Transcript Ecology - Port Washington School District

Ecology
• How is Earth a living planet?
• How do we study it?
Ecology:
– Study of interconnectedness of living things.
– How organisms interact and depend on each
other for survival
– How they interact with and affect their
environments
What’s the Connection?
• Ex: Bee and Flower
• Ex: Squirrel and Oak tree
• Ex: Mosquitoes and Frogs
• Ex: Human driving a car and planet
Levels of Ecological Organization
• Ecologists study different levels within the
environment
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Individual Organisms
Populations
Communities
Ecosystems
Biomes
Biosphere
What might we study about…
Organisms: Looks at behavior of individuals
Only part of the story because individuals depend
on each other for food, shelter and protection
Ex:
– movements,
– feeding behavior,
– offspring produced,
– sleep cycles,
– migration patterns
• Ex: One white tailed deer
What might we study about…
Populations: group of individuals of same species
that live in same area and interbreed
– Ex: Herd of white tailed deer
– Look at how populations utilize resources.
– How large is the population? Is it increasing,
declining?
– What diseases may be affecting it
– What are affects of pollution on population
• Why is it a good adaptation in many species for
the juveniles to consume a different food source
and live in a different part of the environment?
– Adaptation to reduce competition for
resources!
What might we study about…
Communities: populations of different species
that interact and inhabit the same environment.
– A change in one population in a community will usually
change and affect the other populations
• Ex: Forest Community
• How does an increase in hawk population
affect the mouse population?
– What other affects would that have on other
plant and animal species in the community?
What might we study about…
• Ecosystems: Communities of organisms
interacting with each other and with their
physical environment.
– Can involve hundreds of different species
• Terrestrial Ecosystems: on land
– Ex: Forest, meadow, desert, taiga, tundra
• Aquatic Ecosystems: in fresh or salt water
– Ex: Freshwater: Ponds, lakes, rivers, streams
– Ex: Marine (salt): oceans
• What are some of the effects of deforestation
on tropical rainforest ecosystems?
Characteristics of a Balanced Ecosystem
– Constant source of energy (ex: sunlight)
– Population of organisms that can store that
energy in a usable form (autotrophic
“producers”)
– Flow of energy from one population to another
– Way for materials and nutrients to be recycled
• Biomes: group of ecosystems with similar
climates & typical organisms
Tropical Grassland
Tropical Rain Forrest
Temperate Deciduous Forest
Taiga: Coniferous Forest
Desert
Tundra
• Biosphere: portion of planet that supports
life, (land, water, air)
– A very thin layer of Earth’s total area, but it
extends high into atmosphere and deep into
oceans (ex: The peel of an apple)
Living and Nonliving Environment
The physical environment and living
environment are connected in many ways
Some abiotic factors
How might they affect life here?
Biotic and Abiotic Factors
Biotic Factors: living things in an environment
that affect other living things
– Ex:
• Predators, parasites, worms in soil, decomposers recycle materials
Abiotic Factors: nonliving parts of environment that
affect living things
– Ex:
• Light: intensity and duration (depends on latitude)
• Temp: varies with latitude and altitude
• Water: amount of precipitation
Short Clips: Biotic and Abiotic Factors:
http://www.youtube.com/watch?v=woSO0D94VGA&safe=active
http://www.youtube.com/watch?v=7Wfs2L5IydY&safe=active
Limiting Factors
• Resources that are available in the
shortest supply
Ex:
– Availability of food
– Amount of moisture in the desert
– Amount of usable nitrogen in soil
Energy Flow in Ecosystems
• All organisms need energy to power life’s
processes
– Where does this energy come from?
– How is it transferred from one organism to
another?
Trophic Levels
• Each step in a food chain or food web is
called a trophic level.
– Primary producers are always in the first
trophic level
Primary Producers
(First Trophic Level)
Autotrophs
– Utilize energy from
either sunlight or
chemical compounds
to make their own food
– Usually at the base of
a “food chain”
Capturing Energy
• Photosynthesis
– Captures light energy using special pigments
– Converts carbon dioxide and water into sugars
• Chemosynthesis
– Harnesses chemical energy from inorganic
molecules such as hydrogen sulfide
• Ex: Bacteria in deep sea volcanic vents
Consumers
(Second, Third, Forth Trophic Levels etc…)
Heterotrophs
– Acquire energy and nutrients from eating other
organisms
– Can’t make own food
Types of Consumers
Herbivores:
• (Primary Consumers)
– eat plants
Carnivores: (Secondary Consumers)
– usually kill and eat other animals (often eat
herbivores)
Scavengers:
(Secondary/Tertiary
Consumers)
– Eats dead animals (both
herbivores and carnivores)
Omnivores: (Primary & Secondary consumers)
– Eat both plants and animals
Decomposers:
(Saprophytes)
– Break down dead
material at all levels of
food chain
Food Chains and Food Webs
Short Clip:
http://www.youtube.com/watch?v=3Bn7wdCP2v4&safe
=active
• Food Chains: series of steps in which
organisms transfer energy by eating and
being eaten.
• Food Webs: show more complex feeding
relationships and how they are interrelated
– Link together all the food chains in an
ecosystem
Food Webs
Importance of Decomposers:
– Eat both producers and consumers
– Always the final consumer in any food chain or web
– Help return nutrients from dead material back to
environment
– Without them nutrients would remain locked within
dead organisms
– Recyclers!
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Decomposers:
http://www.youtube.com/watch?v=Z6V0a_7N1Mw&safe=active
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Rabbit decomposition:
http://www.youtube.com/watch?v=jrSHku6-LFo&safe=active
Pyramids of Energy
• Show relative
amount of energy
available at each
trophic level
• On average only
10% of the energy is
transferred to the
next level.
Most energy available at bottom
10% Rule
• Part of the energy is lost as heat or is used
by organism to carry out life functions.
• Some food is not completely digested
Pyramids of Biomass
• Shows the total amount (mass) of living
organic matter available at each level.
Pyramid of Numbers
• Shows relative numbers of organisms at
each trophic level
How and Where Organisms Live
Niche: the role a species plays in it’s community
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How it uses and affects its environment.
What it feeds on
Where it lives
What preys on it
• Ex:
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Grass = producer
Mushroom = decomposer
Centipede = predator
Worms = burrow through soil eating organic material
Habitat: where an organism lives it’s life
– Ex: burrow, cave, lake, forest, soil
• Although several species may share a
habitat, the food, shelter and other
resources are divided into separate niches
• Distinct behaviors have developed to
reduce competition for available resources
• Ex: Decaying Log has Many Niches
– Animals feed in different ways on different
materials
• Millipede: eats decaying leaves,
• Worm: eats organic material in soil,
• Centipede eats other insects
Competition: arises when niches overlap
– More than one species has same requirements
– Compete for same resources
– Organisms have evolved to be specialized and
adapted to exist in their specific niche in an
ecosystem
– Interspecific Competition:
• between different species for same niche and
resources
– Intraspecific Competition:
• between same species for same niche and
resources
• Niche Clips:
• http://www.youtube.com/watch?v=6aGxYTUPu0&safe=active
• http://www.youtube.com/watch?v=z3eDLQym9qo&
safe=active
• Food Chain Song:
• http://www.youtube.com/watch?v=TE6wqG4nb3
M&safe=active
• Summary of Key Terms:
• http://www.youtube.com/watch?v=YvZlooi5_kE&
safe=active
• Ecosystems and biomes:
• http://www.youtube.com/watch?v=dTaWsFct32g