Principles of
Ecology
Chapter 15 and 16
What is Ecology?
• Ecology: the study of interactions among
organisms and living and nonliving
components of their environments.
– Reveals relationships among living and nonliving parts of the world
– Observed both in the lab and the
environment
What would an ecologist study or
look for in the environment?
Aspects of Ecological Study
• Biosphere: portion of the earth that supports life.
– Includes:
• Atmosphere
• Hydrosphere:
Oceans and Lakes
• Lithosphere:
Terrestrial Earth
• Ecosphere:
All living organisms
Non-Living Environment
• Abiotic Factors: non-living parts of an organism’s
environment
Examples:
•
•
•
•
•
Air & Water Temperatures
Moisture & Precipitation
Light
Soil
Wind
Why are abiotic factors important in
ecology?
How do they effect living organisms?
Importance of Water!
• Why introduce water as something we
should study?
• Because all living things need water!
• We will be studying how the properties of
water effects what can live there.
Where’s all the water?
•
•
•
•
•
•
Oceans: 97.2 %
Icecaps and Glaciers: 2.0 %
Groundwater: 0.62%
Atmosphere: 0.001%
Freshwater: 0.0009%
Rivers: 0.0001%
Can’t Use!
Useable
Freshwater
Living Environment
• Biotic Factors: all the living things that
inhabit an environment.
Examples: look familiar?
• Animals
• Plants
• Fungi
• Protists
• Bacteria
Levels of Ecological Organization
Biosphere (most diverse)
Ecosystem
Community
Population
Individual (single organism)
Levels of Ecological
Organization
• Individual:
– Made of cells
– Uses energy (food)
– Reproduces
– Responds and adapts
– Grows and develops
What do we know these as?
Levels of Ecological
Organization
• Population:
A group of organisms that:
– Are all the same species
– Interbreed
– Live in the same area at the
same time
– Members of a population may
compete with each other for:
• food, water, mates, or other
resources
Levels of Ecological
Organization
• Community:
– Made of interacting populations in a certain area at
a certain time
– In a community a change in one population may
cause changes in other populations
How can one population influence
other populations?
Levels of Ecological
Organization
• Ecosystem:
– Is made up of interacting populations in a biological
community and the community’s abiotic factors
2 kinds:
• Terrestrial
– Forest, desert, grassland, tundra, mountains
• Aquatic
– Pond, lake, river, deep ocean, reef, estuary
What level is this?
Organisms in Ecosystems
• Habitat: the place where an
organism lives out its life
– Examples: grasslands, trees, muddy banks
• Niche: the role and position a species
has in its environment
– How it meets the needs for survival
– Includes all interactions with the biotic and
abiotic parts of its habitat
Niche
Examples:
– On forest floor there is competition for food and space:
• Millipedes – eat decaying leaves
• Centipedes – eat beetles and other animals
• Ants – eat dead insects
• Earthworms – take organic nutrients from the soil
• Fungi – take nutrients from decaying organic material
Living Relationships
• Some species increase
their chance of
survival by developing
relationships with
other organisms
• Some interactions are
harmful to one
species, others are
beneficial
Relationships cont.
• Predator – Prey relationship
– Predator: animals that consume other animals
– Prey: animals that are consumed
• Examples:
– Lions & wildebeests
• Symbiosis: “living together”
– relationship in which there is a close and permanent
association between different species
Relationships cont.
• Commensalism
– relationship in which one species benefits, while
the other species is neither benefited nor harmed
• Examples:
– Sea anemone & clownfish
– Shark & remora fish
Relationships cont.
• Mutualism:
– Both species benefit from the relationship
• Examples:
– Ants and acacia trees
– Hammerhead sharks & cleaner fish
• Parasitism:
– One species benefits while the other is harmed
• Examples:
– Fleas and dogs
– Ticks and deer
– Tapeworms and humans