13.1 Ecologists Study Relationships
Ecologists study the interactions among
organisms and their environment.
Biome
Population
Ecosystem
Organism
Community
Biosphere
13.1 Ecologists Study Relationships
KEY CONCEPT
Ecology is the study of the relationships among
organisms and their environment.
13.1 Ecologists Study Relationships
Ecologists study environments at different levels of
organization.
• Ecology is the study of the interactions among living
things, and between living things and their surroundings.
13.1 Ecologists Study Relationships
1. An organism is an individual living
thing, such as an alligator.
Organism
Organism
13.1 Ecologists Study Relationships
2. A population is a group of the same
species that lives in one area.
Population
Population
Organism
Organism
13.1 Ecologists Study Relationships
3. A community is a group of different
species that live together in one area.
Community
Community
Population
Population
Organism
Organism
13.1 Ecologists Study Relationships
4. An ecosystem includes biotic (living)
and abiotic (nonliving) factors.
Ecosystem
Ecosystem
Community
Community
Population
Population
Organism
Organism
13.1 Ecologists Study Relationships
An ecosystem includes both biotic and abiotic factors.
• Biotic factors are living things.
– plants
– animals
– fungi
– bacteria
plants
13.1 Ecologists Study Relationships
• Abiotic factors are nonliving things.
– moisture
– temperature
– wind
– sunlight
– soil
sunlight
moisture
13.1 Ecologists Study Relationships
~ some ecosystems have
more biodiversity (variety
of living things) than others
- amount of biodiversity
depends on climate
(temperature and amount
of rain)
13.1 Ecologists Study Relationships
• Biodiversity is the assortment,
or variety, of living things in an
ecosystem.
• Rain forests have more
biodiversity than other
locations in the world, but are
threatened by human
activities.
13.1 Ecologists Study Relationships
~ a keystone species is a species that has an unusually
large effect on its ecosystem.
keystone
13.1 Ecologists Study Relationships
• Keystone species form and maintain a complex web of life.
creation of
wetland
ecosystem
increased waterfowl
Population
keystone species
increased
fish
population
nesting
sites for
birds
13.1 Ecologists Study Relationships
5. A biome is a major community of
organisms; consists of ecosystems with
similar environments; organisms have
similar adaptations that help them
survive in that climate
Biome
Ecosystem
Ecosystem
Community
Community
Population
Population
Organism
Organism
13.1 Ecologists Study Relationships
6. A biosphere consists of all living things
and all the places they are found on
Earth (all biomes together)
Biome
Ecosystem
Ecosystem
Community
Community
Population
Population
Organism
Organism
13.1 Ecologists Study Relationships
Ecological research methods include observation,
experimentation, and modeling.
1. observation is the
act of carefully
monitoring
populations over
time (can be short or
long periods)
13.1 Ecologists Study Relationships
a. visual surveys - observation through binoculars or by
tracking feces & recent kills
Ex: a pride of lions
13.1 Ecologists Study Relationships
b. radio telemetry – using a radio collar to monitor an
animal’s movement
Ex: a pack of coyotes
13.1 Ecologists Study Relationships
c. mark-recapture – used to estimate population size
~ capture animal, tag it, then release it
~ Ex: a prairie-dog population
13.1 Ecologists Study Relationships
d. quadrant sampling - used to monitor plant populations
~ several rectangular frames (look like picture
frames) are randomly laid down in an area and the
plants within the area are counted
~ a mathematic formula is used to determine the
population
13.1 Ecologists Study Relationships
2. experimentation
– in the lab = indoors; environment is controlled
– in the field = outside; in the organism’s natural
environment
~ are more accurate
13.1 Ecologists Study Relationships
– both methods
contain controls
and a manipulated
variable (the one
“man” is testing)
13.1 Ecologists Study Relationships
3. modeling
- uses computers or math
- uses data collected to study how changes to the
ecosystem might affect the population
- used to develop projects such as wildlife
conservation projects
Ecologists use data transmitted
by GPS receivers worn by
elephants to develop computer
models of the animal’s
movements.