IN: Describe an example of how natural or human disturbances can change an ecosystem.

Ecological Succession

Ecological Succession A series of environmental changes As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community Biodiversity increases

Primary Succession On land, succession that occurs on surfaces where no soil exists is called primary succession Example: Volcanic eruptions, glaciers First species to populate = Pioneer species

Primary Succession Lichen (algae and fungi) are the first to grow on the volcanic rocks They help break up the volcanic rocks When the lichen die, they add organic matter to help form soil Plants start to grow on the soil

Secondary Succession

Secondary Succession A disturbance of some kind changes an existing community without removing the soil Examples: Fire (lightening strike) Land cleared for farming

Aquatic Succession

Succession’s Impact on… POPULATIONS As an ecosystem changes, older inhabitants gradually die out and new organisms move in. SPECIES DIVERSITY As more species move into as area, more “niches” are created to be filled.

Environmental Change Anything that causes something to be different in an environment Ex. Temperature increase or decrease; Pollution by humans

Ecosystem Stability Occurs when very little changes happen that can cause ecosystems to be disrupted or made unrecognizable Ex. No Flooding; No Drought Google Images Website: telegraph.co.uk

Ecosystem Stability Depends on the Environment and Available Resources Characteristics include… Large diversity, Plenty of resources, and No interruptions Google Images Website: environment.yale.edu Google Images Website: soilquality.org

OUT: Describe how the 2011 Texas drought caused environmental change OUT: Describe how the 2011 Texas drought caused environmental change. Explain how the drought impacted ecosystem stability. Lake Travis, Austin