unit 2 – life on earth (ecology) part 1
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Ch.4. Unit 2 – Life on Earth (Ecology) Part 1. Human Population & the Environment. Why has human population grown so rapidly in the last 100 years? expansion of agriculture and industrial production and lower death rates from improvements in hygiene and medicine. - PowerPoint PPT PresentationTRANSCRIPT
Unit 2 – Life on Earth (Ecology) Part 1
HUMAN POPULATION & THE ENVIRONMENT
Ch.4
Why has human population grown so rapidly in the last 100 years?
– expansion of agriculture and – industrial production and
– lower death rates from improvements in hygiene and medicine.
o In 2006, the population of
developed countries grew exponentially at 0.1% per year. oDeveloping
countries grew 15 times faster at 1.5%
per year.
Why do the populations in developed countries grow more
slowly than in developing countries?
– more educational opportunities for women leads to more women in the
workforce and a delay in 1st childbearing
– Increased awareness of birth control
Unit 2 – Life on Earth (Ecology) Part 1 Ch.4
Unit 2 – Life on Earth (Ecology) Part 1
POPULATION AGE STRUCTURE Ch.4
oUsed to make population & economic projections
What do each of these structures
indicate?
Populations with a large proportion of its people in the preproductive ages (1-14) have a
large potential for rapid population growth.
Unit 2 – Life on Earth (Ecology) Part 1
EXPONENTIAL VS. LOGISTIC GROWTH Ch.4
No population can grow exponentially indefinitely.
Logistic Growth Curveo “S” shaped
oPop. Growth slows as it reaches carrying capacity
Logistic Carrying Capacity
oBirth rates = Death ratesoNo net change in
population
Unit 2 – Life on Earth (Ecology) Part 1
EXPONENTIAL VS. LOGISTIC GROWTH Ch.4
If a country has a CBR of 21 per 1000 and a CDR of 7 per 1000, the natural annual percent increase of its
population isa) .3%b) 1.4%c) 3%
d) 14%e) 28%
21/1000 – 7/1000 = 14/1000 = 1.4/100 = 1.4%
Unit 2 – Life on Earth (Ecology) Part 1
A DECLINING POPULATION CAN CAUSE PROBLEMS AS WELL:
Ch.4
Which of these problems do you believe are the
most important?
Unit 2 – Life on Earth (Ecology) Part 1
REPRODUCTIVE STRATEGIES
Ch.4
r-strategists (opportunists) Large number of smaller offspring with little parental care (populate quickly but little ability to compete at K).
K-strategists (competitors) Fewer, larger offspring with higher invested parental care (populate slowly but able to compete at K).
r (population growth). K (carrying capacity)
Unit 2 – Life on Earth (Ecology) Part 1
DEMOGRAPHIC TRANSITIONCh.4
As countries become economically developed, their birth and death rates tend to decline.
Population Momentumwhen total fertility
declines, there is a lag period before the rate of
natural increase declines. This is due to all the people already at
reproductive age
Unit 2 – Life on Earth (Ecology) Part 1
Biogeochemical CyclesCh.5
The complete path a chemical takes through the four major components – or reservoirs – of Earth’s systems
– or sinks –
Unit 2 – Life on Earth (Ecology) Part 1
Biogeochemical CyclesCh.5
Limiting Factors
Macronutrients
Micronutrients
S P O N C HRequired by all life
Required in small amounts by all life or in moderate amounts by some living things.
Na K CaWhen elements are not available at the right times, in the right amounts and in the right concentrations relative to each other
Unit 2 – Life on Earth (Ecology) Part 1
Geologic CycleCh.5
Tectonic HydrologicRock
The processes responsible for formation and
change of Earth materials
Unit 2 – Life on Earth (Ecology) Part 1 Ch.5
Geologic Cycle
Tectonic HydrologicRock• Divergent plate boundary:
– Occurs at a spreading ocean ridge, where plates are moving away from one another
– New lithosphere is produced (seafloor spreading)
• Convergent plate boundary– Occurs when plates collide
• Produces linear coastal mountain ranges or continental mountain ranges
• Transform fault boundary– Occurs where one plate slides past
another• San Andreas Fault in California
Unit 2 – Life on Earth (Ecology) Part 1 Ch.5
PrecipitationPrecipitation
Transpiration
Condensation
Evaporation
Ocean storage
Transpiration from plants
Precipitation to land
Groundwater movement (slow)
Evaporation from land Evaporation
from ocean Precipitation to ocean
Infiltration and Percolation
Rain clouds
RunoffSurface runoff
(rapid)
Surface runoff (rapid)
Geologic Cycle
Tectonic HydrologicRock
Unit 2 – Life on Earth (Ecology) Part 1 Ch.5
Hydrogen sulfide
Sulfur
Sulfate salts
Decaying matter
Animals
Plants
Ocean
IndustriesVolcano
Hydrogen sulfide
Oxygen
Dimethyl sulfide
Ammoniumsulfate
Ammonia
Acidic fog and precipitationSulfuric acid
WaterSulfurtrioxide
Sulfur dioxide
Metallicsulfide
deposits
Ecosystem CyclesSulfur – component of the amino acids methionine & cystein
H2S
H2S
(CH3)2S
SO2
SO3
H2SO4
(NH4)2SO4
Na2SO4
Unit 2 – Life on Earth (Ecology) Part 1
Carbon – base of all organic molecules
Ch.5
Burning fossil fuels
Volcanoes
Cellular respiration
Sedimentation
Weathering/ Erosion
Cellular respiration
PhotosynthesisPhotosynthesis
Diffusion
Unit 2 – Life on Earth (Ecology) Part 1
Global Chemical CyclesCh.5
Carbon
Nitrogen
Phosphorus
Gaseous nitrogen (N2)in atmosphere
Ammonia, ammonium in soil Nitrogen-rich wastes,remains in soil
Nitrate in soil
Loss byleaching
Loss byleachingNitrite in soil
Nitrification
Nitrification
Ammonification
Uptake by autotrophsUptake by autotrophs
Excretion, death, decomposition
Loss bydenitrification
Food webs on land
Fertilizers
Nitrogen fixation
NO2
NO3
NH3 NH4
Nitrogen – required for DNA and all amino acids
Unit 2 – Life on Earth (Ecology) Part 1
Phosphorus – used in the structure of ATP
Ch.5
Dissolvedin Ocean
Water
Marine Sediments Rocksuplifting overgeologic time
settling out weatheringsedimentation
LandFoodWebs
Dissolvedin Soil Water,Lakes, Rivers
death,decomposition
uptake byautotrophs
agriculture
leaching, runoff
uptake byautotrophs
excretion
death,decomposition
mining Fertilizer
weathering
Guano
MarineFoodWebs
Unit 2 – Life on Earth (Ecology) Part 1
What is an ecosystem?
Ch.6
Ecosystem & Ecosystem Management
All of the biotic & abiotic factors in an area capable of sustaining life
Matter cycles and energy flows through an ecosystem
An ecosystem changes over time (ecological succession)
Unit 2 – Life on Earth (Ecology) Part 1
Energy Flow in Ecosystems
Ch.6
Unit 2 – Life on Earth (Ecology) Part 1
Keystone Speciesis one whose impact on its community or
ecosystem is disproportionately large relative to its
abundance
Ch.6
Food Web
X
X
Unit 2 – Life on Earth (Ecology) Part 1 Ch.6
Ecosystem Servicesprocesses by which the environment produces resources.
These services are extensive and diverse … affecting the quality of our land, water, food, and health.
All life depends upon the goods & services that ecosystems
provide.These include:• Water filtration• Groundwater recharge• Storm-water control• Air purification• Nutrient recycling• Crop pollination• Soil enrichment
Unit 2 – Life on Earth (Ecology) Part 1 Ch.6
Humans have profoundly impacted the environment in many ways.
(a) Describe human impact in the context of an ecosystem.
(b) Why would it be wise to make every attempt preserve each element of an ecosystem?
(c) What is the underlying cause for this tremendous human impact?(i.) What demographic factors affect the underlying
cause mentioned in c.
Unit 2 – Life on Earth (Ecology) Part 1 Ch.6
Humans have profoundly impacted the environment in many ways.
(a) Describe human impact in the context of an ecosystem.
Full Points: • altering biogeochemical cycles with 2-3 specific
examples• removal of keystone species
Unit 2 – Life on Earth (Ecology) Part 1 Ch.6
Humans have profoundly impacted the environment in many ways.
(b) Why would it be wise to make every attempt preserve each element of an ecosystem?
Full Points: • Discussion of keystone species with a specific
example• Discussion of ecosystem services with 2-3 specific
examples
Unit 2 – Life on Earth (Ecology) Part 1 Ch.6
Humans have profoundly impacted the environment in many ways.
(c) What is the underlying cause for this tremendous human impact?
Full Points: • Exponential human population growth
(i.) What demographic factors affect the underlying cause mentioned in c.
Full Points: • Discussion of Industrialization effect on Birth Rates, &
Death rates