Photo of the Panama Canal from pancanal

1. Species Invasions Photo of the Panama Canal from www.pancanal.com

2. Native & Non-Native Species Native (indigenous) – an organism (or organisms) that came to be found in a given place by natural causes Non-native (exotic, introduced, non-indigenous) – an organism (organisms) that came to be found in a given place by anthropogenic causes Domestic Chicken Wild progenitor = Red Junglefowl, native to Asia; Domesticated & introduced to N. Am. (e.g., LA) Wild Turkey Native to N. Am. (e.g., LA) Common Pheasant Native to Asia; Introduced to N. Am. (e.g., LA) Photos from Wikipedia

3. Native & Non-Native Species Range expansion – natural process whereby a species immigrates into a given place that was previouslyunoccupied by that species Cattle Egret Original range = western Europe, plains of Africa, tropical & subtropical Asia; Flew across Atlantic to north- eastern South America – 1877; Arrived in FL – 1941; First bred in FL – 1953; First bred in Canada – 1962 Considered native to N. Am. (e.g., LA) Photo from Wikipedia

4. Native & Non-Native Species Re-introduction – anthropogenic placement of a species into a given place that was previouslyoccupied by that species American bison subsp. Plains bison Original range = plains, prairies & savannas of N. Am. (incl. LA) There may not be sufficient appropriate habitat available in LA to re-introduce American bison Photo from Wikipedia

5. Invasive Species Your textbook’s definition: Introduced species More commonly used definition: An introduced species that establishes, expands its range, and has an appreciable impact on native organisms & ecosystems We don’t normally consider these two introduced species to be invasive Domestic Chicken Wild progenitor = Red Junglefowl, native to Asia; Domesticated & introduced to N. Am. (e.g., LA) Common Pheasant Native to Asia; Introduced to N. Am. (e.g., LA)

6. Invasive Species Your textbook’s definition: Introduced species More commonly used definition: An introduced species that establishes, expands its range, and has an appreciable impact on native organisms & ecosystems But cats often become devastatingly invasive when feral

7. + - 0 A B A B A B - - - Antagonism (Predation/Parasitism) Amensalism Competition - + 0 A B A B A B 0 0 0 Neutralism (No interaction) Amensalism Commensalism - + 0 A B A B A B + + + Antagonism (Predation/Parasitism) Mutualism Commensalism Pair-wise Species Interactions Influence of species A - (negative) 0 (neutral/null) + (positive) - Influence of Species B 0 + From Abrahamson (1989); Morin (1999), pg. 21

8. Invasive Species – Examples Parasites (disease organisms & other microbes) – e.g., HIV ~ 25 million human deaths since it was first recognized in 1981; 0.6% of humans infected (~40.5 million) Native to western Africa Introduced globally Scanning electron micrograph of virus particles (green) and lymphocyte from Wikipedia

9. Invasive Species – Examples Competitors – e.g., Eurasian zebra mussel U.S. Coast Guard estimates economic losses and control efforts cost ~ $5 billion annually in the U.S. Outcompetes native mollusks Native to Russia Introduced to N. Am., etc. Photographs of color morphs from Wikipedia

10. Invasive Species – Examples Predators – e.g., brown tree snake on Guam 9 of the island’s 11 native forest-dwelling bird species are now extirpated (extinct on Guam) Native to southeast Asia Introduced to Guam Image from http://www.fort.usgs.gov/Resources/Education/BTS (see this Web page for more info.)

11. Introduced, Exotic & Invasive Species …illustrate the physical interconnectedness of the planet & “homogenize” the planet’s biota Today we live in the… “New Pangaea” (spatial focus) “Anthropocene” “Homogocene” (temporal focus) Paul Crutzen Gordon Orians Harold Mooney Photo of Crutzen from Wikipedia; Orians from The Nature Conservancy; Mooney from Stanford

12. Organisms with Large Impact Foundation species – a species that “defines much of the structure of a community” (Dayton 1971) Photo of bamboo forest from Wikipedia

13. Organisms with Large Impact Keystone predator – helps maintain diversity by reducing opportunities for competitive exclusion (Paine 1966) Keystone resource – helps maintain diversity by providing food to many species, especially during lean times (Terborgh 1986) Photo of Pisaster starfish from www.royalbcmuseum.bc.ca ; Photo of barbet feeding on figs from Wikipedia

14. Organisms with Large Impact Ecosystem engineer – creates or significantly modifies habitats (Jones et al. 1994, 1997) Allogenic (physical modifications through their activities) Autogenic (modifications through the presence of their biomass) Photo of beaver from Wikipedia; Map of North American native range from www.icwdm.org; Map of Tierra del Fuego (introduced range) from www.student.britannica.com

15. Impacts of Non-Native Species Impact = Range x Abundance x per-capita Effect I = R x A x E (Parker et al. 1999) Photo of beaver from Wikipedia; Map of North American native range from www.icwdm.org; Map of Tierra del Fuego (introduced range) from www.student.britannica.com

16. Impacts of Non-Native Species Direct & indirecteffects – + Ecological & evolutionaryeffects + + Consider the potential evolutionary consequences of reduced daytime predation on mosquito behavior, e.g., increased daytime activity – + Mosquitoes Photos from Wikipedia

17. Scale & Scope of Biological Invasions North American plains and prairies = 11% of plant spp. Hawaii = 35% of plant spp. Successful invaders in San Francisco Bay = 1 marine sp. every 14 wk (1961 to 1995) Rate of introduction of crustracean zooplankton into Great Lakes region ~50,000 times background natural immigration rate San Francisco Bay & Great Lakes illustrate that the rates are (much) higher than natural rates Refs.: White et al. (2000); Pimentel et al. (2000); Cohen & Carlton (1998); Hebert & Cristescu (2002)

18. How are species introduced? Intentional – agriculture, hunting, fishing, ornamental, etc. Unintentional – transport (airplanes, ships, cars, shoes, etc.), escaped pets, etc. Photo of cornfield from www.ugogrill.com ; Photo of the Panama Canal from www.pancanal.com

19. Successful Invasions Under the right conditions any community can be invaded and any organism can be a successful invader somewhere Potential invaders begin as rare populations, faced with the same disadvantages of any small population (e.g., demographic stochasticity, Allee effects, inbreeding, etc.) Photo of kudzu (Pueraria lobata) in Georgia from Wikipedia

20. Successful Invasions Passing Through Filters Present Past A B C D E F G H I Regional species pool A B C D E F G H I Anthropogenic introductions Biogeographic filter F G H I Physiological filter Biotic filter Local assemblage A B C A B C H I See Fig. 9.9, pg. 307 of Groom et al., Principles of Conservation Biology, 3rd ed.

21. Successful Invasions Escape / Release from Enemies Parasite species richness (S, shown below) and parasite prevalence (% infected hosts) showed similar patterns 1.0 1-to-1 line molluscs crustaceans Standardized S of parasites in introduced range 0.5 amphibians & reptiles fish birds mammals 0 1.0 0 0.5 Standardized S of parasites in native range Redrawn from Torchin et al. (2003) Nature

22. Successful Invasions Making Predictions (it’s a multi-variate problem) Traits of organisms (Not surprisingly one of the best “traits” for predicting invasiveness is whether the speciesis invasive elsewhere) Characteristics (biological and physical) of focal site E.g., Elton’s (1958) biotic resistance hypothesis (species-rich communities are more resistant to invasion) Photo of marine toad (Bufo marinus) from Wikipedia

23. Successful Invasions Many hypotheses… Mechanisms of invasion success (some based on traits of organisms, some based on characteristics of the environment): Enemy release Biotic resistance Evolution of increased competitive ability (EICA) Darwinian pre-adaptation (e.g., extended leaf phenology) Novel weapons (e.g., allelochemicals) Horticultural selection Resource availability Etc.

24. Synergistic Effects: Invasional Meltdown “a process by which a group of nonindigenous species facilitate one another’s invasion in various ways, increasing the likelihood of survival and/or of ecological impact, and possibly the magnitude of impact” Daniel Simberloff (rec’d. Ph.D. 1969; E. O. Wilson’s student who experimentally investigated the Theory of Island Biogeography on mangrove islands in Florida) Definition from Simberloff & Von Holle (1999); photo from www.conservationbytes.com

25. Synergistic Effects: Invasional Meltdown E.g., yellow crazy ants on Christmas Island, Australia Native red crabs drive ecosystem processes Exotic yellow crazy ants kill red crabs Crazy ants also associate with introduced scale insects to exacerbate damage Photos from http://www.environment.gov.au

26. Synergistic Effects: Invasional Meltdown E.g., yellow crazy ants on Christmas Island, Australia (a) Uninvaded site (b) Invaded site, 1-2 yr after ant invasion Figure from O’Dowd, Green & Lake (2003)

27. Control of Introduced & Invasive Species Physical control Chemical control – E.g., chlorine bags over Caulerpa in CA Biological control – Presents the paradox of adding species (“diluting” natural biodiversity) to control or remove other species Invasion prevention – use the Precautionary Principle Photo of Caulerpa from www.outernode.pir.sa.gov.au

28. Legislation National Invasive Species Council’s National Invasive Species Management Plan Established by a Clinton Executive Order, 1999; Coordinates all U.S. federal activity and legislation on introduced species; Updated every 2 yr National Invasive Species Information Center

29. Looking ahead towards our climate change lecture… Let’s listen to a news report from National Public Radio (“Belief in Climate Change Hinges on Worldview,” aired Feb. 23, 2010) that suggests that education alone may not be sufficient to change persons’ opinions (e.g., on subjects relevant to Conservation Biology)