3rd Grade
Part Six
Review
Interactions in
Ecosystems
• Ecosystems include populations, communities,
and habitats, as well as, nonliving things like air,
water, and soil.
• Plants and animals depend on one another to
help them meet their needs.
• Interactions – includes food chains, food webs,
predator-prey relationships, and living and
nonliving
How can ecosystems be changed?
• Natural events such
as floods, fire,
earthquakes, etc.
http://www.uoregon.edu/~donovan/favorite.htm
• Humans
• Animals
http://jazba.wordpress.com/2008/09/08/country-to-hit-another-earthquake-geophysicists/
Ecosystems
Forests
• an area with mostly trees
• receive different amounts
of rainfall, sunshine, and
specific temperatures
Deserts
• an area with very little
rainfall
• some are hot and others
cold
Ecosystems
Freshwater
Mostly found in rivers, streams,
and lakes
Saltwater
Found in oceans, seas, and
some lakes
Food Chains
Producer
Consumer
Consumer
Consumer
• The path of energy from one living thing to another forms
a food chain.
• Energy from the sun is used to produce sugar in plants
which is then passed on to animals.
• Animals must consume their food from other organisms.
Food Chains
Producer
Consumer
Consumer
Consumer
Prey
Predator
Predator
Prey
• Animals that hunt other animals for food
are predators.
• Animals that are hunted are prey.
Decomposers
• Decomposers are
living things that
break down dead
things for food.
• They help clean the
environment as they
break down the
wastes of other living
things.
Learned Behaviors
• Behaviors animals
are taught after birth
http://www.disciplemexico.org/2006/10/like-riding-bicycle.html
http://www.wunderground.com/blog/MikeTheiss/comment.html?entrynum=80
Food Web
• Most ecosystems
have many food
chains that overlap
and link together.
• When a population
increases or
decreases, it can
affect other
populations in the
food web.
Energy Pyramid
• Shows the
amount of
energy available
to pass from
one level of the
food chain to
the next.
hawk
snake
• The higher the
animal is in the
pyramid, the
fewer there are.
rabbit
grass