Classroom Notes on the ecology unit

1. Populations and Ecosystems
The Biosphere
Trophic Levels
Interaction and Adaptation
Changing Ecosystems
Invasive Species
The Structure of the Biosphere
The Biosphere
Biomes
Ecosystems
Communities
Populations

2. The Biosphere: The part of the Earth where living
organisms and organic matter exists
The biosphere includes all areas that contain life, which include the hydrosphere (water
environments) the atmosphere (air environments)and the geosphere (ground and soil
environments). Anywhere that humans habitat is called the anthrosphere.
Biome: Regions of the Earth that share similar climates, vegetation and
animal life. The life found in these regions are specially suited for
survival in that particular environment.
There are six main biomes
Freshwater Marine Desert
Forest Grassland Tundra
Of course, these can be divided up into more specific biomes such as tropical rain forest,
temperate rain forest, coniferous forest, and so on...

3. Ecosystems:
Living organisms interacting with each other and the non-living factors in
an environment
Abiotic vs. Biotic factors
Communities
All the interacting living organisms within an ecosystem
(Animal, plant, fungi...)

4. Population:
The total number of organisms of one species that live in a particular
ecosystem at one time
Abiotic Factors: All the non-living parts of an environment
Biotic factors: All the living factors of an environment

5. Organic Matter: Matter that has come from a once-living organism;
capable of decay, or is the product of decay
Characterized by molecules that contain both carbon and
hydrogen (hydro-carbons)
Inorganic Matter: Matter from a non-living source such as rocks, sand
or plastic;
Molecules do not contain both carbon and hydrogen
Trophic Levels
Energy and the Trophic Pyramid
Energy is the ability to do work. All living things need energy to
survive. This shows how energy is distributed in an ecosysem. Energy
starts at the bottom of the pyramid with the producers and works its
way up to the upper levels.
Tertiary Consumers
Secondary Consumers
Primary Consumers
Primary Producers
Let's look at some examples...

6. It's all a matter of mathematics. An
organism can only survive if there is
enough energy available in the
trophic level below it.

7. Interaction and Adaptation
Interactions: How organisms respond or behave around other
organisms
Competition: The struggle to obtain various limited resources within the
environment.
Resources can include: · Water
· Food
· Living space (habitat)
· Light energy
· Reproduction
Can take place between individuals of the same species or different
species

8. How might plants compete
with each other?
Symbiosis: Individuals of different species
that have a close relationship with each
other

9. Mutualism: The interaction between two different
organisms of different species where both
benefit
Commensalism: The interaction between two different organisms of
different species where one benefits and the other is
unaffected

10. Parasitism: The interaction between two different
organisms of different species where
one benefits and the other is harmed
Adaptation:
Helps organisms survive and thrive in their particular habitat
Adaptations come from variations within the species.
If an organism is born with a sightly different trait (a longer beak, a slightly
darker color, etc.) that gives it a survival advantage, the organism is more likely
to survive and pass that trait onto its offspring
The trait can provide an advantage to surviving...
- In a particular climate
- In a particular habitat
- A predator
- By finding/obtaining a food source
A change in any of these can cause one trait to
become less or more advantageous.

11. There are two types of adaptations:
Behavioral Adaptations: A way an organism behaves or interacts that
gives an organism a survival advantage in a specific ecosystem or habitat
Moving in large groups is a behavioral adaptation; it helps protect the
members of the group from predators.
Structural Adaptations: A physical characteristics that gives an organism
a survival advantage in a specific ecosystem or habitat
An arctic fox has a thick fur coat that helps it survive in extremely cold
weather. It is also white, so it blends in with the snow. A red fox is not able
to hide from its prey in that environment, so it is not as successful.
Natural Selection:
The process in which individuals members of species are
"selected" by the environment for survival because
variations that give the individual an advantage.
These genetic variations make it more likely that an
organism will survive and therefore pass on the successful
trait to its offspring.
The result is a slow change in the species over many years.

12. Changing Ecosystems
Populations change:
All populations change over time: Grow or Decline
--Birth rates
--Available food
--Predators and prey interactions
Limiting Factors:
Factors or conditions in the environment that limit a
population's size
Examples:
Predator/prey relationships? Reproductive?
Available Resources? Seasons?
Carrying Capacity
The maximum number of individuals that an
ecosystem can support
Ecosystems Change Over Time
Succession:
Gradual change of an ecosystem when one community
replaces another.
Primary Secondary