EQ: How do Energy and Matter

Move In an Ecosystem?

• Sunlight is the main source of energy for life on Earth.

• Producers/Autotrophs – use energy from the environment (often sunlight) to make their own food

- Ex: Plants and algae

Plants and algae make food in a process called

Photosynthesis

Remember…6CO2 + 6H2O 6O2 + C6H12O6

• Consumers/Heterotrophs Get energy from the food they eat.

Types of Heterotrophs• Herbivores – eat plants (ex. cows)

• Carnivores – eat other animals (ex. lions)…some even eat dead stuff… they are called Scavengers

• Omnivores – eat plants and animals (ex. humans)

• Decomposers – break down dead organic matter for energy (ex. Bacteria and fungi)

Tracking Energy Flow

• Food Chains: series of steps in an ecosystem in which organisms transfer energy by eating and being eaten.

sun willow elk wolf

Each step in a food chain is called a trophic level

• 1st level: Producers

• 2nd level: Primary (first level) Consumers

• 3rd level: Secondary (second level) Consumers

• 4th level: Tertiary (third level) Consumers

• Top level consumer in an ecosystem is called the Apex predator

• Food webs – shows network of food chains in an ecosystem

• Arrows show the direction energy is being transferred.

leaf caterpillar robin

• Rule of 10 – only 10% of the energy available in one trophic level is transferred to organisms at the next level. Most energy is lost as heat.

Community Interactions

• Competition – for food, water, shelter, mates

• Predation

• Symbiosis – two species live closely together

Types of Symbiosis1. Mutualism – both species

benefit

2. Commensalism – 1 organism benefits; the other is unharmed

3. Parasitism – 1 benefits, 1 is harmed

Mutualism

Commensalisms

Parasitism

• Habitat – where an organism lives

• Niche – an organism’s specific role in its environment

Ex. Place in food web

Limiting Factors

• Limiting factors are things in an environment that prevent a population from growing infinitely.

• Examples include things such as: water, food, mates, space, air, etc.

• All populations are kept in check by limiting factors.

Carrying Capacity

• The largest population that an environment can support

• Once carrying capacity is reached populations will begin to decrease as individuals move away or die off because of limiting factors.