Transcript Chapter 3 Power Point

Chapter 3
 Ecology= study of living organisms and
how they interact with one another as
well as with the non-living world
 Abiotic= Non-living factors that support
an ecosystem (air, water, soil)
 Biotic = living factor that support an
ecosystem (anything that contains cells)\
Earth’s Life Support
Systems

There are 3 basic processes that make
it possible for life not only to exist, but to
flourish
1. One way flow of energy from the sun
2. Cycling of nutrients
3. A consistent force of gravity
One Way Flow of Energy
from the Sun
 Energy from sun arrives at the earth in
the form of solar radiation
 Half of solar radiation is in the form
visible light
 40 % arrives as infrared radiation that is
largely responsible for planetary heating
 The rest of the energy helps to keep the
earth warm
Solar
energy flowing through
the biosphere warms the
atmosphere, evaporates and
recycles water, generates winds
and supports plant growth.
Cycling of Nutrients
 The Earth acts as a closed system for
matter. There is a fixed supply of
nutrients on the planet that must be
continually recycled to support life
Oxygen
(O2)
Sun
Producer
Carbon dioxide (CO2)
Secondary consumer
Primary
(fox)
consumer
(rabbit)
Precipitation
Falling leaves
and twigs
Producers
Soil decomposers
Water
Fig. 3-10, p. 57
4 major systems that
regulate and support life in
biosphere
 Atmosphere= Most of its mass exists
within the first two layers
 Troposphere= layer where weather
occurs
 78 % nitrogen, 21 % oxygen
 Also includes our greenhouse gases that
are responsible for warming the surface
of the earth
Greenhouse gases
 Gases include= water vapor, carbon
dioxide, and methane
 Gases absorb radiation emitted by
earth’s surface
 Molecules gain kinetic energy and vibrate
they release even longer wavelength
infrared radiation which warms the
earth’s surface
 Stratosphere= contains our ozone layer
 Responsible for filtering out 95 % of the
harmful ultraviolet light.
Hydrosphere
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Consists of all the water available on the planet.
Water is found in many various forms on the planet
Liquid= surface and underground
Ice= polar ice, permafrost, and icebergs
Water vapor
Geosphere
 Consists of earth’s crust, mantle, and core
 Crust and mantle contain the soil and rock system that
house nonrenewable fossil fuels and minerals
Ecosystem Structure
 Each organism can only live within a specific range
of tolerance
 Physical & Chemical variations that exist within
their environment
 Range of tolerance may vary
 Optimum Range= range in which growth of a
population is maximized
 Certain abiotic factors like water, temperature,
dissolved oxygen, or salinity will influence what the
optimum range will be for a species.
Optimum Range

Energy flow in
ecosystems
Organisms in the ecosystems are organized
into a hierarchy of feeding orders or (trophic
levels)
 Trophic levels are assigned based on the
organisms method for acquiring energy and
nutrients from the ecosystem
 Energy passes from one trophic level to the
next and organisms are either producing
energy for the ecosystem or consuming energy
from it.
Producers
 These organisms are self feeders, or often
referred to as primary producers (autotrophs)
 Acquire nutrients by converting compounds or
energy from their environment
 They represent the first trophic level in the
ecosystem
 Most of producers acquire nutrients by
photosynthesis
On land dominant producers are =
green plants
Ocean= phytoplankton (single celled
algae)
There are communities that thrive
without the sun for energy
Hydrothermal vent communities
 Bacteria are the producers
 Convert sulfur compounds escaping from
vents into organic compounds for
consumers
 Chemosynthesis
Consumers: Eating and
Recycling to Survive
 Consumers (heterotrophs) get their food by eating
or breaking down all or parts of other organisms
or their remains.
 Herbivores
 Primary consumers that eat producers
 Carnivores
 Primary consumers eat primary consumers
 Third and higher level consumers: carnivores that eat
carnivores.
 Omnivores
 Feed on both plant and animals.
 All use the process of cellular respiration
Types of Consumers
Decomposers &
Detrivores
 Bacteria & Fungi
 Breakdown organic compounds without the use of
oxygen known as anaerobic respiration or fermentation
 Decomposers recycle organic material that
support the growth and development of primary
producers
 Detritivores= Insects or other scavengers that
feed on wastes or dead bodies