ecology. keep this in mind… in california… los angeles, oct. 31 — a 10-year-old boy admitted...
TRANSCRIPT
Ecology
Keep this in mind…
In California…LOS ANGELES, Oct. 31 — A 10-year-old
boy admitted that he accidentally started one of the largest of last week’s Southern California wildfires while playing with matches, enforcement officials say.
Fanned by high winds and hot, dry weather, it spread quickly, driving 15,000 people from their homes, destroying 21 houses and 22 other buildings, injuring three people and blackening more than 38,000 acres
In Iceland…
Volcano in Iceland erupted twice in one month. The volcano has erupted for the second time in less than a month, melting ice, shooting smoke and steam into the air and forcing hundreds of people to flee rising floodwaters. The volcanic ash has forced the cancellation of many flights and disrupted air traffic across.
SUCCESSION
• What happens to an area after a disturbance?A predictable set of stages begins to change
the areaThe changes are plant based; referred to as
ecological succession.
• What does it mean if you call someone a successor?
EXAMPLE: The prince is the king’s successor.
Ecological Succession
Natural, gradual changes in the types of plant species that occupy an area
You have studied pond succession!
Primary Succession
occurs on an area of newly exposed rock, sand, lava or any area that has not been occupied previously by a living (biotic) community
Secondary Succession
takes place where a community has been removed, i.e. a plowed field, clear cut forest, forest fire
Complete the Succession WS
What is a pioneer species? What is a climax community?
Do Now
What type of succession would occur on this land?
If a fire occurred 100 years into succession of this land what type of succession would occur?
HAND IN!
Population
Populations are dynamic!
3 important characteristics of populations: geographic distribution, density and growth rate
What is density?
1. 2.
3. 4.
Nutrients can limit plant growth
Plant life grows best when all nutrients are present
Not present? Limited nutrient
Animals have limiting factors that affect growth as well: Density-dependent factors Density-independent factors
Factors that influence density…
Other Limiting Factorsenvironmental influences that prevent
species from obtaining a high population: generally populations decrease in size
Two categories: Density-dependent limited factors Density-independent limited factors
Density-dependent factor
Density-dependent factors- affects populations due to their size
Example- predation
Density-independent factors
Density-independent factors- affects all populations in similar ways, regardless of population size
Example- hurricane
Density-dependent or density-independent?
CompetitionEarthquakeFloodParasitismDiseaseSeasonal cyclesAvailable mates
Do Now
Define population density. Label each factor as d.dependent or
d.independent: Territory (available space) Food tornado
Population Growth
Three factors affect population size Number of births Number of deaths Number of individuals that enter or leave the
population
Immigration: movement of individuals into an area
Emigration: movement of individuals out of a population
Population
Exponential Growth (J-shaped graph)
Logistic Growth (S-shaped graph)
Exponential Growth
Under ideal conditions with unlimited resources, a population will grow
Industrial revolution: 1820-1870
Current population: ~6 billion
Exponential growth faces problems…
Exponential growth does not continue in natural populations for very long
As resources become less available, the growth of a population slows or stops
Logistic Growth
Acceleration, high growth period, deceleration, fairly steady state
Carrying capacity
the number of individuals who can be supported in a given area within natural resource limits
Carrying capacity- K
Carrying capacity
Patterns of Population Growth
Human population cannot keep growing exponentially forever because Earth and its resources are limited…
Study of human population is demography Birthrate, death rates and the age structure of a
population help predict population increases and decreases of countries
Age-structured diagrams
Population pyramid
Birth vs death rate within a population
US population pyramid
Human limits?
World Resources
Renewable
Nonrenewable
Renewable Resources
A resource that can be continually reproduced
Capable of being replaced by
- natural ecological cycles or- sound management practices
humans need to think of "renewable" asreplenishable only in the right circumstancesand within the laws of the balance of nature
Do NOT Think…
"Oh well, it's renewable so we can use as much as we want"
"It's OK to log these forests- trees grow back”
"Industries can pull all the water they want from the Great Lakes, without limitation. After all, water is a renewable resource, like air."
Renewable" resources become non-renewable due to mis-management by humans and pollution of the environment by humans.
What are examples of renewable resources?
trees, wildlife, oxygen, and fresh water
Nonrenewable Resources
A resource that cannot reproduce
Once the resource is used up- it is gone Humans are using up natural resources at a great rate
and at a great cost to the health of the natural environmentand life on Earth.
What do humans use A LOT of? (think carbon cycle)
Nonrenewable Resources
Fossil fuels- oil, natural gas, coal
How do they form?How long does it take for these resources to
form?
The world at night from space
Human Impact
Acid Rain
What it is, where does it come from and what damage can it cause?
What is acid rain?
Acid rain is rain that is lower on the pH scale than normal rain water…
Acid rain carries the chemicals sulphur dioxide and nitrogen oxide
pH may vary: 5.5 to 3.0 (normal water is ~7-5.6) (ocean water ~7-8)
Acid rain cycle
Damage from acid rain
Lakes and streams are normally acidic, acid rain can make them so acidic that it damages animal and plant life.
Acid rain can cause a mass killing to trees.Area's can become very hazy and foggy due
to acid rainlinked to breathing and lung problems in
children, and people who have asthma. Stone buildings and monuments are targets
of damage from acid rain.
Damage of acid rain
Acid "rain" isn't just rain; acid snow, acid fog or mist, acid gas, and acid dust all have the same effect as acid rain.
So much pollution!!! (don’t write, just read)
40% of America’s rivers and 46% of America’s lakes are too polluted for fishing, swimming, or aquatic life
1.2 trillion gallons of untreated sewage, storm water, and industrial waste are discharged into US waters annually.
Polluted drinking waters are a problem for about half of the world’s population. Each year there are about 250 million cases of water-based diseases, resulting in roughly 5 to 10 million deaths.
Each year, U.S. factories spew 3 million tons of toxic chemicals into the air, land, and water.
Every year, one American produces over 3,285 pounds of hazardous waste.
Seventy-three different kinds of pesticides have been found in groundwater, which is potential drinking water
Over 80% of items in landfills can be recycled, but they’re not.
What should be recycled?
NOT GUM!!! Plastic bottles, cans, paper, card board
Pollution…
Biomagnification
Humans use of DDT (Dichloro-diphenyl-trichloroethane)
insecticide and pesticide (world-wide use)30 years prior to its cancellation, a total of
approximately 1,350,000,000 pounds of DDT was used domestically
DDT is a persistent, toxic chemical which easily collects in the food chain posing a proven hazard to non-target organisms such as fish and wildlife and otherwise upsetting the natural ecological balance
Biomagnification
Prime example of a non-target animal that was hurt by the use of DDT
The bald eagle-
What can be done to help?
RecycleTurn off electronicsTake shorter showersEducate yourself!
ALTERNATIVE ENERGY
Alternative Energy
The Alternative Energy Institute (AEI) was formed in 1977 at West Texas State University, Texas, USA
Consequences are minimalrenewable and are thought to be "free"
energy sourceslower carbon emissions, compared to
conventional energy sources
Alternative Energy
These include Biomass Energy, Wind Energy, Solar Energy, Geothermal Energy, Hydroelectric Energy sources
Alternative energy
Human Impact
What is the differences and similiarities between… Ozone layer depletion Greenhouse effect Global warming
Ozone layer
Affects earths climateGas that occurs naturallyvital role by shielding humans and other life from harmful ultraviolet light from the Sun
Ozone depletion
chemicals, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs)
Depleted protective layerInternational agreement to limit emissions
Greenhouse effect
Affects earths climate, especially temperaturePositive and natural occurrenceGreenhouse gases: such as water vapor,
carbon dioxide, ozone and methaneGreenhouse gases slow down the rate at
which heat is released back into space
Too much of these gases is a bad thing!
Greenhouse effect
Global warming
Affects the earths climate Especially temperature! Not only in the air but on land
Overabundance of greenhouse gases higher temperature
Burning of fossil fuel, deforestationPossible effects of global warming:
Melting ice results in water level rising Stronger hurricanes Ice age More drastic weather cycles