*Refer to Chapter 16 in your Textbook
Learning Goals:
1. List the organizational levels of ecology in
order.
2. Identify abiotic and biotic factors that effect
ecology.
3. Determine a populations’ growth rate and
carrying capacity.
What is Ecology?
Ecology is the science that studies how organisms
relate to each other and their environment.
Organizational Levels of Ecology:
1. Biosphere: the entire planet, including the land, ocean, and
atmosphere, and all living things = WORLD
2. Biome: a group of ecosystems that share similar climates
and organisms = COUNTRY
3. Ecosystem: a group of communities with interacting
organisms through which energy is transferred = STATE
Organizational Levels of Ecology:
4. Community: a collection of different populations living and
interacting within an ecosystem = TOWN
5. Population: a group of individuals (same species!) that live
and interact within a community = HOUSE
6. Species: a single organism = INDIVIDUAL
Factors that affect Ecology:
Biotic Factors: biological influences (living)
 Ex: Plants & Animals
Abiotic Factors: physical influences (non-living)
 Ex: Temperature, sunlight, soil, water
Species (#6):
Habitat: includes the area and its factors where an
organism lives
 Can be either specific or broad depending on the organism
Niche: an organisms role/job within its habitat
(Ex: cleaner fish eat parasites and dead skin off of fish on
reefs)
Population (#5):
Population density refers to the number of individuals per
unit area.
(Example: A population of ducks in a pond may have a low
density, while fish and other animals in the same pond
community may have higher densities.)
Population (#5):
Dispersion refers to how individuals in a population are
spaced out across the range of the population—randomly,
uniformly, or in clumps.
(Ex. Dolphins travel in pods or clumps)
Population (#5):
A population’s growth rate determines whether the
population size increases, decreases, or stays the same.
How do we determine growth rate?
• Birth rate
• Death rate
• Immigration (enter)
• Emigration (exit)
Population (#5):
Carrying capacity is the maximum number of individuals of a
particular species that a particular environment can support.
When (Birth rate + Immigration = Death rate + Emigration)
population growth stops and you get your carrying capacity
How Scientists Get Population (#5) Info?
How do scientists determine the density, dispersion,
growth rate, & carrying capacity of a population?
By safely sampling or capturing organisms and recording
information (2 common examples):
1.Random Sampling Technique
2.Mark & Recapture Technique