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Ecology 2010
Introduction to Ecology3.1 What is Ecology
3.2 Energy, Producers, and Consumers
3.3 Energy Flow in Ecosystems
3.4 Cycles of Matter
p. 62-93
4.1 Climate
4.2 Niches and Community Interactions
4.3 Succission
4.4 Biomes
4.5 Aquatic Ecosystems
p. 94-125
Key Terms• Biosphere
• Population
• Community
• Ecology
• Ecosystem
• Biome
• Biotic factor
• Abiotic factor
• Autotroph
• Primary producer
• Photosynthesis
• Chemosynthesis
• Heterotrophs
• Consumer
• Carnivore
• Herbivore
• Scavenger
• Omnivore
• Decomposer
• Detritivore
• Food chain
• Food web
• Phytoplankton
• Trophic level
• Ecological pyramid
• Biomass
• Biogeochemical cycle
• Nutrient
• Nitrogen fixation
• Denitrivication
• Limiting nutrient
• Weather
• Climate
• Microclimate
• Greenhouse effect
• Tolerance
• Habitat
• Niche
• Resource
• Competitive exclusion
principle
• Predation
• Herbivory
• Keystone species
• Symbiosis
• Mutualism
• Parasitism
• Commensalism
• Ecological succession
• Primary succession
• Pioneer species
• Secondary succession
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Review ?
• How can a constantly changing
environment might affect evolution?
Populations can evolve by natural selection
With respect to heritable traits that favor
reproductive success and survivorship in
each particular environment
• Can humans have an impact on the
environment?
Ecology 2010
Objectives
• Identify a key theme in ecology
• Describe an example showing the effects of interdependence upon organisms in their environment.
• Identify the importance of models to ecology
• State the five different levels of organization at which ecology can be studied
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What is Ecology? (house/ study of)
• Ecology is the study of interactions between
organisms and the living and nonliving
components of their environments. Each of
the variety of organisms on Earth depends in
some way on other living and nonliving things in
its environment. Ecology is a broad science that
involves collecting information about organisms
and their environments, observing and
measuring interactions, looking for patterns, and
seeking to explain these patterns.
Ecology 2010
Organisms and their Environment
• All organisms interact with other
organisms in their surroundings and with
the nonliving things in the environment
• The survival depends on the interactions
• This is called the interconnectedness or
interdependence
• The things you need to survive
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Ecological models
• Ecology is complex thing to study
• Used ecological models to represent or
describe the components of an ecological
system
• Helps to study environmental interactions
and make predictions
• Can not always account for influences or
variables in an environment
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The Science of Ecology– Ecology is the scientific study of interactions
among and between organisms and their physical
environment.
– Interactions within the biosphere produce a web
of interdependence between organisms and the
environments in which they live.
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Studying Our Living Planet
– The biosphere consists
of all life on Earth and all
parts of the Earth in which
life exists, including land,
water, and the atmosphere.
– The biosphere extends
from about 8 km above
Earth’s surface to as far as
11 km below the surface of
the ocean.
Ecology 2010
Ecology 2010
Levels of organization
• Biosphere- thin volume of earth and its
atmosphere that supports life
• Ecosystem- all of the organisms and the
nonliving environment found in one place
• Community-all the interacting organisms living
in an area
• Populations- all the members of a species that
live in one place at the same time
• Web cd 34 a,
• holtclip
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Ecology 2010
Objectives
• Compare abiotic factors with biotic factors
and list two examples of each
• Describe two mechanisms that allow
organisms to survive in a changing
environment
• Explain the concept of the niche
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Ecology of Organisms
• The place where an organism lives is its
habitat. But why does it live there and not
elsewhere? What parts of its habitat does
it use? The answers to these questions
depends on an organism’s evolutionary
history, its abilities, and its needs
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Ecosystem components
Factors that influence an organism into two types
1. Living components- biotic factors
2. Nonliving factors- abiotic factors (changing)a) Temperature
b) Humidity
c) pH
d) Salinity
e) Oxygen concentrations
f) Amount of sunlight
Web cd 34 b
Ecology 2010
Organisms in a changing environment
• Each organism is able to survive within a limited
range of environmental conditions
• Tolerance curve- helps to determine an
organisms performance versus values of an
environmental variable (temps, salt)
• May still survive but performance limited
• Some organisms can acclimate, adjust
tolerance levels
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Control of internal conditionsHow do they deal with environments changing daily?
Two ways
1. Conformers-organisms that do not
regulate their internal
conditions, they change
as their external
environments changes
2. Regulators- use
energy to control some
of their internal
conditions over wide
variety of environmental
conditions
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Escape from unsuitable conditions
• Escape them temporarily
Ways-
1. Hide underground or shade till cool
2. Active at night when cooler (desert
species)
3. Long term- dormancy, reduce activity
(bears)
4. Migration- move habitat (birds)
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The nicheto nest
The specific role or way of life of an organisms in its environment
Includes:
1. Range of conditions
2. Resources
3. Ways to obtain resources
4. Number of offspring
5. Time of reproduction
6. Predator/prey
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Two different types of species
1. Generalist- species with broad niches, can
tolerate range of conditions and use a variety
of resources
ex. Opossum feeds on eggs, fruits, dead animals
2. Specialist- narrow niches,
ex koala only feeds on eucalyptus trees
*More than one- some species have more than
one niche during a lifetime (caterpillars eat
leaves, butterflies eat nectar)
Ecology 2010
Objectives
• Summarize the role of produces in an ecosystem
• Identify several kinds of consumers in an ecosystem
• Explain the important role of decomposers in an ecosystem
• Compare the concept of a food chain with that of a food web
• Explain why ecosystems usually contain only a few tropic levels
THINK ABOUT IT
– What happens to energy stored in body tissues
when one organism eats another?
– Energy moves from the ―eaten‖ to the ―eater.‖ Where
it goes from there depends on who eats whom!
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Ecology 2010
Energy transfer
• All organisms need energy to carry out essential
functions, such as growth, movement,
maintenance and repair, and reproduction. In an
ecosystem, energy flows from the sun to
autotrophs, then to organisms that eat the
autotrophs, and then to organisms that feed on
other organisms. The amount of energy an
ecosystem receives and the amount that is
transferred from organism to organism affect the
ecosystem's structure.
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Producers
• Autotrophs- make their own food, plants,
some protists and bacteria
• Most are photosynthetic use sunlight to
make food
• Chemosynthesis- breakdown molecules to
produce carbohydrates
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consumers• Heterotrophs- can not make own food, eat
other organisms
Grouped based on types of food they eat:
1. Herbivores- eat producers (antelope)
2. Carnivores- eat other consumers (lion)
3. Omnivores- eat producers and consumers (grizzly bear)
4. Detritivores- consumers that feed on wastes, dead organisms (vulture)
5. Decomposers- break down organisms (bacteria, fungi)
Decomposers and Detritivores in
Food Webs At the same time, the decomposition process releases
nutrients that can be used by primary producers. They
break down dead and decaying matter into forms that
can be reused by organisms, similar to the way a
recycling center works.
• Without decomposers, nutrients would remain locked in
dead organisms.
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Energy Flow
• Transfer of energy from one organism to another
• Trophic levels- organism’s position in a
sequence of energy transfers
• Food chain- single pathway of feeding
relationships between organisms in an
ecosystem that results in energy transfer
• Food web- interconnected food chains
• Web cd 37 c, d, e
• Fig: 18.9, 18.10, 18.11
Food Chains– A food chain is a series of steps in which
organisms transfer energy by eating and
being eaten.
– Food chains can vary in length. An example
from the Everglades is shown.
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Food Webs – In most ecosystems, feeding relationships are much
more complicated than the relationships described in
a single, simple chain because many animals eat
more than one kind of food.
– Ecologists call this network of feeding interactions a
food web. An example of a food web in the
Everglades is shown.
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Limitations on trophic levels
• Only 10% of the energy available at one
trophic levels is transferred to the next
trophic level not enough to support more
levels
• Higher tropic levels contain less energy
support fewer organisms
Pyramids of Biomass and
Numbers – The total amount of living tissue within a
given trophic level is called its biomass.
– The amount of biomass a given trophic level
can support is determined, in part, by the
amount of energy available.
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Objectives
• List four major biogeochemical cycles
• Summarize three important processes in
the water cycle
• Outline the major steps in the carbon cycle
• Describe the role of decomposers in the
nitrogen cycle
• Summarize the major steps of the
phosphorus cycle
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Ecosystem Recycling
• As energy and matter flow through an
ecosystem, matter must be recycled and
reused. Substances such as water,
carbon, nitrogen, calcium, and phosphorus
each pass between the living and
nonliving worlds through biogeochemical
cycles.
Recycling in the Biosphere
– Unlike the one-way flow of energy, matter is
recycled within and between ecosystems.
– Elements pass from one organism to another
and among parts of the biosphere through
closed loops called biogeochemical cycles,
which are powered by the flow of energy.
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4 major cycles
1. Water cycle
2. Carbon cycle
3. Nitrogen cycle
4. Phosphorus cycle
Web cd 37 f, g, h,
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Ecosystem Diversity
Coral reefs are among the most diverse and
productive marine ecosystems on Earth.
? How do animals take advantage of a CR?
? Why CR community is so rich in number
and kinds of organisms?
A: as a home, food, protection, growth
A: many opportunities for food, safety,
interactions, resources
Ecology 2010
Objectives • Identify two types of predator adaptations
and two types of prey adaptations
• Identify possible causes and results of
Interspecific competition
• Compare parasitism, mutualism,
commensalisms, and be able to give
examples
Ecology 2010
Species interactionsJust as populations contain interacting members of
a single species, communities contain
interacting populations of many species. Many
species have specific types of interactions with
other species. This chapter introduces the five
major types of interactions among species:
predation, competition, parasitism, mutualism,
commensalisms, These categories are based on
whether each species causes any benefit or
harm to the other species in a given relationship
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Predation• The relationship between a predator and a prey
• Predator eats the prey (snake eats mouse)
• Can affect how each species lives
1. Predator adaptations-
– Snakes have poor scent, have heat detectors
– Spiders spin webs
– Speed of cheetah
• Predators relies on if they can catch food and
prey relies on ability to not get caught
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Predation2. Adaptation in animal prey
• Ability to flee
• Chemical defenses
• Mimicry- resembles another species
- Batesian- harmless looks like deadly
- mullerian- 2 or more dangerous look similar (bees)
2. Adaptation in plant prey-
• sharp thorns, spines, sticky hairs
• Secondary cpds- chemical defense (poison ivy)
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Herbivore-Plant Relationships
– An interaction in which one animal (the herbivore) feeds on
producers (such as plants) is called herbivory.
– Herbivores, like a ring-tailed lemur, can affect both the size
and distribution of plant populations in a community and
determine the places that certain plants can survive and
grow.
– For example, very dense populations of white-tailed deer
are eliminating their favorite food plants from many places
across the United States.
Ecology 2010
Keystone Species Sometimes changes in the population of a single species, often
called a keystone species, can cause dramatic changes in
the structure of a community.
– In the cold waters off the Pacific coast of North America, for example,
sea otters devour large quantities of sea urchins.
– Urchins are herbivores whose favorite food is kelp, giant algae that
grow in undersea ―forests.‖
– A century ago, sea otters were nearly eliminated by hunting.
Unexpectedly, the kelp forest nearly vanished.
– Without otters as predators, the sea urchin population skyrocketed,
and armies of urchins devoured kelp down to bare rock.
– Without kelp to provide habitat, many other animals, including
seabirds, disappeared.
– Otters were a keystone species in this community.Ecology 2010
Ecology 2010
Competition1. Interspecific competition- type of interaction
in which two or more species use the same limited resources (plants and sunlight)
Web cd 37 A
2. Competitive exclusion- one species gets eliminated from the community due to resources
3. Reduce niche size- interactions with other species,
-fundamental- potentially use,
-realized niche- what is actually used
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The Competitive Exclusion
Principle – The competitive exclusion principle states that no
two species can occupy exactly the same niche in
exactly the same habitat at exactly the same time.
– If two species attempt to occupy the same niche,
one species will be better at competing for limited
resources and will eventually exclude the other
species.
– As a result of competitive exclusion, natural
communities rarely have niches that overlap
significantly.Ecology 2010
The Competitive Exclusion
Principle – In the experiment shown in the graph, two
species of paramecia (P. aurelia and P.
caudatum) were first grown in separate
cultures (dashed lines) . In separate cultures,
but under the same conditions, both
populations grew. When organism were put in
the same culture one species dies off.
– However, when both species were grown
together in the same culture (solid line), one
species outcompeted the other, and the less
competitive species did not survive.Ecology 2010
Ecology 2010
Competition4. Character displacement- evolution of
differences in a characteristic due to competition, way to reduce niche overlap, finches
5. Resource partitioning- when similar species coexist each species may avoid competition with others by using a specific part of an available resource (warbler eating insects at diff parts of tree)
Dividing Resources
– Instead of competing for similar
resources, species usually divide
them.
– For example, the three species of
North American warblers shown all
live in the same trees and feed on
insects.
– But one species feeds on high
branches; another feeds on low
branches, and another feeds in the
middle.
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Ecology 2010
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symbiosisClose long term relationship between two organism
3 major examples
1. parasitism- one is harmed/ one benefit• http://oldnewsbaby.com/site/click/8b0c2347f6ec462a9f82592cb0a664c7
• http://user.it.uu.se/~svens/larverna/normal.html
• http://www.neatorama.com/2006/08/21/six-horrifying-parasites/
2. mutualism- both benefits
3. commensalisms- one is helped/ one is
neither helped or harmed
Examples1. Tapeworms live in the intestines of mammals, where they absorb large
amounts of their hosts’ food.
– Fleas, ticks, lice, and the leech shown, live on the bodies of mammals
and feed on their blood and skin.
2. The sea anemone’s sting has two functions: to capture prey and to protect the
anemone from predators. Even so, certain fish manage to snack on anemone
tentacles.
The clownfish, however, is immune to anemone stings. When threatened by a predator,
clownfish seek shelter by snuggling deep into an anemone’s tentacles.
3. Barnacles often attach themselves to a whale’s skin. They perform no known
service to the whale, nor do they harm it. Yet the barnacles benefit from the
constant movement of water—that is full of food particles—past the swimming
whale.
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Ecology 2010
Objectives
• Describe the factors that affect species
richness in a community
• Explain how disturbances affect
community stability
• Distinguish between types of succession
and explain why succession may not be
predictable
Ecology 2010
Patterns in communities
The investigating of community properties and interactions is and active area of ecology. Which properties are most significant in structuring a community? What determines then umber of species in a community? How do communities recover from disturbance?
These questions are central to a study of communities.
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Species richness
• The number of species in a community,
simple count of population
• Species evenness- relative abundance of
each species, takes into account how
common each species is in the community
• Most study species richness
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Community stability and richness
• Disturbances- events that change the
community
• Stability- tendency of a community to
maintain relatively constant conditions
THINK ABOUT IT
– In 1883, the volcanic island of Krakatau in the Indian
Ocean was blown to pieces by an eruption. The tiny
island that remained was completely barren.
– Within two years, grasses were growing. Fourteen
years later, there were 49 plant species, along with
lizards, birds, bats, and insects. By 1929, a forest
containing 300 plant species had grown. Today, the
island is blanketed by mature rain forest.
– How did the island ecosystem recover so quickly?
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Succession- changes• Ecological succession- gradual regrowth of a
community of species
• Primary- development of a community in an
areas that has not supported life previously,
sand dune, rock Web cd 37 b
• Secondary- replace of species that follows the
disruption (soil is present)
• Pioneer species- small, grow quick, reproduce
quick, invade disturbed habitats
• Climax community- stable end pt
Primary Succession
– Volcanic explosions can create new land or sterilize
existing areas.
– Retreating glaciers can have the same effect,
leaving only exposed bare rock behind them.
– Succession that begins in an area with no remnants
of an older community is called primary succession.
Ecology 2010
Primary Succession – For example, in Glacier Bay, Alaska, a retreating
glacier exposed barren rock.
– Over the course of more than 100 years, a series of
changes has led to the hemlock and spruce forest
currently found in the area.
– Changes in this community will continue for
centuries.
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Primary Succession
– The first species to colonize barren areas are
called pioneer species.
– One ecological pioneer that grows on bare
rock is lichen—a mutualistic symbiosis
between a fungus and an alga.
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Secondary Succession Sometimes, existing communities are not completely destroyed by
disturbances. In these situations, secondary succession occurs.
• Secondary succession proceeds faster than primary succession, in part because soil
survives the disturbance. As a result, new and surviving vegetation can regrow
rapidly.
• Secondary succession often follows a wildfire, hurricane, or other natural disturbance.
• We think of these events as disasters, but many species are adapted to them.
Although forest fires kill some trees, for example, other trees are spared, and fire can
stimulate their seeds to germinate.
• Secondary succession can also follow human activities like logging and farming.
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Why Succession Occurs – Every organism changes the environment it lives in.
– One model of succession suggests that as one species alters
its environment, other species find it easier to compete for
resources and survive.
– For example, as lichens add organic matter and form soil,
mosses and other plants can colonize and grow.
– As organic matter continues to accumulate, other species
move in and change the environment further.
– Over time, more and more species can find suitable niches and
survive.
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Climax Communities– Ecologists used to think that succession in a given area always
proceeds through the same stages to produce a specific and stable
climax community.
– Recent studies, however, have shown that succession doesn’t
always follow the same path, and that climax communities are not
always uniform and stable.
– Ecosystems may or may not recover from extensive human-
caused disturbances.
– Clearing and farming of tropical rain forests, for example, can
change the microclimate and soil enough to prevent regrowth of the
original community.
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Ecosystems
Biomes
1. Tundra
2. Taiga
3. Temperate Forest
4. Tropical Rain Forest
5. Temperate Grasslands
6. Savanna
7. Chapparral
8. Desert
9. Ocean
- Intertidal zone
- Neritic zone
- Oceanic zone
10. Estuaries
11. Lakes and ponds
12. Rivers and streams
13. FW wetlands
Web cd 34 c, d
Defining Biomes
The map shows the locations of the major biomes.
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Weather and Climate– Weather is the day-to-day condition of Earth’s atmosphere.
– Climate refers to average conditions over long periods and is
defined by year-after-year patterns of temperature and
precipitation.
– Climate is rarely uniform even within a region. Environmental
conditions can vary over small distances, creating microclimates.
– For example, in the Northern Hemisphere, south-facing sides of
trees and buildings receive more sunlight, and are often warmer
and drier, than north-facing sides. These differences can be very
important to many organisms.
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Solar Energy and the
Greenhouse Effect – The main force that shapes our climate is solar
energy that arrives as sunlight that strikes Earth’s
surface.
– Some of that energy is reflected back into
space, and some is absorbed and converted into
heat.
Ecology 2010
Solar Energy and the
Greenhouse Effect – Some of the heat also radiates back into
space, and some is trapped in the
biosphere.
– The balance between heat that stays in
the biosphere and heat lost to space
determines Earth’s average temperature.
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Solar Energy and the
Greenhouse Effect – Earth’s temperature is largely controlled by
concentrations of three atmospheric gases—carbon
dioxide, methane, and water vapor.
– These ―greenhouse gases‖ function like glass in a
greenhouse, allowing visible light to enter but
trapping heat through a phenomenon called the
greenhouse effect.
Ecology 2010
Solar Energy and the
Greenhouse Effect – If greenhouse gas concentrations rise, they trap
more heat, so Earth warms. If their concentrations
fall, more heat escapes, and Earth cools.
– Without the greenhouse effect, Earth would be
about 30°C cooler than it is today.
Ecology 2010
