Download Ecological Succession

Ecological
Succession
2013-2014
Ecological Succession: The gradual
change in species abundance and diversity
after a disturbance.
• Community = ecological unit composed of a group of
populations of different species occupying a particular
area
Resilience VS. Persistence
• Resilience: Ability of an ecosystem to come back
• Inertia/persistence: Ability of ecosystem to survive
• A Rainforest has so many species it would rarely die off,
chances are one species would live, it is persistent. However
it is so complex that if it dies off it cant come back, it is not
resilient.
• Grasslands are all one species and could get sick and die
easily, they are not persistent. How ever grass can easily
come back, they are resilient.
Create this table in your notes
Primary succession
Secondary succession
Primary succession
• The establishment of
a biotic community
from a previously lifeless terrain
• Uncommon
• Take 1000’s of years
to build soil
• Ex-Parking lot, Lava
Secondary
succession
• Follows a disturbance
in an ecosystem that
has damaged or
removed part of the
established
community.
• Leaves soil or
sediments.
• Ex- Fire, clear cutting
Aquatic succession
A waterway slowly gets filled with sediments and is eventually overgrown
Case Study:
Red woods and Timber companies
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The tallest trees in the world.
Live to be 2,000 years old
96% of them have been cut down.
Can grow to be 368ft tall.
Two strategies for cutting trees
1. Clear cutting
• Completely destroyed an area of forest, but leaves other areas
untouched.
• Cheaper
2. Selective cutting
• Allows animals to stay in the same place, does not completely
kill environment.
• Cost more