Ecological Succession:

http://www.mass.gov/envir/forest/images/multiLayerForest.jpg

Studying how ecological communities respond to change …

• Ecological communities = the plants and animals found in an area.

• Succession = Sequence of communities a region goes through over time.

• Change can occur for many reasons: new resources, disturbances, and biotic changes.

Sequence of communities = the order that communities change

Climax Community:

• A diverse, stable community.

• Usually the final community in succession.

http://www.uga.edu/aquarium/assets/NATURE%20IMAGES/mossoak.jpg

Primary Succession:

• A sequence of communities forming in an originally lifeless habitat (no soil).

•Very slow process due to lack of soil.

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What are some common disturbances leading to primary succession of an

area?• Volcanic eruption• Glaciers• Rock Slides (maybe

—depends if it’s just rock or rock and soil)

http://www.eos.ubc.ca/research/landslides/landslides_files/image019.jpg

http://nsidc.org/glaciers/gallery/images/glacial_retreat_nv.jpg

http://www.geo.mtu.edu/volcanoes/hazards/primer/images/volc-images/puuoo.jpg

Primary Succession• Pioneer Species = the first

species to inhabit an otherwise lifeless area

• For example: lichen– Lichen is fungi and algae living

together in a mutually beneficial (symbiotic) relationship:

– Algae = makes its own food and provides food for the fungi

– Fungi = breaks down organic material and makes soil

Inhabit = to live in

www.ccs.k12.in.us

Secondary Succession

• A sequence of communities forming in an area with soil.

• Usually when a region has been cleared by a disturbance that does not destroy the soil.

What are some common disturbances that can lead to changes?

• Flood• Fire• Hurricanes• Tornadoes• Human activity• Rock Slides

http://www.weathersafety.ohio.gov/images/aerial-flood06_350.jpg

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http://www.atmo.ttu.edu/Hill%20City%20Tornado%20Enhanced.jpg

http://serc.carleton.edu/images/research_education/nativelands/nezperce/logging.jpg

http://www.eos.ubc.ca/research/landslides/landslides_files/image019.jpg

Secondary Succession …

• Plants that were not able to compete with pine now can grow.

For example, after this rockslide:

Succession Review

• Pioneer species comes in

• First species of plant to arrive after a disturbance.

• Generally are plants that grow quickly and produce many seeds.

(weeds)Fireweed

Succession Review …

• As time progresses, taller grass grows and shades out pioneer species.

• Better roots take nutrients from soil faster

• Pioneer species cannot compete and die out.