Download Ecology of Organisms

Ecology Unit
Part 2:
Ecology of Organisms
Ecosystem Components
• Ecologists separate the
environmental factors that
influence an organism into two
types:
– Biotic factors
– Abiotic factors
Abiotic Factors
• Are the nonliving factors, the
physical and chemical
characteristics of an environment
• Include soil, temperature, humidity,
pH, salinity, oxygen concentration,
amount of sunlight, availability of
nitrogen, precipitation, and wind
Biotic Factors
• Include all the living things that
affect an organism
• Such as: predators eating their prey,
and a butterfly feeding on pollen
from a flower
Abiotic & Biotic Factors
• The importance of each factor
varies from environment (habitat) to
environment (habitat)
• They are not independent
• Organisms change their environment
and are influenced by those changes
• Abiotic factors are not constant
Organisms in a Changing
Environment
• Each organism is able to survive
within a limited range of
environmental conditions
• One way to study this is to make a
graph of performance versus the
values of an environmental variable,
such as temperature
• This graph is called a tolerance curve
Acclimation
• Is the process through which some
organism can adjust their
tolerance to abiotic factors
• This process occurs within the
lifetime of an individual organism
• It is different from adaptation
Control of Internal Conditions
• Environments fluctuate in their abiotic
factors
• There are two ways for organism to deal
with some of these changes
– Conformers: are organisms that do not
regulate their internal conditions, they
change with their environments
– Regulators: are organisms that use
energy to control some of their internal
conditions
Examples of Conformers &
Regulators
•
•
•
•
Conformers
Komodo dragon
Gecko
African spurred
tortoise
• Anole lizard
• Chameleon
• Anaconda
•
•
•
•
•
•
Regulators
Sperm whale
Orangutan
Koloa
Armadillo
Great Horned
Owl
• Human
Escape from Unsuitable
Conditions
• Some species survive unfavorable
environmental conditions by
temporarily escaping them
• Desert animals are nocturnal
• Some organisms enter a state of
reduced activity called dormancy
• Another strategy is migration, which
moving away from the unfavorable
habitat
The Niche
• Organisms do not use or occupy all
parts of their habitat at once
• The specific role of an organism
within its environment is called its
niche
• Some species have more than one
niche in their lifetime
What does a Niche Include?
• the range of conditions that the
species can tolerate
• the resources its uses
• the methods by which it obtains
resources
• the number of offspring
• its time of reproduction
• and all other interactions with its
environment
Generalists vs. Specialists
•
•
•
•
•
Are
species
with
Are species with
narrow niches
broad niches
Can tolerate a range • Have a limited range
of conditions that
of conditions
can be tolerated
Can use a variety of
• Have specific
resources
resource needs
Ex. Pigs
• Ex. Koala