1. Aim: Energy & Nutrients in Ecosystems
Enter Date
Warm-up:
HW:
Regents Biology

2. Food chains Feeding relationships
Level 4
Food chains
Tertiary consumer
Sun
Top
carnivore
Feeding relationships
all food chains start with energy from the sun
first level of all food chains is plants
all levels connect to decomposers
Level 3
Secondary consumer
Carnivore
Level 2
Primary consumer
Herbivore
Level 1
Producer
Fungi
Decomposers
Bacteria
Regents Biology

3. 10% Rule: Loss of energy
90% of energy lost between levels of food chain
To where is the energy lost? The cost of living!
10%
growth
only this energy moves on to the next level in the food chain
energy lost to daily living
35%
cellular
respiration
55%
waste (feces)
Regents Biology

4. Limits to population size
Food chain can only have 4 or 5 levels
only 10% of energy is passed to next level
each level up the food chain can support fewer and fewer organisms
Regents Biology

5. Food chain pyramid Loss of energy between levels of food chain
can feed fewer animals in each level
Population size 10
100
1,000
10,000
Regents Biology

6. Energy flows through… producers (plants) sun secondary consumers
(carnivores)
loss of energy
sun
loss of energy
primary consumers
(herbivores)
loss of energy
producers (plants)
Regents Biology

7. Food webs Food chains are linked together into food webs
predators eat different kinds of prey
Regents Biology

8. Regents Biology

9. But what about nutrients?
Decomposers return nutrients to the soil after creatures die
fungi
bacteria n u t r i e s
decomposers
Regents Biology

10. Nutrients cycle around… through decomposers
consumers
decomposers
producers
phosphorus
potassium
iron
carbon
nitrogen
soil
magnesium
calcium
Regents Biology

11. So what controls population size?
Natural controls
abiotic
sunlight, temperature
water
nutrients
biotic
predators
diseases
parasites
competitors
food
nesting sites
Regents Biology

12. Carrying Capacity Maximum population size supported by the environment
Regents Biology