4.1 - What
is an Ecosystem?Ecology
is the study of the
of the things in the environment that are living or were living at one time.
This includes plants, animals, fungi, bacteria, etc.
are all of the things in the
environment that are not living, and never were alive. This includes air,
water, light, heat, rock/sand, etc.
- One complete living thing. Population
- All of the
members of one species in an area. Community
- All of the
living things that interact within an area. Ecosystem
The community of organisms in an area and their
(All biotic and abiotic factors.) Biome
- A large area
with a specific climate and certain types of
communities that live
- The part of the Earth that supports
is the place where an
variety of organisms (or species) in an area.
is the replacement of one type of
community with another in a certain location over a period of time.
A biome is a large area with
a specific climate and certain types of communities that live there.
is the average weather in an area
over a long period of time. The two key climate factors that determine what
biomes can exist in an area are temperature
Three Major Groups of
- warm, near the
a. Tropical Rain Forests
- receive a large amount of
b. Savannas (Tropical Grasslands)
- have long, dry seaons
and short, wet seasons
c. Tropical Deserts
- receive very little
- mid-latitudes, wide range of temp. over
a. Temperate Forests
- mild climates with plenty of
- deciduous (broadleaf trees that lose leaves
- coniferous (cone-bearing trees that don't lose
- mixed forest (both types of trees)
- have moderate precipitation, cooler temps than
c. Temperate Deserts
- very little precipitation, wide
(Polar) - cold
- coniferous forests in cold, wet areas
- long, cold
winters - most precipitation falls in summer
- only short plants with shallow
roots survive there
Four Major Groups of
1. Freshwater Ecosystems
- bodies of fresh water (lakes, ponds, rivers, etc.)
- link between land and fully aquatic
- dominated by water-loving plants
- wetlands control
flooding and filter water
- places where
fresh and salt water mix (rivers meet ocean)
- ocean habitats4.2 - Energy Flow
Trophic Levels are the steps in a food chain or
energy pyramid. each trophic level is a step in the transfer of energy through
1. Producers are organisms that produce
their own food inside
their bodies. Plants are producers because they
use sunlight to
make sugar in their leaves by photosynthesis.
Consumers are orgsnisms that must take in food. Animals
consumers because they must eat food to survive.
Herbivores are consumers that only eat plants.
Carnivores are consumers that only eat animals.
Omnivores are consumers that eat both plants and animals.
Decomposers are organisms that break down dead material
and return it to the soil.
Chain - A diagram that shows one set of relationships in an
Food Web - A diagram that shows many sets of
Energy Pyramid - A
triangular diagram that shows an
ecosystem's energy loss as energy is
passed up the food chain.
The Ten Percent
- Only 10% of the energy that a consumer takes in becomes
of the consumer's body.
- The other 90% is used by the
- Only the 10% that is stored can be passed on to a
4.3 - Cycling of Matter
The Water Cycle is the process by which the Earth purifies
and recycles its water. There are seven main parts to the Water Cycle:
1. Evaporation happens when water changes
from a liquid to a gas.
2. Condensation happens when water
changes from a gas to a liquid.
3. Precipitation is the name
for water falling from the sky.
4. Run-Off is water flowing
along the surface of the ground.
5. Percolation happens when
water soaks into the ground.
6. Groundwater is water in the
7. Transpiration is evaporation caused by
Carbon is cycled back and forth between living things and
their nonliving environment.
1. Photosynthesis is carried
out by plants and changes CO2
(carbon dioxide) into O2 (oxygen).
Respiration is carried out by animals, plants, and other
organisms and changes O2 into CO2.
3. Combustion is the
burning of a substance; it changes O2
Decomposition is the breaking down of dead matter; it
changes O2 into CO2.
Nitrogen is important in making proteins. The nitrogen in
the air (N2) is not accessible to most organisms, and must be changed to another
1. Nitrogen Fixation is the process by which bacteria
N2 with hydrogen (H2) to make ammonia (NH3). N2 can also
be fixed into NH3 by lightning and burning fossil fuels.
Ammonification is the process by which nitrogen in
waste or dead matter is converted into NH3.
Nitrification is the process by which NH3 is converted
4. Assimilation is the process
where plants absorb NH3 and
NO3 from the soil. (The nitrogen can then be
passed up the
5. Denitrification is when
NO3 is changed back into N2 and
released into the atmosphere.
Phosphorus is important in making DNA and ATP (an energy
a. Phosphorous is found in the soil as calcium phosphate
(CaPO4). CaPO4 also makes up 70% of bone tissue.
b. CaPO4 dissolves in water
to form phosphate.
c. Plants absorb phosphate through their roots. (The
can then be passed up the food chain.
d. When organisms
die, phosphorous is returned to the soil.