1. Trophic Levels and Food Chains
Quaternary consumers
Food Chain:
set of food (energy) transfer from trophic level to trophic level
Carnivore
Carnivore
Tertiary consumers
Carnivore
Carnivore
Secondary consumers
Carnivore
Carnivore
Primary consumers
Herbivore
Zooplankton
Producers
Plant
Phytoplankton
Figure 19.21
A terrestrial food chain
A marine food chain

2. Herbivores: eat plants, algae, or autotrophic bacteria, are the primary consumers of an ecosystem
Carnivores, which eat the consumers from the levels below
Secondary consumers include many small mammals, such as rodents, and small fishes that eat zooplankton
Tertiary consumers, such as snakes, eat mice and other secondary consumers
Quaternary consumers include hawks and killer whales.

3. Decomposers:
What is a decomposer and what do they do? What trophic level would you put them at?
Derive their energy from the dead material left by all trophic levels
Are often left off of most food chain diagrams
Figure 19.22

4. Figure 19.23 Quaternary, tertiary, and secondary consumers
Secondary and
primary consumers
Primary consumers
Producers (plants)
Figure 19.23

5. Energy Pyramids
When energy flows as organic matter through the trophic levels of an ecosystem, much of it is lost at each link in a food chain. Why?
When you burn energy to run down the mile in gym what happens to most of the energy you are using?

6. Plant material eaten by caterpillar
Does all the energy this caterpillar eats get
passed to the bird who eats him?
Plant material eaten by caterpillar
100 kilocalories (kcal)
35 kcal
Cellular respiration
50 kcal
Feces
15 kcal
Growth
Figure 19.25

7. Energy pyramid
Is a diagram that represents the cumulative loss of energy from a food chain

8. What happens to energy as you go up trophic levels? Why?
Tertiary consumers
10 kcal
Secondary consumers
100 kcal
Primary consumers
1,000 kcal
Producers
10,000 kcal
Figure 19.26

9. CHEMICAL CYCLING IN ECOSYSTEMS
Depend on a recycling of chemical elements
What gets recycled in our ecosystem?
Energy?? NOOO
Water
Carbon
Phosphorus

10. Generalized scheme for biogeochemical cycles
Consumers
Producers
Detritivores
Nutrients available to producers
Abiotic reservoir
Geologic processes
Figure 19.28

11. Higher-level consumers
The carbon cycle
CO2 in atmosphere
Photosynthesis
Burning
Producers
Wood and fossil fuels
Cellular respiration
Higher-level consumers
Primary consumers
Decomposition
Detritivores
Detritus
What do we eat that has carbon?
(a) The carbon cycle
Figure 19.29a

12. Producers: Plants take in CO2 and make sugar by photosynthesis.
Carbon Cycle
Producers: Plants take in CO2 and make sugar by photosynthesis.
Consumers: Animals eat plants to get energy (respiration) from sugar and make proteins from the carbon.
Breath out CO2 as a waste product of respiration.
Animals die and dentritus (decomposers) break down the carbon and other elements back into the soil and air for plants to use again.

13. The nitrogen cycle Detritus Nitrates (NO3– ) Decomposition
Nitrogen (N2) in atmosphere
Detritus
Amino acids and proteins in plants and animals
Denitrifying bacteria
Detritivores
Assimilation by plants
Nitrogen-fixing bacteria in root nodules of legumes
Nitrates (NO3– )
Decomposition
Nitrogen fixation
Nitrogen-fixing bacteria
in soil
Ammonium (NH4+ )
Nitrifying bacteria
(b) The nitrogen cycle
Figure 19.29b

14. Nitrogen Fixation by bacteria
Plants need nitrogen but cannot take it in from the air.
Bacteria in the soil on the roots of plants take in nitrogen (N2) and make ammonia (NH4) which plants can then use to get nitrogen.

15. Precipitated (solid) phosphates Phosphates in solution
The phosphorous cycle
Uplifting of rock
Phosphates in rock
Weathering of rock
Phosphates
in organic compounds
Consumers
Producers
Detritus
Rock
Phosphates
in soil (inorganic)
Precipitated (solid) phosphates
Phosphates in solution
Detritivores in soil
What part of you has phosphate?
(c) The phosphorus cycle
Figure 19.29c

16. The water cycle Net movement of water vapor by wind (36) Solar heat
Water vapor over the land
Water vapor over the sea
Precipitation over the land (95)
Evaporation and transpiration (59)
Precipitation over the sea (283)
Evaporation from the sea (319)
Surface
water and groundwater
Flow of water from land to sea (36)
Oceans
(d) The water cycle
Figure 19.29d