Unit: Ecology
Ecology
- Scientific study of interactions between
their
.
Levels of
Organization
- Species = organisms that can
and produce
- Population = group of organisms that belong to the same
living together
- Community = different
living together
- Ecosystem (living & nonliving) = Collection of all the organisms in a
- Biome = group of
&
- Biosphere = The layer of
is home to all living things
Trophic levels
and
that have similar
,
, and
that
- The way in which
flows through an ecosystem
- Each step in a
or
- Sunlight is the main source of
for life on Earth
use sunlight to make their own food
(photosynthesis).
- Producers = make their own food (
)
- Consumers = eat other organisms for food (
)
*Each consumer depends on the trophic level below it for energy.
- Decomposers = break down dead organisms
1) Energy Pyramids
- Shows the amount of
at each trophic level.
- 10% RULE:
• Only
of the energy available in one trophic level is
transferred to organisms at the next trophic level.
• Because much of the energy is used for life processes:
respiration, movement & reproduction
2) Food Chains
- Shows how energy flows through each level
- Each step in the chain is a trophic level
Ex: Grass  Grasshopper  Frog  Snake  Hawk
- Arrow shows
3) Food Web
- Links all the
Ex:
wolf
together in an ecosystem
hawk
mouse
rabbit
seed
Cycles of matter
snake
lizard
- Unlike the one-way flow of energy, matter is
within and between
.
- Matter can cycle because biological systems do not use up matter,
they
it.
- Matter is assembled into living tissue or passed out of the body as
waste products.
1) Water Cycle
- Evaporation: the process by which water changes from
- Transpiration:
from the leaves of plants
- Precipitation: when water returns to Earth’s surface in the form of
2) Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean
Fossil fuel
Carbonate
Rocks
and
recycle carbon between
and
- Ways carbon enters the atmosphere:
• Respiration
• Human activity (
• Volcanic activity
• Decomposition of organic matter
- Ways carbon is used:
• Photosynthesis to make
eaten and pass through the food web
.
)
that get
3) Nitrogen Cycle
- Ways nitrogen enters the atmosphere:
• Denitrification: Soil bacteria convert nitrates into
- Ways nitrogen is used:
• Nitrogen fixation: bacteria convert
allowing producers to use it
• Producers use it to make
• Consumers eat producers and use their
make their own
*Questions:
into
to
4) Phosphorous Cycle
- Phosphate does not enter the atmosphere.
- It cycles between
and the
.
- Organic phosphate moves through the food web, from producers to
consumers, and to the rest of the ecosystem.
- It forms
and
!
1) Why are
decomposers important
in an ecosystem?
2) Why are
producers important
in an ecosystem?
Structure of an
Ecosystem
- Ecosystems have many components
1) Habitat – place where an organism
2) Niche – meeting needs for
- No
can share the same niche in the same
habitat.
3) Biotic Factors - All of the
interacts with
4) Abiotic Factors wind, nutrient availability, sunlight)
Community
Interactions
Types of
Biomes
Ecological
Succession
things an organism
parts of an ecosystem (climate,
- Competition = organisms trying to use
in the same
place and at the same time
- Predation = one organism feeds on another
• Prey = what is being hunted
• Predator = what is hunting for food
- Symbiosis = interaction between
or more species
• Mutualism =
• Commensalism = one species
; one species is
• Parasitism = one species
1) Terrestrial (
)
- Tropical Rain Forest
- Tundra
- Taiga (boreal forest)
- Desert
- Temperate deciduous forest
- Grassland
2) Aquatic (
)
- Saltwater (
)
- Freshwater (
- Series of
over time
- Can result from
disturbance caused by
1)
occurs where no
- Pioneer species =
; one species is
)
changes that occurs in a community
changes over time or by natural
(clearing forests)
exists
= succession that
2) ______________________
= succession
following a disturbance that destroys a community
- Ex:
Ozone depletion
- The ozone layer absorbs
- UV exposure can:
rays before they reach Earth
- Holes in the ozone layer could be caused by gases called
which were used in various products (aerosol cans)
,
Climate
- All life on Earth depends on climate conditions such as
.
- The term used to describe the
in the average
of the biosphere is
.
- One sign of global warming is
.
- Hypothesis: Warming is related to
that
add
and other
to the atmosphere.
Biodiversity
- Biological diversity, or biodiversity, is the
the genetically based
biosphere.
Types
1)
world.
of
in the
includes the variety of
, and
,
in the living
2)
the biosphere
is the number of different species in
3)
forms of
living on Earth today
is the sum total of all the different
carried by all organisms
Importance
- Species of many kinds have provided us with:
o
o
o
Threats to
Biodiversity
- Human activity can reduce biodiversity by:
- altering
- hunting species to
- introducing
- introducing
- results in:
▪ more
▪ Disruption of
Conservation
Goals
- Wise management of natural resources, including preservation of
habitats and wildlife.
Population
Growth
- Important characteristics of a population:
- 3 factors that affect population size:
1) # of
2) # of
3)
Exponential
Growth
=
o
o
Logistic Growth
=
o Resources become
o Population reaches its
o
o Carrying capacity =
Factors limiting
a population
1)
- depends on population density (# of individual in the population)
- Ex:
2)
- affect all population regardless of population density
- Ex:
factors such as
, natural
disasters,