1. Invasive Species, part 1 Wed. Mar. 30

2. Seed Dispersers and the Ecologically Viable Population Size Concept http://www.birding.in/images/Birds/great_hornbill.jpg http://bp0.blogger.com/_ Seed dispersers in Borneo Seeds need to be moved some distance from the parent to survive. The greater the dispersal radius, the greater the chance that one will be dropped in a favorable place. Seed dispersers thus have a major ecological role. What happens when they are decreased?

3. Ecologically Functional Populations MacArthur's "Strong interactors" – species that have large effects regardless of their normal abundance (not depleted abundance). Also called "fundamentally important species", many are dominant or keystone species. Large mature fig trees as strong interactors in tropical systems. Many species depend on these dominant species and numerous interactions center around them. For example, if fig abundance decreases, so do hornbills and some primates. Hornbills and macaque monkeys are in turn strong interactors with other tree species and most importantly, they are strong interactors with fig trees! (it works both ways). Imagine the cascade here if the figs or seed dispersers fail.

4. Ecologically Functional Populations no effect not enough to support largest sizes followed by accelerated loss of seed production no seed bearing trees average seed crop size # seeds dispersed Dracontomelon dao macaques only Polyalthea glauca Hornbills and siamangs compete http://homepage.mac.com /wildlifeweb/mammal/siam ang/

5. Why Is the EFP Concept Important? 1.Maintain community function. 2.EFP is generally larger than MVP -- will require larger areas to meet EFP and therefore more effective ecosystem conservation. 3.Ecocentrism.

6. End of material for Exam #2

7. Invasive Species and their Implications for Conservation

8. Examples of Accelerating Effects of Invasives Conservation Implications Brown tree snake induced electrical outages on Guam. Acceleration of invasives in SF Bay

9. Impacts of Invasives http://www.hear.org/images/captured_snakes_640x480.jpg http://www.wettropics.gov.au/st/rainforest_explorer/Resources/Images/animals/snakes/B rownTreeSnake.jp Introduced predators Due to the important role that predators play in communities, unchecked introduced predators can greatly alter structure and function – and they can cause extinctions. This is especially a problem with islands where many species may be endemics and could easily be driven to world-wide extinction. Guam is an isolated, mid- Oceanic island

10. Guam and Brown Tree Snakes Boiga irregularis was introduced, probably as a boat stowaway shortly after the end of WWII. It originated in the SW Pacific. For more information: http://www.fort.usgs.gov/Resources/Education/BTS/http://www.fort.usgs.gov/Resources/Education/BTS/ Note the severe reduction in diversity. Note also the shift towards predominance of introduced species (asterisk).

11. The Effects of Zebra Mussels http://www.epa.gov/glnpo/atlas/images/photo405.gif http://webhost.bridgew.edu/dpadgett/zebra%2520mussel%2520pic.jpg introduced competitors planktonic vs. host dispersed

12. The Atlantic Ctenophore in the Black Sea http://www.underwaterphotography.com/Upload%5C UP%5CCompetition%5C25174.jpg http://www.imagequest3d.com/pages/general/news/blackseajellies/Beroe%20eating%20Mn emiopsis.jpg Beroe eating Mnemopsis Mnemopsis-caused reductions in commercially important species.

13. One Invasive Helping Another 1.Gulf of Maine 2.Remove ground fish 3.Increase urchins 4.Decrease kelp 5.Harvest urchins 6.Kelp did not return completely and Asian macroalga and a bryozoan invade 7.Bryozoans encrust kelp causing breakage in winter storms, opens area for alga invasion. 8.Asian alga spread by breakage in winter storms

14. Effects on Other Species' Behaviors http://www.flickr.com/photos/unclejefejefe/3367700309/in /photostream/ Pollinators such as bumblebees judge nectar sources by a number of criteria (specific choices are not innate). If the invader produces nectar that is more desirable to a native pollinator, there will be fewer visits to the native and lower seed set – an interesting and very significant form of competition.

15. Change in Preference and Dependence http://upload.wikimedia.org/wikipedia/commons/3/3b/Plantago_major2.jpg http://floralore.com/fauna/butterflies/euphydryasEditha.jpg This appears to be selection for a genetic preference (unlike bumblebees). What is the (immediate at least) effect of attempting to remove the non-native plantain?

16. Genetic Impacts http://www.birdcapemay.org/gallery/ http://www.flickr.com/photos/23505652@N0 3/3229683119/ Hybrids http://sdakotabirds.com/species/photos/american_black_duck.jpg American Black Duck (NE native) http://www.haryana-online.com/images/Birds/BhupendraYadav/Mallard.jpg Mallard F&M (Eurasian)

17. Invasives and Ecosystem Damage - - Nutria in North America http://www.sivae.it/images/nutria%203.jpg http://nas.er.usgs.gov/ARCIMS/interactive/interactive.asp?SpeciesID =1089 http://www.iiseagrant.org/EXOTICSP/nutria.htm

18. Invasives and Ecosystem Damage http://www.scn.org/savelake/NL.Spr.Sum.2006/NL.Spr.Sum.2006_ files/Current_Nutria_Damage_5_06.JPG http://www.conservewildlife.org/gfx/bad_marsh.jpg