Transcript Chapter 52 Notes

Chapter 52
An Introduction to Ecology and
the Biosphere
Planet Earth
• Chapter 52-Intro to Ecology and the
Biosphere
• Chapter 53-Population Ecology
• Chapter 54-Community Ecology
• Chapter 55-Ecosystems
Ecology
• The study of the
interactions
between
organisms and
their
environment.
Ecology
• Integrates all areas of biological
research and informs
environmental decision making.
Organisms
• All living things.
• Studied at many levels.
Ecology - levels
1. Organismal Ecology
2. Population Ecology
3. Community Ecology
4. Ecosystem Ecology
5. Landscape Ecology
6. Global Ecology
See page 1145 for definitions and
examples
Distribution of Species
• Limited by interactions
between organisms and
the environment.
Environment
•
Abiotic Factors: non-living factors.
Ex: Temperature, Light, Water
Nutrients
•
Biotic Factors: effect of other
organisms.
Ex: Competition, Predation
Abiotic Factors
1. Temperature
2. Water
3. Salinity
4. Sunlight
5. Rocks and soil
6. Wind
7. Disturbance
Temperature
• Effects biological processes.
• Ex:
– Cold – cells will rupture if they expand
while freezing.
– Hot – many proteins denature above
45 oC.
• Point – life can only exist over a
fairly narrow temperature range.
Water
• Review the properties of water
from Chapter 3.
• Cells must maintain a correct water
potential (keep from exploding or
drying out).
Salinity
• Salt concentration affects osmotic
potential and water balance.
• Most aquatic organisms are limited
by their ability to osmoregulate.
Sunlight
• Provides energy for Ps, which
drives most food webs.
• Plants often compete for light
because of shading or absorption
of light by deep columns of water.
Rocks and Soil
• Physical structure, pH, mineral
composition of rocks and soil limit
where plants can grow.
Ex. Se soils.
• Plants limit what animals can be
found in an area.
Wind
• Effects temperature and water
conditions for many organisms.
• May carry abrasive particles that
limit plant growth by killing the
growth points.
• Can change dispersal of organisms
Disturbance
• Disturbance is often an important part
of an environment.
• Allows organisms to re-colonize an
area.
• Ex: Fire
Humans
Wind
Climate
• Shapes environments and what
organisms can live in a particular
area.
• Temperature, precipitation,
sunlight and wind.
Global Climate Patterns
• Determined largely by solar energy
and the movement of heat across
the planet.
Great Ocean Currents
Wind Patterns
Climatic Factors
• Solar Radiation and Latitude
• Axis Tilt/Seasons
• Air/Water Circulation Patterns
Solar Radiation and Latitude
• Changes the amount of light and
energy delivered per surface area.
Result
• Poles: less light
• Equator: more light
• The unequal heating causes air and
water to circulate.
Seasons
• Caused by the Earth's tilt.
• Day length changes over time.
• Many organisms are restricted in
range by how well they adapt to
changing seasons.
• If Earth’s axis of rotation suddenly
became perpendicular to the plane
of its orbit, the most predictable
effect would be.
a) No more night and day
b) A big change in the length of the year
c) A cooling of the equator
d) A loss of seasonal variation at high latitudes
e) The elimination of ocean currents
• If Earth’s axis of rotation suddenly
became perpendicular to the plane
of its orbit, the most predictable
effect would be.
a) No more night and day
b) A big change in the length of the year
c) A cooling of the equator
d) A loss of seasonal variation at high latitudes
e) The elimination of ocean currents
Global Air Patterns
• Air rises when heated, sinks when
cools.
• Zones of rising/sinking are created.
• Earth's rotation causes zones to "twist”.
Result
• Air circulation patterns.
• Rainfall patterns.
– rising air: wet areas
– descending air: dry areas
Biomes
• Broad geographical regions with
characteristic communities of
organisms.
Aquatic Biomes
Fresh water Biomes
• Have <1% salt concentration.
• Strongly influenced by temperature
and light.
• Classification – based on water
flow patterns.
Freshwater Biomes
• Lakes
• Wetlands
• Streams and Rivers
• Estuaries
See Pg 1159-1160 for details
Marine Biomes
• Cover 3/4 of the Earth's surface.
• Average 3% salt.
• Controlled by light and the
distance to the shore.
Marine Biomes
1. Intertidal
2. Oceanic Pelagic
3. Coral Reefs
4. Benthos
See page 1161-1162
Light Zones
• Photic - Enough light for Ps.
Red light lost rapidly as depth
increases.
• Aphotic - Lacks enough light
for Ps and depends on food
made in photic zone for energy.
Part of the most extensive
biome on the planet.
Estuaries
• Where a
freshwater river
meets the
ocean.
• Salinity variable.
• Very productive
Biome.
Coral Reef
• Characterized by
coral.
• Found in shallow
warm waters.
• Very productive.
• High species
diversity.
Benthos
• Bottom area.
• Usually fed by nutrients drifting
down from upper levels.
• Fairly rich in life.
Biomes Controlled by:
• Temperature
• Water
• Geography
Terrestrial Biomes
• Recognize all, but be able to
describe features of 2-3 types.
• See pages 1153-1156.
Tropical Forests
• Areas covered with dense growth of
trees and vines.
• Climate:
– Warm temperatures.
– Constant day length.
– High water.
Tropical Forests
Tropical Forests
• Have the greatest diversity of
species of any area on Earth.
• Soil is usually very infertile. Most of
the nutrients are in the plant life.
• One of the most endangered Biomes.
Savanna
• Grasslands with a few trees.
• Climate with three growing
seasons:
– Cool and dry
– Hot and dry
– Warm and wet
Savanna
• Rich in herbivores and predator
species.
• Only major biome not found on
North America.
Desert
• Characterized by plants adapted to dry
growing conditions.
• Climate:
– Dry (<30cm/yr).
– May be cold or hot.
• Often found in areas of descending air
masses.
• Low productivity, but still fairly diverse
in species.
Chaparral
• Characterized by spiny evergreen
shrubs.
• Climate:
– Mild rainy winters
– Hot summers
• Ex: Southern California
Chaparral
• Maintained by fires.
• Plants adapted to periodic fires by
seeds or re-growing from the roots.
Temperate Grasslands
• Grasses and other herbs are the
dominant vegetation.
• Climate:
– Intermediate water
– Relatively cold winters
Grasslands
• Very productive for agriculture.
(wheat, corn)
• Need disturbance (fires) to keep
trees out.
• Come in several types:
– Tall grass
– Short grass
Temperate Forests
• Deciduous trees dominate.
• Climate:
– Relatively high rain
– Cold winters
• Very little natural area left.
• Good diversity of species.
Taiga or Northern Coniferous
Forest
• Coniferous trees dominate.
• Climate:
– Long cold winters
– Short wet summers
– Long summer daylength
Taiga or Northern Coniferous
Forest
• Relatively low species diversity.
• Being logged at an alarming rate.
Tundra
• Grasses and sedges dominate.
• Climate:
– Very cold and dry
– Low light in winter
Tundra
• Permafrost present.
• Plants low in height.
• Poor species diversity.
Altitude and Latitude
• Mirror each other.
• Their Biomes are similar because
the environments are similar.
• Ex: Alpine = Tundra
Summary
• Know what is involved with the
study of “Ecology”.
• Know the major factors of planet
Earth that shape climate.
• Know the major aquatic and
terrestrial biomes and the factors
that control them.