1 Mon. Tues. Wed. Thurs. Fri. Week of Nov. 24 No lab – Thanksgiving No lecture Week of Dec. 1 Independent project presentations Exam 3 Week of Dec. 8 Final Exam Dec. 11 Last lecture Week of Dec. 15 Grades in by 10 pm

2 Sp. interactions – (through fig. 18.7), (only covering p. 391) Community ecology – Don’t read 23,25, and 26 just yet

3 Communities What is a community? How are communities described? How are species organized within a community? How do communities change over time?

4 Figure 22.2

5 New substrate Climax community Disturbed area Multiple successional stages Multiple successional stages Primary succession Secondary succession

6 Figure 22.9

7 Figure 22.5 Lake Michigan

8 Why does succession occur??? 1.Organisms change environment during succession - how? 2.Organisms face trade-offs

9 Why does succession occur??? 1.facilitation 2.inhibition 3.tolerance Mechanisms for species establishment

10 Figure 22.11

11 Figure 22.10

12 Why does succession occur??? 1.facilitation 2.inhibition 3.tolerance Mechanisms for species establishment

13 Figure 22.13

14 Why does succession occur??? 1.facilitation 2.inhibition 3.tolerance – establishment not dependent on which species are already there Mechanisms for species establishment

15 1. Annual plants 2. Herbaceous perennials 3. Early sucessional trees/shrubs 4. Late successional trees Succession on abandoned fields

16 Figure tolerance inhibition

17 Why does succession occur??? 1.Organisms change environment during succession 2.Organisms face trade-offs - can’t be good at all things - as succession occurs – organisms are more or less adapted to new environment

18 (Pioneer) (Climax) EarlyLate Characteristic Succession Succession Number of seeds Seed size Dispersal ability Shade tolerance Growth rate Competitive ability

19 How does species richness change over the course of succession? Time Species richness

20 How do communities change over time and space? -succession – changes over time -biogeography – study of differences and similarities in communities in different regions (space)

21 Temperate forests in N. America have more tree species than temperate forests in Europe Examples of biogeographical patterns

22 Figure 24.9

23 Figure 25.11

24 Evolutionary history affects current distribution of organisms Examples of biogeographical patterns

25 Figure 24.6

26 Figure 24.4

27 Figure 24.7