Transcript Chapter 4: Living Things and their Environment

All the living and nonliving things in an
area
 Ecology-the study how all these things
interact in order to survive
 There are many different types of
ecosystems
 All have the same parts:
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◦ Abiotic factors
◦ Biotic factors
Abiotic Factors
Nonliving parts
of an ecosystem
 Living things
need these
nonliving things
to survive
 Water, minerals,
sunlight, air,
climate and soil
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Biotic Factors
 Living parts of an
ecosystem
 Plants, animals,
fungi, protists
and bacteria
Located in Texas
 Largest remaining prairie in America
 Was once covered in wild grasses
 Rich black soil was found here
 Land was occupied by buffalo
 snakes, lizards, types of birds, raccoons,
coyotes, deer and bats
 50 different kinds of tall and short
grasses
 Many types of flowers
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Now the prairie is used for planting
crops (wheat, corn) and cattle grazing
 When towns, cities and farms were built
the buffalo and many other animals
left, such as black bears and jaguars
 Some animals came, such as armadillos
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All the organisms of a species living in
the same area
 Populations of the Blackland prairie
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◦ Armadillos
◦ Badgers
◦ Indian grass
◦ Pond algae
◦ Soil bacteria
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Scientists want to know how these
populations interact with one another
All the populations living in an area
 Scientists study the interactions of
different populations in an ecosystem’s
community
 This helps them to understand what
makes an ecosystem grow
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The place where an organism lives
 Examples:
◦ red bat’s habitat is above ground
◦ Chorus frog-ponds of Blacklands
◦ Bees-beehive
◦ Sharks-live in the ocean
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Role of an organism in the community
No 2 species can have the same niche
◦ They would have to be identical for this to
occur
◦ No 2 species are identical
Scientists study niches and habitats to find
out if a community is healthy or in trouble
Includes:
◦ What a species eats
◦ What eats the species
◦ Active by day or night
◦ Kind of environment the species needs to live
in
Habitats can change year to year
 This affects the organisms
 Animals either finds a new habitat or
adapt to the changes in their
environment
 Ex: spadefoot toad is able to survive
during a drought
◦ The toad digs with its hind feet to
cover itself with soil
◦ Absorbs water from the soil which
contains clay
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Treasure is the soil
 Topsoil-dark brown to black
 Rich in humus-partly decayed plant
matter produced by bacteria and fungi
 Full of minerals
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◦ Magnesium-helps produce chlorophyll
◦ Calcium-important element of cell walls
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Good to grow crops
Energy in an ecosystem comes from the
sun
 The energy in food is passed from one
organism to another
 Represents the movement of energy from
one organism to another
 1st organism is a plant (producers)
◦ Sun’s energy is stored in foods the plant
makes
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2nd organism is consumer (herbivore)
 3rd organism is consumer (carnivore)
 All organisms receive the sun’s energy
 Food chains end with decomposers-eat
dead animals and plants
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Shows the relationship between all of
the species in a community
 Shows how populations must compete
for food
 Map of overlapping food chains
 Begin with producers
◦ use Sun’s energy to make their own
food
◦ Ex: grasses, trees, algae (oceans)
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Consumers-can’t make their own food
◦ Get energy from other organisms
◦ Grouped according to what they eat
◦ Herbivores-eat only plants (producers)
 Ex: grasshoppers, rabbits, mice
◦ Carnivores-eat only other animals
 Ex: wolves, foxes, sharks
◦ Omnivore-eats both plants and animals
 Ex: humans, bears
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Decomposers:
◦ Every food web ends with decomposers
◦ Breakdown dead matter into
substances that can be used by
producers
◦ Some of the substances return to the
soil
◦ Ex: insects, bacteria, fungi
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Populations in an ecosystem are connected
together
If one animal population changes, it will
affect the animal population that eats that
animal
A change in a population affects all the
organisms in the food web
Organisms may adapt to the changes,
especially when they eat more than one
animal
Animals compete for food
Sometimes competition causes an animal to
change its habitat
Producers get energy from the sun
 Consumers get energy from the foods
they eat
 Energy is lost as it passes from one
organism to another
 This is shown in the energy pyramid
 Shows there is less food at the top of the
pyramid than at the base
 Organisms decrease as you move up the
pyramid
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energy decreases as you move up the
pyramid
 90% of energy is lost from one level to
the next
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Dead matter is important to living
things
 Decomposers turn dead matter into
substances other organisms need to
survive
 Break down dead plant parts into carbon
dioxide and ammonia-contains nitrogen
 All organisms need nitrogen in order to
make proteins
 Nitrogen found in plant fertilzers
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Is a way to recycle plant material
 Compost is used to make soil more
fertile
 To make compost take 3 parts leaves
and plant material, 1 part fresh grass
and 1 part food scraps
 Earthworms can be used to turn the
leaves, grass and food scraps into
compost
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Nonrenewable resources will eventually
be used up, such as oil and natural gas
 Renewable resources, such as wood, can
be replenished
 If we recycle paper and paper products
we will be decreasing the destruction of
forests
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