1. Trophic Level – a feeding position in a food web
What are the top predators in this food web?
What are the primary producers?
Do you expect there are more grasshoppers or owls in this ecosystem?

2. The relative energy in trophic levels in a Silver Springs, Florida, ecosystem is shown.
Trophic Pyramid – a graphic representation of all the energy or biomass at each trophic level

3. Put the organisms from your Yellowstone food web into trophic levels.
Primary producer
Primary consumer
Secondary consumer
Tertiary consumer
Quaternary consumer

4. Put the organisms from your Yellowstone food web into trophic levels.
Primary producer
trees, berries, nuts, grasses
Primary consumer
elk, deer, squirrel, mouse, vole
Secondary consumer
weasel, coyote
Tertiary consumer
wolf, grizzly bear
Quaternary consumer
Where do decomposers fit in a trophic pyramid?

5. Where do decomposers fit in a trophic pyramid?

6. Figure Distribution of biomass or energy at different trophic levels in an ecological system. Primary consumers are those animals that eat plants, also known as herbivores. A secondary consumer eats primary consumers, and a tertiary consumer eats secondary consumers. Secondary consumers and above are also known as carnivores or predators.
The relative energy in trophic levels in a Silver Springs, Florida, ecosystem is shown.

7. ?? Where does the energy in an ecosystem come from? photosynthesis
energy is stored in carbon-rich molecules
energy comes from sunlight ??
photosynthesis
Where do you get your energy?

8. CO2 equation

9. CO2 CO2 Where does the mass of a tree come from?
When you lose weight (mass), where does the weight go?
CO2

10. List the ways that CO2  glucose
photosynthesis
List the ways that glucose  CO2
respiration (living organisms burning calories for work, giving off CO2)
decomposition (respiration by decomposers)
combustion (burning wood & fossil fuels)

12. Figure Energy relationships in saltmarsh planthoppers and katydids. Estimates are from Teal (1962). He estimated 85% assimilation efficiency for planthoppers because they feed on liquid sugar solutions from plants (which are easy to digest), not cellulose (which is a plant structural chemical that is not easy to digest). The assimilation efficiency for grasshoppers, which consume mostly cellulose, was estimated to be 30%.

13. Which animal loses more energy in feces?
Are planthoppers or katydids better at converting food into animal body?
(Calculate % production =
production/consumption.)
Which animal loses more energy in feces?
(Calculate % feces =
feces/consumption)
Figure Energy relationships in saltmarsh planthoppers and katydids. Estimates are from Teal (1962). He estimated 85% assimilation efficiency for planthoppers because they feed on liquid sugar solutions from plants (which are easy to digest), not cellulose (which is a plant structural chemical that is not easy to digest). The assimilation efficiency for grasshoppers, which consume mostly cellulose, was estimated to be 30%.
Which animal provides more energy for secondary producers to eat?

14. Which animal loses more energy in feces?
Are planthoppers or katydids better at converting food into animal body?
(Calculate % production =
production/consumption.)
planthoppers =
70.0/323.5 = 21.6%
katydids =
10.8/99.4 = 10.9%
Which animal loses more energy in feces?
(Calculate % feces =
feces/consumption)
Figure Energy relationships in saltmarsh planthoppers and katydids. Estimates are from Teal (1962). He estimated 85% assimilation efficiency for planthoppers because they feed on liquid sugar solutions from plants (which are easy to digest), not cellulose (which is a plant structural chemical that is not easy to digest). The assimilation efficiency for grasshoppers, which consume mostly cellulose, was estimated to be 30%.
planthoppers =
48.5/323.5 = 15.0%
katydids =
70/99.4 = 70.4%
Which animal provides more energy for secondary producers to eat?
planthoppers = 70.0 kcal/m2/year
katydids = 10.8 kcal/m2/year

15. cordgrass & algae planthoppers & katydids spiders, wrens & dragonflies
primary producers
cordgrass
& algae
36,380
8200
primary consumers
planthoppers
& katydids
422.9
80.8
secondary consumers
spiders, wrens
& dragonflies 28 5
consumption
production

16. it is used for activity/respiration
What percent of the energy that is converted from sunlight to glucose by plants is converted into plant material (biomass)?
primary producers
cordgrass
& algae
36,380
8200
primary consumers
planthoppers
& katydids
8200/36,380 kcal/m2/year
= 22.5%
422.9
80.8
secondary consumers
spiders, wrens
& dragonflies 28
What happens to the energy that is converted from sunlight to glucose but not made into biomass? 5
consumption
production
it is used for activity/respiration
What percentage of the available plant biomass is consumed by planthoppers & katydids?
422.9/8200 kcal/m2/year = 5.2%
What happens to the biomass that is not consumed by animals in a higher trophic level?
is it consumed by decomposers after death

17. an emergent property of energy flow in ecosystems:
Biomagnification

18. an emergent property of energy flow in ecosystems:
Biomagnification

19. Figure Eggshell thickness in natural populations (circles) and in captive populations fed diets with different concentrations of DDE (Xes). Each point represents the mean for a clutch of eggs. From Lincer, 1975, Figure 3, © 1975 British Ecological Society.

20. Figure Relationship between concentration of DDE in eggs and percentage decrease in eggshell thickness in North American raptors and population status. The two Cooper’s hawk points are from the same population. * refers to fertile eggs, and † refers to broken eggs. From Lincer, 1975, Figure 4 and Table 4, © 1975 British Ecological Society.