1. Biol 302 succession 1 COMMUNITY CHANGE (SUCCESSION) Krebs cpt. 21; pages 403-424; 431

2. Biol 302 succession 2 SUCCESSION …. Is the non-seasonal, directional and continuous pattern of colonization and extinction on a site by populations. Is the replacement of one kind of community by another kind; the progressive changes in vegetation and animal life that may culminate in the climax community (Krebs 622)

3. Biol 302 succession 3 PRIMARY SUCCESSION …. … recovery from a new sterile area that has been uncovered by a retreating glacier, or created by an erupting volcano. SECONDARY SUCCESSION …. … recovery of a disturbed site.

4. Biol 302 succession 4 PRIMARY SUCCESSION Mt. St. Helens pp403-405 Lake Michigan dunes pp416-419 Glacier Bay pp413-416

5. Biol 302 succession 5 Krebs Fig. 21.7; p414 Ice recession in Glacier Bay, Alaska, since 1760 1940 1860 1760

6. Biol 302 succession 6 SECONDARY SUCCESSION Krebs pp419-422

7. Biol 302 succession 7 From Drury and Nisbet 1973 “Succession can be considered as an expression of differences in colonizing ability, growth and survival of organisms adapted to a particular set of conditions on an environmental gradient.” “The replacement of one of several species or groups of species by others results from interspecific competition and the interactions of herbivores, predators, and disease which permit one group plants to suppress slower-growing or less tolerant ones.”

8. Biol 302 succession 8 1. OBLIGATORY SUCCESSION SUCCESSION PATHWAYS (HENRY HORN) ABCD

9. Biol 302 succession 9 1.OBLIGATORY SUCCESSION 2.CHRONIC, PATCHY DISTURBANCE AB C D

10. Biol 302 succession 10 1.OBLIGATORY SUCCESSION 2.CHRONIC, PATCHY DISTURBANCE 3.COMPETITIVE HIERARCHY ABCD

11. Biol 302 succession 11 1.OBLIGATORY SUCCESSION 2.CHRONIC, PATCHY DISTURBANCE 3.COMPETITIVE HIERARCHY 4.QUASI-REALITY

12. Biol 302 succession 12 Institute Woods, Princeton, N.J. (Henry Horn) Eastern deciduous hardwood forests

13. Biol 302 succession 13 Grey Birch, Betula populifera Black Gum, Nyssa sylvatica

14. Biol 302 succession 14 Red Maple, Acer rubrum Beech, Fagus sylvatica

15. Biol 302 succession 15 4. QUASI-REALITY GRAY BIRCH BLACK GUM RED MAPLE BEECH

16. Biol 302 succession 16 4. QUASI-REALITY GRAY BIRCH BLACK GUM RED MAPLE BEECH GRAY BIRCH BLACK GUM RED MAPLE BEECH

17. Biol 302 succession 17 4. QUASI-REALITY GRAY BIRCH BLACK GUM RED MAPLE BEECH

18. Biol 302 succession 18

19. Biol 302 succession 19 No. of individuals IN 50 YEARS GRAY BIRCH BLACK GUM RED MAPLE BEECH No. of individuals NOW GRAY BIRCH536509 BLACK GUM1572517 RED MAPLE-145531 BEECH-1396 Values in cells are percentages, and represent the probability (% probability) that any particular individual tree living now will be replaced by any other individual tree 50 years from now. e.g. out of every 100 individuals of grey birch now living, in 50 years, 36 of those grey birch will have died and will have been replaced by black gum.

20. Biol 302 succession 20 FOR EXAMPLE: The number of Red Maple and 50 years will be: 50% Gray Birch (now) 25% Black Gum (now) 55% Red Maple (now) 3% Beech (now)

21. Biol 302 succession 21 The predicted percentage composition of a forest consisting initially of 100% Grey Birch. Age of forest (yrs) Now50100150200  Data from old forest GRAY BIRCH100510000 BLACK GUM03629231853 RED MAPLE05039302494 BEECH093147588693

22. Biol 302 succession 22 From Connell and Slatyer 1977  FACILITATION  TOLERANCE (COMPETITION)  INHIBITION

23. Biol 302 succession 23 FACILITATION …later stages depend upon early-stage species to prepare a favorable environment for them

24. Biol 302 succession 24 TOLERANCE…later successional species tolerate lower resource levels [i.e. have lower R*] than earlier occupants, and can invade and displace them by reducing resources to levels below those tolerated by earlier occupants

25. Biol 302 succession 25 TOLERANCE…later successional species tolerate lower resource levels [i.e. have lower R*] than earlier occupants, and can invade and displace them by reducing resources to levels below those tolerated by earlier occupants i.e. the community is composed of those species most efficient at exploiting resources

26. Biol 302 succession 26 INHIBITION…all species resist the invasion of competitors and are displaced only by death, or damage by factors other than competition.

27. Biol 302 succession 27 INHIBITION…all species resist the invasion of competitors and are displaced only by death, or damage by factors other than competition. i.e. colonizers will hold a side against all comers until death

28. Biol 302 succession 28

29. Biol 302 succession 29 FACILITATION TOLERANCE INHIBITION

30. Biol 302 succession 30 A study from abandoned farmland illustrates some aspects of Facilitation, Tolerance and Inhibition (see Krebs pp496-498) FIELD ABANDONED IN FALL 1. INITIAL INVASION: Horseweed Horseweed a winter annual a winter annual produces abundant seed produces abundant seed self-allelopathic self-allelopathic Conyza canadensis

31. Biol 302 succession 31 2. NEXT SEASON: AstersAsters More susceptible to decaying roots of horseweed, than horseweedMore susceptible to decaying roots of horseweed, than horseweed Tolerant of dry conditionsTolerant of dry conditions

32. Biol 302 succession 32 3. SECOND AND THIRD SEASONS 3. SECOND AND THIRD SEASONS: BluestemBluestem Seedlings invading since initial abandonmentSeedlings invading since initial abandonment BroomsedgeBroomsedge Seedlings invading since initial abandonmentSeedlings invading since initial abandonment More tolerant of dry conditions than AstersMore tolerant of dry conditions than Asters Decaying roots of Horseweed promote growthDecaying roots of Horseweed promote growth

33. Biol 302 succession 33 Bluestem Broomsedge

34. Biol 302 succession 34 FACILITATION: Broomsedge promoted by decaying root TOLERANCE: Broomsedge displaces Aster through competition for water INHIBITION: Horseweed seedlings more tolerant of horseweed decomposition than Asters SUMMARY

35. Biol 302 succession 35 THE RESOURCE RATIO HYPOTHESIS OF PLANT SUCCESSION David TILMAN

36. Biol 302 succession 36 TILMAN, D. 1985. The resource-ratio hypothesis of plant succession. American Naturalist 125:827-852 READING FOR THESE LECTURES: Krebs: selections from pp. 182-186

37. Biol 302 succession 37 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

38. Biol 302 succession 38 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

39. Biol 302 succession 39 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

40. Biol 302 succession 40 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

41. Biol 302 succession 41 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

42. Biol 302 succession 42 0 1 2 3 4 5 6 7 8 9 10 Resource level [1] Population growth [death] rate mortality Species A birth R*

43. Biol 302 succession 43 OPTIMAL FORAGING Any (plant) species will absorb resources in the proportion by which it is equally limited by them. This proportion is the ratio of the two values of R* R* = the Requirement Value i.e. the level of resource required to hold a population (of a species) at equilibrium: i.e. where birth rate = death rate

44. Biol 302 succession 44 OPTIMAL FORAGING Any (plant) species will absorb resources in the proportion by which it is equally limited by them. This proportion is the ratio of the two values of R* R* = the Requirement Value i.e. the level of resource required to hold a population (of a species) at equilibrium: i.e. where birth rate = death rate

45. Biol 302 succession 45 OPTIMAL FORAGING Any (plant) species will absorb resources in the proportion by which it is equally limited by them. This proportion is the ratio of the two values of R* R* = the Requirement Value i.e. the level of resource required to hold a population (of a species) at equilibrium: i.e. where birth rate = death rate

46. Biol 302 succession 46 0 1 2 3 4 5 6 7 8 9 10 Resource level [2] Population growth [death] rate mortality Species A birth R*

47. Biol 302 succession 47 0 1 2 3 4 5 6 7 8 9 10 Resource level [1] Population growth [death] rate mortality Species B birth R*

48. Biol 302 succession 48 0 1 2 3 4 5 6 7 8 9 10 Resource level [2] Population growth [death] rate mortality Species B birth R*

49. Biol 302 succession 49 Population growth [death] rate 0 1 2 3 4 5 6 7 8 9 10 SPECIES A SPECIES B Resource 1Resource 2 1 24 3

50. Biol 302 succession 50 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

51. Biol 302 succession 51 0 1 2 3 4 5 6 7 8 9 10 Species A Resource [2] 8765432187654321 Resource [1] Births [A] > Deaths [A] Population increases Births [A] < Deaths [A] Population declines Zero Net Growth Isocline [ZNGI]: Births = Deaths

52. Biol 302 succession 52 0 1 2 3 4 5 6 7 8 9 10 Species B Resource [2] 8765432187654321 Resource [1] Births [B] > Deaths [B] Population increases Births [B] < Deaths [B] Population declines Zero Net Growth Isocline [ZNGI]: Births = Deaths

53. Biol 302 succession 53 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

54. Biol 302 succession 54 0 1 2 3 4 5 6 7 8 9 10 Species A and B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B]

55. Biol 302 succession 55 0 1 2 3 4 5 6 7 8 9 10 A Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B] B

56. Biol 302 succession 56 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B] Neither species can survive A wins B wins Both species can grow

57. Biol 302 succession 57 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B]

58. Biol 302 succession 58 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B] Neither species can survive A wins B wins A & B coexist

59. Biol 302 succession 59 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B] Neither species can survive A wins B wins A & B coexist WHY?

60. Biol 302 succession 60 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B]

61. Biol 302 succession 61 0 1 2 3 4 5 6 7 8 9 10 A B Resource [2] 8765432187654321 Resource [1] ZNGI [A] ZNGI [B]

62. Biol 302 succession 62 Resource Ratio Hypothesis One species and one resource One species and two resource Two species and two resources Multiple species and two resources

63. Biol 302 succession 63 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [2] 8765432187654321 Resource [1] A B C D E

64. Biol 302 succession 64 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [2] 8765432187654321 Resource [1] A B C D E None AAB BC C CD D DE E B

65. Biol 302 succession 65 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [2] 8765432187654321 Resource [1] A B C D E None AAB BC C CD D DE E B Random Resource Supply

66. Biol 302 succession 66 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [2] 8765432187654321 Resource [1] A B C D E None AAB BC C CD D DE E B Positively Correlated Resources

67. Biol 302 succession 67 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [2] 8765432187654321 Resource [1] A B C D E None AAB BC C CD D DE E B Negatively Correlated Resources

68. Biol 302 succession 68 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [Light] 8765432187654321 Resource [Nitrogen] A B C D E A AB BC C CD D DE E B PRIMARY SUCCESSION

69. Biol 302 succession 69 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [Light] 8765432187654321 Resource [Nitrogen] A B C D E A AB BC C CD D DE E B SECONDARY SUCCESSION Poor soilRich soil

70. Biol 302 succession 70 0 1 2 3 4 5 6 7 8 9 10 Resource [Light] 8765432187654321 Resource [Nitrogen] Aspen Black Oak & Aspen Black Oak Red Oak & Black Oak Red Oak White Oak & Red Oak White Oak Sugar Maple & White Oak Sugar Maple

71. Biol 302 succession 71 0 1 2 3 4 5 6 7 8 9 10 A B C D E Resource [Light] 8765432187654321 Resource [Nitrogen] A B C D E 0 1 4 2 DIVERSITY

72. Biol 302 succession 72 TILMAN THE END

73. Biol 302 succession 73 FORCIER, Keith Studied trees in a New Hampshire forest Trees with dbh <2 cm (400 plots) 90% of canopy: Sugar maple American beech Yellow birch

74. Biol 302 succession 74 SPECIES Density (#/m 2 ) (d min /d max ) x 100 % plots with at least 1 seedling Mass/ind (mg) Yellow birch 21.32928 Sugar maple 105773268 Beech 3.96655569

75. Biol 302 succession 75 Number of cohort alive at beginning of interval Age interval Yellow birch Sugar maple Beech 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 1000 70 <30 1000 583 317 225 166 118 84 54 48 42 1000 410 262 188 138 121 110 92 87 83

76. Biol 302 succession 76 CANOPYSEEDLINGSSAPLINGS < 0.5m tall0.5 – 2 m tall Yellow birch Sugar maple Beech ++0++0 -+--+- Sugar maple Yellow birch Sugar maple Beech 0++0++ 0 ++ BeechYellow birch Sugar maple Beech 00+00+ 0 Seed - Sprouts +

77. Biol 302 succession 77 CATASTROPHIC DISTURBANCE Yellow birch Sugar Maple Beech (seed) Beech (sprouts) MINOR DISTURBANCE Successional communities

78. Biol 302 succession 78

79. Biol 302 succession 79

80. Biol 302 succession 80

81. Biol 302 succession 81