Transcript Principles of Ecology

Principles of Ecology
O’Connor/Chapter 2
Ecology
• The study of interactions that take place
between organisms and their environments.
• Biosphere ~ the portion of Earth that
supports living things. Extends from high
in the atmosphere to the bottom of the
oceans.
Living vs. Nonliving
Abiotic Factors
• Biotic Factors
• Nonliving parts parts
of an organism’s
environment.
• All living organisms
that inhabit an
environment.
• Ex. Air currents,
temp., moisture, light,
and soil.
• Ex. Animals & plants.
Levels of Organisms
• To understand interactions of the biotic and
abiotic parts of the world, ecologists have
organized the living world into levels –
The organism itself, populations, communities
& ecosystems.
Populations
• A group of organisms, all of the same
species, which interbreed and live in the
same area at the same time.
Map of populations by country
Biological Communities
• Interacting populations in a certain area at a
certain time.
Ecosystems
• Interacting populations in a biological
community and the community’s abiotic
factors.
Types of Ecosystems
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Terrestrial
Forrest
Old farm field
Meadow
Yard
Garden plot empty lot
Compost heap
Volcano site
Rotting log
Aquatic
• Freshwater
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Pond
Lake
Stream
Estuary
Marine (salt H2O)
-ocean
-estuary
-aquarium
Other Ecosystems
• Human Body - ex. Skin
• Buildings
- ex. Basement
• Food
- moldy food
Habitat
• A place where an organism lives out its life.
Niche
• A role or position a species has in its
environment- how it meets its specific
needs for food & shelter, how & where it
survives, and where it reproduces in its
environment.
Symbiosis
• Relationship where there is a close and
permanent association between organisms
of different species. Three kinds:
• Mutualism
• Commensalism
• parasitism
Mutualism
• Both species benefit + +
• Ex. Ants & acacia trees- ants feed off it &
protect it from damaging predators
Commensalism + o
• One species benefits and the other species is
neither harmed nor benefited.
Parasitism + • When one species benefits at the expense of
another species.
Flea bites on human
How organisms Obtain Energy
• The producers – autotrophs
• The consumers – heterotrophs
• The decomposers
Energy Flow Through the Ecosystem
A food Chain - Web
• A model that scientists use to show how
matter & energy move through an
ecosystem.
• In a chain nutrients & energy move from
autotrophs to heterotrophs & eventually to
decomposers.
The arrow points to the mouth the eats it.
Which of these is an omnivore?
Levels of heterotrophs
• First –order (primary consumers)ex. Herbivores
like deer, turtles & fish. Obtain food by eating
photosynthetic organisms.
• Second-order (secondary consumers) Carnivores
like owls. They eat first order heterotrphs like mice.
• Third-order -Carnivores that feed on second order
heterotrophs. Ex. Bears, lions, humans
Biomass
• Foundation species (also known as primary
producers) harvest an energy source such as
sunlight and turn it into biomass.
• Primary production is generation of biomass
through photosynthesis.
Biomass Production
The highest producers of biomass are
• tropical rain forests, 2000 g/m²/yr of biomass
• swamps and marshes, 2500 g/m²/yr of biomass
• algal beds and reefs, 2000 g/m²/yr of biomass
• Lowest producers are
• deserts and frozen areas (less than 200 g/m²/yr
of biomass)
Trophic Levels
Cycles in nature
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The water cycle
The carbon cycle
The nitrogen cycle
The phosphorus cycle
• The materials of life, such as carbon &
nitrogen, are used and reused as they cycle
through the ecosystem.
Water Cycle
Carbon Cycle
Nitrogen Cycle
Phosphorus Cycle