The difference between a fundamental niche and a realized
niche. The role of competitive exclusion in interspecific
competition. The symbiotic relationships of parasitism, mutualism,
and commensalism The impact of keystone species on community
structure The difference between primary and secondary
succession
Slide 4
Community: A collection of populations that interact with one
another in a given area. Within a community, different populations
will play different roles. What do we call the role a population
plays in its community? Its Niche
Slide 5
Inter- means between different groups. Intra- means within the
same group. Intraspecific competition for resources are examples of
density dependent limiting factors for a single population.
Slide 6
Community interactions can be classified by whether they help,
harm, or have no effect on the species involved relationships
between species interspecific interactions Ecologists call
relationships between species in a community interspecific
interactions Examples include: competition predation herbivory
symbiosis (parasitism, mutualism, and commensalism)
facilitation
Slide 7
Interspecific interactions Interspecific interactions can
affect the survival and reproduction of each species, and the
effects can be summarized as positive (+), negative (), or no
effect (0)
Slide 8
the carrier crab carries a sea urchin on its back for
protection against predators
Slide 9
Interspecific competition (/ interaction) Occurs when species
compete for a resource in short supply Two different species
compete for the same limited resource Squirrels and black bears
compete for acorns
Slide 10
Slide 11
Strong competition can lead to competitive exclusion, local
elimination of a competing species two species competing for the
same limiting resources cannot coexist in the same place The
competitive exclusion principle states that two species competing
for the same limiting resources cannot coexist in the same place
What will decide which species will win out?
Slide 12
Ecological niche (ecological role) Sum of an organisms use of
biotic and abiotic resources Interspecific competition occurs when
the niches of two populations overlap Competition lowers the
carrying capacity of competing populations
Slide 13
FundamentalRealized The potential niche a species can occupy.
The actual niche a species occupies
Slide 14
Ecologically similar species can coexist in a community if
there are one or more significant differences in their niches
Resource partitioning Resource partitioning is differentiation of
ecological niches, enabling similar species to coexist in a
community
Slide 15
A. distichus perches on fence posts and other sunny surfaces.
A. insolitus usually perches on shady branches. A. ricordii A.
aliniger A. insolitus A. distichus A. christophei A. cybotes A.
etheridgei
Slide 16
When two organisms interact closely in a way that benefits both
species. Honeybees have a mutualistic relationship with flowers.
How is this so?
Slide 17
Reef-building corals require mutualism Photosynthetic
dinoflagellates Live in the cells of each coral polyp Produce
sugars used by the polyps Provide at least half of the energy used
by the coral animals
Slide 18
Slide 19
Predation (+/ interaction) refers to interaction where one
species, the predator, kills and eats the other, the prey Some
feeding adaptations of predators are claws, teeth, fangs, stingers,
and poison
Slide 20
Predation benefits the predator but kills the prey Prey adapt
using protective strategies Camouflage Mechanical defenses Chemical
defenses
Slide 21
(a)Cryptic coloration (b) Aposematic coloration Canyon tree
frog Poison dart frog (c) Batesian mimicry : A harmless species
mimics a harmful one. (d) Mllerian mimicry: Two unpalatable species
mimic each other. Hawkmoth larva Cuckoo bee Yellow jacket Green
parrot snake
Slide 22
Camouflage
Slide 23
Poison
Slide 24
Herbivory (+/) (type of predation) refers to an interaction in
which an herbivore eats parts of a plant or alga It has led to
evolution of plant mechanical and chemical defenses and adaptations
by herbivores
Slide 25
Slide 26
Herbivory is not usually fatal to the plant Plants must expend
energy to replace the loss Plants have numerous defenses against
herbivores Spines and thorns Chemical toxins Herbivores must adapt
to the defenses created by their food.
Slide 27
Coevolution: A series of reciprocal evolutionary adaptations in
two species. A change in one species acts as a new selective force
on another Poison-resistant caterpillars seem to be a strong
selective force for Passiflora plants
Slide 28
Eggs Sugardeposits Heliconius, caterpillar has enzymes to break
down poison of Passiflora (plant). The Plant has since adapted
sugar-deposits to mimic butterfly eggs. The Heliconius butterfly
will not lay eggs on a leaf with another butterflies eggs already
attached.
Slide 29
Slide 30
parasitism parasitenourishment host harmed In parasitism (+/
interaction), one organism, the parasite, derives nourishment from
another organism, its host, which is harmed in the process
endoparasites Parasites that live within the body of their host are
called endoparasites Such as nematodes and tapeworms ectoparasites
Parasites that live on the external surface of a host are
ectoparasites Such as mosquitoes and ticks
Slide 31
Ticks Tapeworms Liver flukes
Slide 32
Pathogensdisease-causing parasites Pathogens are
disease-causing parasites Pathogens can be bacteria, viruses
(non-living), fungi, or protists Non-native pathogens Non-native
pathogens can have rapid and dramatic impacts American chestnut
devastated by chestnut blight protist A fungus-like pathogen
currently causing sudden oak death on the West Coast Non-native
pathogens can cause a decline of the ecosystem
Slide 33
Slide 34
What adaptations have predators & prey evolved in order to
help survive? Explain coevolution. Explain using examples why
non-native parasitism, or pathogens, are typically dramatic for an
ecosystem. Explain and give an example of an autotrophic organism.
Explain and give an example of an heterotrophic organism. What do
you think the suffix trophic refers to?
Slide 35
Create a food chain that spans 4 trophic levels. Be sure to
start with a producer.
Slide 36
Trophic structure A pattern of feeding relationships consisting
of several different levels Food chain Sequence of food transfer up
the trophic levels
Slide 37
Producers Support all other trophic levels Autotrophs
Photosynthetic producers Plants on land Cyanobacteria in water
Slide 38
Where does the energy for life processes come from?
Slide 39
Producers Without a constant input of energy, living systems
cannot function. What do you think is the main energy source for
life on Earth? Sunlight
Slide 40
Only plants, some algae, and certain bacteria can capture
energy from sunlight and use that energy to produce food.
Autotrophs What are these organisms called?
Slide 41
In a few ecosystems, some organisms obtain energy from a source
other than sunlight.
Slide 42
Life Without Light Some autotrophs can produce food in the
absence of light. Chemosynthetic bacteria are important in deep sea
ecosystems.
Slide 43
Slide 44
Some chemosynthetic bacteria live in very remote places on
Earth, such as volcanic vents on the deep-ocean floor and hot
springs. Others live in more common places, such as tidal marshes
along the coast.
Slide 45
Consumers Organisms that rely on other organisms for their
energy and food supply are called ________________. Heterotrophs
are also called consumers. heterotrophs
Slide 46
There are many different types of heterotrophs. ____________
eat plants. ____________ eat animals. ____________ eat both plants
and animals. ____________ feed on plant and animal remains and
other dead matter. _____________, like bacteria and fungi, break
down organic matter. Herbivores Carnivores Omnivores Scavengers
Decomposers
Slide 47
Consumers Heterotrophs Primary consumers: Eat Producers
Secondary consumers Tertiary consumers Quaternary consumers
Detritivores and decomposers: Derive energy from dead matter and
wastes
Slide 48
Plant A terrestrial food chain Producers Phytoplankton An
aquatic food chain
Slide 49
Plant A terrestrial food chain Producers Phytoplankton An
aquatic food chain Primary consumers Grasshopper Zooplankton
Slide 50
Plant A terrestrial food chain Producers Phytoplankton An
aquatic food chain Primary consumers Grasshopper Zooplankton
Secondary consumers Mouse Herring
Detritivores, such as scavengers, eat detritus, or dead organic
material. Decomposers, mainly fungi & prokaryotes, secrete
enzymes to digest molecules in organic material and convert them to
inorganic forms. Great Circle Of Life Think of the Great Circle Of
Life.
Slide 54
Slide 55
Copyright 2009 Pearson Education, Inc. Food web A network of
interconnecting food chains
Slide 56
Producers (plants) Primary consumers Secondary and primary
consumers Tertiary and secondary consumers Quaternary, tertiary,
and secondary consumers
Slide 57
This food web shows some of the feeding relationships in a
salt-marsh community.
Slide 58
Species diversity is the variety of organisms that make up the
community It has two components: Species richness Species richness
is the total number of different species in the community Relative
abundance is the proportion each species represents of the total
individuals in the community Plant species diversity in a community
affects the animals Species diversity has consequences for
pathogens
Slide 59
Community 1 A: 25%B: 25%C: 25%D: 25% Community 2 A: 80%B: 5%C:
5%D: 10% ABCD Compare and contrast the species richness and species
abundance for communities 1 & 2.
Slide 60
Slide 61
Communities with higher diversity are: More productive and more
stable in their productivity Better able to withstand and recover
from environmental stresses More resistant to invasive species,
organisms that become established outside their native range
Slide 62
Which would you expect to have higher species diversity, a
well-maintained lawn, or one that is poorly maintained? Explain.
The poorly maintained lawn would have higher species diversity. A
well-maintained lawn should have low species diversity. While a
lawn that is cared for may not be a perfect monoculture, any weeds
that are present would have low relative abundance.
Slide 63
Explain competitive exclusion Difference between a fundamental
and realized niche. When 2 species are competing for a resource,
the species with a slight advantage will eliminate the other.
Fundamental niche is the niche potentially occupied by the species.
The realized niche is the portion of the fundamental niche the
species actually occupies.
Slide 64
What is symbiosis? A +/- symbiotic interaction in which one
organism derives nourishment from a host. An interspecific
interaction that benefits both species. Symbiotic relationship that
benefits one of the species but neither harms nor helps the other.
A fern growing in the shade of another plant is an example. When
individuals of 2 or more species live in direct contact with one
another. Parasitism Mutualism Commenalism
Slide 65
Dominant Species Population in a community that has the highest
biomass Biomass is the sum weight of all the members of a
population.
Slide 66
Keystone species exert strong control on a community by their
ecological roles, or niches A keystone species has a much larger
impact on its community than its biomass would suggest. Field
studies of sea stars illustrate their role as a keystone species in
intertidal communities Keystone absent
Slide 67
Pisaster ochraceus may prey on sea urchins & mussels with
no other natural predators. If the sea star is removed from the
ecosystem, the mussel population explodes, driving out most other
species The urchin population annihilates coral reefs
Slide 68
EXPERIMENT RESULTS With Pisaster (control) Without Pisaster
(experimental) Year 737271706968676665641963 0 5 10 15 20 Number of
species present
Slide 69
RESULTS With Pisaster (control) Without Pisaster (experimental)
Year 1963 0 5 10 15 20 Number of species present
64656667686970717273
Slide 70
Slide 71
The beaver is an ecosystem engineer transforms its territory
from a stream to a pond or swamp. Beavers affect the environment by
cutting down older trees to use for their dams. allows younger
trees to take their place. Beaver dams alter the riparian area
(where water and land interact) Dams change the edges of streams
and rivers into wetlands, meadows, or riverine forests. Beneficial
to groups of species such as amphibians, salmon, and song
birds
Slide 72
Disturbances Events that damage biological communities Storms,
fire, floods, droughts, overgrazing, or human activity The types,
frequency, and severity of disturbances vary from community to
community
Slide 73
Communities change drastically following a severe disturbance
Ecological succession Colonization by a variety of species A
success of change gradually replaces other species
Slide 74
Slide 75
Slide 76
Primary succession Begins in a virtually lifeless area with no
soil Secondary succession When a disturbance destroyed an existing
community but left the soil intact
Slide 77
Time Shrubs Annual plants Perennial plants and grasses Softwood
trees such as pines Hardwood trees Primary or secondary
succession?
Slide 78
Slide 79
After what type of natural disasters would one expect to see
primary succession?
Slide 80
Primary succession could occur on the barren slopes of a
recently erupted volcano.
Slide 81
A large-scale fire struck Yellowstone National Park in 1988. It
quickly responded. Would this be primary or secondary succession?
(a) Soon after fire(b) One year after fire
Slide 82
Slide 83
55
Slide 84
Ecosystem All the organisms in a community as well as the
abiotic environment Components of ecosystems Energy flow Passage of
energy through the ecosystem Chemical cycling Transfer of materials
within the ecosystem Why is this important to us? What are the four
major macromolecules, what do they look like? Where do we get the
material to make these molecules?
Slide 85
Slide 86
Energy flow Light energy Chemical energy Chemical elements Heat
energy Bacteria and fungi Chemical cycling A terrarium has the
components of an ecosystem
Slide 87
Primary production The amount of solar energy converted to
chemical energy Carried out by producers (autotrophs) Produces
biomass Amount of living organic material in an ecosystem
Slide 88
gross primary production (GPP). The total primary production in
an ecosystem is known as that system gross primary production
(GPP). The amount of energy available to consumers is the net
primary production (NPP). What is the difference? NPP = GPP-R R is
the energy used in respiration by the producers.
Slide 89
Open ocean Estuary Algal beds and coral reefs Desert and
semidesert scrub Tundra Temperate grassland Cultivated land Boreal
forest (taiga) Savanna Temperate deciduous forest Tropical rain
forest 0 500 Average net primary productivity (g/m 2 /yr) 1,000
1,500 2,5002,000
Slide 90
Trophic Levels Each step in a food chain or food web is called
a trophic level. Producers make up the first trophic level.
Consumers make up the second, third, or higher trophic levels. Each
consumer depends on the trophic level below it for energy.
Slide 91
So energy is created by producers and then consumed by
consumers. Is there a limit to the trophic levels this energy can
travel?
Slide 92
At each stage of consumption, or trophic level, some energy is
lost as heat to the environment. This is why most producers can
only support 4-5 consumer levels.
Slide 93
Explain the difference between populations, communities, and
ecosystems.
Slide 94
Ecological Pyramids An ecological pyramid is a diagram that
shows the relative amounts of energy or matter contained within
each trophic level in a food chain or food web.
Slide 95
0.1% Third-level consumers 1% Second-level consumers 10%
First-level consumers 100% Producers Energy Pyramid: Shows the
relative amount of energy available at each trophic level.
Slide 96
What do you notice about the amount of stored energy as it
passes from one trophic level to the next? What does this mean
about the amount of living tissue (biomass) able to be supported at
each level? Because each trophic level harvests only about one
tenth of the energy from the level below, it can support only about
one tenth the amount of living tissue.
The more levels that exist between a producer and a top-level
consumer in an ecosystem, the less energy that remains from the
original amount. Only about 10 percent of the energy available
within one trophic level is transferred to organisms at the next
trophic level.
Slide 99
Ecosystems are supplied with a continual influx of energy Sun
Earths interior Life also depends on the recycling of chemicals
Organisms acquire chemicals as nutrients and lose chemicals as
waste products
Slide 100
Biogeochemical cycles Nutrient cycles that contain both biotic
and abiotic components. Cycle chemicals between organisms and the
Earth Can be local or global Decomposers play a central role in
biogeochemical cycles
Slide 101
Consumers Geologic processes Producers Decomposers Nutrients
available to producers Abiotic reservoir 4 1 2 3
Slide 102
Carbon is the major ingredient of all organic molecules
respiration balances photosynthesis The return of CO 2 to the
atmosphere by respiration closely balances its removal by
photosynthesis The carbon cycle is affected by burning wood and
fossil fuels (these increase CO 2 in the atmosphere)
Slide 103
Photosynthesis Decomposers (soil microbes) Cellular respiration
Detritus 4 1 2 3 5 Plants, algae, cyanobacteria Primary consumers
Higher-level consumers Burning CO 2 in atmosphere Plant litter;
death Wastes; death Decomposition Wood and fossil fuels
Slide 104
Moves nitrogen from the atmosphere through the living world.
Nitrogen is a common limiting factor of plant growth.
Slide 105
Nitrogen is an essential component of proteins and nucleic
acids Nitrogen has two abiotic reservoirs Air Soil Nitrogen
fixation converts N 2 to nitrogen used by plants Carried out by
some bacteria and cyanobacteria
Slide 106
The Nitrogen Cycle Certain types of bacteria that live in the
soil and on the roots of plants can convert nitrogen gas (N 2 )
into ammonia in a process known as nitrogen fixation.
Slide 107
nitrification Other bacteria in the soil convert ammonia into
nitrates and nitrites in a process known as nitrification. Once
these products are available, producers can use them to make
proteins. Consumers then eat the producers and reuse the nitrogen
to make their own proteins.
Slide 108
Nitrogen (N 2 ) in atmosphere 8 Plant Animal Assimilation by
plants Organic compounds Organic compounds Death; wastes
Denitrifiers Nitrates in soil (NO 3 ) Detritus Decomposers
Decomposition Nitrifying bacteria Ammonium (NH 4 + ) in soil
Nitrogen fixation Nitrogen fixation Nitrogen-fixing bacteria in
root nodules Free-living nitrogen-fixing bacteria and cyanobacteria
6 1 2 7 4 3 5
Slide 109
Water moves between the ocean, atmosphere, and land.
Slide 110
Water molecules enter the atmosphere as water vapor, a gas,
when they evaporate from the ocean or other bodies of water.
Slide 111
Water can also enter the atmosphere by evaporating from the
leaves of plants in the process of transpiration.
Slide 112
Water vapor condenses into tiny droplets that form clouds. The
water returns to Earths surface in the form of precipitation. Water
enters streams or seeps into soil where it enters plants through
their roots. Water can also infiltrate the ground and travel as
groundwater.groundwater
Slide 113
Copyright 2009 Pearson Education, Inc. 1. Describe the
characteristics of a community 2. Explain how interspecific
interactions affect the dynamics of populations 3. Describe the
trophic structure of a community 4. Explain how species diversity
is measured 5. Describe the role of environmental disturbance on
ecological succession 6. Explain energy and nutrient cycling in
ecosystems
Slide 114
Why is it important to study communities? What is a community?
Give both an aquatic and land organism examples of predation. Give
both an aquatic and land organism examples of mutualism. Give both
an aquatic and land organism examples of competition. Give an
example of commensalism. Give an example of parastism.
Slide 115
Name two adaptations that may enable predators to capture prey.
Name two adaptations that may enable prey to evade predators. Write
a brief (fiction or nonfictional) scenario about two organisms
coevolving in a predator-prey relationship. Write a brief (fiction
or nonfictional) scenario about two organisms coevolving in a
mutualism relationship.
Slide 116
Imagine the fields behind the school as an ecosystem: Name a
producer, primary consumer, and secondary consumer. How much of the
producers potential energy will be consumed to the secondary
consumer? From where does each trophic level obtain its carbon
& nitrogen? Think back to musical chairs when would one expect
interspecific competition occur?
Slide 117
What are detritivores and what do they do for an ecosytem?
Explain what is meant by species richness in an ecosytem. What are
keystone species and what would happen if they were removed from an
ecosystem? Explain and provide examples of primary & secondary
succession. Explain what invasive species are and the impact they
play on an ecosystem.
Slide 118
Slide 119
Slide 120
Explain what this equation means: NPP = GPP R a Net Primary
Production = Gross energy used in respiration
Slide 121
Amount of light and the depth it can reach. Light decreases
with depth. What is a limiting factor? Limits growth of populations
Most common limiting factors in marine environments are nitrogen
and phosphorous. A lake that is nutrient-rich and supports a vast
array of algae is said to be eutrophic.
Slide 122
Conservation Biology and Global Change Chapter 56 Chapter 56
(only section 1)
Slide 123
Scientists have named and described 1.8 million species
Biologists estimate 10200 million species exist on Earth Tropical
forests contain some of the greatest concentrations of species and
are being destroyed at an alarming rate Humans are rapidly pushing
many species toward extinction
Slide 124
Slide 125
Slide 126
Conservation biology, which seeks to preserve life, integrates
several fields Ecology Physiology Molecular biology Genetics
Evolutionary biology
Slide 127
Bioremediation: Using organisms, like prokaryotes, plants and
fungi to detoxify polluted ecosystems. Bioaugmentation: Is the
intorduction of desirable species such as nitrogen fixers to add
essential nutrients.
Slide 128
Rates of species extinction are difficult to determine under
natural conditions The high rate of species extinction is largely a
result of ecosystem degradation by humans Humans are threatening
Earths biodiversity
Slide 129
Biodiversity has three main components Genetic diversity
Species diversity Ecosystem diversity
Slide 130
Genetic diversity in a vole population Species diversity in a
coastal redwood ecosystem Community and ecosystem diversity across
the landscape of an entire region
Slide 131
Genetic diversity comprises genetic variation within a
population and between populations
Slide 132
Species diversity is the variety of species in an ecosystem or
throughout the biosphere According to the U.S. Endangered Species
Act An endangered species is in danger of becoming extinct
throughout all or a significant portion of its range A threatened
species is likely to become endangered in the foreseeable
future
Slide 133
Conservation biologists are concerned about species loss
because of alarming statistics regarding extinction and
biodiversity Globally, 12% of birds, 20% of mammals, and 32% of
amphibians are threatened with extinction Extinction may be local
or global
Slide 134
Philippine eagle Javan rhinoceros Yangtze River dolphin
Slide 135
Human activity is reducing ecosystem diversity, the variety of
ecosystems in the biosphere More than 50% of wetlands in the
contiguous United States have been drained and converted to other
ecosystems
Slide 136
The local extinction of one species can have a negative impact
on other species in an ecosystem For example, flying foxes (bats)
are important pollinators and seed dispersers in the Pacific
Islands
Slide 137
Slide 138
Human biophilia allows us to recognize the value of
biodiversity for its own sake Species diversity brings humans
practical benefits
Slide 139
Species related to agricultural crops can have important
genetic qualities For example, plant breeders bred virus- resistant
commercial rice by crossing it with a wild population In the United
States, 25% of prescriptions contain substances originally derived
from plants For example, the rosy periwinkle contains alkaloids
that inhibit cancer growth
Slide 140
Slide 141
The loss of species also means loss of genes and genetic
diversity The enormous genetic diversity of organisms has potential
for great human benefit
Slide 142
Ecosystem services encompass all the processes through which
natural ecosystems and their species help sustain human life Some
examples of ecosystem services Purification of air and water
Detoxification and decomposition of wastes Cycling of nutrients
Moderation of weather extremes
Slide 143
Most species loss can be traced to four major threats Habitat
destruction Introduced species Overharvesting Global change
Slide 144
Human alteration of habitat is the greatest threat to
biodiversity throughout the biosphere In almost all cases, habitat
fragmentation and destruction lead to loss of biodiversity For
example In Wisconsin, prairie occupies
