Transcript Populations

Ecology : Populations
Compare Exponential & Linear Population
Growth
***Unlimited Resources allow for this type of growth***
1. Exponential:
a. The population multiplies by the same
number every week/month/year.
b. If a population has a constant birth rate
through time and is never limited by
food or disease
c. Occurs when number of organisms
increases rapidly
d. Produces J-shaped curve on graph
2. Linear:
a. The population adds the
same number every
week/month/year.
b. Shows slow steady growth
c. Birth & death rates are
equal
d. Produces straight line on
graph
**Limited Resources cause this type of growth**
Limits to growth
• Limiting factors- a factor that causes population
growth to decrease
– Density independent: Usually are abiotic in nature; Any
factor in the environment that does NOT depend on the
members in a population per unit area. Drought, Human
disturbances
– Density dependent: Are usually biotic in nature; Any
factor in the environment that depends on the number of
members in a population per unit area. Competition,
Predation,Parasitism, Disease
Describe Carrying Capacity
Carrying Capacity
1. The number of organism that an environment
can support
2. Limits the population
3. Affected by: temperature, food supply,
reproduction, hunting
Describe Factors that affect population
size
1. Predation:
2. Competition:
a. Predators limit number
of prey
a. Compete for
resources
b. Pick out the sick, old,
young
b. Water, food, living
space, mates
3. Environmental
changes:
a. pollution, thermal
warming, unfit
water, disease, all
effect the
population number
Write this below your graphs on
IN: 44
• 4. Immigration- movement of organisms
into an area.
• 5. Emmigration- movement of organisms
out of an area.
Ex. Animals leave b/c they reach maturity,
Food shortage.
Siberian tiger
4. May cause species to become
threatened or endangered
Manatee
a. Threatened - when population
declines rapidly
b. b. Endangered - when numbers
are so low that extinction is
possible in near future
c. Extinction - disappearance of
species
Bald Eagle
Use of Resources
A. Compare types of resources
• Natural resource - part of natural environment
– EX: soil, water, crops, oil, gas, wildlife
• Renewable - replaced or recycled by natural
processes (Biodegradable)
– EX: plants, animals, crops, soil
• Nonrenewable - available in limited amounts
– EX: fossil fuels, metals
Ways to Sustain Agriculture-natural resources
Cover Crops
Legumes, grasses, and other
cover crops recycle soil nutrients,
reduce fertilizer need, and
prevent weed growth.
Contour Plowing
Contour plowing reduces
soil erosion from land runoff.
On hilly areas, plowing is done
across the hill rather than
straight up and down.
Controlled Grazing
By managing graze periods and herd
densities, farmers can improve nutrient
cycling, increase the effectiveness of
precipitation, and increase the carrying
capacity of pastures.
A
B
Yr. 1
Yr. 3
oats alfalfa
oats alfalfa
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Section:
C
Crop Rotation
Different crops use and
replenish different nutrients.
alfalfa By rotating crops, the loss
corn alfalfa (plowed in) of important plant nutrients
is decreased.
corn
Yr. 2
Biological Pest Control
The use of predators and parasites
to control destructive insects
minimizes pesticide use as well as
crop damage
corn
Species Diversity
Section 6-3
Insects
54.4%
Protists
4.2%
Other Animals
19.7%
Plants
18%
Fungi
3.4%
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Section:
Bacteria
0.3%
C. Identify major sources of air, water,
and land pollution
1. Pollution - contamination of any part of
environment
2. Air pollution
a. Caused most by burning fossil fuels
b. Particulates - solid soot particles, form smog
c. Can cause cancer, respiratory difficulties
3. Acid rain
a. Water mixes with carbon dioxide to form
carbonic acid
b. Damages plants, affects fish, contaminates water
c. More in cities and industrialized areas
Figure 6-12 The Formation of
Acid Rain
Section 6-2
Emissions to Atmosphere
Nitrogen oxides
Sulfur dioxide
Chemical Transformation
Nitric acid
Sulfuric acid
Condensation
Dry Fallout
particulates, gases
Industry
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Section:
Transportation
Ore smelting
Power generation
Precipitation
Acid rain, fog,
snow, and mist
4. Ozone depletion
a. Ozone layer - high in stratosphere; protects
Earth from U.V.
b. Depletion allows lethal doses of UV rays to reach
earth
c. Caused by CFC’s(chlorofluorocarbons),
styrofoam products, some aerosol sprays
5. Greenhouse effect causes global warming
a. Natural process that traps heat in atmosphere
b. Atmospheric gases (CO2, methane) prevent heat
from escaping into space
c. Process where heat is retained by gases in the
environment
d. Thought to be caused by combination of
different pollutants( car exhaust, etc)
*Due to excess pollution and forest
destruction the carbon cycle cannot
remove the gases fast enough!
The Greenhouse Effect
Section 4-1
Sunlight
Some heat
escapes
into space
Greenhouse
gases trap
some heat
Atmosphere
Earth’s surface
Go to
Section:
Figures 4-1 and 4-2 Heating of the Earth’s
Surface and Some Factors That Affect
Climate
Section 4-1
Greenhouse Effect
Different Latitudes
90°N North Pole
Sunlight
Sunlight
Some heat
escapes
into space
Greenhouse
gases trap
some heat
Arctic circle
Sunlight
Most direct sunlight
66.5°N
Tropic of Cancer
Equator
0°
Tropic of Capricorn 23.5°S
Sunlight
Atmosphere
Arctic circle
Earth’s surface
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Section:
23.5°N
Sunlight
66.5°S
90°S South Pole
6. Water pollution
a. Sewage, industrial wastes, fertilizer runoff
b. Contaminates groundwater (soil doesn't filter out
contaminants)
7. Land pollution
a. Trash is burned or buried instead of being
recycled
b. Biodegradable - wastes broken down naturally
c. Nonbiodegradable - stay in environment for 100's
to 1000's of years
Figure 6-16 Biological
Magnification of DDT
Section 6-3
Magnification of
DDT Concentration
Fish-Eating Birds
10,000,000
DDT-A chemical
banned in the 1970’s
Large
Fish
1,000,000
Small Fish 100,000
Zooplankton 10,000
Producers 1000
Water
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Section:
1
Concept Map
Section 6-1
Human
Activities
that have changed the biosphere include
Hunting and
gathering
may have once caused
Industrial
growth
Agriculture
often relies on the methods of the
Extinctions of
large animals
Green
revolution
Food supply
Go to
Section:
Pesticide use
have resulted in
High standard
of living
which increased
Monoculture
use
Urban
development
Increased
pollution
1. Examine the list of natural resources
shown below. Then, classify each
natural resource as either renewable or
nonrenewable.
a. Wood
b. Fossil fuels
c. Aluminum
d. Wool
e. Gold
2. Describe the impact that the loss of
nonrenewable resources would have on the
environment.
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Section:
Interest Grabber continued
Section 6-4
• Rank the following items in order of their
importance to you. Then, next to each item,
write down how much you would be willing
to pay for it.
• 1. Fresh, clean drinking water
• 2. Clean air to breathe
• 3. An endangered plant containing a
substance that can cure cancer
Go to • 4. Gas for your family car
Section:
• Remember the
importance of the Water,
Carbon and Nitrogen
Cycles to ensure a healthy
environment.
Fig 3-11 The Water Cycle
Section 3-3
All living things require
water to survive. Where
does it all come from?
Evaporation
Condensation
Precipitation
Transpiration
Runoff
Seepage
Root
Uptake
It moves between the ocean,
atmosphere, and land.
This figure shows how water molecules can change forms and be
used through evaporation (change from liquid to gas) and transpiration
Go(by
to evaporating from the leaves of plants).
Section:
Figure 3-13 The Carbon Cycle
Section 3-3
Carbon is especially important
to living systems because it is
the key ingredient in all living
organisms.
Carbon is found
in the oceans, in the air, and
in certain types of rocks.
This figure shows how these
processes move carbon through
the biosphere.
Go to
Section:
CO2 in
Atmosphere
CO2 in Ocean
Figure 3-14 The Nitrogen Cycle
Section 3-3
N2 in Atmosphere
All organisms require nitrogen to
make amino acids,
which in turn, are
used to build
proteins.
NH3
NO3and NO2-
This figure shows how the different forms of nitrogen cycle through
The biosphere.
Go to
Section:
Nitrogen Cycle
Is driven primarily by the activities of unicellular organisms
in the soil and
oceans.
1. Nitrogen is in the atmosphere all the time.
2. Bacteria change the nitrogen into nitrates, which is a kind of natural fertilizer taken in by
the roots of plants and trees and used to build plant protein.
3. Animals then eat the plants with protein in them
4. Animal and plant waste then releases protein into the soil through decomposition.
5. Finally, more kinds of bacteria break down plant protein to a form that releases nitrogen
back into the atmosphere.