1. COMMUNITY CHANGE (SUCCESSION) Krebs chap. 21; pages 403-424; 431 “the non-seasonal, directional and continuous pattern of colonization and extinction of species populations on a site”

2. PRIMARY SUCCESSION Mt. St. Helens pp403-405 Lake Michigan dunes pp416-419 Glacier Bay pp413-416

3. SECONDARY SUCCESSION Krebs pp419-422 Abandoned fields Forest regrowth Abandoned lots

4. Mount St. Helens Vegetation recovery

5. Sand dune ecology Vegetation hummock Beach grass

6. Fig 21.11Profile of Lake Michigan sand dunes succession “SFT” – space-for-time substitution pastpresent

7. “Polyclimax” sand dune successions Fig. 21-12

8. Krebs Fig. 21.7 Ice recession in Glacier Bay, Alaska, since 1760 1940 1860 1760

9. Alders and cottonwoods covering the hillsides 50 years

10. Spruce coming into the alder and cottonwood forest 100 years

11. Spruce and hemlock forest 250 years

12. Fig 21.9Change in soil-N Topsoil Mineral soil

13. 1 year later Wildfire

14. Wind disturbance (“blowdowns”)

15. Opax Mountain Silvicultural Systems Trial (near Kamloops, BC)

16. Control burning

18. Control burn plot

19. Monitoring succession after fire