1. Announcements:  No Section this week  Holiday Friday: no class  Pick up Midterm exams tomorrow (Thursday 12-2 in TA office)  HW passed out (posted soon): due in section next week  Guest Lecture Monday: Come on time!!!  Skim Chapters 3, 18, 19 before class to get most out of lecture!

2. Community Change ES 100: November 7 th, 2006

3. Millenium Ecosystem Assessment: Largest inventory of the health of Earth’s ecosystems  Experts and Review Process  Prepared by 1360 experts from 95 countries  80-person independent board of review editors  Review comments from 850 experts and governments  Includes information from 33 sub-global assessments  Governance  Called for by UN Secretary General in 2000  Authorized by governments through 4 conventions  Partnership of UN agencies, conventions, business, non-governmental organizations with a multi-stakeholder board of directors

4. Significant and largely irreversible changes to species diversity  The distribution of species on Earth is becoming more homogenous  Humans have increased the species extinction rate by as much as 1,000 times over background rates typical over the planet’s history (medium certainty)  10–30% of mammal, bird, and amphibian species are currently threatened with extinction (medium to high certainty)

5. How do non- native species arrive? Accidentally seeds parasites unintended cargo Deliberately food timber pets biocontrol Data source: Eurostat. Source of figure: CNT, 2004 Data source: US Department of Transportation, 2004

6. Who are these invaders? Plants Animals Microorganisms

7. What makes an invader successful? r-strategists grow quickly produce many offspring short generation time good dispersion generalists: highly adaptable to new conditions broad geographic range in native environment broad diet It has not coevolved with members of its new environment

8. What makes a community vulnerable to invasion? human disturbance early succession climate similar to native habitat absence of predators or pathogens wrong ones for the invader no predators or pathogens at all - islands

9. What do invasive animals do? Change foodweb structure Hyperpredation drive out native competitors and prey

10. Invasive Plant and Animal Mutualism +

11. Management Options  Do nothing  Understand life strategy  Vulnerabilities, limiting factor  Predict where it will invade, rate of spread, during what time periods….  Mathematical models!  Remote sensing  ERADICATE!  Other creative solutions????

12. Eradication  Physical control  Chemical control  Thermal control  Biological control  Predator  Virus  Grazing www.dailynexus.com Coalition Drops Black Rat Poison on Anacapa Island by Rebecca Turek - Staff Writer Thursday, December 6, 2001

13. Arundo: historic and future issues  Past, Present, Future  Uses  Music  Fiber (thatching)  Lectin  Biofuel?

14. The new trend…… ADAPTIVE MANAGEMENT:  Treat management as an experiment  Learn from experience

15. How can we avoid invasive species and preserve biodiversity?  “Co-habitable” land use  Land uses consistent with biota  Give up the green lawn!  Organic/crop rotation based agriculture (but what is the cost?)  Habitat enhancement  Variation of landscape  Restore disturbance regimes  Re-introduction  Laws and Regulations

16. Questions to Ponder:  How long do you have to inhabit an area to be a native?  What point in time should we restore to?  Is fighting invasives a losing battle? What are the costs of doing nothing?  Which species would you say is most invasive?

17. How do communities change? What we see now wasn’t always here communities do change Spatial scale is important global vs. local change Time scale is important long term change measured in 10’s of thousands of years or more short term change measure on a decadal time scale

18. Short-Term Change Succession Textbook definition: “a change in species that occupy a given area, with some species invading and becoming more numerous while others decline in population and disappear” Can be thought of as the replacement of one community by another

19. Primary vs. Secondary Succession Primary: Community gets established on a new surface Lava flow Meteor crater Glacial moraine Secondary: Recovery following disturbance Fire Flood Post-agriculture

20. Succession in Sycamore Canyon?

24. Who Wins? Early vs. Late Succession Species Early shade intolerant nutrient demanding short-lived poor competitors Late shade tolerant adapted to lower nutrient conditions long-lived good competitors

25. Who wins in the beginning? Secondary succession space, light, and nutrients are abundant classic r-selected species (opportunists) Primary succession space and light are abundant nutrients may not be N-fixing plants are common convert atmospheric N 2 into NH 4 +

26. How does succession happen? Facilitation early succession species alter conditions to favor the growth of late succession species N-fixers make soil richer dune grass stabilizes sand Acceleration late succession species alter conditions to favor their own growth and prevent the growth of early succession species some plants produce toxic litter

27. Is Rate of Community Change Increasing?  Depends on time scale but consider:  More human-induced disturbance  Global affects (changing climate, sea levels, soil temperature/structure)  Invasive Species!!!

28. Predestined Communities? A community is a group of living organisms that occupy a certain area and interact with one another. Clement’s climax community theory

29. Classic Succession Clements’ idea of “climax community” eventually, a given system reaches a predictable steady-state independent of the early succession community Community predestined by climate?

30. Mixed Beech-Maple Forest Oak-Hickory Willow shrub Cattail marsh Aquatic plants Swamp Oak woodland Sumac-Pine Broomsedge Aster-Goldenrod Annual weeds Old field Oak forest Pine forest Poplars Dune grass Sand dune

31. The Role of Randomness (aka Stochasticity)  2 species are equally suited to be next “successors”  Outcome is CHANCE (dispersal, weather, ect.)

32. Why Is Succession Important?  Understanding ‘natural’ disturbance recovery can aid human’s restoration efforts.  Biotic and Abiotic processes are important  Management plans must recognize that disturbance is not intrinsically bad!

33. Announcements:  No Section this week  Holiday Friday: no class  Pick up Midterm exams tomorrow (Thursday)  HW passed out: due in section next week  Guest Lecture Monday: Come on time!!!  Skim Chapters 3, 18, 19 before class to get most out of lecture!