1. Ecological Succession

2. Sudden Changes Sudden changes can occur in ecosystems in a many ways o Forest Fire o Volcanic Eruptions Often times, this is very apparent when the vegetation of an area has been wiped out

3. Ecological Succession Ecological Succession – Transition in the species composition of a biological community following ecological disturbance or The establishment of a biological community in an area virtually barren of life

4. Types of Succession There are two kinds of ecological succession: o Primary o Secondary

5. Primary Succession Primary Succession – A change in composition of species over time in an area that never previously supported living things The soil or substrates in these places have never had plants growing in it, and soil has not been formed yet

7. Primary Succession Two common primary succession examples Succession on Rock or Lava o Lichens become established o Fungus attach lichens to rocks, and hold moisture that would otherwise flow away o Lichens flourish and produce acids that speed rock erosion, accelerating formation of soil o Bacteria, protists, and mosses and fungi appear in soil, helping put nutrients into the soil o Grasses and weeds begin to grow o Eventually trees and shrubs will develop

8. Primary Succession Example 2 Succession on sand dunes o Grasses that have evolved to grow in sand grow and help to anchor down the sand (6yrs) o Shrubs begin to grow after that o Over the next 50-100 years pines and oaks follow o Over the next 750-1000 years, beech maple trees begin to develop

9. Secondary Succession Secondary Succession – Begins in habitats where communities were destroyed by some kind of event but soil remains intact

10. Secondary Succession Examples Succession on Abandoned Cropland and Farms Grass and weeds will develop first due to the high abundance of their seeds Pines will often take root in the soil next, followed by oak, hickory, and dogwoods

12. Climax Community The last stage in ecological succession is known as a climax community Climax Community – A constant balance of organisms that remains unchanged until another catastrophic event Sometimes called an old growth forest