TRANSFERS OF ENERGY AND MATTER
ECOSYSTEMS AS OPEN SYSTEMS
Ecosystems and Energy-Matter Dynamics
Ecosystems are composed of biotic communities interacting with their abiotic environment,
with energy and matter constantly being exchanged among organisms and their surroundings.
Key Concepts
● Matter: Anything with mass and volume, including nutrients, gases, and essential
substances for life.
● Energy: The capacity to do work or drive biological processes (e.g., growth,
reproduction).
Thermodynamics in Ecosystems
The principles of thermodynamics explain energy flow and transformation in biological
systems, including ecosystems.
● System Types:
○ Open Systems: Exchange both
energy and matter with
surroundings.
■ Examples: Ecosystems
like rainforests or
grasslands, which receive
sunlight (energy) and
cycle nutrients (matter).
○ Closed Systems: Exchange
energy but restrict matter flow.
■ Examples:
■ Mesocosms:
Controlled setups
simulating
ecosystems for
research.
■ Mechanical
systems like hair
dryers (energy
input, fixed mass).
○ Isolated Systems: Theoretical
systems with no exchange of
energy or matter.
■ Example: The universe is often considered isolated, though this is
debated.
,ENERGY FLOW IN ECOSYSTEMS
Energy is the driving force behind life in ecosystems, powering the metabolic processes
organisms need to survive. Its movement within ecosystems supports all trophic levels,
sustaining life and maintaining ecological balance.
● Primary Energy Source:
○ The Sun provides most of the energy for ecosystems.
○ Through photosynthesis, plants and other photosynthetic organisms convert
sunlight into chemical energy, creating energy-rich organic compounds.
○ Plants are called producers because they transform energy into a usable form
for other organisms.
● Energy Transfer:
○ Producers: Store chemical energy in organic compounds.
○ Herbivores: Consume plants, extracting stored energy.
○ Carnivores: Feed on herbivores, transferring energy further up the food chain.
This progression forms the basis of food chains
While sunlight powers most ecosystems, some environments lack sunlight, requiring
organisms to adapt to alternative energy sources
- deep-sea hydrothermal vents
- caves
These organisms use → chemosynthesis
Chemosynthetic organisms → specialized bacteria that extract energy from inorganic
compounds like minerals or sulphur, instead of relying on sunlight
, FOOD CHAINS & FOOD WEBS
Food chains: are models that illustrate the transfer of energy through a sequence of organisms
in an ecosystem. In a food chain diagram, the arrows always indicate the direction in which
energy and matter are flowing.
Food chains don’t fully capture the complexity of feeding relationships in an ecosystem
Food webs are models that consist of many interconnected food chains
ECOSYSTEMS AS OPEN SYSTEMS
Ecosystems and Energy-Matter Dynamics
Ecosystems are composed of biotic communities interacting with their abiotic environment,
with energy and matter constantly being exchanged among organisms and their surroundings.
Key Concepts
● Matter: Anything with mass and volume, including nutrients, gases, and essential
substances for life.
● Energy: The capacity to do work or drive biological processes (e.g., growth,
reproduction).
Thermodynamics in Ecosystems
The principles of thermodynamics explain energy flow and transformation in biological
systems, including ecosystems.
● System Types:
○ Open Systems: Exchange both
energy and matter with
surroundings.
■ Examples: Ecosystems
like rainforests or
grasslands, which receive
sunlight (energy) and
cycle nutrients (matter).
○ Closed Systems: Exchange
energy but restrict matter flow.
■ Examples:
■ Mesocosms:
Controlled setups
simulating
ecosystems for
research.
■ Mechanical
systems like hair
dryers (energy
input, fixed mass).
○ Isolated Systems: Theoretical
systems with no exchange of
energy or matter.
■ Example: The universe is often considered isolated, though this is
debated.
,ENERGY FLOW IN ECOSYSTEMS
Energy is the driving force behind life in ecosystems, powering the metabolic processes
organisms need to survive. Its movement within ecosystems supports all trophic levels,
sustaining life and maintaining ecological balance.
● Primary Energy Source:
○ The Sun provides most of the energy for ecosystems.
○ Through photosynthesis, plants and other photosynthetic organisms convert
sunlight into chemical energy, creating energy-rich organic compounds.
○ Plants are called producers because they transform energy into a usable form
for other organisms.
● Energy Transfer:
○ Producers: Store chemical energy in organic compounds.
○ Herbivores: Consume plants, extracting stored energy.
○ Carnivores: Feed on herbivores, transferring energy further up the food chain.
This progression forms the basis of food chains
While sunlight powers most ecosystems, some environments lack sunlight, requiring
organisms to adapt to alternative energy sources
- deep-sea hydrothermal vents
- caves
These organisms use → chemosynthesis
Chemosynthetic organisms → specialized bacteria that extract energy from inorganic
compounds like minerals or sulphur, instead of relying on sunlight
, FOOD CHAINS & FOOD WEBS
Food chains: are models that illustrate the transfer of energy through a sequence of organisms
in an ecosystem. In a food chain diagram, the arrows always indicate the direction in which
energy and matter are flowing.
Food chains don’t fully capture the complexity of feeding relationships in an ecosystem
Food webs are models that consist of many interconnected food chains
