Ecology Unit
A: organization of the Environment
B: Interactions in the Environment
C: Humans and the Environment
Main Idea- The interactions between organisms and the relationships
between the organisms and the environment.
Vocabulary:
1. Ecology- the branch of biology that deals
with the interactions between organisms ,
and the relationships between the organisms
and the environment.
2. Population- members of the same species
living in a given area.
3. Community- includes all populations in a
given area.
4. Ecosystem- all living things and the physical
environment that they live in.
5. Biosphere- the portion of the Earth where life
exists.
Requirements for a Stable Ecosystem:
 A constant supply of energy (SUN).
 Living organisms that can turn energy from
the sun into organic compounds.
 Material must be recycled between
organisms and the environment.
(Ex.- an aquarium is a stable, balanced
ecosystem.)
Abiotic Factors:
 The non-living parts of the environment.
 Abiotic factors are:
 Air
 Water
 Soil
 Light (Sun)
 Temperature
 Minerals
Biotic Factors:
 The living things that directly or indirectly
affect the ecosystem.
 Examples of Biotic Factors are:
 Producers- organisms that make
their own food.
 Consumers- organisms that get
their food from other sources.
 Decomposers- break down, and
recycle, dead and decaying
organisms.
Habitats and Niches:
 A habitat is the place in and
ecosystem where an organism lives.
 A Niche is the role or job an organism
has in an ecosystem.
Biomes:
 The Biosphere is organized into smaller
units known as biomes.
 A Biome is a large geographic area
identified by a particular type of
common plant or animal.
 There are Terrestrial biomes:
 Tundra
 Tiaga
 Temperate Deciduous Forest
 Rainforest
 Grassland
 Desert
 Land biomes are determined
by the major climate zones of
the world.
 Water is a major limiting factor.
 Latitude and Altitude are
important factors in
determining the climate
conditions and the types of
plant and animal life that will
inhabit the area.
 There are Aquatic biomes:
 Marine (salt water)
 Freshwater
 Aquatic biomes make up the
largest ecosystem on the
Planet.
 More than 75% of the Planet is
covered by water.
 Factors that affect water
biomes are:
 Amounts Of CO2, and O2
 Temperature and light
 Amounts of dissolved
minerals.
Biodiversity:
Biodiversity is the diversity of species on the
Planet as a result of the evolutionary process.
 Biodiversity increases the chance that
at least some species will survive in the
face of large environmental changes.
 Biodiversity also increases the stability
of an ecosystem and guarantees the
availability of a variety of genes (large
gene pool).
Interactions in the Environment:
 Food relationships involve interacting
organisms.
 Organisms are either Autotrophs
(organisms that make their own foodplants) or Heterotrophs (organisms that
get their food from other sources).
 There are 3 types of Heterotrophs:
 Herbivore- eat plants
 Carnivore- eat meat
 Omnivore- eat plants and
meat
 Carnivores can be further divided into
3 groups:
 Predators- carnivores that kill
and consume their prey.
 Prey- the animals that are
killed and eaten.
 Scavengers- eat the dead
animals they find that are left
over from the predators.
Symbiotic Relationships:
Symbiosis involves organisms of different species
living together in close association with at least
one of the organisms benefiting.
 Mutualism- both organisms benefit
 Commensalism- one organism
benefits, the other is not harmed.
 Parasitism- one organism benefits
(parasite), the other organism is
harmed (host).
Food Chains:
Producer  Primary Consumer  Secondary
Consumer
**Decomposers are found at every level of a
food chain.
Food Webs:
A food web is made up of many
interconnecting food chains.
Energy Pyramid:
 The Sun is the primary source of energy
in an ecosystem.
 Energy is lost at each level on the
energy pyramid.
 The greatest amount of energy is
found at the producer level (bottom).
 The higher up in the pyramid the less
energy.
Material Cycles:
Materials must be recycled between the
living and the non-living environment.
There are 3 Material Cycles:
 Oxygen-Carbon Dioxide Cycle(photosynthesis, cellular respiration)
 Nitrogen Cycle- dead and decaying
organisms, nitrogenous wastes are
converted.
 Water Cycle- evaporation,
condensation, and precipitation.
Ecological Succession:
 Ecological succession is the gradual
replacement of one community by
another community.
 Succession leads to the formation of a
stable environment.
 A stable community is called a Climax
Community.
 Succession occurs in steps or stages.
 The first organisms to repopulate a
given location are called Pioneer
Organisms.
Climax Communities:
 The permanent plant and animal
species that make-up a stable
ecosystem.
 Climax communities have populations
that remain the same because they
are in balance with one another and
the environment.
 Stable populations- numbers
remain constant.
 Unstable populations- species
numbers are drastically
reduced…….endangered
species.
Exploding Populations:
 Conditions may favor the rapid
reproduction of a species leading to a
“population explosion”.
Competition:
 Competition occurs when there is a
struggle for the same limited resources.
 Competition may eventually cause
one species to become extinct.
 Competition usually establishes one
species per niche in a community.
Humans and the Environment:
 Humans differ from all other kinds of
organisms in their ability to change the
environment.
 Human activities upset various natural
systems and have negative effects on
the biotic and abiotic environment.
 Some changes in the environment can
be repaired, some can not.
 In order for humans to survive as a
species they must interact with many
different forms of life, as well as, the
non-living parts of the environment.
 The abiotic environment provides us
with essential components upon which
our survival depends.
 Acid Rain
 Greenhouse Effect
 Air Pollution
 Water Pollution
 Global Warming
These are just some examples of negative effects
that mankind has had on the environment.
These changes are caused by advances in
technology.
The ways in which we change our physical
environment will ultimately determine the survival
of all living things and our own species.
Human Population Growth:
 Human population growth is not unstable.
 Population is growing rapidly because our
medical knowledge and education is
increasing.
 One negative effect of HPG is starvation
because of increased competition for
food.
 One positive effect of HPG increased food
production due to scientific discoveries.
Environmental Pollution:
 A pollutant is something that is put into
the air, water, or soil that makes it dirty
and unfit for living things.
 Pollutants are toxic (poisonous).
 Pollutants are by products of
technology.
Negative Human Activities:
Over-hunting
Importing of organisms
Exploitation
Poor land management
Deforestation
Improper waste disposal
(biodegradable)
 Use of biocides (pesticides, herbicides)
 Poaching
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Conservation of Natural Resources:
 Conservation involves the protection
and wise use of our natural resources.
 Natural resources include the basic
things in the natural world (soil, air,
water, energy, wildlife, and open
space).
 Renewable resources are able to be
reused or replaced.
 Nonrenewable resources cannot be
replaced.
 Recycling resources that are
nonrenewable is recommended to
conserve them.
 Erosion causes much soil to be lost
because it is worn away by wind and
water.
 Wildlife preservation is efforts to help
endangered species and to protect
other forms of wildlife.
 Laws to protect wildlife continue to be
passed to help protect wildlife in
danger of becoming extinct.
We can make a difference in our Planet!
We can effect positive changes in our world!
We must all get involved!