1. Ecological Succession

2.  Ecological succession is the observed process of change in the species structure of an ecological community over time.

3.  Birth  Growth  Maturity  Stability  Death

4.  Those species that can grow the most efficiently and produce the most viable offspring will become the most abundant organisms in an ecosystem

5.  Changes that takes place during succession can depend on four things: 1. Abiotic factors - moisture, temperature, and wind 2. Biotic factors – invasive species (ex. Weeds) 3. Human Actions 4. Natural Disasters

6.  Primary succession: invasion of life onto abiotic environment examples: lichens and mosses on rocks start making soil airborne seeds germinate in sand or ash  Secondary succession : changes after biotic community is established or after a disturbance example: fire -- meadow – old field – thicket – seral forest – climax forest

8.  Weed species are considered as an invasive species. What makes them successful? They are:  Better competitors (they outcompete grasses and other plant for nutrients)  Greater growth rates (grow fast, grab nutrients)  Greater dispersal ability (seeds move great distances from parent plants for nutrients)

9.  Better colonizers of disturbed ground  Greater reproductive potential (mature quickly and produce many seeds)  Greater tolerance to environmental extremes  Lower rates of disease

10.  Succession can occur in a typical garden very quickly if weeds are allowed to take root. 1. It begins when weed seeds blow into a garden, take root, grow, and develop and out-compete the existing natural garden species. 2. The weeds will absorb all the water and nutrients, grow tall and tower over the natural garden species, robbing them of sunlight 3. The last step of ecological succession occurs when the native species die out, and the weeds will become the dominant species of the garden.

11.  Succession occurs after an environment gets destroyed, as a volcanic eruption.  Ex. Lichens and mosses spring up in rocks in which water collects, eventually weathering the lava rock to form soil. Lichens are called “pioneer organisms” because they help establish the soil for seeds to take root, to continue to the next stage of succession

12. Succession occurs because of :  facilitation: growth of one species increases the growth of another  examples: lichens/mosses create soil: benefits other plants legumes fix nitrogen, fertilizing soil: benefits other plants  competition: growth of one species hinders the growth of another  example: tall-growing trees shading out