Transcript Life and the Environment

Life and the
Environment
Biosphere
• The part of the earth that supports life.
• Only a small portion of Earth.
• Includes the topmost part of the crust, the
earth’s waters, and the atmosphere.
Biomes
• Large geographic areas that have similar
climates and ecosystems.
• Ex: tundra, taiga, temperate deciduous forest,
tropical rain forest, grassland, desert,
freshwater, and saltwater biomes.
Climate/Ecosystem
• Climate - average weather conditions in an
area over a long period of time.
• Factors include temperature, latitude,
elevation, and precipitation.
• Ecosystem – made of communities and the
non-living factors that affect them.
Ecology
• The study of interactions of organisms with
other organisms and with the physical
environment.
Abiotic Factors
• The non-living features or conditions of the
environment.
• Ex: soil, water, light, air and temperature.
• Have effects on living things and often
determine the organisms that are able to live
in a certain environment.
Biotic Factors
• Living or once-living organisms in the
environment.
Habitat
• The physical location where an individual
lives, the “home”.
• Provides the kinds of food and shelter, the
temperature, and the amount of moisture the
organism needs to survive.
Niche
• The role the individual plays in the
ecosystem, its “job”.
• What it eats
• How it gets its food
• How it interacts with other organisms
Carrying Capacity
• The largest number of individuals an
environment can support and maintain for a
long period of time.
Limiting Factor
• Any biotic or abiotic factor that restricts the
number of individuals in a population.
• Ex: food, water, living space, mates, nesting
sites.
Competition
• The struggle among organisms to obtain
the resources they need to survive and
reproduce.
• As population density increases, so does
competition among individuals.
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Space
Light
Food
Water
Reproduction
Biological
Relationships
• Predation – when one organism feeds on
another, the prey organism (a limiting
factor to the prey species).
• Symbiosis – any close relationship between
two or more different species.
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Mutualism – both species benefit. (lichen - fungus
and alga working together)
Commensalism – benefits one species, but neither
helps nor harms the other.
Parasitism – benefits one species but definitely harms
the other. (parasite worms, leeches)
Mutualism
“I win - you win”
Parasitism
“I win – you lose”
Commensalism
“I win - and I don’t
really care if you
win or lose”
Energy Flow Through
Ecosystems
• Most of the interactions between members
of different species are feeding
relationships.
• They involve the transfer of energy from
one organism to another.
• Energy moves through an ecosystem in the
form of food.
Food Chain
• A simple way to show how food (energy)
transfers from sun to producer to consumer.
Phytoplankton  Insects  Bluegill  Bass
Clover  Rabbit  Fox  Decay microorganisms
Producers
• Organisms that capture
energy from the sun.
Consumers
• Organisms that obtain energy when they
feed on producers or other consumers.
• Primary
• Secondary
• Tertiary
Types of Consumers
• Herbivore – plant eater
• Carnivore – meat eater
• Omnivore - both
Decomposers
• Organisms that break down
dead or decaying organisms
and turn them into nutrients
in the soil.