Chapter 2

1
Chapter 2 Ecology I. Ecology - the study of
interactions that take place between organisms
and their environment

• This wildfire affects plants, animals, and
  humans living in this area

2
A. The Environment is made up of Biotic and
Abiotic Factors 1. Biotic Factors living
parts of the environment Bacteria (our
gut) Fungi (mushroom) Protists
(algae) Plants (cotton) Animals
(bobcat)
3
2. Abiotic Factors nonliving parts of the
environment ? air, temperature, light,
minerals, water, soil
Food Production in Salt Bush
15
10
Food production (mg of glucose/hr)?
5
10
20
30
40
50
Temperature (C)
? This graph shows how the plants food
production is affected by temperature
4
II. Ecologists have organized the living world
into levelsthe organism by itself, populations,
communities, ecosystems, biomes, the
biosphere A. Organism an individual living
thing 1 antelope
5
B. Population a group of organisms (all of
the same species) which interbreed and live
in the same area at the same time 1. They
compete with each other for food, water,
mates, or resources a group of antelope
6
C. Community - made up of several different
interacting populations in a certain area at
a certain time antelope and
zebras 1. Different popns. may or may not
compete for the same resources 2. Predation
some organisms pursue others for food (prey)
7
D. Ecosystem biotic factors that interact
with each other in a given area and with the
abiotic factors of that area antelope,
kudu, water, air, trees
8

• E. Biome large group of ecosystems that
  share the same climate have similar types
  of communities

9
F. Biosphere - the portion of Earth that
supports living things made of all the
biomes 1. It extends from the atmosphere to
the bottom of the oceans
? No life in the mantle or core, inside the earth
10
III. Types of Ecosystems A. Terrestrial
located on land forest old farm
field volcano rotting log
11
B. Aquatic freshwater and saltwater
forms 1. Freshwater Ecosystems pond
stream lake 2. Saltwater/Marine
Ecosystems oceans,
estuaries, aquariums
12
C. Other Ecosystems digestive system
skin mold in walls refrigerator
13
IV. Organisms in Ecosystems A. Habitat - the
place where an organism lives out its life
(its address) B. Niche - the role or position a
species has in its environment (its
profession) includes how it gets its energy
(autotroph or heterotroph)
Example an oak leaf ? Habitat a forest ? Niche
absorb sun, make food, provide shelter for
animals, etc.
14
C. Symbiosis a close relationship between
2 species 3 kinds 1. Mutualism - both
species benefit (/) A grouper fish
gets its mouth cleaned by a goby fish, the goby
fish gets food from the groupers mouth
15
2. Commensalism 1 species benefits,
other is neither helped nor harmed (/0) ?
the clown fish gets shelter, the sea anemone
is not helped or harmed 3. Parasitism 1
species benefits, other is harmed
(/-) ? a tapeworm weakens a cow,
but doesnt kill it
16
V. Nutrition Energy Flow A. Food Chain route
showing how energy flows through autotrophs,
heterotrophs, eventually decomposers in an
ecosystem 1. Arrows show the
direction of energy flow plant
? grasshopper ? mouse ? snake 2. Decompos
ers can break down organisms at any
trophic level 3. Usually consists of 2,
3, or 4 transfers
17
B. Trophic Levels each feeding step in a
food chain or food web 1. 1st order
heterotroph - feeds on plants
(grasshopper) 2. 2nd order heterotroph feeds
on 1st order heterotroph (mouse) 3. 3rd
order heterotroph feeds on 2nd order
heterotroph (snake) C. Food Web model
showing the many interconnected food chains
routes in which energy flows through a
community
Ecosystem Ecology (CrashCourse)
Food Chain song
18
D. Pyramids 1. Energy, Biomass, Numbers in
each transfer is less than the level before
some energy is used to make new cells or
fuel the organisms at that level, some is
lost as heat (a byproduct of metabolism)