Energy Flow and Nutrient Cycle - Environment Science Community and Ecosystem Concept
Energy flows through an ecosystem from producers to consumers. Energy flows from one trophic level to the next.
(troph = feeding)
Nutrients (matter) cycle in an ecosystem.
The processes of photosynthesis and aerobic respiration are important in nutrient cycling and energy flow.
2. Describe the different
niches organisms occupy
in food chains and
diagram a model of a food
web that includes several
food chains.
1
Compare and contrast
how matter and energy
move through ecosystems
and explain how each
process relates to the laws
of conservation of mass
and energy.
2
Discuss the potential
ecological, environmental,
and social impacts of a
primary plant-based or
primary meat-based diet
in a human society.
3
Identify how living
organisms influence
global and local cycles of
matter (ex. Carbon,
nitrogen, phosphorus, and
water cycles)
4
3. Energy flows through an
ecosystem from producers to
consumers. Energy flows from
one trophic level to the next.
(troph = feeding)
Nutrients (matter) cycle in an
ecosystem.
The processes of photosynthesis
and aerobic respiration are
important in nutrient cycling
and energy flow.
4. Primary Producers – plants, algae, photosynthetic bacteria,
some archaea cells.
Most are photoautotrophs.
Some are chemoautotrophs
(use chemicals in the environment
instead of sunlight to produce food)
5. • Food Chains – show the trophic relationship between
organisms in an ecosystem.
• A single food chain is just one link in a food web
Primary
Producer
Primary
Producer
Primary
Producer
Primary
Consumer
Primary
Consumer
Primary
Consumer
Secondary
Consumer
Secondary
Consumer
Secondary
Consumer
Tertiary
Consumer
Tertiary
Consumer Quaternary Consumer
6. Food Webs show all the interacting food chains in an ecosystem.
7. Energy flow in an ecosystem is not efficient between trophic levels,
which can be seen in an energy pyramid.
F
igure 54.11
Tertiary
consumers
Secondary
consumers
Primary
consumers
Primary
producers
1,000,000 J of sunlight
10 J
100 J
1,000 J
10,000 J
The 10% rule
(a) Most biomass pyramids show a sharp decrease in biomass at
Trophic level Dry weight
(g/m2)
Primary producers
Tertiary consumers
Secondary consumers
Primary consumers
1.5
11
37
809
Biomass pyramids also
decline as the trophic level
increases.
Why?
Energy lost in
the form of heat.
Energy used for
metabolic
purposes.
Indigestible
material
Only about 10% of all energy is passed
from one trophic level to the next
8. The dynamics of energy flow through ecosystems have important
implications for the human population.
Consider the resources needed to grow, feed, process, and transport beef.
9. Discussion Question: As human populations continue to grow, will
humans be able to sustain a diet that relies on animals for protein?
Trophic level
Secondary
consumers
Primary
consumers
Primary
producers
10. Decomposers and Detritivores play an important role in recycling
nutrients in an ecosystem.
11. The chemical cycling in an ecosystem is an essential component of
ecosystem function.
Also called Biogeochemical Cycles
CO2 in atmosphere
Photosynthesis
Cellular
respiration
Burning of
fossil fuels
and wood Higher-level
consumers
Primary
consumers
Detritus
Carbon compounds
in water
Decomposition
THE CARBON CYCLE
N2 in atmosphere
Denitrifying
bacteria
Nitrifying
bacteria
Nitrifying
bacteria
Nitrification
Nitrogen-fixing
soil bacteria
Nitrogen-fixing
bacteria in root
nodules of legumes
Decomposers
Ammonification
Assimilation
NH3 NH4
+
NO3
NO2
Rain
Plants
Consumption
Decomposition
Geologic
uplift
Weathering
of rocks
Runoff
Sedimentation Plant uptake
of PO4
3
Soil
Leaching
THE NITROGEN CYCLE THE PHOSPHORUS CYCLE
12. The Carbon Cycle is a global biogeochemical cycle
What are some living and non-living reservoirs of carbon?
What are some of the processes that occur that change carbon from one form to another?
In what form(s) is carbon utilized by living things?
13. The nitrogen cycle is a global biogeochemical cycle
What sort of organisms convert nitrogen from one form to another?
Why are each of these processes essential for an ecosystem food web?