil Exposure to competitors, predators and fire Affects seedling growth which competes with parent plant (Bond and Slingsby. 1984) http://www.viarural.com.ar/viarural.com.ar/agricultura/aa-hormigas/iridomyrmex-humilis.htm

5. Australian rangelands constitute 70 % of the Australian continent Rate of naturalization is 10 species per year Weeds are able to reach high densities and biomass-dominating the stratum Weeds sequester resources otherwise available to native plant species Landscape dysfunction- ramifications for food web Effect on specialist herbivores; decomposers Alter fire regimes Native plant species richness decease; native animal species may respond positively or negatively (Grice. 2004) Weeds in Australian rangelands

6. The Black striped mussel in Australia • Native to tropical and sub-tropical waters of the Western Atlantic (Columbia to the Gulf of Mexico) [1] • Detected in Darwin Harbour (1999) in Australia’s Northern Territory • Introduction via vessel hull fouling; fouling of aquaculture; ballast • Bivalves able to form dense monospecific mats • Reduction in biodiversity, fouling of wharves, seawater systems and marine farms [1] • Treatment with copper sulphate and sodium hypochlorite [4] • Total cost of $ 2.2 million per annum (excluding personnel costs) [1] http://images.google.co.za/imgres?imgurl=http://www.marine.csiro.au/LeafletsFolder/images/blstriped.jpg&imgrefurl=http://www.marine.csiro.au/LeafletsFolder/blstriped.html&h=159&w=250&sz=15&hl=en&start=8&tbnid=03k-GoxsbIAOjM:&tbnh=71&tbnw=111&prev=/images%3Fq%3DBlack%2Bstriped%2Bmussel%26gbv%3D2%26svnum%3D10%26hl%3Den%26sa%3DG

7. Acacia mearnsii in South Africa • Native to Australia and was introduced into South Africa about 150 years ago as a source of bark products [2] • Invasive in South Africa and other countries such as China, Japan, New Zealand, France, United States [3] • S. mearnsii able to produce copious amounts of long lived seeds [2][3] • Forms monospecific crowns which shades other vegetation [2] • Competes with grazing grasses resulting in decreased grass cover • Taps into South Africa’s already dwindling water supply (577 million cubic meters annually) [2] • Increased fuel loads affects fire intensity (Ehrenfeld. 2006) • Nitrogen enrichment (due to nitrogen fixation) makes habitat unsuitable for growth of indigenous species, and more susceptible to invasion by other exotics (Ehrenfeld. 2006) • Infested areas shows decreased species richness of birds and ground plant cover [2]

8. http://www.hear.org/Pier/species/acacia_mearnsii.htm

9. The Cane Toad (Bufo marinus) in Australia • Indigenous to South America, Central America, Mexico, Southern United States • Deliberately introduced into Australia as a biological control agent to prevent French’s Cane Beetle from destroying sugar cane in Northern Queensland [4] • Very fecund (females produce 8000-35 000 eggs, usually twice a year [4] • Adaptable: able to loose 50 % of its body water, tolerate salinities up to 15 % [4] • Competes with native amphibians for breeding ground and food • Toxic at all life stages and causes death of indigenous animals • Current research for control: biological control from a native amphibian virus (gene manipulation) [4]

10. http://www.jcu.edu.au/school/tbiol/zoology/herp/tfrg/bufo.jpghttp://www.jcu.edu.au/school/tbiol/zoology/herp/tfrg/bufo.jpg

11. Native to parts of Europe and was introduced into Australia, New Zealand, North America and South America [5] Invades natural and planted forests, rangelands, grasslands, shrublands, tundra Prevents regeneration of preferred plant species (may cause canopy collapse in woodland and forest settings) [5] Change structure and composition of native ecosystems Competes with native deer species such as (Hippocamelus bisulcus) in Chile [5] Loss of heather cover in the highlands of Scotland (Clutton-Brock et al. 2004) The invasive Red deer (Cervus elaphus)

12. www.hlasek.com/foto/cervus_elaphus_db0704.jpg

13. Recognized as one of the world’s top 100 invaders by the ISSG (Invasive species specialist group) [7] Native to the coastal rivers and estuaries of the Yellow Sea (West China, Korea) [7][8] Has spread widely in the US (Great Lakes, California, Pacific Northwest, Louisiana, mouth of the Mississippi River) and become established in Northern Europe Introduction via live seafood trade, ballast, ship hull fouling Success of E. sinensis is due to tolerance to a varying hydrological conditions and high female fecundity [7] Pest: consume young rice shoots, commercial fishing, human health concern [6] Affects landscape and biodiversity in infested areas : degrade estuarine and freshwater food webs; compete directly with indigenous invertebrates; successive burrowing causes landscape instability [6] The Chinese Mitten Crab (Eriocheir sinensis)

14. http://cars.er.usgs.gov/posters/Nonindigenous/Nonindigenous_Crustaceans/crab2a.jpghttp://cars.er.usgs.gov/posters/Nonindigenous/Nonindigenous_Crustaceans/crab2a.jpg http://cars.er.usgs.gov/posters/Nonindigenous/Nonindigenous_Crustaceans/crabmap2a.gif

15. Alien red mangroves (Rhizophora mangle) and pickleweed (Batismaritima) are major invasive plants in Hawaiian wetlands Nu’upia fish pond complex home to 10 % of Hawaii’s endangered black-necked stilts (Himantopus mexicanus knudseni) Pickleweed introduced from South America in 1859 Excludes shorebirds and waterbirds from foraging and nesting on mudflats (Rauzon and Drigot. 2001) Mangroves introduced from Florida in 1902 to mitigate erosion Decrease water circulation, increases algal production, anoxia, increases temperature, salinity and acidity of water Stilts more vulnerable to predation by egrets and herons Control measures include: Amphibious Assault Vehicles (pickleweed control); manual cutting down of trees; possible biological control (Rauzon and Drigot. 2001) Invasive Red mangroves and pickleweed in Hawaiian wetlands

16. http://www.botany.hawaii.edu/faculty/webb/BOT410/Roots/Mangroves/RedMangrovePhoto.jpghttp://www.botany.hawaii.edu/faculty/webb/BOT410/Roots/Mangroves/RedMangrovePhoto.jpg http://www.life.uiuc.edu/ib/335/BreedingSystems/mangrove.jpg

17. As a biodiversity issue, it is not always possible to say that invasive species are inherently bad (McNeely. 2001) Globalization causes homogenization Homogenization not synonymous to low diversity at a local scale Dramatic increase in species numbers at a local level, is at expense of native species Loss of rate native species, leads to global species and genetic diversity loss (McNeely. 2001) Consensus dependant partly on scale (McNeely. 2001) The local and global effects of invasive species on biodiversity

18. Davis M (2003) Biotic Globalization: Does Competition from introduced species Threaten Biodiversity? BioScience 53: 481-488 Bond W, Slingsby P (1984) Collapse of an ant-plant mutualism: The Argentine ant (Iridomyrmex humilis) and myrmecochorous Proteaceae. Ecology 65:1031-1037 Chapin F, Zavaleta E, Eviner V, Naylor R, Vitousek P, Reynolds H, Hooper D, Lavorel S, Sala O, Hobbie S, Mack M, Diaz S (2000) Consequences of changing biodiversity. Nature 405: 234-242 Clutton- Brock T, Coulson T,Milner J (2004) Red deer stocks in the Highlands of Scotland. Nature 429:261 Ehrenfeld J (2006) A potential novel source of information of screening and monitoring the impact of exotic plants on ecosystems. Biological Invasions 8: 1511-1521 Grice A (2004) Weeds and the monitoring of biodiversity in Australian rangelands. Austral Ecology 29: 51-58 McNeely J (2001) Invasive species: a costly catastrophe for native biodiversity. LandUse and Water Resources Research 1: 1-19 Rauzon M, Drigot D (2001) Turning the tide: the eradication of invasive species. IUCN SSC Invasive Species Specialist Group, Cambridge p240-248 References

19. http://www.biodiv.org/doc/case-studies/ais/cs-ais-au-black-mussel-en.pdfhttp://www.biodiv.org/doc/case-studies/ais/cs-ais-au-black-mussel-en.pdf http://www.issg.org/database/species/impact_info.asp?si=51&fr=1&sts= http://www.hear.org/species/acacia_mearnsii/ http://www.aph.gov.au/senate/committee/ecita_ctte/invasive_species/report/c04.pdf http://www.fao.org/docrep/008/j6854e/J6854E12.htm http://www.wsg.washington.edu/outreach/mas/nis/leastwanted.pdf http://cswgcin.nbii.gov/portal/server.pt?open=512&objID=798&&PageID=2259&mode=2&in_hi_userid=2&cached=true http://cars.er.usgs.gov/posters/Nonindigenous/Nonindigenous_Crustaceans/nonindigenous_crustaceans.html http://en.wikipedia.org/wiki/Invasion_biology_terminology