Energy Flow in Ecosystems

Ecosystem

A biological community and its physical environment interacting as a system

What are the 2 components of an ecosystem?

Biotic and abiotic factors

Biotic factors

Living organisms

Abiotic factors

Non-living elements like sunlight, water, and minerals

What is the primary energy source for most ecosystems?

Sunlight

Photosynthesis

Conversion of light energy into chemical energy by producers

Chemosynthesis

Energy from inorganic chemical reactions, used by some bacteria

Autotrophs

Organisms that produce their own food (plants)

Heterotrophs

Organisms that consumes other organisms

What are the 3 heterotrophs?

1. Herbivores

2. Carnivores

3. Omnivores

Herbivores

Organisms that only eat plants

Carnivores

Organisms that only eat animals

Omnivores

Organisms that eat both plants and animals

Decomposers

Organisms that break down dead matter (ex. Fungi and bacteria)

Primary production

Amount of light energy converted to chemical energy by autotrophs

Gross primary production (GPP)

Total primary production

Net primary production (NPP)

GPP minus energy uses by producers for respiration

Secondary production

Biomass generated by heterotrophs consuming autotrophs

Food chains

A linear sequence of organisms through which nutrients and energy pass

What are the trophies levels of food chains?

1. Producers

2. Primary consumers

3. Secondary consumers

4. Tertiary consumers

Producers

Base of the food chain

Primary consumers

Herbivores on the food chain

Secondary consumers

Carnivores eating herbivores on the food chain

Tertiary consumers

Carnivores eating other carnivores on the food chain

Energy pyramid

Graphical representation of energy flow

Energy transfer efficiency

Approximately 10% of energy is transferred to the next tropic level

Implications of trophies levels and energy pyramids

Limits the number of trophies levels due to energy loss

What are the 3 reasons for energy loss

1. Respiration

2. Heat loss

3. Waste

Energy uses for metabolic processes

Respiration

Energy lost as heat

Heat loss

Energy in undigested materials

Waste

What are the ecosystem implications with the loss of energy?

Energy flow is unidirectional; continuous input is needed