california science standards #6a,b,c ecology: succession “beauty for ashes”

California Science Standards #6a,b,c

Ecology: Succession

“Beauty for Ashes”

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Fire Bad In 1988, a forest fire swept through

Yellowstone National Park Officials feared the worst

Loss of animal life Loss of plant life Loss of tourism

© Oregon Dept. of Forestry Initially tried to stop the

flames Quickly raged out of control

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Fire Bad … or is it? Despite the initial devastation, ecologists

were optimistic about the recovery of this national park

Why? Succession =

The gradual, sequential re-growth of species in an area

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Two Types Primary Succession-

No life there previously Secondary Succession

Community was disrupted by Natural disaster

Fire, storm, earthquake, flood, volcano, glacier, etc.

Human activity Farming, logging, mining

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Primary Succession

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Primary Succession Slower of the two

Need minerals for plants to grow Barren rock + freezing/ thawing = broken rock lichens colonize broken rock

Lichen is a pioneer species (first life on the scene)

Acids in lichen + rain = wash minerals from rock Dead lichen + minerals = soil (thin layer) Grassy plants grow & die = more soil Shrubs and trees follow

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Lichen Mutualistic association between

Fungi and algae, or Fungi and cyanobacteria

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Secondary Succession

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SecondarySuccession

Faster because Soil already present Seeds already

available And, most pine species

of a mature forest in a climax community cannot germinate without the high temperatures that a fire produces

© Oregon Dept. of Forestry

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Climax Community In both cases,

succession “ended” with a climax community Stable end point Organisms in each

stage prepared the way for organisms in subsequent stages

Reality- more complex, dynamic Interruptions

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Primary or Secondary?

Pictures taken by Rick Collins, AP Biology student. http://www.bishops.ntc.nf.ca/science/Biology/

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Primary or Secondary?

7/25/99 9/11/99

Pictures taken by Rick Collins, AP Biology student. http://www.bishops.ntc.nf.ca/science/Biology/

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