Download Energy Flow in Ecosystems

Biology
Class Notes
Lesson 14 Energy Flow in Ecosystems
Objective: 2.1.1, 4.2.2
Biomass: All living organisms on earth.
Ecology: The branch of science that studies relationships between living
organisms and their environment.
*The primary focus is on interdependence (i.e. how species interact and
the effects of these interactions).
Trophic Level (TL): Each feeding level in ecosystem.
Feeding Strategies for Each Trophic Level
Consumers (Heterotrophs): Organisms that obtain their energyy eating
other organisms.
Producers (Autotrophs) (TL 1): Organisms that capture energy and
convert it into chemical energy stored in the chemcial bonds of glucose.
Primary Consumer (TL 2): Organisms that eat producers.
Ex: Rabbits, cardinals, and squirrels.
Seondary Consumers (TL 3): Organisms that eat primary
consumers.
Ex: Fox, coyotes and red-tailed hawks
Tertiary Consumers (TL 4) Organsims that eat seondary
consumers.
Ex: Bear and mountain lions.
Quaternary Consumers (TL 5): Oranisms that can
eat tertiary consumers.
Ex: Aligators
Decomposers: Organisms that obtain energy from organic wastes such as
fallen leaves or dead organisms.
Meat or Vegtable?
Herbivores: Consumers that eat mostly plants (producers).
Carnivores: Secondary consumer that east most meat (other consumers).
Omnivores: Secondary consumers that eat both plants and meat (producers
and consumers).
Heirarchy of Life
Biosphere: All parts of the Earth and its atmosphere that supports life.
• Life is not distributed evenly and most life is found near the surface
of land or water.
Ecosystem: Organisms interacting as interdependent communities in a
large area.
• Has both living and non-living parts
• Types vary and include: forests, rivers, lakes, oceans, coral reefs,
etc.
• The environment determines the boundaries of an ecosystem.
Ex: Desert Ecosystem vs. Temperatate Forest Ecosystem
Population: A group of individuals of the same species in a given
area.
Ex: Western Diamondback Rattlesnakes vs. White Oak trees
Organism: An individual member of a population.
Ex: one W. Diamondback Rattlesnake vs. one White Oak
tree.
“This we know. The earth does not belong to man, man belongs to earth. All
things are connected, like the blood which connects one family. Whatever
befalls the earth befalls the children of the earth. Man did not weave the web
of life, he is merely a strand in it. Whatever he does to the web, he does to
himself”. Chief Seattle, 1854
Food Chains and Energy Pyramids
• Describe the energy flow in ecosystems.
• Begin with the sun trapped by producers.
• Energy is exchanged from producers to consumers.
• Each step is a trophic level.
• **Only ~10% of the available energy is passed from one level the next.
Food Webs
• Connects multiple food chains.
• Producers and consumers can belong to multiple food chains.
• Food webs: on land = terrestrial food webs, in fresh water = aquatic
food webs, an in the ocean- marine food webs.
Key Words:
Ecosystem
Producer
Consumer
Primary consumer
Secondary consumer
Decomposer
Food chain
Food web
Trophic level
Hervivore
Carnivor
Omnivore
Energy pyramid
Biomass