Transcript COMMUNITY ECOLOGY

COMMUNITY ECOLOGY cont
pp. 405-410
Environmental Science
 The study of the interactions between
humans and their own environment
EARTH’S LAYERS
Geosphere
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Earth’s rock interior that extends
from the core to the crust
EARTH’S LAYERS
Hydrosphere
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Portion of earth that is water
EARTH’S LAYERS
Atmosphere
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Above geo/hydrosphere
Mixture of gases that surrounds earth
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78% N2, 21% O2, 1% other gases (H2O , &
CO2)
EARTH’S LAYERS
Atmosphere
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Ozone: important because it
absorbs most of the sun’s UV light.
Greenhouse gases: gases that trap
heat (CO2, and methane)
EARTH’S LAYERS
Biosphere
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Portion of earth that contains life
~ 9 km above surface and ~11km
below surface
Disturbance
events that change communities, remove or destroy
organisms
 Abiotic Examples: droughts, fires, floods etc.
 Biotic Examples: elephants tearing up trees,
prairie dogs moving soil for burrows etc.
 Human examples: bulldozing, paving etc.
Stability
ability to withstand a disturbance and maintain
constant conditions
 Pattern seen:
 ↑species richness and ↑ evenness leads to ↑ stability
ECOLOGICAL SUCCESSION
 Sequential and gradual growth of a community
 Two types: primary and secondary
1. Primary succession occurs when community is first formed
(expanding a community)
 Microbes, lichens and mosses must create soil before other
plants can grow.
 Pioneer species: first species to dominate early in succession
(small and fast growing)
 Climax Community: marked by the domination of longlived species and great diversity
2. Secondary succession occurs when succession
must start over after the destruction of a climax
community
 takes place on sites that have already supported
life
Day Before Eruption
1980 Eruption
Today
 http://www.pbslearningmedia.org/asset/nat08_vid_travco
m/
Create a Double Bubble for Primary and
Secondary Succession
 Place the following terms in bubbles
 Takes ~100 years
 Takes over 100+ years
 Creates an ecosystem
 Makes a new ecosystem
 Makes a pre-existing ecosystem
 Pioneer species
 Disturbance occurred
 Ecosystem expanding
 Makes soil
 Soil already present