Ecosystem Ecology I. Introduction II. Energy Flow III. Biogeochemical Cycles.
I. Energy Flow
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Transcript of I. Energy Flow
I. Energy Flow
A. Producers Make their own food through
photosynthesis using sun, water, and carbon dioxide
Plants, algae
B. Consumers Feed on other organisms, cannot
make their own food Example: humans, bear, fox, cow,
insects
C. Decomposers Break down dead organisms, recycling
chemicals to soil, water, & air Example: fungi, bacteria, certain
insects like earthworms, centipedes, sow bugs
D. Energy enters ecosystems as LIGHT is converted to CHEMICAL ENERGY by producers and exits the ecosystem as HEAT.
II. Food Chain
A. Trophic levels
Feeding level, represents
position in food chain/food web
B. Food Chain pathway of food transfer from one trophic level to another
You always start with PRODUCERS on the left/bottom of a food chain.
C. Producer --> Primary Consumer--> Secondary Consumer--> Tertiary
Consumer
D. Decomposers are found at EACH trophic level.
III. Food Web
A. Definition: pattern of feeding represented by
interconnected branching food chains- more realistic representation of feeding relationships.
B. Draw a simple food web
IV. Three Kinds of Ecological Pyramids
A. Energy pyramid Description: diagram representing energy
loss from one trophic level to the next
10% Rule- an average of 10% of the available energy at a trophic level is converted to biomass in the next higher trophic level.
B. Biomass Pyramid Description: represents the actual
dry mass of organisms at each trophic level
C. Pyramid of Numbers Description: the number of
individual organisms in each trophic level of an ecosystem
V. Chemical Cycles
A. Basic plan Producers Consumers Decomposers
B. Carbon-Oxygen Cycle
CO2 Used for photosynthesis
Product of photosynthesis is sugar and oxygen
During cellular respiration, sugar is broken down in presence of oxygen, and CO2 is release into air
The Carbon Cycle
The Carbon Cycle
C. NITROGEN CYCLE
Nitrogen found in amino acids, make
proteins
80% of it is in atmosphere
Nitrogen Fixation- certain bacteria “fix” nitrogen gas into ammonium
Found near peas, beans, alfalfa
Nitrification- other bacteria convert ammonium into nitrate
Plants can USE nitrate
Eutrophication!
The Nitrogen
Cycle
The Nitrogen
Cycle