Transcript trophic levels

Trophic Levels and Food Chains
Quaternary
consumers
• Food Chain:
Carnivore
Carnivore
– set of food (energy)
transfer from
trophic level to
trophic level
Tertiary
consumers
Carnivore
Carnivore
Secondary
consumers
Carnivore
Carnivore
Primary
consumers
Zooplankton
Herbivore
Producers
Plant
Figure 19.21
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A terrestrial food chain
Phytoplankton
A marine food chain
• 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.
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• 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
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Quaternary,
tertiary,
and
secondary
consumers
Tertiary
and
secondary
consumers
Secondary
and
primary
consumers
Primary
consumers
Producers
(plants)
Figure 19.23
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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?
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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
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• Energy pyramid
– Is a diagram that represents the cumulative loss of
energy from a food chain
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What happens to energy as you go up trophic levels? Why?
Tertiary
consumers
10 kcal
Secondary
consumers
100 kcal
Primary
consumers
Producers
1,000 kcal
10,000 kcal
Figure 19.26
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CHEMICAL CYCLING IN ECOSYSTEMS
• Ecosystems
– Depend on a recycling of chemical elements
– What gets recycled in our ecosystem?
• Energy?? NOOO
• Water
• Carbon
• Phosphorus
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• Generalized
scheme for
biogeochemical
cycles
Consumers
Producers
Detritivores
Nutrients
available to
producers
Abiotic
reservoir
Geologic
processes
Figure 19.28
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• The carbon
cycle
CO2 in
atmosphere
Photosynthesis
Burning
Producers
Wood and
fossil fuels
Cellular respiration
Higher-level
consumers
Primary
consumers
Decomposition
Detritivores
Detritus
(a) The carbon cycle
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
What do we eat that has carbon?
Figure 19.29a
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.
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• The nitrogen
cycle
Nitrogen (N2)
in
atmosphere
Detritus
Amino
acids and
proteins in
plants and
animals
Denitrifying
bacteria
Detritivores
Assimilation
by plants
Decomposition
Nitrates
(NO3– )
Nitrogenfixing bacteria
in root
nodules of
legumes
Nitrogen
fixation
Nitrifying
bacteria
(b) The nitrogen cycle
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Ammonium
(NH4+ )
Nitrogenfixing
bacteria
in soil
Figure 19.29b
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.
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• The phosphorous
cycle
Uplifting
of rock
Phosphates
in rock
Weathering
of rock
Phosphates
in organic
compounds
Consumers
Producers
Phosphates
in soil
(inorganic)
Rock
Precipitated
(solid)
phosphates
Phosphates
in solution
Detritus
Detritivores
in soil
What part of you has phosphate?
(c) The phosphorus cycle
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Figure 19.29c
• The water
cycle
Net movement of
water vapor by
wind (36)
Solar heat
Water vapor
over the sea
Precipitation
over the sea
(283)
Water vapor
over the
land
Evaporation and
transpiration (59)
Precipitation
over the land
(95)
Evaporation
from the sea
(319)
Surface
water and
groundwater
Oceans
(d) The water cycle
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Flow of water
from land to sea
(36)
Figure 19.29d