Part 1 Review
APES year in review
2009
Easter Island
Easter Island– flourishing population of
10,000+ used up islands trees faster than they
could regenerate. Without trees, islanders
couldn’t build canoes, fish, build homes, etc.
People starved and within 300 years, only
2000 remained
Sustainability
- A system/process can
continue indefinitely without
depleting resources used.
*no sacrifice to future
generations*
Scientific Method
You may be asked to set up an experiment.
1. Define the problem (?) One that is testable.
2. Research
3. Hypothesis
4. Experiment
-Variable (s)
- Independent- (tested) * only one.
- Dependent (measured)
•Valid – measures what it was intended to.
•Reliable- repeatable
5. Collect Data
– Quantitative- numbers
–-Qualitative- appearance
6. Conclusion
7. Report
(Need large trial groups)
10 +
Ecosystems
Levels of organization of matter
Universe
Ecosphere/biosphere
Ecosystems
Communities
Populations
Organisms
Cells
Atoms
Ecosystems
Plants and animals interacting with their abiotic
environment. Ecosystems exist in biomes.
• Climate – av. temperature over time
•*Weather – daily variations in temp and precipitation
• Microclimate and Other Abiotic Factors
* Light intensity
* Soil type
* Topography
Trophic Relationship
Food webs
• Trophic levels
* producers
* herbivores
*primary carnivores
Biomass and Biomass Pyramid
• All biomass gets its energy from the sun
• Only 10% of energy from one trophic level moves
to the next trophic level
• Energy released is high potential energy
molecules (like glucose) then converted to low
potential energy molecules (like carbon dioxide)
* concept of eating lower on the biomass pyramid
Ecosystem Diversity
• Biodiversity depends on: latitude
(tropical is most diverse, polar is lowest .
•
Depth in aquatic systems – diversity increases to ~ 2000m,
then declines (in aquatic, diversity declines w/pollution)
Species
• Generalist species (R-species) have broad niches, and can
survive in many places, a Specialist pecies (K-species)
has a narrow niche, and can only survive under certain
conditions.
• Keystone Species -species are more important than biomass
suggests (ex: flying foxes/bat pollinate plants, elephants
uproot trees creating forest openings, beaver dams) =
stabilizing effect on ecosystem
– Loss can lead to domino effect – loss of more and
more species
• Indicator Species- indicates environmental changes.
* frogs- water pollution.
•
Invasive Species-(non-native) – Cane toad.
Relationships
• Mutualism
* Flowers & insects
•Commensalism
•Parasitism
•Predator/prey
• Host/ Parasite
• Competition
• habitat vs. niche
Competitive interactions
Intraspecific competition – b/t
members of the same species
Interspecific competition – b/t 2 or
more different species for food,
space, etc.
Interference competition – one may
limit another’s access to some
resource
Explotative competition - one species
can use a resource faster (exploit it)
– humans do this often
Limiting Factors –Biotic & Abiotic
Temperature, light, oxygen,
carbon dioxide, precipitation
• Optimum levels
• Zones of stress
• Limits of Tolerance
• Range of Tolerance
* Pond Water Gizmo
Synergistic effects – The interaction of two or more factors is
greater than the sum of the effects when each acts alone.
Example: pollution and disease
Carrying Capacity
Major Terrestrial Biomes: ecological communities adapted
to climate of the region (most have ECOTONES).
– Desert – near equator. hot & cold
– Grassland– enough rain for grass to live, but not enough for big trees,
-can be:
» Tropical (savanna) – biggest in Africa = warm all year, 2 long dry
seasons has lots of grazing animals)
» Temperate (in the plains in N.&S. America =.cold winter, hot/dry
summers, not much rain, so deep fertile soil, prairie grass) **often
used to grow crops, can lead to erosion of soil.
» Chaparral– temperate shrubland along coastal areas, naturally
maintained w/periodic fires (people in this area – like CA, experience
fire loss often)
» Tundra (v. cold, no trees, ice/snow, reindeer/caribou (don’t hibernate
instead have thick coats), has spongy mat of short plants which grow
during 6-8 weeks of sun) **contains permafrost – stays frozen year
round and prevent liquid water from getting deep underground =
marshy in the summertime. * Melting
» Alpine tundra – above limit of tree growth, similar to arctic tundra, has
no permafrost
– Forest – mod. to high precipitation, lots of trees/smaller vegetation
» Tropical Rainforest= lots of biodiversity (50-80% of terrestrial species),
dead decompose quickly, little leaf litter, large canopy
» Temperate (deciduous forest = avg. rain and change significantly during
the seasons, deciduous forests (*lose leaves in winter) including: oak,
hickory, maple, poplar, many plants at ground level – have been cleared
to make tree plantations
» Evergreen Coniferous (called boreal or taiga) = v. cold winters, short,
mild summers, cone-bearing trees (*have leaves year-round, needleshaped, waxy – ex: spruce, fir, cedar, hemlock, pine), low plant diversity,
slow decomposition of leaf litter.
• An ecotone is a transition area between two adjacent
ecological communities.
(ecosystems).
Riparian
•
•
•
Aquatic Biomes:
Oceans
Euphotic zone (lighted upper zone w/photosynthesis, high DO, low
nutrients, predatory fish),
Bathyal zone (dimly lit middle zone, zooplankton/smaller fish).
Abyssal zone (dark lower zone/little DO/lots of nutrients
Downwelling/
Oxygen
Upwelling /
Nutrients
Lakes
– littoral zone (shallow sunlit water near shore/to depth plants stop
growing),
– limnetic zone (open sunlit surface layer away from shore/produces
food for the lake),
– profundal zone (deep ocean water/too dark for photosynthesis),
– benthic zone (bottom of lake inhabited by organisms that tolerate
low DO and temp.)
Oligotrophic lake – nutrient poor lake
Eutrophic lake – nutrient rich lake – sometimes
caused by runoff of fertilizer (nitrates/phosphates
into lake – cultural eutrophication
Freshwater streams/rivers
•
•
•
Source zone (turbulent
headwaters, lots DO, fish
w/flattened bodies).
Transition zone (headwaters
merge = wider, deeper streams =
more producers, lower DO)
Floodplain zone (streams join
into rivers that meander across
valleys, higher temp, less DO,
empty into ocean)
Energy flow - * very important / energy is
most often stored in glucose.
•
Photosynthesis: CO2 + water + solar energy 
glucose + O2
– Very inefficient (Only 1% of the energy from
the sun is used)
•
Cellular respiration
– Aerobic resp.: Glucose + oxygen  CO2 + water
+ energy
– Anaerobic respiration: breaking down glucose
in the absence of oxygen – products are
methane (CH4), ethyl alcohol, acetic acid,
hydrogen sulfide (H2S) * pew
Ecological succession – gradual change in species composition
of a given area.
Primary succession (can take thousands of years)
Secondary succession (150-200 years) –
Fires in Ecosystem
• Maintain balance of species and energy in ecosystems over the long run.
• Beneficial b/c provide nutrients for soil. * grasslands
• We avoid natural fires, but the problems like Crown Fires- (not natural)
kill the whole tree
• 1988 Yellowstone fires changed climax ecosystems of white bark pine
trees to huckle berries. * Grizzlies eat both.
Carbon Cycle
•
Carbon Cycle – based on CO2 gas which makes up 0.0036% of
our troposphere, important because it is a major component of
the earth’s thermostat Movement of Carbon in the sea:
» Soluble in water, so can stay dissolved in the sea
» REMEMBER: the warmer the water, the LESS gas the
water can hold, so as water warms, more CO2 returns to
the atmosphere. * Colder water holds more O 2
» Some removed by photosynthesis producers
» Some reacts with seawater to form carbonate ions (CO3-2) – which
later can react with Ca ions to form CaCO3 hardened shells of many
sea creatures (when the organism dies, the shells can then be
converted to limestone over time), plants in the sea can also die and
over the years form fossil fuels.

Carbon Sinks-,
sediments , oceans, biofauna.
Movement of Carbon on land:
» Autotrophs – absorb CO 2
» Aerobic respiration –gives of
CO 2
» Buried dead plants (over
millions of years) are
compressed, form fossil fuels
(like coal/oil) when burned
give of CO 2
Nitrogen cycle
• Main reserve in the atmosphere
• Living things must get N from ammonium (NH4) or
nitrate (NO3)
• N from the atmosphere must be fixed
• Change N2 into ammonium or nitrate
– Rhizobium (bacteria living in roots of legumes) ---Lightning
– Burning fossil fuels
* Industrial
Phosphorus cycle
• No gas phase, only solid and liquid. * Rocks
• Man-made fertilizers contain organic phosphates
• Because P is a limiting factor in aquatic systems, it leads to
eutrophication.
• The rain forest is very good at recycling P, except when we cut it
down…
Main
nonliving
reservoir
Main living
reservoir
Other
nonliving
reservoir
Human-induced problem
Carbon
C
Atmosphere
Carbohydrates
(CH2O)n
And all organic
molecules
Hydro
Carbonate
(CO3-2)
Bicarbonate
(HCO3-)
Litho minerals
Global warming
Carbon from fossil fuels
underground are burned and
released into the air as CO2
Nitrogen
Atmosphere
Proteins and
other Ncontaining
organic
molecules
Hydro
Ammonium
NH4+
Nitrate
NO3Nitrite NO2-
Eutrophication
Fertilizers contain humanmade nitrates that end up in
the water
DNA
ATP
phospholipids
Hydro
Phosphate
PO4- 3
Eutrophication
Fertilizers contain humanmade phosphates that end up
in the water
Cutting down rainforest stops
recycling of P
Element
N
Phosphorous
P
CO2
N2
Lithosphere
rocks as
PO4-3
*no gas
phase
Diversity ?
•Top 6 most abundant elements in living things
(not in order)
* NCHOPS
•Top 8 elements in the earths crust (in order)
* O, Si, Al, Fe (iron), Ca, Na (sodium), P, Mg
Only silly apes in college study past midnight.
Evolutionary Change
Vocabulary that you need to know
* DNA
* Chromosome
* Gene
* Allele
Central Dogma:
DNA- blueprint
RNA- carpenter
Protein- house, wood
Geological time scale
You are
here.
Cambrian Explosion- “Life”
Why do species change?
•
•
•
Environmental resistance and biotic potential.
Selective pressure on mutations.
Speciation
*
creation of a new species based on reproductive isolation.
Evolution– the change in a population’s genetic makeup
through successive generations
-Microevolution – small genetic changes that occur in a population.
»
Occurs in species with genetic variation, one genetic
variation is more adapted to survive, that genetic
variation reproduces more, becomes more common
(example: peppered moth)  natural selection
-Macroevolution – long-term, large-scale evolutionary
changes, leads to a new species forming and the other
species being lost to extinction.
-Co-evolution – occurs when two populations of two
different species interact over a long period of time,
changes occur in the gene pool of one species lead to
changes in the other
» Usually occurs with carnivores: Owls that have better
eyesight can catch more mice, so they thrive  mice
that run faster avoid being eaten by the owls.
Mutations
• Mutations (changes) are naturally random
events.
* Normal variation- diversity of organisms
* Chemical
* UV
* Radiation
• * Genetic Trait- only passed down if an
organism reproduces. “Survival of the Fittest”
Natural Selection
–Directional – changing environmental
conditions cause individuals at one
end average to become more
common than mid-range – “it pays to
be different”
-Stabilizing – eliminates individuals on
either end of genetic spectrum, favors
individuals w/avg. genetic makeup –
“pays to be average”
-Diversifying – environmental conditions
favor individuals at both extremes –
“it does not pay to be normal”
Water
• Figure 9-1 Earth’s water supply
Water Facts
• The primary use for fresh water in U.S. is for
agriculture.
• In our homes, we use the most fresh water to
wash, clean and flush.
• The typical person in an industrialized nation
uses 700-1000 gallons per week!
World Fresh Water Supply
•
Largest lake 20 %. of fresh water
Lake Baikal , Russia
4000
Miles
.
Water cycle – powered by the sun and gravity, a
natural cycle that acts to purify water **only cycle that
does NOT involve a chemical reaction (only a physical change of state)
Evaporation (liquid water to water vapor)
–
–
–
–
–
–
Transpiration (liquid water on leaves/roots into water vapor)
Condensation (water vapor to liquid water – clouds/fog)
Precipitation (rain/sleet/hail/snow)
Infiltration (liquid water into the soil)
Percolation (downward flow of water into the soil and aquifers)
Runoff (down slope surface movement of water back to the sea
to resume the cycle)
Human effects on the Hydrologic Cycle
Figure 9-3 The Hydrologic cycle
Aquifer
-Salt water intrusion
Rain shadow
Figure 9-6 Rain shadow
Mono Lake
• Excellent example of human interference with the
water supply.
• The water in the lake was diverted from the lake to
the city of Los Angeles. It became a salt bed.
• ↑ Salt concentration due to evaporation
Three Gorges Dam in China
• China needs to meet the growing demand for energy
• Huge environmental impact
• Hundreds of thousands of people will be displaced (not to
mention the ecosystems which will be flooded)