Download Chapter 4 Ecosystems and Communities

Chapter 4
Ecosystems and Communities
4-1 The Role of Climate
A.
What is Climate?
1. Climate is the average yearly condition
of temperature and precipitation in a
region.
2. It's caused by latitude, winds, ocean
currents, and the shape and height of
land masses.
3. Climate affects ecosystems, because all
organisms have certain needs for
temperature
B.
The Greenhouse Effect
1. The greenhouse effect keeps the
temperature on Earth within a good
range for life.
2. The gases in the atmosphere trap
heat-CO2, CH4, water vapor
3. Heat energy cannot pass back out
as easily as light energy enters
C.
The Effect of Latitude on a Climate
1. Differences in latitude determine the
angle of sunlight that hits and
then heats the Earth's surface.
2. Differences in heating cause three
main climate zones:
a. Polar Zone - very cold areas
b. Temperate Zone - ranges from
hot to cold depending on
the season.
c. Tropical Zone - always warm
D.
Heat Transport in the Biosphere
1. Unequal heating of Earth's surface
causes winds and ocean currents.
2. Winds and currents move heat
through the biosphere.
4-2 What Shapes an Ecosystem?
A. Biotic and Abiotic Factors
1. Organisms are influenced by
- biological (biotic) and
- physical (abiotic) factors.
2. Biotic factors include all living
things
3. Abiotic factors include climate,
humidity, soil type, and other
nonliving factors
B.
The Niche
1. A niche includes what an organism
eats and how it gets its food, as well as
the physical conditions, and when and
how it reproduces.
“the role an organism plays in its environment”
2. No 2 species can occupy the same niche.
C.
Community Interactions
1.
Communities interact in one of three
ways:
a. Competition - organisms try to use
the same resources they need to live.
Competition often results in one organism
dying out.
b. Predation - this occurs when one
organism (predator) captures and eats
another (prey)
c. Symbiosis - occurs when two species live
together in one of three ways:
i. Mutualism - both species benefit from the
relationship
What are some examples?
ii.Commensalism - one species benefits
and the other is neither helped nor harmed
Examples?
iii. Parasitism - one species benefits by
living in or on the other and the other is
harmed. Examples?
D.
Ecological Succession
1. As an ecosystem ages, older inhabitants
die out and new organisms move in.
2. Ecological Succession is the predictable
changes that occur in a community.
a. primary succession
b. secondary succession
4-3 Biomes
A. Biomes and Climate
1. A biome is a group of communities on
land that covers a large area and is
characterized by certain soil and climate.
B.
The Major Biomes
1.
There are ten major biomes:
- Tropical Rain Forest
- Tropical Dry Forest
- Tropical Savanna
- Desert
- Temperate Grassland
- Temperate Woodland and Shrubland
- Temperate Forest
- Northwestern Coniferous Forest
- Boreal Forest (Taiga)
- Tundra
Tropical Rain Forest
Tropical Dry Forest
Tropical Savanna
Temperate Woodland and Shrubland
Temperate Forest
Temperate Grassland
Desert
Boreal Forest (Taiga)
Northwestern Coniferous Forest
Tundra
4.4 Aquatic Ecosystems
 A. Freshwater Ecosystems
1. Flowing-Water—such as rivers,streams
creeks. The turbulent water has more dissolved
O2 than still water.
2. Standing-Water—lakes, ponds. These
contain phytoplankton (single-celled algae) and
zooplankton.
3. Freshwater wetlands—water either covers
soil or is at or near the surface of the soil for at
least part of the year.
 3 types of wetlands:
– Bogs—dominated by sphagnum moss
– Marshes—shallow wetlands along rivers
– Swamps—usually have slowly flowing water,
and have trees and shrubs
B. Estuaries—where rivers meet the sea; serve as
spawning and nursery grounds for fish and
shellfish
2 types: salt marshes—temperate zone
estuaries; and mangrove swamps—across tropical
regions
 C. Marine Ecosystems
– Divided into areas according to amount of
sunlight or depth and distance from shore
1. Sunlight: photic zone—depth to which sunlight
penetrates; aphotic zone—sunlight does not
reach, so chemosynthetic autotrophs are found
here
What are some other adaptations organisms
would need to survive here?
2. Depth and distance from shore: intertidal zone,
coastal ocean, open ocean, coral reefs, and
benthic zone