The student will demonstrate an understanding of the
interrelationships among organisms and the biotic and abiotic
components of their environments.
Slide 2
B-6.1 Explain how the interrelationships among organisms
(including predation, competition, parasitism, mutualism, and
commensalism) generate stability within ecosystems. Key Concepts:
Ecosystem: stable ecosystem Predation: predator, prey Competition:
niche Symbiotic relationships: parasitism, mutualism, commensalism
An ecosystem is defined as a community (all the organisms in a
given area) and the abiotic factors (such as water, soil, or
climate) that affect them.
Slide 3
A stable ecosystem is one where population #s of each organism
fluctuate at a predictable rate supply of resources in physical
environment fluctuates at a predictable rate energy flows through
ecosystem at a fairly constant rate over time These fluctuations in
populations and resources ultimately result in a stable
ecosystem!
Slide 4
Organisms in an ecosystem constantly INTERACT! interactions
among the organisms generate stability within ecosystems
Slide 5
Predation interaction between species in which one species (the
predator) eats the other (the prey) helps regulate the population
within an ecosystem thereby causing it to become stable
Fluctuations in predatorprey populations are predictable At some
point: prey population grows so numerous that they are easy to
find, so predator population
Slide 6
A graph of predatorprey density over time shows how the cycle
of fluctuations results in a stable ecosystem. As prey population
increases, predator population increases. As predator population
increases, prey population decreases.
Slide 7
Competition relationship that occurs when 2 or more organisms
need same resource at same time can be among members of same or
different species usually occurs with organisms that share the same
niche ecological niche: role of an organism in its environment
including type of food it eats how it obtains its food how it
interacts with other organisms 2 species with identical ecological
niches cannot coexist in the same habitat!! usually results in a
decrease in population of a species less adapted to compete for a
particular resource
Slide 8
Symbiotic Relationships exist between organisms of 2 different
species that live together in direct contact balance of ecosystem
is adapted to symbiotic relationship If population of 1 or other of
the symbiotic organisms becomes unbalanced, populations of both
organisms will fluctuate in an uncharacteristic manner. Symbiotic
relationships include Parasitism Mutualism Commensalism
Slide 9
Parasitism symbiotic relationship in which one organism (the
parasite) benefits at the expense of the other organism (the host
Some parasites live within the host tape worms, heartworms,
bacteria Some parasites feed on the external surface of a host
aphids, fleas, mistletoe Generally, parasite does not kill the
hostWHY? Parasite-host populations that have survived have been
those where neither has a devastating effect on the other.
Parasitism that results in rapid death of host is devastating to
both parasite and host populations. important that host survive and
thrive long enough for parasite to reproduce and spread _ Hornworm
caterpillar host will eventually die as its organs are consumed by
wasp larvae. Parasitism +
Slide 10
Mutualism symbiotic relationship in which both organisms
benefit Because 2 organisms work closely together, they help each
other survive. For example: bacteria, which have the ability to
digest wood, live within the digestive tracts of termites plant
roots provide food for fungi that break down nutrients the plant
needs
Slide 11
Commensalism symbiotic relationship in which one organism
benefits and the organism is not affected For example, barnacles
that attach to whales are dispersed to different environments where
they can obtain food and reproduce burdock seeds that attach to
organisms and are carried to locations where they can germinate Our
eyelashes are home to tiny mites that feast on oil secretions and
dead skin. Eyelash mites find all they need to survive in the tiny
follicles of eyelashes. +
Slide 12
REVIEW! EXPLAIN how the interrelationships among organisms
generate stability within ecosystems EXPLAIN how the
interrelationships among organisms generate stability within
ecosystems cause-and-effect model showing how predation,
competition, parasitism, mutualism, and commensalism affect the
stability of an ecosystem cause-and-effect model showing how
predation, competition, parasitism, mutualism, and commensalism
affect the stability of an ecosystem summarize how a stable
ecosystem is obtained summarize how a stable ecosystem is obtained
identify or illustrate the roles of various organisms in an
ecosystem (predator, prey, parasite, host) using pictures,
diagrams, or words identify or illustrate the roles of various
organisms in an ecosystem (predator, prey, parasite, host) using
pictures, diagrams, or words interpret a graph of predator/prey
numbers over time interpret a graph of predator/prey numbers over
time explain how the numbers of various organisms fluctuate in an
ecosystem to maintain stability explain how the numbers of various
organisms fluctuate in an ecosystem to maintain stability exemplify
biological relationships exemplify biological relationships explain
how a significant change in the numbers of a particular organism
will affect the stability of the ecosystem explain how a
significant change in the numbers of a particular organism will
affect the stability of the ecosystem classify a symbiotic
relationship as mutualism, parasitism, or commensalism classify a
symbiotic relationship as mutualism, parasitism, or commensalism
summarize each of the types of biological relationships summarize
each of the types of biological relationships compare how various
types of biological relationships affect the organisms involved
compare how various types of biological relationships affect the
organisms involved
Slide 13
B-6.2 Explain how populations are affected by limiting factors
(including density-dependent, density-independent, abiotic, and
biotic factors). Key Concepts: Population: population density
Limiting factors: density-dependent density-independent Abiotic
Biotic A population is a group of organisms belonging to the same
species that live in a particular area. Populations can be
described based on their size, density, or distribution.
Slide 14
Population density measures the number of individual organisms
living in a defined space Regulation of a population is affected by
limiting factors that include density-dependent density-independent
Abiotic factors Biotic factors
Slide 15
Density-dependent Limiting factors that operate more strongly
on large populations than on small ones. Competition Predation
Parasitism Disease triggered by increases in population density
(crowding)
Slide 16
Slide 17
Density-independent Limiting factors that occur regardless of
how large the population is and reduce the size of all populations
in the area in which they occur by the same proportion abiotic
(such as weather changes) Human activities (such as pollution)
natural disasters (such as fires)
Slide 18
Abiotic and biotic factors Abiotic factors chemical or physical
water, nitrogen, oxygen, salinity, pH, soil nutrients and
composition, temperature, amount of sunlight, and precipitation
Biotic factors all the living components of an ecosystem bacteria,
fungi, plants, and animals A change in either may decrease size of
a population if it cannot acclimate, adapt to, or migrate from the
change. A change may increase size of a population if that change
enhances its ability to survive, flourish or reproduce.
Slide 19
REVIEW! explain how populations are affected by limiting factor
cause-and-effect models of how each limiting factor (including
density- dependent, density-independent, abiotic, and biotic
factors) can affect a population in an ecosystem and in turn, the
entire ecosystem. summarize how limiting factors (as listed in the
indicator) affect population size exemplify or classify each type
of limiting factor (as listed in the indicator) compare
density-dependent limiting factors to density-independent limiting
factors and biotic limiting factors to abiotic limiting factors
infer the result of a change in a limiting factor on the size of a
population
Slide 20
B-6.3 Illustrate the processes of succession in ecosystems. Key
Concepts: Ecological succession Primary succession: pioneer species
climax community Secondary succession ecological succession: series
of changes in an ecosystem when one community is replaced by
another community as a result of changes in abiotic and biotic
factors two types: primary and secondary
Slide 21
Primary succession occurs in an area that has not previously
been inhabited Bare rock surfaces from recent volcanic lava flows
rock faces that have been scraped clean by glaciers a city
street
Slide 22
Slide 23
Beginning of primary succession depends on presence of unique
organisms that can grow without soil and facilitate process of soil
formation Lichens (mutualistic relationships between fungi and
algae) some mosses Break down rock into smaller pieces Among the
most important pioneer species (the first organisms) in the process
of primary succession At this stage of succession there are the
fewest habitats for organisms in the ecosystem. Once enough soil
and nutrients: small plants, such as small flowers, ferns, and
shrubs, grow plants break down rock further, provide more soil Then
seeds of other plants and small trees are able to germinate and
grow Over time more species grow and die. decomposed bodies add
nutrients to soil larger plant species able to populate area
Slide 24
Ch-Ch-Ch-Ch-Changes! As the species of plants change, species
of animals able to inhabit the area also change! organisms in each
stage may alter ecosystem in ways that hinder their own survival
but make it more favorable for future organisms In this way, one
community replaces another over time.
Slide 25
As long as no disturbances occur... composition of species
perpetuates itself climax community of a particular area is
determined by limiting factors of the area As scientists have
studied changes in ecosystems found that processes of succession
are always changing ecosystems
Slide 26
Secondary succession begins in area where there was a
preexisting community and well-formed soil abandoned farmland
vacant lots clear-cut forest areas open areas produced by forest
fires similar to later stages of primary succession after soil has
already formed Something halts the succession (fire, hurricane,
human activities) destroys established community but soil remains
intact When disturbance is over, ecosystem interacts to restore
original condition of community
Slide 27
Succession is a continual process Some stages (and organisms
that compose communities that characterize these stages) may last
for a short period of time, while others may last for hundreds of
years. Any ecosystem disturbance will affect rate of succession in
a particular area Usually secondary succession occurs faster than
primary succession because soil is already present When
disturbances are frequent or intense area will be mostly
characterized by species present in early stages of succession When
disturbances are moderate area will be composed of habitats in
different stages of succession succession occurs in all ecosystems
forest succession pond succession coral reef or marine succession
desert succession
Slide 28
Which is primary? Secondary?
Slide 29
REVIEW! illustrate the processes of succession in ecosystems
illustrate the processes of succession in ecosystems show how one
biological community replaces another community show how one
biological community replaces another community identify
communities that characterize the stages of succession identify
communities that characterize the stages of succession explain the
environmental conditions that are necessary for pioneer species to
survive; explain the environmental conditions that are necessary
for pioneer species to survive; infer what type of organisms will
be present in a given area in the future based on the a description
of the areas current species infer what type of organisms will be
present in a given area in the future based on the a description of
the areas current species exemplify the conditions for primary and
secondary succession exemplify the conditions for primary and
secondary succession summarize the processes of primary and
secondary succession summarize the processes of primary and
secondary succession
Slide 30
B-6.4 Exemplify the role of organisms in the geochemical cycles
(including the cycles of carbon, nitrogen, and water). Key
Concepts: Geochemical cycles Carbon cycle Nitrogen cycle: elemental
nitrogen, nitrogen fixation, denitrifying bacteria Water cycle
(hydrologic cycle) Role of organisms in the geochemical cycles
Slide 31
Geochemical cycles movement of a particular form of matter
through living and nonliving parts of an ecosystem Earth is a
closed system and must continually cycle its essential matter
Matter changes form but is neither created nor destroyed; it is
used over and over again in a continuous cycle. Organisms are an
important part of this cycling system! Matter placed into
biological systems is always transferred and transformed. Matter,
including carbon, nitrogen, and water, gets cycled in and out of
ecosystems.
Slide 32
Carbon Cycle Carbon = one of major components of biochemical
compounds of living organisms proteins, carbohydrates, lipids,
nucleic acids Found in Atmosphere In many minerals and rocks Fossil
fuels (natural gas, petroleum, and coal) In the organic materials
(compose soil, aquatic sediments)
Slide 33
Organisms play a major role in recycling C from 1 form to
another: Photosynthesis: Photosynthetic organisms take in CO 2 from
atmosphere and convert it to simple sugars Respiration: Organisms
break down glucose C is released into atmosphere as CO 2
Decomposition: When organisms die, decomposers break down C
compounds Enrich the soil or aquatic sediments are eventually
released into atmosphere as CO 2 Conversion of biochemical
compounds: Organisms store C as carbs, proteins, lipids, and
nucleic acids When animals eat plants and animals, some compounds
used for energy others converted to cmpds suited for predators body
other compounds (methane, other gases) released to atmosphere
Slide 34
Other methods of releasing stored C: Combustion: Burning wood
or fossil fuels releases CO 2 into atmosphere were formed from once
living organisms! Weathering of carbonate rocks Bones, shells fall
to ocean/lake bottom incorporated into sedimentary rocks (calcium
carbonate) Sedimentary rocks weather and decompose C released into
ocean, eventually into atmosphere
Slide 35
Slide 36
Nitrogen Cycle Nitrogen critical component of amino acids
needed to build proteins in organisms found in atmosphere as
elemental nitrogen (N 2 ) in living organisms (as proteins and
nucleic acids) in organic materials that compose soil and aquatic
sediments
Slide 37
Slide 38
Organisms play a major role in recycling N from one form to
another: Nitrogen-fixation: Nitrogen-fixing bacteria convert
elemental N found in air/dissolved in water into forms available
for use by plants found in soil, root nodules of plants, aquatic
ecosystems Intake of N into the organisms: Plants take in the N
through their root systems as ammonia or nitrate N enters the food
chain! Decomposition: Decomposers return N to soil organism dies
animal waste products Denitrification: Denitrifying bacteria break
down N compounds in soil Release elemental nitrogen, N 2, into
atmosphere
Slide 39
Water Cycle (Hydrologic cycle) Water necessary for life
processes of all living organisms! found in Atmosphere On surface
of Earth Underground In living organisms water cycle driven by Suns
heat energy causes water to evaporate from water reservoirs (the
ocean, lakes, ponds, rivers) on Earth and also from organisms
Slide 40
Organisms play a role in recycling water from one form to
another: Intake of water into the organisms: Organisms take in
water and use it to perform life functions Photosynthesis transport
of nutrients Transpiration: Plants release water back into
atmosphere through transpiration evaporative loss of water from
plants Respiration: All organisms metabolize food for energy
Produce water as a by-product of respiration Elimination: Most
organisms need water to assist with elimination of waste
products
Slide 41
Slide 42
REVIEW! exemplify the role of organisms in geochemical cycles
give examples of the ways that organisms are involved in nutrient
cycles, such as the nitrogen cycle, the carbon cycle, and the water
cycle summarize the ways that organisms are a vital part of each
cycle (carbon, nitrogen, and water) in various ecosystems interpret
a diagram, description, or illustration of an ecosystem in order to
describe how various organisms play a major role in the cycling of
nutrients explain the role of various organisms on the carbon,
nitrogen, and water cycles
Slide 43
B-6.5 Explain how ecosystems maintain themselves through
naturally occurring processes (including maintaining the quality of
the atmosphere, generating soils, controlling the hydrologic cycle,
disposing of wastes, and recycling nutrients). Key Concepts:
Atmosphere: ozone layer, greenhouse effect, sink Geosphere: soil
erosion, deposition Hydrologic cycle There are naturally occurring
Earth processes that help ecosystems maintain the materials
necessary for the organisms in the ecosystem.
Slide 44
Earth systems are interconnected Biosphere Portion of Earth
inhabited by life Atmosphere Hydrosphere Geosphere All must
interact efficiently in order for an ecosystem to maintain
itself.
Slide 45
Maintaining the Quality of the Atmosphere composition of Earths
atmosphere is mostly result of life processes of organisms which
inhabit Earth (past and present) Photosynthetic organisms need to
produce enough oxygen for themselves and all other organisms on
Earth maintain balance of atmospheric CO 2 and O 2 Oxygen produced
through photosynthesis is also responsible for the atmospheres
ozone layer prevents much of the Suns ultraviolet radiation from
reaching Earths surface protects biosphere from harmful
radiation
Slide 46
Maintaining the Quality of the Atmosphere, contd. normal
cycling of O 2 and CO 2 occurs as plants produce more O 2
(photosynthesis) than they consume (respiration) animals use this O
2 (for cellular respiration) and release CO 2 used by plants in
photosynthesis Nitrogen is maintained in the atmosphere through the
N cycle
Slide 47
Maintaining the Quality of the Atmosphere, contd. Water is
maintained in atmosphere through water cycle water vapor condenses
in atmosphere impurities (dust and particulates) removed from
atmosphere fall to Earth with precipitation air is cleaned after a
rain or snow fall
Slide 48
Greenhouse effect normal warming effect when gases trap heat in
atmosphere Greenhouse gases trap heat energy & maintain Earths
temperature range carbon dioxide, oxygen, methane, and water vapor
Dont allow heat to pass through very well heat that Earth releases
stays trapped under the atmosphere
Slide 49
Slide 50
Carbon dioxide in the atmosphere Amount cycles in response to
the degree to which plants and other photosynthetic organisms cover
Earth and absorb carbon dioxide the degree to which oceans cover
Earth salt water of oceans acts as a sink for carbon dioxide,
absorbing what plants do not use converting it to various salts
such as calcium carbonate
Slide 51
Slide 52
Generating Soils part of geosphere Soils on Earth are
constantly being generated and eroded 4 distinct components
inorganic minerals, organic matter, water, air Process of soil
generation continues: weathering of inorganic materials from wind,
water, and ice decaying of organic materials Soil erosion and
deposition are natural processes that move soil from one location
to another due to water, wind, ice and other agents. In most areas,
presence of plants allows process of soil production to be
consistent with process of soil erosion so that overall amount of
soil remains constant. presence of soil in an ecosystem allows for
succession to take place!
Slide 53
Controlling the Hydrologic Cycle: maintained by energy of Sun
and effect of weather Purifies water in several ways: Evaporated
water is pure water containing no impurities. As water seeps down
through soil and rock its physically filtered of impurities. As
water flow slows, heavier particles of sediment settle out, leaving
purified water to travel toward the oceans.
Slide 54
Disposing of Waste & Recycling Nutrients Waste materials
from organisms are decomposed by bacteria or other organisms in
soil or aquatic ecosystems Nutrients cycled through ecosystem from
organisms to environment and back series of specific processes
geochemical cycles
Slide 55
REVIEW! explain how ecosystems maintain themselves through
naturally occurring processes Cause-and-effect model showing how
the natural processes including maintaining the quality of the
atmosphere, generating soils, controlling the hydrologic cycle,
disposing of wastes, and recycling nutrients of Earth maintain the
environment. summarize how various aspects of an ecosystem are
naturally maintained (quality of the atmosphere, generation of
soils, controlling of the water cycle, disposing of wastes, and the
recycling of nutrients.) interpret diagrams, charts, tables, and
graphs in order to describe how naturally occurring processes
maintain balance in an ecosystem exemplify various naturally
occurring processes that ensure the quality of the atmosphere, the
generation of soils, the control of the water cycle, the disposal
of wastes, and the recycling of nutrients
Slide 56
B-6.6 Explain how human activities (including population
growth, technology, and consumption of resources) affect the
physical and chemical cycles and processes of Earth. Key Concepts:
Carrying capacity Sustainability: population growth, technology,
consumption of resources Technology: agricultural, industrial,
alternative energy Resources: renewable, nonrenewable Humans play a
role in ecosystems and geochemical cycles
Slide 57
People depend on... resources and geochemical cycles of Earth
to provide clean water breathable air soil capable of supporting
crops Human activities can affect cycles and processes of Earth
Population growth Technology Consumption of resources
Slide 58
Carrying capacity maximum population size that can be supported
by available resources Various factors determine carrying capacity
of Earth for human population energy, water, oxygen, nutrients
sustainability meet the needs of humans to survive indefinitely
needs to be a balance between Earths resources and carrying
capacity needs of humans and needs of other species on Earth
Slide 59
Factors that affect the sustainability of humans: Population
Growth Technology Consumption of Resources
Slide 60
Human Population Growth grown exponentially world-wide
Scientists predict population will continue to grow at a rapid rate
Based on current trends
Slide 61
Natural slowing of population growth as it nears Earths
carrying capacity due to an increase in death rate and a decrease
in birth rate Result of: Food and water shortages Pollution of the
environment Spread of diseases
Slide 62
Increasing human population can have effect on amount of
available clean water If clean water depleted at greater rate than
it can be purified It is not considered renewable in our
lifetime
Slide 63
Increasing human population can have effect on amount of waste
produced Although there are mechanisms in place to control disposal
of some waste products, more waste is produced than can be managed
effectively Some waste products require complicated, costly means
for removal once introduced into environment
http://www.storyofstuff.com/
Slide 64
Increasing human population can have effect on amount of
available fertile soil for agriculture (food resources) Soil is
often lost when land is cleared, making land unsuitable for
agriculture.
Slide 65
Other Soil Problems Worldwide demand for land (agriculture or
habitation) has led to deforestation Cut down forests fewer trees
to absorb atmospheric CO 2 increase contributes to global warming
by preventing heat from radiating back into space Deforestation can
increase erosion rate (wind and water) and decrease rate of soil
generation
Slide 66
Even More Soil Problems! Human population growth has depleted
amount of fertile soil, clean water and available land in many
areas of the world. resources scarce many natural processes are
affected water cycle carbon cycle nitrogen cycle physical process
of soil regeneration
Slide 67
Technology Different types have applied scientific knowledge to
help meet the needs of humans find solutions to problems develop
products Has benefited humankind, but has also contributed to
pollution of the air, water, and land. For sustainability, humans
depend on technology to now provide cleaner energy sources, safer
ways to deal with waste, and better methods for cleaning up
pollution. Technological advances in agriculture, industry, and
energy can have a positive or negative impact on Earth.
Slide 68
Agricultural technology Advances in agricultural methodology,
tools, and biotechnology have improved the ability to grow crops to
sustain a growing world population. Sustainable agricultural
practices can help conserve fertile soil and reduce soil erosion.
BUT--- Farm machinery (such as tractors and combines) consumes
nonrenewable resources and can contribute to erosion and air
pollution. Addition of substances (such as fertilizers, pesticides,
fungicides, livestock waste) to environment can alter soil
composition and can have a positive or negative effect on water,
carbon or nitrogen cycles.
Slide 69
Industrial technology Advances in industrial technology have
changed the world and have lead to developments in communication,
transportation, and industry. Development of certain chemicals
(CFCs chlorofluorohydrocarbons) contributes to ozone layer
depletion results in increased ultraviolet rays reaching Earth CFCs
used in producing foam packing materials cleaning electrical
components refrigeration chemicals (Freon)
Slide 70
Technological advances have revolutionized the communication
industry BUT...disposal of outdated or damaged equipment is
becoming an increasing concern!!
Slide 71
Burning of fossil fuels for industry and transportation
increases sustainability of the growing human population, BUT it
also: increases greenhouse gases released in atmosphere (mainly
carbon dioxide) increases global temperatures (global warming) that
affect sea levels, climate and atmospheric composition produces
acid rain (pollutants in the air combining with water to cause the
normal water pH to be lowered) decreases soil pH can leach
nutrients from soils or destroy plant life changes pH of aquatic
ecosystems therefore affects types of organisms that can survive
there
Slide 72
Alternative energy technology Using natural renewable energy
sources wind, water, geothermal, or solar energy decreases burning
of fossil fuels increases quality of atmosphere and cycles involved
Using nuclear energy technology provides an alternative energy
source that does not impact the atmosphere. BUT...waste produced
from is becoming an increasing concern
Slide 73
Consumption of Resources As human population increases and
technology expands, demand for Earth resources also increases BUT
there is a limited supply of these resources available to sustain
the human population!
Slide 74
Renewable Resources food, clean water, timber can be produced
at roughly the same rate that they are consumed have factors that
limit their production amount of grain that can be produced is
limited by amount of land available for farming fertility of the
land productivity of the grain availability of clean water
Slide 75
Nonrenewable Resources fossil fuels cannot be produced at same
rate theyre consumed Demand for minerals, metals, and ores
increases because these strategic materials are vital to industry
but are decreasing in availability. Minerals are nonrenewable
because mineral deposits that can be extracted economically are
formed so slowly by geological processes that their formation as a
means of replacing what we are using is NOT PRACTICAL!
Slide 76
Sustainable use of resources can be accomplished by reducing
consumption reusing products rather than disposing of them
recycling waste Protect the environment!!
Slide 77
REVIEW! explain how human activities affect the physical and
chemical cycles and processes of Earth cause-and-effect models of
how human population growth, technology, and consumption of
resources can influence the geochemical cycles and processes of
Earth interpret diagrams, charts, tables, and graphs in order to
describe how human activities affect the geochemical cycles and
process of Earth summarize how various human activities affect the
geochemical cycles and processes of Earth; illustrate ways that the
geochemical cycles and processes of Earth have been altered by
human activities infer the future effect of human activities on the
geochemical cycles and processes of Earth based on current
trends