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Energy Flow in ecosystems?. Most of Earth’s energy comes from the sun Some of Earth’s inhabitants have adapted to convert solar energy to chemical potential energy in carbon bonds. Food chains trace a single flow of energy and show trophic levels -the levels of nourishment in a food chain. - PowerPoint PPT Presentation
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Most of Earth’s energy comes from the sunSome of Earth’s inhabitants have adapted to convert solar energy to chemical potential energy in carbon bonds.Food chains trace a single flow of energy and show trophic levels-the levels of nourishment in a food chain
Energy Flow in ecosystems?
April 19, 2023
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Energy Flow in Ecosystems
First law of thermodynamics
– Energy cannot be created or destroyed
– It can be converted to other forms
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Energy Flow in Ecosystems
There is loss of energy with conversion, usually in the form of heat
The heat energy still exists, but cannot be used Example: Internal combustion engines in cars are 25%
efficient in converting chemical energy to kinetic energy; the rest is not used or is lost as heat.
Second law of thermodynamics
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Energy Flow in Ecosystems
THINK ABOUT IT
1. What happens to energy stored in body tissues when one organism eats another? Energy moves from the “eaten” to the “eater.” Where it
goes from there depends on who eats whom!
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Energy Flow in Ecosystems
How does energy flow through ecosystems?
Energy flows through an ecosystem in a one-way stream, from primary producers to various consumers.
Many types of consumers Herbivores - eat plants, algae, or autotrophic bacteria, are the
primary consumers of an ecosystem
Carnivores - which eat the consumers from the levels below– Secondary consumers include many small mammals, such as
rodents, and small fishes that eat zooplankton
– Tertiary consumers, such as snakes, eat mice and other secondary consumers
– Quaternary consumers include hawks and killer whales.
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Energy Flow in Ecosystems
• Omnivores
• Detritivores
• Decomposers
• Scavengers
• Derive their energy from the dead material left by all trophic levels
• Digest complex organic chemicals into inorganic nutrients that are used by producers
• Completes the cycle of matter. April 19, 2023
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Energy Flow in Ecosystems
Quaternary,
tertiary,
and secondary consumers
Tertiary and
secondary consumers
Secondary and
primary consumers
Primary consumers
Producers (plants)
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Energy Flow in Ecosystems
Ways of obtaining energy
Producers Also called autotrophs Obtain energy from
nonliving sources Most capture energy
during photosynthesis to make simple sugars
Consumers Also called heterotrophs Obtain energy from
living or once-living organisms
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Energy Flow in Ecosystems
How producers get their energy?
Photosynthesis Chemosynthesis
Source of energy:
• Sunlight
CO2 + water sugars CO2 + water + H2S + O2 sugars + sulfuric acid
Source of energy:
• Chemicals
• Sulfer-rich salt marshUse non-
living sources for
energy
Examples:-Green plants-Cyanobacteria
Examples:-Deep sea vent bacteria
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Energy Flow in Ecosystems
Energy from the Sun is stored as GLUCOSE
Created during photosynthesis from carbon dioxide
Broken down during cellular respiration (in consumers) and released as carbon dioxide Glucose
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Energy Flow in Ecosystems
Associated terms with energy production and energy flow.
Primary production: Fixation of energy by autotrophs in an ecosystem.
Rate of primary production: Amount of energy fixed over a given period of time.
Gross primary production (GPP): Total amount of energy fixed by autotrophs.
Net primary production (NPP): Amount of energy leftover after autotrophs have met their
metabolic needs.
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Energy Flow in Ecosystems
Primary Productivity in Ecosystems
Gross primary productivity (GPP)• The rate at which an ecosystem's producers capture and store a
given amount of chemical energy as biomass in a given length of time.
Net primary productivity (NPP)• Rate at which all the plants in an ecosystem produce net useful
chemical energy; equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (gross primary productivity) and the rate at which they use some of that energy through cellular respiration.
• (NPP = GPP – Respiration)
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Energy Flow in Ecosystems
The rate of production of new biomass by consumers, i.e., the rate at which consumers convert organic material into new biomass of consumers.
Note that secondary production simply involves the repackaging of energy previously captured by producers--no additional energy is introduced into the food chain.
And, since there are multiple levels of consumers and no new energy is being captured and introduced into the system, the modifiers gross and net are not very appropriate and are not usually used.
Secondary productivity:
Coral reefs and Marine ecosystems have the highest primary productivity?
WHY?Highest rates of primary production by marine
phytoplankton are generally concentrated in areas with higher levels of nutrient availability.
Highest rates found along continental margins. Nutrient run-off from land. Sediment disturbance
Open ocean tends to be nutrient poor. Vertical mixing main nutrient source.
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Energy Flow in Ecosystems
Terrestrial primary production generally increases with moisture and temperature
•Rosenwitz studied net primary production across biomes
•Compare NPP to actual evapotranspiration
What controls primary productivity?
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Energy Flow in Ecosystems
Terrestrial and aquatic primary production is also limited by nutrient availability
What controls primary productivity?
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Energy Flow in Ecosystems
