1. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession A. Definitions B. Types C. Mechanisms - facilitation, tolerance, and inhibition

2. Facilitated: early species change environment and increase the probability of successful colonization by later species. examples: colonization of bare rock: lichens, moss, herbs; colonization of carcasses: beetles, flies, etc. Aspen fix nitrogen that helps nitrogen- limited trees colonize

3. Tolerance: Tolerance: early species have no effect on later species. This occurs if there is 'ecological equivalence' among the species. Many stages in later forest succession seem dominated by this mechanism. Also, later species tolerate early species... so shade tolerant species come to dominate because they tolerate the shade of early species.

4. Inhibition: Early species retard the colonization success of later species. If these effects vary among early species, there can be "priority effects". The species that gets there first has a differential and deterministic effect on the subsequent structure of the community. Important where allelopathic interactions occur. Bryozoans block colonization of tunicates and sponges.

5. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession A. Definitions B. Types C. Mechanisms D. Model – Tilman 1985

6. 3. Model: Tilman (1985).... ready? AA, B B Our old 2-species model with stable coexistence possible.

7. 3. Model: Tilman (1985) AA, B B If resource supply rates are negatively correlated, then the community may succeed from A to A-B coexistence to B as concentrations change

8. 3. Model: Tilman (1985) AA, B B B, C C...and then to B,C and C.... and etc....

9. 3. Model: Tilman (1985) AA, B B B, C C...and then to B,C and C.... and etc.... C, D D

10. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession A. Definitions B. Types C. Mechanisms D. Model – Tilman 1985 E. Community Patterns

11. E. Community Patterns (From Morin, 1998) VariableEarlyLate Organism Sizesmalllarge life historyrK Biomasslowhigh Richness, Diversitylowhigh Structural complexitylowhigh Nichesbroadnarrow Nutrient cyclesopenclosed Stabilitylowhigh trophic relationshipslinearweb-like connectancelowhigh

13. BIODIVERSITY

14. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession V. Biodiversity: Patterns and Processes A.The Species-Area Relationship 1. The pattern

15. "species - area relationship"

16. S = CA z log 10 S = log 10 C + z log 10 A where C is the y intercept and z is the slope of the line.

17. "species - area relationship" Breedings Birds - North Am.

18. "species - area relationship" Island Area log(square km) Number of Bat Species log(N)

22. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession V. Biodiversity: Patterns and Processes A.The Species-Area Relationship 1. The pattern 2. The Theory of Island Biogeography

23. MacArthur and Wilson (1967) THEORY OF ISLAND BIOGEOGRAPHY Edward O. Wilson Prof. Emer., Harvard Robert MacArthur 1930-1972

24. MacArthur and Wilson (1967) THEORY OF ISLAND BIOGEOGRAPHY - Species Richness is a balance between COLONIZATION (adds species) and EXTINCTION (subtracts species)

25. - Colonization Increases with Area - larger target - more habitats Mainland

26. confirmation: greater immigration rate on larger islands

27. - Colonization Increases with Area - larger target - more habitats

28. - Colonization Increases with Area - larger target - more habitats (except very small) Niering, W.A. 1963. Terrestrial ecology of Kapingamarangi Atoll, Caroline Islands. Ecological Monographs 33:131-160.

29. - Colonization Increases with Area - larger target - more habitats - Extinction Decreases with Area - more food means larger populations that are less likely to bounce to a size of "0" (extinction)

30. - Extinction Decreases with Area Wright, S.J. 1980. Density compensation in island avifaunas. Oecologia 45: 385- 389. Wright, S. J. 1985. How isolation affects rates of turnover of species on islands. Oikos 44:331-340. Reduced Turnover on larger islands

32. RATE species richness COL - small EXT - small COL - large EXT - large SMALLLARGE

33. - Colonization Decreases with Distance - fewer species can reach Mainland

34. saturation is the % of species found on a patch of mainland that size - Colonization Decreases with Distance - fewer species can reach

35. - Extinction Increases with Distance - recolonization less likely at distance Mainland "Rescue Effect"

36. - Extinction Increases with Distance - recolonization less likely at distance Wright, S.J. 1980. Density compensation in island avifaunas. Oecologia 45: 385- 389. Wright, S. J. 1985. How isolation affects rates of turnover of species on islands. Oikos 44:331-340.

37. RATE species richness COL - far EXT - far COL - close EXT - close far close

39. Equilbrium Island Biogeography & Turnover Turnover on "Landbridge" islands (California Channel Islands) Island Area km2 Distance km Bird Spp. 1917 Bird Spp. 1968 Extinctio ns Human Introd. Immigratio ns Turnover % Los Coronados 2.61311 40436 San Nicholas 579811 62450 San Clemente 14579282491425 Santa Catalina 19432303461924 Santa Barbara 2.66110670362 San Miguel3642111540846 Santa Rosa218441425111132 Santa Cruz24931363761517 Anacapa2.921151450431 Diamond, J.M. 1969. Avifaunal equilibria and species turnover rates on the Channel Islands of California. Proc. Natl. Acad. Sci 64: 57-63. Jones, H.L. and Diamond, J.M. 1976. Short-time-base studies of turnover in breeding bird populations on the Channel Islands of California. Condore 73: 526-549. [+] + equilibria

40. Equilbrium Island Biogeography & Turnover Turnover on "Landbridge" islands (California Channel Islands) Island Area km2 Distance km Bird Spp. 1917 Bird Spp. 1968 Extinctio ns Human Introd. Immigratio ns Turnover % Los Coronados 2.61311 40436 San Nicholas 579811 62450 San Clemente 14579282491425 Santa Catalina 19432303461924 Santa Barbara 2.66110670362 San Miguel3642111540846 Santa Rosa218441425111132 Santa Cruz24931363761517 Anacapa2.921151450431 Diamond, J.M. 1969. Avifaunal equilibria and species turnover rates on the Channel Islands of California. Proc. Natl. Acad. Sci 64: 57-63. Jones, H.L. and Diamond, J.M. 1976. Short-time-base studies of turnover in breeding bird populations on the Channel Islands of California. Condore 73: 526-549. [+] + equilibria and turnover

42. Dramatic evidence that, although the communities had recovered in terms of species richness, the composition was very different with typically about 80% of the species turning over.

43. Community Ecology I. Introduction II. Multispecies Interactions with a Trophic Level III. Multispecies Interactions across Trophic Levels IV. Succession V. Biodiversity: Patterns and Processes A.The Species-Area Relationship 1. The pattern 2. The Theory of Island Biogeography 3. Why is this important? Fragmentation

44. - Why is this important? - all habitats except the atmosphere are islands. Continents - big islands

46. White-faced Saki (Pithecia pithecia)

47. Monk Saki (Pithecia monachus)

48. White-faced Saki (Pithecia pithecia) Monk Saki (Pithecia monachus) White-footed Saki (Pithecia albicans)

49. White-faced Saki (Pithecia pithecia) Monk Saki (Pithecia monachus) White-footed Saki (Pithecia albicans) Rio Tapajos Saki (Pithecia irrorata)

50. Minnesota: Land O'Lakes

51. "Sky Islands" High elevation habitats separated by inhospitable (desert) habitat.

52. - Why is this important? - all habitats except the atmosphere are islands. - human activity fragments a landscape, making lots of islands, too.

62. Bolivia has lost 50% of its rainforest in last 30 years

63. Even Costa Rica has lost 95% of its old growth forest that is outside of national parks...