Ecological Succession Notes Ecological Succession Gradual replacement of simple organisms with more complex organisms overtime Role of succession is to make an ecosystem more sustainable/biodiverse Can happen in a microhabitat, like a garden being taken over with weeds No organisms OR small plants & insects grass, rabbits shrubs/bushes Forest Pioneer Species – first organisms to arrive in an area Climax community The oldest stage of succession The most stable/balanced ecosystem Example: Forest (depends on the biome) Number of species plateaus or remains constant Invasive Species (non-native) New species to an area that do not have any natural predators/enemies Population grows uncontrollably Replaces other species, native species population decreases Examples: weeds like dandelions, zebra mussels Eutrophication – succession in an aquatic area that can turn it into land Primary Succession Begins in a place without soil; ROCK Events that trigger: Volcanic Eruptions (lava hardens into rock), Rock slide Pioneer Species – Lichen and moss (grow in extreme conditions; break down rock into soil) Can reach a climax community in 1,000 years ROCK Lichen & Moss Grass small plants & insects grass, rabbits shrubs/bushes Forest Change in number of species is very slow at the beginning Secondary Succession Begins in an area that only has SOIL, but used to have organisms Events the trigger: Construction (bulldozing or clearing land), Natural disasters like floods or hurricanes Pioneer Species – Grass (seeds are already in soil or brought in by wind/water/animals) Can reach a climax community in 100 years Grass small plants & insects grass, rabbits shrubs/bushes Forest Change in number of species happens at a steady rate .