Title: Ecosystems: What Are They and How Do They Work?
1Ecosystems What Are They and How Do They Work?
2All things come from earth and to earth they all
return
3How environmentally true is the previous
statement? Explain.
4Main Questions of this chapter
- What is ecology?
- What is an ecosystem and its main components?
- What happens to matter and energy in an ecosystem
and how does that keep us alive?
5(No Transcript)
6Core Case Study Tropical Rain Forests Are
Disappearing
- Cover about 2 of the earths land surface
- Contain about 50 of the worlds known plant and
animal species - Disruption of rain forest will have three major
harmful effects - Reduce biodiversity
- Accelerate global warming (burn, less absorption
of greenhouse gases) - Change regional weather patterns
7Natural Capital Degradation Satellite Image of
the Loss of Tropical Rain Forest
83-1 What Is Ecology?
- Concept 3-1 Ecology is the study of how
organisms interact with one another and with
their physical environment of matter and energy. - Ecology is the study of connections in nature
9Cells Are the Basic Units of Life
- Cell Theory (all living things are composed of
cells , the smallest and most fundamental unit of
life)
Eukaryotic cells have membranes, nucleus and
organelles (internal specialized parts)
10Prokaryotic cell Has membrane No distinct
nucleus No specialized internal parts All
bacteria consist of a single prokaryotic cell
Stepped Art
Fig. 3-2, p. 52
11Animation Prokaryotic and eukaryotic cells
12Species Make Up the Encyclopedia of Life
- Species
- 1.75 Million species identified
- Insects make up most of the known species
- Perhaps 1014 million species not yet identified
13_________ of Glassfish in the Red Sea
14__________ Diversity in a Caribbean Snail
Population
15Ecologists Study Connections in Nature
- Levels of organization
- Population
- Group of individuals that live in same place
- Genetic diversity (variation in a population)
- Habitat place where a population lives
- Community
- All populations that live in a particular place
- Ecosystem
- Describes the interaction of a community and
their habitats - Biosphere
- consists of parts of the earth where life is
found, in effect the largest ecosystem
16Stepped Art
Fig. 3-3, p. 52
17Size of ecosystems
- Range from a puddle of water to an ocean
- Do not have clear boundaries
- Not isolated from each other
- Can be natural or man made
18Think about the school in terms of how life can
be grouped
- Populations
- Communities
- Ecosystems
19Are insect populations important to the health of
human populations?
- Which group needs the other more? Humans or
insects?
20Science Focus Have You Thanked the Insects
Today?
- Pollinators
- Eat other insects
- Loosening and renewal of soil
- Reproduce rapidly (food source)
- Very resistant to extinction, fast evolutionary
process
21Do you think there is a useless population on
earth?
- Explain your answer by defining the term
useless first.
22Active Figure Levels of organization
23Section Check
- Q1 Distinguish between a eukaryotic and a
prokaryotic cell. Name an example of living
organism that has them for each type. - Q3 What of all living species do we have
information on? Which class of organism most
likely has the greatest number of species? - Q4 What are the main differences between a
population, a habitat and a ecosystem? Name an
example of each.
243-2 What Keeps Us and Other Organisms Alive?
- Concept 3-2 Life is sustained by the flow of
energy from the sun through the biosphere, the
cycling of nutrients within the biosphere, and
gravity.
25What are the 4 majors parts (spheres) of the
earth life support system?
26The Earths Life-Support System Has Four Major
Components
- Atmosphere
- Troposphere closest, weather, warmth, air
- Stratosphere - farther away from surface, ozone
- Hydrosphere
- Geosphere- includes interior, minerals, oil, soil
- Biosphere- all living things in all other spheres
27Vegetation and animals
Atmosphere
Biosphere
Soil
Rock
Crust
Natural Capital
Lithosphere
Mantle
Biosphere (living organisms)
Atmosphere (air)
Core
Crust (soil and rock)
Mantle
Hydrosphere (water)
Geosphere (crust, mantle, core)
Fig. 3-6, p. 55
28What is a Biome?
29Life Exists on Land and in Water
- Biomes (land)
- regions of earth with one dominant type of
environment (Deserts, plains, deciduous
forests) - Aquatic life zones
- Freshwater life zones
- Lakes and streams
- Marine life zones
- Coral reefs
- Estuaries
- Deep ocean
30Major biomes along 39th parallel in US
Average annual precipitation
100125 cm (4050 in.) 75100 cm (3040
in.) 5075 cm (2030 in.) 2550 cm (1020
in.) below 25 cm (010 in.)
Denver
Baltimore
San Francisco
St. Louis
Appalachian Mountains
Coastal mountain ranges
Sierra Nevada
Great American Desert
Rocky Mountains
Great Plains
Mississippi River Valley
Deciduous forest
Coastal chaparral and scrub
Coniferous forest
Desert
Coniferous forest
Prairie grassland
Fig. 3-7, p. 55
31Three Factors Sustain Life on Earth
- One-way flow of high-quality energy beginning
with the sun - From sun through food cycle to environment
exiting back into space - Dictated by 2nd law of Thermo, high to low
quality energy - Cycling of matter or nutrients
- Earth is basically closed in terms of matter
- Nutrients must be recycled, in seconds or in
centuries - Gravity (law of gravity)
- How does gravity help sustain life on Earth?
-
32How does gravity help?
- Allows earth to hold on to an atmosphere
- Allows movement of materials, life on earth
33How do you think the troposphere stays warm?
34- The name of the effect is ______________
- How do you think this effects works?
- Is this effect natural or man-made?
35What Happens to Solar Energy Reaching the Earth?
- UV, visible, and IR energy (forms of
electromagnetic radiation (waves)) - Radiation
- Is absorbed by ozone
- Is absorbed by the earth
- Is reflected by the earth, as heat
- Some is trapped in troposphere
- The raising heat moves the air , creating wind
36Energy flow to/from Earth
Solar radiation
Reflected by atmosphere
Radiated by atmosphere as heat
UV radiation
Lower Stratosphere (ozone layer)
Most absorbed by ozone
Troposphere
Visible light
Heat radiated by the earth
Heat
Absorbed by the earth
Greenhouse effect
Fig. 3-8, p. 56
37Natural Greenhouse Effect
- Energy from sun is reflected back towards space
as infrared radiation (felt as heat) - Encounter greenhouse gases (CO2, CH4, No3- and
O3) - Causes gas molecules to vibrate more
- More vibration ? greater KE and Heat
- Warmer atmosphere and surface
381) What if there was no greenhouse effect?
- 2) What would happen if the greenhouse effect is
increased?
39Too cold, or too hot
40Active Figure Energy flow from the Sun to Earth
41Section Check
- Q5 How do the stratosphere and the troposphere
differ? What are the main benefits humans
derive from each? - Q8 How are Biomes and Aquatic Life Zones
similar? - Q9 What are the 3 factors that sustain life on
Earth? What the laws that relate to the factor?
42Section Check Green House Gasses
- Q6 What are greenhouse gases and how do they
affect life on the planet? - Q10 What is the benefit of the ozone in the
troposphere? What would be the result if it were
removed? - Q11 How is wind generated by solar energy?
- Q12 How do greenhouse gases keep the earth warm?
433-3 What Are the Major Components of an
Ecosystem?
- Concept 3-3A Ecosystems contain living (biotic)
and nonliving (abiotic) components. - Concept 3-3B Some organisms produce the
nutrients they need, others get their nutrients
by consuming other organisms, and some recycle
nutrients back to producers by decomposing the
wastes and remains of organisms.
44Ecosystems Have Living and Nonliving Components
- Abiotic Non-living components
- Water
- Air
- Nutrients
- Rocks
- Heat
- Solar energy
- Biotic
- Living and once living
45Precipitation
Oxygen (O2)
Carbon dioxide (CO2)
Major Biotic and Abiotic components of an
Ecosystem
Producer
Secondary consumer (fox)
Primary consumer (rabbit)
Producers
Decomposers
Water
Soluble mineral nutrients
Fig. 3-9, p. 57
46Identify the autotrophs and heterotrophs (all
levels, groups)
47List of groups
- Autotrophs
- Primary consumers
- Secondary consumers
- Tertiary (and higher) consumers
- Omnivores
- Decomposers
- Detritivores
48Active Figure Roles of organisms in an ecosystem
49Range of Tolerance
Higher limit of tolerance
Lower limit of tolerance
No organisms
Few organisms
Few organisms
No organisms
Abundance of organisms
Population size
Zone of intolerance
Zone of physiological stress
Optimum range
Zone of physiological stress
Zone of intolerance
Temperature
Low
High
Fig. 3-10, p. 58
50Several Abiotic Factors Can Limit Population
Growth
- 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 at or near the optimal
range of tolerance - Principle of sustainability connection
population control
51Producers and Consumers Are the Living Components
of Ecosystems (1)
- Producers, autotrophs
- Photosynthesis sunlight-sugar
- Chemosynthesis no sunlight- not sugar
- Consumers, heterotrophs
- Primary- feed off of plants
- Secondary- feed off of herbivores
- Third and higher level
52What type of consumers are they
Insect B
Insect C
Insect A
53Producers and Consumers Are the Living Components
of Ecosystems (2)
- Decomposers
- release nutrients from dead bodies
- Mushrooms, Bacteria
- Detritivores-
- feed off of wastes and the dead
- Worms and Vultures
54Producers and Consumers Are the Living Components
of Ecosystems (2)
- Aerobic respiration
- uses oxygen to convert sugar (glucose) to CO2
H2O energy - Anaerobic respiration, fermentation
- does not use oxygen to convert sugar to energy
55Detritus feeders
Decomposers
Carpenter ant galleries
Termite and carpenter ant work
Bark beetle engraving
Dry rot fungus
Long-horned beetle holes
Wood reduced to powder
Mushroom
Time progression
Powder broken down by decomposers into
plant nutrients in soil
Fig. 3-11, p. 60
56The Main Structural Components of an Ecosystem
57Active Figure Matter recycling and energy flow
58Animation Energy flow in Silver Springs
59Who are these guys?
60Science Focus Many of the Worlds Most
Important Species Are Invisible to Us
- Microorganisms (Microbes)
- Bacteria
- Protozoa
- Fungi
- Some Benefits
- Break down food in our stomachs
- Protect lungs
- Purify water
- Produce foods (bread, cheese, yogurt)
- Decomposers
- Phytoplankton take up CO2
61Questions on 3-3
- Q13 Distinguish between the abiotic and biotic
components of an ecosystem. - Q19 What is the difference between photosynthesis
and chemosynthesis? Where does chemosynthesis
occur on earth? - Q15 List an example of a specific organism for
each of the following categories decomposer,
secondary consumers, omnivores, producer and
primary consumers.
623-4 What Happens to Energy in an Ecosystem?
- Concept 3-4A Energy flows through ecosystems in
food chains and webs. - Concept 3-4B As energy flows through ecosystems
in food chains and webs, the amount of chemical
energy available to organisms at each succeeding
feeding level decreases.
63Energy Flows Through Ecosystems in Food Chains
and Food Webs
- Food chain
- Food web
- Difference?
64A Food Chain
65Simplified Food Web in the Antarctic
66Animation Prairie food web
67Active Figure Rainforest food web
68Animation Diet of a red fox
69Animation Prairie trophic levels
70Usable Energy Decreases with Each Link in a Food
Chain or Web
- Biomass
- dry weight of all organic matter on a certain
level - Ecological efficiency
- of useable energy transferred from one level to
next. - 2-40, 10 average
- Where does 90 go?
- Pyramid of energy flow
71Stepped Art
Fig. 3-15, p. 63
72Some Ecosystems Produce Plant Matter Faster Than
Others Do
- Gross primary productivity (GPP)
- Rate producers solar energy into bio-mass with
chemical energy - Net primary productivity (NPP)
- GPP energy needed by producers
- Ecosystems and life zones differ in their NPP
- Faster rate, more energy available to consumers
73Understanding the difference between (GPP) and
(NPP)
74Estimated Annual Average NPP in Major Life Zones
and Ecosystems
Terrestrial Ecosystems
Swamps and marshes
Tropical rain forest
Temperate forest
Northern coniferous forest
Savanna
Agricultural land
Woodland and shrubland
Temperate grassland
Tundra (arctic and alpine)
Desert scrub
Extreme desert
Aquatic Ecosystems
Estuaries
Lakes and streams
Continental shelf
Open ocean
4,000
9,600
8,800
800
1,600
2,400
8,000
7,200
3,200
6,400
5,600
4,800
Average net primary productivity (kcal/m2/yr)
Fig. 3-16, p. 64
75Questions on 3-4
- Q22 Why cant there be 16 trophic levels in a
food chain or in food web? - Q23 Why is a vegetarian diet more energy
efficient than a meat based diet? -
- Q25 Why are tigers few in number and the species
vulnerable to premature extinction because of
human activites? - Q26 Why are there so many insects in the
world?
763-5 What Happens to Matter in an Ecosystem?
- Concept 3-5 Matter, in the form of nutrients,
cycles within and among ecosystems and the
biosphere, and human activities are altering
these chemical cycles.
77Nutrients Cycle in the Biosphere
- Biogeochemical cycles, nutrient cycles
- Hydrologic
- Carbon
- Nitrogen
- Phosphorus
- Sulfur
- Connect past, present, and future forms of life
78Water Cycles through the Biosphere
- Natural renewal of water quality three major
processes - Evaporation
- Precipitation
- Transpiration
- Alteration of the hydrologic cycle by humans
- Withdrawal of large amounts of freshwater at
rates faster than nature can replace it - Clearing vegetation
- Increased flooding when wetlands are drained
79Hydrologic Cycle Including Harmful Impacts of
Human Activities
Global warming
Condensation
Condensation
Ice and snow
Evaporation from land
Evaporation from ocean
Transpiration from plants
Precipitation to land
Surface runoff
Increased flooding from wetland destruction
Precipitation to ocean
Runoff
Reduced recharge of aquifers and flooding from
covering land with crops and buildings
Lakes and reservoirs
Point source pollution
Infiltration and percolation into aquifer
Surface runoff
Groundwater movement (slow)
Ocean
Aquifer depletion from overpumping
Processes
Processes affected by humans
Reservoir
Pathway affected by humans
Natural pathway
Fig. 3-17, p. 66
80Active Figure Hydrologic cycle
81Water cycle Lab
82Biogeochemical Cycles lab
83Science Focus Waters Unique Properties
- Properties of water due to hydrogen bonds
between water molecules - Exists as a liquid over a large range of
temperature - Changes temperature slowly
- High boiling point 100C
- Adhesion and cohesion
- Expands as it freezes
- Solvent
- Filters out harmful UV
84Carbon Cycle Depends on Photosynthesis and
Respiration
- Link between photosynthesis in producers and
respiration in producers, consumers, and
decomposers - Additional CO2 added to the atmosphere
- Tree clearing
- Burning of fossil fuels
85 Carbon dioxide in atmosphere
Carbon Cycle
Respiration
Photosynthesis
Burning fossil fuels
Forest fires
Animals (consumers)
Diffusion
Deforestation
Plants (producers)
Carbon in plants (producers)
Transportation
Respiration
Carbon in animals (consumers)
Carbon dioxide dissolved in ocean
Carbon in fossil fuels
Decomposition
Marine food webs Producers, consumers, decomposers
Carbon in limestone or dolomite sediments
Compaction
Processes
Reservoir
Pathway affected by humans
Natural pathway
Fig. 3-18, p. 68
86Active Figure Carbon cycle
87Nitrogen Cycles through the Biosphere Bacteria
in Action (1)
- Nitrogen fixation
- Lightning (ionizes the nitrogen in air)
- Nitrogen-fixing bacteria and blue green
algae(combine gas N2 and H to make ammonia) - Nitrification
- converted to ammonia ions- bacteria
- Then converted to proteins, nucleic acids,
vitamins, amino acids- plants - Products used by animals
- Denitrification reverse process
88Nitrogen Cycles through the Biosphere Bacteria
in Action (2)
- Human intervention in the nitrogen cycle
- Additional NO and N2O
- Destruction of forest, grasslands, and wetlands
- Add excess nitrates to bodies of water
- Remove nitrogen from topsoil
89 Nitrogen in atmosphere
Denitrification by bacteria
Electrical storms
Nitrogen in animals (consumers)
Nitrogen oxides from burning fuel and using
inorganic fertilizers
Nitrogen cycle
Volcanic activity
Nitrification by bacteria
Nitrogen in plants (producers)
Nitrates from fertilizer runoff and decomposition
Decomposition
Uptake by plants
Nitrate in soil
Nitrogen loss to deep ocean sediments
Nitrogen in ocean sediments
Bacteria
Ammonia in soil
Fig. 3-19, p. 69
90Active Figure Nitrogen cycle
91Annual Increase in Atmospheric N2 Due to Human
Activities
92Phosphorus Cycles through the Biosphere
- Cycles through water, the earths crust, and
living organisms - May be limiting factor for plant growth
- Impact of human activities
- Clearing forests
- Removing large amounts of phosphate from the
earth to make fertilizers
93Processes
Phosphorous Cycle
Reservoir
Pathway affected by humans
Natural pathway
Phosphates in sewage
Phosphates in fertilizer
Plate tectonics
Phosphates in mining waste
Runoff
Runoff
Sea birds
Runoff
Phosphate in rock (fossil bones, guano)
Erosion
Ocean food webs
Animals (consumers)
Phosphate dissolved in water
Phosphate in shallow ocean sediments
Phosphate in deep ocean sediments
Plants (producers)
Bacteria
Fig. 3-21, p. 71
94Animation Phosphorus cycle
95Sulfur Cycles through the Biosphere
- Sulfur found in organisms, ocean sediments, soil,
rocks, and fossil fuels - SO2 in the atmosphere
- H2SO4 and SO4-
- Human activities affect the sulfur cycle
- Burn sulfur-containing coal and oil
- Refine sulfur-containing petroleum
- Convert sulfur-containing metallic mineral ores
96Sulfur Cycle
Sulfur dioxide in atmosphere
Sulfuric acid and Sulfate deposited as acid rain
Smelting
Burning coal
Refining fossil fuels
Sulfur in animals (consumers)
Dimethyl sulfide a bacteria byproduct
Sulfur in plants (producers)
Mining and extraction
Uptake by plants
Decay
Sulfur in ocean sediments
Decay
Processes
Sulfur in soil, rock and fossil fuels
Reservoir
Pathway affected by humans
Natural pathway
Fig. 3-22, p. 72
97Active Figure Sulfur cycle
983-6 How Do Scientists Study Ecosystems?
- Concept 3-6 Scientists use field research,
laboratory research, and mathematical and other
models to learn about ecosystems.
99Some Scientists Study Nature Directly
- Field research muddy-boots biology
- New technologies available
- Remote sensors
- Geographic information system (GIS) software
- Digital satellite imaging
100Some Scientists Study Ecosystems in the
Laboratory
- Simplified systems carried out in
- Culture tubes and bottles
- Aquaria tanks
- Greenhouses
- Indoor and outdoor chambers
- Supported by field research
101Some Scientists Use Models to Simulate Ecosystems
- Computer simulations and projections
- Field and laboratory research needed for baseline
data
102We Need to Learn More about the Health of the
Worlds Ecosystems
- Determine condition of the worlds ecosystems
- More baseline data needed
103Your Questions?
- Connected to the information presented in this
chapter
104UN Project Questions
- What are the main foods for the middle class and
poor in your country? On what trophic level are
the most common foods of the poor and middle
class come from? - List the main Biomes type that exist in your
country. Using your textbook, determine the NPP
for the major biomes. - Describe some producers, herbivores, carnivores,
decomposers and scavengers that are native to
your country - What are some of the human based effects on the
major nutrient cycle?