Transcript Interdependence of Living Things Unit

Interdependence of
Living Things
The
Biosphere
Ecosystems and Communities
Populations
Humans in the Biosphere
The Biosphere
What is ecology?
– study of interactions among and
between organisms and their environment
 Biosphere – contains the combined
portions of the earth in which all life exists
 Ecology

8 km above Earth’s surface  11 km below
the ocean surface
 Levels

of organization:
Individual  population  community 
ecosystem  Biome  Biosphere
Energy flow

Producers
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Main form of energy on Earth = sunlight
Capture energy from sunlight (photosynthesis) or
from chemical energy (chemosynthesis) = producers
Autotrophs = capture energy from sunlight to make
food (photosynthesis)
Consumers

Rely on other organisms for energy and food (cellular
respiration) = “heterotrophs” or “consumers”
Feeding Relationships

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Energy flows from producers to various heterotrophs
Food chain

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Food web

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Energy is transferred by eating and being eaten
Links all the food chains in an ecosystem together
Trophic level
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Each step in a food chain or web
Producers are the first trophic level
Consumers make up the 2nd, 3rd, or higher levels
Each consumer depends on the level below for energy
Energy Pyramid

Only 10% of the
energy available
within one tropic level
is transferred to the
next
 The rest of the energy
is used during cellular
processes and
escapes as heat!!!
Biomass Pyramid

Total amount of living
tissue within each
trophic level
 grams of organic
matter/ unit area
 Potential food for
each level
Pyramid of Numbers

Number of
individuals at each
trophic level
Toxins that do not follow the
flow of energy model
Bioaccumulation
• This happens when a
top predator consumes
organisms that have a
small amount of toxin
in their bodies, but
over time, that toxin
builds up to harmful
levels in the top
predator.
Biomagnification
• This happens when an
organism has a small
amount of toxin in its
system and when
consumed, it passes all
of that toxin to the
next organism.
• The cycle continues
up the food chain.
Recycling in the Biosphere
 Matter
is recycled within and between
ecosystems
 Matter is not used up…it is transformed!!!
 Matter is recyled through biogeochemical
cycles:
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Water cycle
Nutrient cycles (carbon, nitrogen,
phosphorus)
The Water Cycle
 gas (evaporation)
 Evaporation from plants = transpiration
 Water is recycled through the Biopshere
 1 water molecule  4000 years to
complete one cycle
 Liquid
Nutrient Cycles
 Living
things need nutrients to grow and
carry out essential life functions.
 Nutrients are often in short supply in an
ecosystem
 Recycling nutrients is vital to ecosystem
health
 Prevents toxic concentrations of chemicals
Ecosystems and
Communities
The Role of Climate
Weather  day-to-day local condition of Earth’s
atmosphere
 Climate  average, year-after-year condition of
temperature and precipitation in a particular
region
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
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Factors include: trapping of heat by the atmosphere,
the latitude, the transport of heat by winds and ocean
currents, the amount of precipitation that results, the
shape and elevation of landmasses
Energy of sunlight is the ultimate driver of climate
Biomes
 Each
biome is defined by a
unique set of:
1.
2.
abiotic factors (particularly
climate)
a characteristic ecological
community
Climatograms
 Create
a climatogram using data from
South Kingstown RI

What biome do we belong to?
 Compare
our climatogram to the Biome
you have been working with.

Prompt: Compare the climatogram for South
Kingstown (temperate forest biome) to the Biome you
have been studying. How are they similar? How are
they different? Use specific evidence to support your
response.
The Greenhouse Effect

Carbon dioxide,
methane, water
vapor, and
other gases 

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Trap heat
energy
Maintains
Earth’s
temperature
range
Effect of Latitude on Climate

The Earth is tilted on its axis!
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Solar radiation strikes different regions of the Earth’s
surface at an angle
THUS, Earth has 3 main climate zones:
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Polar zone  very low angle (cold areas – 66.5° –
90° N and S)
Temperate zone  angle changes over the year
(warm and cold areas – 23.5° – 66.5° N and S)
Tropical zone  nearly direct angle (always warm 0° - 23.5° N and S)
Heat Transport in the Biosphere

Unequal heating of Earth’s surface drives winds and
ocean currents
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Wind currents
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Warm air rises, cool air sinks
The prevailing (global) winds affects the climate in a given region
Ocean currents
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Transport heat throughout the biosphere
Warm water rises, cool water sinks
The global ocean currents affects the climate of nearby
landmasses
Landmasses
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Mountain ranges can interfere with air mass movement
Rain shadow effect  one side is wet and the other dry
Biotic and Abiotic Factors that
Shapes Ecosystems
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Biotic Factors
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Abiotic Factors
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Biological influences on organisms within an
ecosystem
Includes the entire living cast of characters with which
an organism might interact
Physical or nonliving influences that shape
ecosystems
Includes: temperature, precipitation, humidity, wind,
nutrient availability, soil type, sunlight
TOGETHER (Biotic and Abiotic factors)
“Habitat” of an organism
The Niche
 The
full range of biotic and abiotic
conditions in which an organism lives and
uses those conditions.

Example: It’s place in the food web, the
range of temperatures needed for survival, etc.
 No
2 species can share the same niche!!!
Community Interactions
interact constantly  shapes
ecosystems
 3 main types =
 Organisms
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Competition
Predation
Symbiosis
• Mutualism
• Commensalism
• Parasitism
Competition
 Occurs
when a resource is being used at
the same time in the same place.
 Resource = any necessity of life (water,
nutrients, light, food, or space)
 Often results in a winner and a loser.
 Competitive Exclusion Principle:

No 2 species can occupy the same niche in
the same habitat at the same time.
Predation
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Interaction where one organism captures
and feeds on another organism
 Predator = one that does the killing
 Prey = one that is being eaten
Symbiosis
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Any relationship in which 2 species live closely together
(3 main types)
Mutualism:
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Commensalism:
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Both species benefit from the relationship
Example = flower pollination by insects
One member of the relationship benefits and the other is neither
helped nor harmed
Example = barnacles on whales
Parasitism:
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One organism lives on (ectoparasite) or inside (endoparasite)
another organism and harms it.
Example = fleas on a dog
Ecological Succession
 Ecosystems
constantly change in
response to natural and human
disturbances
 As an ecosystems changes  older
inhabitants gradually die out and new
organisms move in = “ecological
succession”
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Primary succession
Secondary succession
Primary Succession
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Succession that occurs on surface with NO soil
 Example = on newly formed volcanic rock or on
bare rock exposed when glaciers melt
 1st species to populate = pioneer species
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Lichens (a fungus and an alga simbiont can live on
bare rock)
When they die lichens help form soil that allows new
organisms to move in
Lichens  mosses  grasses  shrubs  trees
• What types of animals would you see at each stage?
Bare rock with lichens
Secondary Succession

When a disturbance of some kind changes an
existing community WITHOUT removing the soil
 Example: land is cleared for farming, a wildfire
burns a woodland
 Myth of the climax community (a mature, stable
community that does not undergo further
succession)
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No community is ever at this point
Climate change and human disturbances are always
at work.
Populations
Homework: Ch.5 vocab flashcards
How Populations Grow
 Characteristics

of Populations:
Geographic distribution (range) –
• The area or range inhabited by a population

Population density –
• The number of individuals per unit area

Growth rate –
• Determined by # of births, # of deaths, #
immigrated, # emigrated
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Age structure –
• The range of ages in a population
Population Growth
 Factors
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that affect population size:
# of births  causes an increase in population
size
# of deaths  causes a decrease in
population size
Immigration (the movement of individuals into
an area)  causes an increase
Emigration (the movement of individuals out
of an area)  causes a decrease
Exponential Growth
growth  occurs when the
individuals in a population reproduce at a
constant rate
 Occurs only under ideal conditions
 Exponential
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Abundant space and food
Protected from predators and disease
 J-shaped
curve
Logistic Growth
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As resources become scarce, the growth of a
population slows or stops

Birth rate may decrease, death rate may increase,
immigration may increase, emigration may decrease,
or any combination of these.
Carrying capacity  the largest # of individuals
that a given environment can support
 S-shaped curve

Population Trends
Fruit Fly Population Growth
Rabbit Population Growth
Days
Generations
# of fruit flies
# of rabbits
5
10
1
100
10
50
2
105
15
100
25
1000
20
200
37
1600
25
300
55
2400
30
310
72
3350
35
320
86
8000
40
320
100
13,150
1. Make a graph of each data table.
Population Trends: Data Analysis
Answer the following in your notebooks!!!

What type of growth pattern is exhibited by the
fruit fly population? Is it the same as the rabbit
population? Explain.
 Does either graph indicate there is a carrying
capacity? If so…when? What is the maximum #
of individuals that can be supported at one time?
 What might happen if a group of predators
moved into the rabbits’ habitat during the 10th
generation and began eating rabbits?
Limits to growth
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Limiting Factors:
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In context of populations
A factor that causes population growth to decrease
Density-dependent OR Density-independent
Examples that affect population size:
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Competition
Predation
Parasitism and disease
Drought and other climate extremes
Human disturbances
Density-Dependent Factors
 Depends

on population size
Factor only becomes limiting when the
population density reaches a certain level
 Includes:
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Competition
Predation
Parasitism
Disease
Competition
 When
populations get crowded, they
compete for food, water, space, sunlight,
and other essentials of life (resources
become scarce).
 Major force behind evolutionary change!
 Can occur:
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Between members of the same species
Between different species
Predation
 In
nature, populations are often controlled
by predators
 Predator-prey relationship

Interactions that affect population growth of
both predator and prey
 Example:

Remember the Wolf and deer population
activity
Parasitism and Disease
 Parasites
range in size
 Similar to predators
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Take nourishment at the expense of the host
(causing disease and/or death)
 Example:
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

WOW bug pets
They lay their eggs on a larva
The eggs hatch and consume the larva
Density-Independent Factors
 Affects
different populations the same way
regardless of population size
 Examples include:
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Unusual weather
Natural disasters
Seasonal cycles
Human activity
Human Population Growth
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The size of the human population has grown over
time.
Human Population Videos
World Population
growth from 1 A.D.
Exponential Growth
lecture
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Produced by Population
Connection in 2000. Population
Connection is a nonprofit,
501(c)(3) organization
David

http://www.youtube.com/watc
h?v=4BbkQiQyaY
Suzuki “Forces of nature”
– speaking about exponential
growth
http://www.youtube.com/watch?
v=Q9xoFCS33kg
Patterns of Human Population
Growth
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Demography
 Study of human populations
The Demographic Transition
 When population growth in a country has slowed in
response to industrialization.
 Transition is complete when birthrate falls to meet
deathrate (population growth stops)
• More children survive to adulthood, more adults
living to old age
rd world countries have yet to undergo this process
 3
Age Structure
 Population profiles (# of people in different age
groups)
Humans in the
Biosphere
Ch. 6 vocab flashcards
Earth as an Island
 We
share a limited resource base
 We all depend on the natural ecological
processes that sustain these resources
 Take the earth calculator test now…
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How many earth’s do you need if everyone
lived like you?
Is it fair to use resources the way you do?
What are some ways you could decrease
your impact?
Human Activities that have
transformed the Biosphere
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Hunting and gathering
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Subsistence hunting
Agriculture
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Domestication of animals (overgrazing, increased
water use)
Traditional  Modern Agriculture (increased
irrigation, increased use of chemical fertilizers, new
types of farming equipment)
Green Revolution  governments introduced new,
intensive farming techniques to increase yields.
• “miracle strains”: improved harvest
• Monoculture: a single crop/species was planted to increase
yield
Industrial Growth and Urban
Development
 Certain

Pollute air, water, and soil
 Dense

kinds of industrial processes:
human communities:
Produce wastes that must be disposed of
 Suburban

sprawl:
Consumes farmland and natural habitats
 All
place stress on plant and animal
populations and on the biosphere’s life
support systems!!!
The Tragedy of the Commons
 “Any
resource that is open to everyone
(air or ocean) will eventually be destroyed
because everyone can use it but no one is
responsible for preserving it.”
 Constructed Response Prompt:
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
(On the provided handout - write approx. ½ 1 page)
In your opinion is the “tragedy of the
commons” true? Use evidence/quotes from
the reading to support your answer.
Renewable vs. Nonrenewable
Reources
 Work
with a partner.
 Using your book or the computer:
 Generate a list of 10 renewable
resources and 10 nonrenewable
resources.
Sustainable Use

With your partner choose one of the following
resources:
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Land
Forest
Ocean
Air
Water
What are some ways to use these resources in a
sustainable way?

You have 20 minutes to put together a 1 minute
presentation on the topic.
Biodiversity
 “Sum
total of the genetically based variety
of all organisms in the biosphere”
 One of the Earth’s greatest natural
resources
 Includes:
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Ecosystem diversity
Species diversity
Genetic diversity
Threats to Biodiversity
 Human
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Activity can reduce biodiversity by:
Altering habitats through development
Hunting species to extinction
Introducing toxic compounds into food webs
• Failing septic systems (our water quality lab!!!)
• DDT (biological magnification)– Rachel Carson’s
book Silent Spring

Introducing foreign species into new
environments (invasive species)
Charting a Course for the Future
2
major global phenomena affect the
biosphere:

Ozone depletion
• UV light is a mutagen!

Global Warming
• Caused by a natural warming trend AND Human
activity!!!