1. Forest succession is the gradual replacement of one community of plants by another, usually driven by differences in shade tolerance. Pioneer species that colonize first are shade-intolerant, while climax species that eventually remain are most shade tolerant. 2. In an eastern deciduous forest, pioneer species like black locust and loblolly pine establish first following clearing before being replaced by oak trees with intermediate tolerance and later more tolerant maple and beech. 3. Forest succession can be influenced by disturbances like clearing or fire that allow pioneers to grow, while lack of disturbance allows climax species suited to the location to persist indefinitely.

1. Forest Succession

2. Forest Succession : The gradual supplanting of one community of plants by another, usually as a result of differences in shade tolerance .

4. Eastern Deciduous Forest

7. Shade Tolerance

11. Pioneer species quickly occupy a site following clearing. They grow rapidly to compete with grasses and shrubs.

12. As the crowns of pioneer species close, seedlings from these trees are unable to survive in the resulting shade.

13. Different species that have a higher tolerance to shade soon become established beneath the pioneers.

14. As the short-lived pioneers near the end of their life spans, the more tolerant trees in the forest understory begin to take over the site. The result is a major change in plant and animal species.

15. Spruce begins to take over an aspen dominated site in northern Minnesota as the short-lived pioneer aspen crowns thin with aging .

16. Beneath the second successional stage species, that often form thicker crowns than pioneers, new species that are even more shade tolerant become established.

17. The process of succession continues until the most shade-tolerant species suitable for the site (climax species) become established.

18. Seedlings of highly shade tolerant climax species thrive in the shade of their parents. Because of this, climax species will persist until disturbance sets back the succession process to the pioneer or some other stage.

24. The first vegetation to grow is that which likes full sunlight

25. Succession stage 1: Herbaceous opening

26. Succession stage 2: Shrub/seedling brush

27. Succession stage 3: Sapling/pole

28. Old field species (red-cedar) being overtopped by hardwoods

29. Succession stage 4: Mature forest Natural habitat features develop

30. Early Successional Species Vary by Region (hawthorn, sweetgum, red-cedar,)

32. Just Stop Mowing (But be ready to control invasive species)

33. Tree Planting: Push succession ahead Forest Harvesting: Push succession back

35. Tolerant or Intolerant? Loblolly Pine American Dogwood

37. Each stage of succession supports different wildlife

39. Different stages of succession represent different habitat patches (i.e. mature forest, old field, young forest, etc)

40. Take a look at the commercial harvest of aspen in Minnesota .

41. Clearcut harvesting in Minnesota aspen.

42. Aspen harvest site one year following clear-cut harvest.

43. A good site several years following harvest. 50,000 to 100,000 stems per acre from stump sprouting.

44. Mature aspen stand. 65-70 years old. Approximately 200 stems/acre. Question: Assuming that 50,000 stems occupied each acre of the harvested site several years following stand establishment, what happened to the other 49,800 trees?

45. When reproduction of species with medium to high shade tolerance is desired following logging, selective harvest methods can be used.

46. Old Aerial Photo (1994)

47. 2006 Photo