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Understanding Biodiversity Patterns Through Time and Space

Explore patterns in biodiversity, from succession to community dynamics, across time and space, with a focus on species relationships, community structures, and ecological mechanisms. Learn about colonization, extinction, and equilibrium in diverse ecosystems.

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Understanding Biodiversity Patterns Through Time and Space

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  1. Patterns in Biodiversity I. Patterns Through Time: Succession

  2. Patterns in Biodiversity • Patterns Through Time: Succession • A. Types:

  3. Primary succession

  4. Primary succession

  5. Primary succession

  6. Primary succession

  7. Bog succession

  8. Secondary Succession

  9. Variation in the ‘climax’ community

  10. Disturbance-mediated Succession

  11. Patterns in Biodiversity • Patterns Through Time: Succession • A. Types: • B. Mechanisms:

  12. 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

  13. 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.

  14. 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.

  15. Patterns in Biodiversity • Patterns Through Time: Succession • A. Types: • B. Mechanisms: • C. Community Patterns

  16. E. Community Patterns (From Morin, 1998) Variable Early Late Organism Size small large life history r K Biomass low high Richness, Diversity low high Structural complexity low high Niches broad narrow Nutrient cycles open closed Stability low high trophic relationships linear web-like connectance low high

  17. Patterns in Biodiversity • Patterns Through Time: Succession • Patterns Across Space • A. The Species Area Relationship

  18. "species - area relationship"

  19. S = CAz log10S = log10C + z log10A where C is the y intercept and z is the slope of the line.

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

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

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

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

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

  25. confirmation: greater immigration rate on larger islands

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

  27. - 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)

  28. COL - large RATE EXT - small COL - small EXT - large SMALL LARGE species richness

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

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

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

  32. - 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.

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

  34. equilibria

  35. equilibria and turnover

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

  37. White-faced Saki (Pithecia pithecia)

  38. Monk Saki (Pithecia monachus) White-faced Saki (Pithecia pithecia)

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

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

  41. Minnesota: Land O'Lakes

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

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

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