Transcript EE II Chapter 2 Kinds of Ecosystems and Communities

Kinds of Ecosystems and Communities
Chapter 2
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Succession
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____________ - A series of regular,
predictable changes in community structure
over time.
– Activities of organisms change their
surroundings and make the environment
suitable for other kinds of organisms.
 _____________ - Relatively stable,
long-lasting community, primarily
determined by climate.
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Succession
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Primary Succession _________________________________________
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_________________
– Ex. Lava Flow or Glacier Scrape
Secondary Succession - Begins with disturbance of
an existing ecosystem.
– Much more commonly observed, and generally
proceeds more rapidly.
– Ex.
_______________________________________
__________________________
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Primary Succession on Land
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____________________________
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Occurs when an existing community is
disturbed or destroyed.
– With most disturbances, most of the soil
remains, and many nutrients necessary for
plant growth may be available for
reestablishment of previous ecosystem.
 Nearby undamaged communities can
serve as sources of seeds and animals.
 Tends to be more rapid than primary
growth.
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Secondary Succession on Land
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Biomes: Terrestrial Climax Communities
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Biome - Terrestrial climax communities with
wide geographic distributions.
– Usually defined by undisturbed natural
plant communities.
 Two main non-biological factors
determining biomes:
 ___________
 ___________
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Biomes of the World
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Elevation Effects on Climate and Vegetation
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As altitude increases, average temperature
decreases.
– Moving from sea level to mountain tops, it
is possible to pass through a series of
biomes similar to what would be
encountered moving from the equator to
the north pole.
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Desert
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Less than 25 cm annual precipitation.
– Unevenly distributed throughout the year.
Climate: Large daily temperature
fluctuations, Likely to be windy, Infrequent
cloud cover.
Many species, but low numbers.
Most species exhibit specialized adaptations
to climate.
– Burrow During Day
– Water Conservation
– Flower only when moisture is available.
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Desert
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Grassland
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Also known as prairies or steppes.
Receives _______ cm of annual
precipitation.
Fire regime usually present.
– Rainfall sporadic enough to cause
droughts.
Historically evolved with large herds of
migratory grazing mammals.
– Supply fertilizer and discourage invasion
by woody species.
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Grassland
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Savanna
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Receives ________ cm annual precipitation.
– Unevenly distributed throughout year.
Seasonally structured ecosystem.
Fire is a common feature.
Many trees involved in nitrogen fixation.
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Differs from grassland due to scattered trees.
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Savanna
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Mediterranean Shrublands
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Also known as ______________.
Receives 40-100 cm annual precipitation.
– Wet, cool winters and hot, dry summers.
 Typical of Mediterranean coast, coastal
southern California, as well as parts of
Africa, Chile, and Australia.
Vegetation dominated by woody shrubs
adapted to hot, dry summers.
Fire is a common feature.
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Mediterranean Shrubland
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Tropical Dry Forest
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Annual precipitation ranges 50-200cm.
Many exhibit monsoon climate.
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Rainfall highly seasonal.
 Drought resistant plants.
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Tropical Dry Forest
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Tropical Rainforest
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Located near equator where temperature is relatively
warm and constant.
Most areas receive 200+ cm annual rainfall.
– (Some in excess of 500 cm)
Soil allows high levels of leaching, thus most
nutrients are tied-up in biomass.
Multi-layered canopy.
Very high species diversity:
– Ex. Tree Frogs, Large Vines, Fruit Eating Birds
Threats: Logging, Agriculture, and Ranging
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Tropical Rainforest
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Temperate Deciduous Forest
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Receives _______ cm annual precipitation.
– Evenly distributed throughout the year.
Trees typically lose their leaves during the
winter and replace them the following spring.
Mild winters
Long growing season (6 months).
Relatively few species.
Shade-tolerant spring wildflowers.
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Temperate Deciduous Forest
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Taiga, Northern Coniferous (Boreal) Forest
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Receives _______ cm precipitation annually.
Short, cool summers.
Long winters with abundant snowfall.
Humid climate
Trees adapted to winter conditions:
– Needle-shaped leaves prevent water loss.
– Flexible branches
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Taiga, Northern Coniferous (Boreal) Forest
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Tundra
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Less than 25 cm annual precipitation.
Permanently frozen soil (permafrost).
Short, wet summer.
Waterlogged soils and shallow ponds and
pools in spring and summer.
Plants usually less than 20 cm tall.
Alpine Tundra found on mountaintops.
Abundance of Migratory Birds.
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Tundra
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Major Aquatic Ecosystems
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Marine Ecosystems
– Freshwater Ecosystems - Low salt content.
– Marine Ecosystems - High salt content.
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Marine Ecosystems
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Marine Ecosystems
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Benthic Marine Ecosystems
– __________ organisms, attached or nonattached, live on the ocean bottom.
 Substrate and Temperature are very
important characteristics in determining
benthic community development.
Ex. Seaweed and Angler Fish
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Marine Ecosystems
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Coral Reef Ecosystems ____________________________________
____________________________________
____________________________________
– Contain single-celled algae and carry on
photosynthesis.
– Require warm water, thus are found only
near the equator.
 Most require clear, shallow water with
ample sunlight penetration.
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Marine Ecosystems
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__________________________
– Occupy region near shore.
– Trees tolerate high salt content.
 Excrete salt from leaves.
– Extensively developed roots.
 Can extend above water.
– Trap sediment in shallow areas.
 Develop terrestrial ecosystems.
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Marine Ecosystems
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Estuaries
– Shallow, partially enclosed areas where
freshwater enters the ocean.
– Extensive production because areas are
shallow, warm, and nutrient-rich.
 Nursery sites for fish and crustaceans.
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Estuary
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Freshwater Ecosystems
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Two broad categories:
– __________________
 Lakes, Ponds, and Reservoirs
– _______________ (Downhill)
 Streams and Rivers
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Review
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Succession
– Primary
– Secondary
– Climax Community
– Terrestrial
– Aquatic
Biomes
Aquatic Ecosystems
– Freshwater
– Marine
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