Transcript Ecosystems: What Are They and How Do They Work?

Ecosystems: What Are They and How
Do They Work?
G. Tyler Miller’s
Living in the Environment
14th Edition
Modified By Mr. Manskopf
Chapter 4
Key Concepts
Basic ecological principles
Major components of ecosystems
Matter cycles and energy flow
Ecosystem studies
Principles of Sustainability
Section 1: The Nature of Ecology
• What is ecology?
• What species rule the
world?
• What is population
and levels of
organization of matter
in nature?
• What are communities
and ecosystems?
What is ecology?
Ecology: is the study of
how organisms interact
with another and the
nonliving world.
• Connections in nature
Organism: any form of life
Cell: basic unit of life
Eukaryotic: nucleus/organelles
Prokaryotic: bacteria/algae
What is ecology?
Species: groups of
organisms that resemble
each other in
appearance, behavior,
chemistry and genetic
makeup…able to
reproduce
• 3.6 to 100 million
species (1.4 identified)
• Mostly insects/micro
• Tropical forests
Other animals
281,000
Fungi
69,000
Insects
751,000
Prokaryotes
4,800
Known
species
1,412,000
Plants
248,400
Protists
57,700
What species rule the world?
• What types of
organisms do you think
your body contains
billions of?
Hint: they can be both
very important to your
survival or make you
ill.
What species rule the world?
Microbes (bacteria,
protozoa, fungus, yeast)
rule the world.
• Malaria
• Germs
• Good versus bad
microbes
• Help keep us alive
What are levels of organization in
nature
Ecology focuses on 5
levels of organization
in nature:
1) Organisms
2) Populations
3) Communities
4) Ecosystems
5) Biosphere
The Nature of Ecology
Ecosystem organization
Organisms
Populations
Communities
Ecosystems
Biosphere
Fig. 4-2 p. 57
Section 2: The Earth’s Life Support
Systems
• What are the major
parts of earth’s lifesupporting systems?
• How does the sun
sustain life of earth?
Earth’s Life Supporting Systems
The Earth is made up of
interconnected spherical
layers that contain:
•
•
•
•
•
Air
Water
Soil
Minerals
Life
All parts are
interconnected and the
goal is to understand
how they all interact.
The Earth’s Life-Support Systems
Troposphere
Stratosphere
Hydrosphere
Lithosphere
Biosphere
Fig. 4-7 p. 60
Natural Capital: Sustaining Life of
Earth
Solar energy, the cycling
of matter and nutrients,
and gravity all sustain
life on earth as we
know it.
KEY IDEA: remember
energy and matter can
not be created or
destroyed.
Natural Capital: Sustaining Life of
Earth
 One-way flow
of energy from Sun
 Cycling of
Crucial Elements
 Gravity
Fig. 4-8 p.60
Solar Capital: Flow of Energy to and
from the Earth
Gigantic nuclear
fusion 93 million
miles away
sustains life.
•One-billionth of sun’s
energy reaches earth.
•Energy in MUST
equal energy
out…WHY?
Section 3: Ecosystem Components
• What are the major components of
ecosystems?
• What are tolerance limits?
• What factors limit population growth?
• What are producers, consumers, decomposers
and what role do they play in ecosystems?
• What is biodiversity?
Life on Land and Sea
Biomes: land portions of the
biosphere…
• Forests, deserts, grasslands,
tundra classified by climate
and species adapted to it.
Aquatic Life Zones: watery
parts of biosphere…
• Fresh water (lakes, streams,
etc.)
• Marine Life Zones (coral
reefs, deep ocean, etc.)
Natural Capital: Major Biomes
 Biomes
 Role of
climate
 Aquatic
life zones
Fig. 4-10 p. 62
Ecosystem Factors
Abiotic factors Range of tolerance
Limiting factors
Biotic factors
Availability of matter and energy resources can limit organisms population.
Ecosystem Factors
Limiting Factor Principle:
too much or too little of
any abiotic factor can
limit or prevent growth of
a population, even if all
other factors are near or
above optimum.
• Why are there no citrus
fruit growing in NJ?
• Why do trees grow toward
the sky?
Major Biomes found across the US at 390 North
Latitude.
Major components of a freshwater
ecosystem
Major components of a field ecosystem
What are the biotic and abiotic factors?
What might some limiting factors be?
Major components of a marine
ecosystem
Limiting factors
may include:
•Salinity
•Ph
•Sunlight
•Dissolved oxygen
•Temperature
Components of Ecosystems
 Abiotic chemicals
 Photosynthesis
 Producers
(autotrophs)
 Consumers
(heterotrophs)
 Aerobic
respiration
 Decomposers
Fig. 4-17 p. 67
Photosynthesis: Producers
CO2 + H2O + Solar Energy >>> Glucose + Oxygen
6CO2 + 6 H2O + Solar Energy >>> C6H12O6 + 6O2
Detritus Feeders (Detritivores)
no waste in natural ecosystems
Aerobic Respiration
Glucose + Oxygen >>> Carbon Dioxide + Water + Energy
C6H12O6 + 6O2 >>> 6CO2 + 6H2O + energy
What is Biodiversity?
Genetic diversity
Species diversity
Ecological diversity
Many scientists feel the loss of
biodiversity is the greatest
threat humans face.
Importance of Biodiversity
• http://www.undp.org/biodiversity/biodiversityc
d/bioImport.htm
Extinctions…
• Extinction occurs when there are no longer any
living individuals of a species left.
• There have been five periods of mass
extinction's on earth 440m, 370m, 250m, 210m
and 65m years ago.
• Scientists estimate that currently, living
organisms represent only 1% of all the species
that have ever been (i.e. 99% have been and
gone)
Energy Flow in Ecosystems
There is a decrease in the
amount of energy
available to each
succeeding organisms
in a food chain or web.
• What does that mean?
• Where does the energy
go?
Connections: Energy Flow in
Ecosystems
Food chains: the sequence of organisms
food sources
Trophic Levels: producer to primary consumer
to secondary consumer and so on…
Food webs: real ecosystems are more complex
as most consumers feed on more than one organism.
Trophic Levels
Primary consumer (herbivore)
Secondary consumer (carnivore)
Tertiary consumer
Omnivore
Detritivores and scavengers
Decomposers
Connections: Food Chains and Energy
Flow in Ecosystems
Fig. 4-18 p. 68
Ecological Pyramids
 Pyramid of
energy flow
 Ecological
efficiency
 Pyramid of
biomass
 Pyramid of
numbers
90% energy loss each step!
Ranges from 60 to 98% (90% is typical)
Primary Productivity of Ecosystems
Estimated productivity per unit area of major
ecosystems
Earth’s productivity: On land forests are highly productive in
dark green, deserts least in brown. At sea, red indicates high
productivity and deep oceans dark blue.
Productivity of Ecosystems
The number of consumer
organisms the earth can
support is determined
by how fast producers
can supply them with
energy.
Planet’s limiting factor
Productivity of Ecosystems
Clear Cut Forest in OR
Humans are using,
wasting and
destroying the
world’s biomass
faster than
producers are able
to make it.
• Habitat destruction
Section 6: Soils Key Idea
Origins
Importance
Maturity and Horizons
Variations with Climate and Biomes
Variations in Texture and Porosity
What is Soil and Why Is It Important?
Soil is a thin layer over
most land that is a
complex mix of rock,
nutrients, decaying
matter, water, air and
billions of
organisms…many
microscopic
decomposers.
What is Soil and Why Is It Important?
• Renewable
resource…SLOW
• Depends upon climate
(1cm in 15yrs.)
• Basis of life
• Filters water
• Water storage
• Habitat
Soil Profiles
Mature
Soil have a
long time
to form and
are
arranged
into layers
called
horizons.
Simplified food web found in soils
Soil
Horizons
in
Different
Biomes
Fig. 4-27, p. 75
Soil particles
come in
different
textures…sand,
clay, silt gravel
Section 7: Matter Cycling in Ecosystems
 Biogeochemical cycles
 Group 1: Hydrologic cycle (H2O)
 Group 2: Carbon cycle
 Group 3: Nitrogen cycle
 Group 4: Phosphorus cycle
 Group 5: Sulfur cycle
Hydrologic (Water) Cycle: Group 1
Fig. 4-28 p. 76
The Carbon Cycle (Marine): Group 2
Fig. 4-29, p. 78
The Carbon Cycle (Terrestrial):
Group 2
Fig. 4-29, p. 78
The Nitrogen Cycle: Group 3
Fig. 4-31 p. 80
The Phosphorus Cycle: Group 4
Fig. 4-33 p. 82
The Sulfur Cycle: Group 5
Fig. 4-34 p. 83
How Do Ecologists Learn About
Ecosystems?
Field research
Remote sensing
Geographic information systems (GIS)
Laboratory research
Systems analysis
Geographic Information System
(GIS)
Fig. 4-35 p. 84
Systems Analysis
Fig. 4-36 p. 85