Agricultural Ecology

1. Intro to Ecology
Biology

2. By completing this lesson, you will
learn about…
• The scope of
Ecology
• Ecological
Organization
• Energy Flow
• Feeding
Relationships
• Chemical Cycles

3. Studies in Ecology Concept Map
Biology
Ecology
Population Ecology
Community Ecology
Conservation Ecology
Ecosystem Ecology

4. Energy Flow Concept Map
Chemical
Cycles
Feeding
Relationships
Energy Flow
Trophic
Levels

5. The Scope of Ecology
• Introduction
• Ecological Organization
• The Branches of Ecology

6. What is Ecology?
• ECOLOGY – The study of interactions
between organisms and environments.

7. Ecological Organization
• Ecological relationships range from an
individual organism to the entire
biosphere.

8. Population
Community
Biome
Biosphere
Ecosystem
Organism A single living thing
A group of organisms of the same species that
live together.
A group of Populations that live together
Communities and their physical environments
A group of ecosystems that have the same climate.
All the biomes on Earth. Thus, all the living areas
of the planet.

9. Population
Community
Biome
Biosphere
Ecosystem
Organism

10. Branches of Ecology
Population Ecology
Study of how populations grow
Conservation Ecology
Study of how to preserve
And create a healthy,
Lasting biosphere
Community Ecology
Study of how populations interact
with each other
Ecosystem Ecology
Study of how populations
interact with their
physical environment

11. Question: Levels of Organization
Match the terms on the left with the definitions on the right
Population Ecology
Areas of same climate
Study of group growth
Example of a biome
Biome
Tundra

12. Question: Levels of Organization
Match the terms on the left with the definitions on the right
Population Ecology
Areas of same climate
Study of group growth
Example of a biome
Biome
Tundra

13. Energy Flow 1: Feeding
Relationships
• Overview
• Trophic levels
• Food Webs

14. Overview: Energy Flow Ecosystem
Level of ecological study that includes all
organisms in a given area along with the
factors with which they interact.
A community and its physical environment.
Most ecosystems
are driven
by energy
from
sunlight
Energy flow and chemical cycling are two interrelated processes that occur
by transfer of substances through the feeding levels of ecosystems.

15. Key Concept:
One of the ways in which energy flows
through an Ecosystem is by feeding. Different
living organisms eat each other, and the food
is energy moving from one organism to the
next.

16. What is a Food Web?
• The feeding relationships in an
ecosystem. Also called a food chain.

18. Example of a food web
grass
(seeds)
grasshopper
mouse
snake
rabbit
decomposers
Bacteria & Fungus

19. What are Trophic levels?
• Trophic level – each feeding level in a
food web or chain.

20. Trophic level organisms: Producers
Producers are the backbone trophic level
Producers are autotrophs which gets energy from the sun
using photosynthesis. Plants, algae & phytoplankton

21. Trophic level: Consumers
Consumers is a trophic level of heterotrophs
Consumers are heterotrophs which eat other organisms for energy,
such as snails and pigs. There are many trophic levels of consumers.
Herbivores eat plants only. (cows)
Carnivores eat animals only. (sharks)
Omnivores eat plants and animals.(humans, mice)
Decomposers break down dead, rotting remains.
( bacteria, mushrooms)

22. Trophic levels of food webs
PRODUCERS
Autotrophs
CONSUMERS
(Heterotrophs)
Herbivores
Carnivores
Omnivores
decomposers
waste and
remains
detritivores

23. Trophic level Pyramid
Producers
Autotrophs
Primary Consumer
Heterotrophs
Herbivores
Secondary
Consumer
Tertiary
Consumer
Uses the sun’s energy to make its own food- photosynthesis

24. Trophic level Pyramid
Producers
Autotrophs
Primary Consumer
Heterotrophs
Herbivores
Secondary
Consumer
Tertiary
Consumer
Uses the sun’s energy to make its own food- photosynthesis
About 10% of
available NRG
is passed up
1000
100
10

25. Trophic level Pyramid
Producers
Autotrophs
Primary Consumer
Heterotrophs
Herbivores
Secondary
Consumer
Tertiary
Consumer
Uses the sun’s energy to make its own food- photosynthesis
About 10% of
available NRG
is passed up
1000
100
10
The rest is lost as
Heat and Waste

27. Primary Productivity
The rate at which light energy is converted to the chemical energy
of organic compounds by autotrophs in an ecosystem.
primary productivity is limited by a variety of factors that depend on
the specific ecosystem as well as change in season.
Usually only about 10% of the chemical energy available at one
trophic level appears at the next.

28. Question: Trophic Levels
• What type of organisms
consume wastes?
1.______________
2.______________
The food web is organized by
__________ levels.

29. Question: Trophic Levels
• What type of organisms
consume wastes?
1. Detritivores
2. Decomposers
The food web is organized by
Trophic levels.

30. Energy Flow II: Chemical Cycles
• Overview
• Carbon Cycle
• Nitrogen Cycle
• Water Cycle
• Phosphorous Cycle

31. Another way in which energy flows through
an ecosystem is by the cycling of chemical
materials.
Chemical materials are energy, which move
as they cycle from one location to another.

32. Overview: Chemical Cycles
Biogeochemical cycles_________________
The various material circuits, which involve both the
nutrient and physical components of an ecosystem.
Carbon, Nitrogen, Phosphorous and Water are needed by
every organism on Earth. C is needed to build organic
molecules. N is needed for nucleic acids. P is needed for
energy molecules. Water is needed to maintain life. How
does every organism on Earth have access to these limited
resources?
Chemical Cycling
Carbon cycle Nitrogen cycle Phosphorous cycle Water cycle

33. Carbon Cycle
The Carbon cycle reflects the connected processes
of photosynthesis and cellular respiration.
1. Producers convert inorganic carbon dioxide
into organic molecules.
2. Consumers eat the producers.
3. Consumers breathe out CO2 which is
reused by the autotrophs.
Since photosynthesis generates oxygen, the oxygen cycle
is coupled with the carbon cycle.

36. Nitrogen cycle
Certain prokaryotes
fix Nitrogen in the
atmosphere into
ammonia which other
bacteria convert into
nitrites and nitrates.
Plants absorb ammonia and
nitrates and convert them
into proteins that can be
passed onto the food chain.
Nitrogen in the soil is returned
to the atmosphere in the form
of free nitrogen by denitrifying
bacteria for prokaryotes to fix
again.
Detritivores reduce dead
plants, animals and their
products into ammonia
which can be reused by
plants or deposited
in the soil.

38. Phosphorous cycle
Phosphorous from rocks leaks
into the soil by sediment runoff.
Phosphorous is added to the
soil as phosphate.
Plants absorb the phosphate.
Animals eat the plants.
The oceans deposit the
phosphorous onto rocks.
Consumers excrete feces
or decomposers break down
the wastes, which drains by
run-off to the oceans.

40. Water cycle
Rain precipitates water
onto the Earth.
Water lands into the
oceans. It also lands
on soil, and runs-off
into the oceans after use
by living things.
Water from the ocean
evaporates into the air.
Water in the air
condenses into
clouds
Water moving through a plant is called Transpiration

42. Questions: Chemical cycles
Which cycle has a chemical
which become deposited
on rocks?
Which cycle provides the
basis of organic molecules?
Which cycle requires the help
of bacteria?

43. Questions: Chemical cycles
Which cycle has a chemical
which become deposited
on rocks?
Which cycle provides the
basis of organic molecules?
Which cycle requires the help
of bacteria?
Phosphorous cycle
Carbon cycle
Nitrogen cycle

44. What you have learned..
Feeding relationships
circulate energy from
the sun to producers
to consumers.
Ecology can be studied
at the organism, population,
community, ecosystem,
biome and biosphere level.
Ecology is the
study of
interactions
between
organisms and
environments.
Chemical cycles
circulate raw materials
for organisms to use.
Four major cycles
Carbon, Nitrogen,
Phosphorous and Water
Energy flow is how the
earth circulates energy
to support life. Two types
of energy flow include
feeding relationships and
chemical cycles.