Chapter 2
Main Ideas:
1. Biotic & abiotic factors interact in complex ways in communities &
ecosystems.
2. Autotrophs capture energy, making it available for all members of
a food web.
3. Essential nutrients are cycled through biogeochemical processes.
Principles of Ecology
I.
Organisms & Their Environment
Everyday we interact with many different people, but we also
in with our environment. Think about getting ready for school
& your drive to school this morning. List a few things you
noticed this morning in the margin.
Weather, bacteria, any animals, etc
A. Ecology
1. ecology involves research
B. Types of Ecology
1. organismal ecology
a. physiological ecology
b. behavioral ecology
2. population ecology
a. understand factors that affect a pop’s growth
b. influenced by species interactions
3. ecosystem ecology
C. Biosphere
1. allows for a very diverse group of organism to survivewhy?
2. biosphere has both living & nonliving factors
a. abiotic factors
what are some abiotic factors in this room?
eventhough these factors are nonliving they can still
impact organismshow?
c. biotic factors
II.
how do organisms in an ENVR interact?
Levels of Organization
Ecologists examine organisms at different levels w/i their ENVR
A. population
a. how do organisms live within a population?
B. biological community
a. what factors influence populations?
1.
2.
3.
4
5.
a. predator-prey relationship
b. increase/decrease in a species population
C. ecosystem
a. 2 types
1. can be extremely large as an ocean, desert, or
forest; it can also be a small pond or sand dune
2. always subject to changewhy?
3.
D.
III. Ecosystem Interactions
A. keep in mind that an ecosystem is all living organisms &
abiotic factors
B.
C. habitat
1.
name some habitats
2.
3.
a. what can happen when different species compete for
resources?
D. niche
1. includes both abiotic & biotic factors of its habitat
2. can different species occupy the same niche?
a. only for a short time, why?
b. competition
c. predation
d. can lead to extinction, migration, or adaptation
e. different species use many different strategies &
adaptations to survive in their habitats
f. could a polar bear & a brown bear switch habitats?
g. what happens if you have both a cat & a dog?
E. Symbiosis
1. 3 types of symbiotic relationships
a. mutualism
b. commensalism
c. parasitism
IV.
Nutrition and Energy Flow
All living organisms require energy. The sun is the main source
of energyhow?
A. How Organisms Obtain Energy
1. autotrophs
a.
b.
c. set the tone for the rest of the habitat/communityhow?
2. heterotrophs
a.
b. different types of heterotrophs
1. herbivore
2. carnivore
3. scavenger
a. why are scavengers important?
4. omnivore
5. decomposer
a. break down complex compounds into simpler
molecules that can be more easily absorbed
b. essential to the recycling of nutrients
c. include bacteria, fungi, & protozoans
B. Flow of Matter & Energy in Ecosystems
1.Whenever any organism eats something, it is consuming
matter. You probably do not think about this when you eat, but
the matter you are consuming when eating contains carbon,
nitrogen, & other elements.
2. To understand how matter & energy flow through an
ecosystem, you need to understand that it begins with the
producers & that some energy is lost at each level as heat.
3. Food Chains:
a. food chain
b. always begins with producers & ends with
decomposerswhy?
c. uses arrows to show the direction in which the energy is
transferred from one organism to the next
1. acornsdeerbear
d.
e. a food chain represents only 1 possible way for energy &
mass to move via an ecosystem; there are many
possibilities
4. Trophic levels
a. 1st order heterotroph eats the producers
b. 2nd order heterotroph eats the 1st order heterotrophs
c. depending on the scope of the food chain 3rd & 4th order
heterotrophs may be present
5.Food web
a. more complex than a food chain
6. Energy & trophic levels:
a.
b. 3 different ecological pyramids
1. pyramid of energy
a.
b.
c. law of conservation of energyenergy is neither
created nor destroyed, the total amount of energy
remains the same
2. pyramid of numbers
3.pyramid of biomass
a. biomass
V. Cycles in Nature
A. b/c sunlight is the primary source of all the energy we’ve
discussed so far, it is constantly replenished by the sun.
B. nutrients
1.nutrients(nitrogen, carbon, oxygen, & H2O) are not
replenished, they are recycled
C.matter
D. biogeochemical cycle
1. Water Cycle
a. H2O moves constantly b/t the ATMS & the Earth
b. involves several processes
1. evaporation
2.
3. H2O that has fallen back to land can:
a.
b.
c.
4.
2. Carbon Cycle & Oxgen Cycles
a.
b. also involves several processes
1. via death & decay plants & animals release C that
becomes fossil fuels
2. fuel combustion & burning of matter release C into
ATMS
3. animals & humans release C in the form of CO2 into
the ATMS via respiration
4. autotrophs use photosynthesis to convert CO2 to
energy rich compounds
5. heterotrophs consume the autotrophs & some C is
released into the ATMS
3. Nitrogen Cycle
a.
b.
c. plants use N to make proteins
d. animals eat the plants & use the N to make proteins
e. animals excrete N in waste products which is absorbed
into the soil
f. also when plants & animals die N is released into the soil
& ATMS
g. denitrification
4. Phosphorous Cycle
a.
b.
c. plants receive PO4 from the soil & animals get PO4 when
they eat the plants
d. when plants & animals die PO4 is released into the soil
e. if PO4 enters H2O, PO4 will eventually settle to the
bottom & become part of the rock
f. via mountain bldg & weathering PO4 will be released