Download Organisms and Their Environment

Principles of Ecology
KEY CONCEPT
Ecology is the study of the relationships among
organisms and their environment.
Food Chains And Food Webs
Principles of Ecology
Interdependence: A key theme in Ecology
• Species interact with both other species and their
nonliving environment
• One change can affect all species in an ecosystem
Food Chains And Food Webs
Principles of Ecology
Ecologists study environments at different levels of
organization.
- each level has unique properties resulting from
interactions with its components
Food Chains And Food Webs
Principles of Ecology
• An organism is an individual living
thing, such as an alligator.
Food Chains And Food Webs
Organism
Organism
Principles of Ecology
• A population is a group of the same
species that lives in one area.
Food Chains And Food Webs
Population
Population
Organism
Organism
Principles of Ecology
• A community is a group of different
species that live together in one area.
Food Chains And Food Webs
Community
Community
Population
Population
Organism
Organism
Principles of Ecology
• An ecosystem includes all of the
organisms as well as the climate, soil,
water, rocks and other nonliving things
in a given area.
Ecosystem
Ecosystem
Food Chains And Food Webs
Community
Community
Population
Population
Organism
Organism
Principles of Ecology
• A biome is a major regional or global
community of organisms characterized
by the climate conditions and plant
communities that thrive there.
Biome
Ecosystem
Ecosystem
Food Chains And Food Webs
Community
Community
Population
Population
Organism
Organism
Principles of Ecology
The Biosphere
• The broadest, most inclusive level of organization is the
biosphere, the volume of Earth and its atmosphere that
supports life.
Food Chains And Food Webs
Organisms and Their Environment
KEY CONCEPT
Every ecosystem includes both living and nonliving
factors.
Organisms and Their Environment
An ecosystem includes both biotic and abiotic factors.
• Biotic factors are living things.
– plants
– animals
– fungi
– bacteria
plants
Organisms and Their Environment
• Abiotic factors are nonliving things.
– moisture
– temperature
– wind
– sunlight
– soil
sunlight
moisture
Organisms and Their Environment
Organisms in a Changing Environment
• Acclimation
– Some organisms can adjust their tolerance to abiotic
factors through the process of acclimation.
– Occurs within the lifetime of an individual organism
• Adaptation
– Genetic change in a species
or population that occurs
from generation to
generation over time
Organisms and Their Environment
Organisms in a Changing Environment
• Control of Internal Conditions
– Conformers
Organisms that do not regulate their internal condtions; they
change as their external environment changes
– Regulators
Use energy to control some
of their internal conditions
Organisms and Their Environment
Organisms in a Changing Environment
• Escape from Unsuitable Conditions
– Some species survive unfavorable environmental
conditions by becoming dormant or migrating.
Organisms and Their Environment
Changing one factor in an ecosystem can affect many
other factors.
• 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.
Organisms and Their Environment
• A keystone species is a species that has an unusually
large effect on its ecosystem.
keystone
Organisms and Their Environment
• 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
Organisms and Their Environment
The Niche
• A niche is a way of life, or role in an ecosystem
– Range of conditions a species can tolerate
– Resources it uses
– Methods by which it obtains resources
– Number of offspring
– Time of reproduction
– All other interactions
with its environment