An ecological system consists of a living community and its physical habitat. Energy enters through sunlight and powers primary producers like plants through photosynthesis, generating glucose. Primary consumers then eat producers, and secondary consumers eat primary consumers, forming a food chain that transfers 10% of energy between trophic levels. Decomposers recycle nutrients by breaking down dead organisms.

2.  An ecological system
 consists of a living community and all of the
physical aspects of its habitat
 physical factors are known as abiotic factors and can
include:
▪ light, temperature, precipitation, soil type, water
availability, soil and water pH, etc
 the members of the living community are
known as the biotic factors in an ecosystem
 include organism like animals, plants, mushrooms, and
bacteria

3.  Ecosystems rely on energy
-The amount of energy available in an
ecosystem determines how many
organisms can live in that ecosystem

4.  How does energy enter an ecosystem?
- Sunlight is the primary source of energy
for most ecosystems on earth
No sun = No energy
No Energy = No Life
No Life = BUMMER!

5.  Divided intoTrophic (feeding) levels.
 Primary producers/autotrophs
 Primary consumers/herbivores-plant eaters
 Secondary consumers/carnivores –meat eaters
 Tertiary consumers/carnivores
 Detritivores/decomposers- vital part of the
ecosystem. They recycle abiotic materials from
dead organisms – without them, life would stop.
- they play a role in nutrient cycling

6.  Primary producers are the first producers of energy rich
compounds that are later used by organisms
 Autotrophs: “self feeders”, organisms that can capture
energy from nonliving sources and convert it into forms
that living cells can use
 Example: plants obtain energy from sunlight and turns
it into nutrients that can be eaten and used for energy
by animals such as a caterpillar

7.  Sunlight needs to be converted to be used in an
ecosystem.
 Who converts the sunlight?
- plants, algae, some bacteria
- organisms that convert the energy from
sunlight into a useable form are known as
producers
- How do they do convert the energy?
Photosynthesis

8.  Why is it important?
 traps the sun’s energy and stores it in a sugar
called glucose.
 The stored energy is used by living things

9. 6 CO2 + 6 H2O + Energy C6H12O6 + 6 O2
Carbon Water Sunlight Glucose Oxygen
Dioxide

10.  Who uses the energy trapped by producers?
 All living things use the energy trapped by
producers
 producers use this energy themselves
 Other living things, called consumers eat
producers for their energy

11. Chemosynthesis: chemical energy is used to produce
carbohydrates
Primary producers like bacteria harness chemical energy
from inorganic molecules such as hydrogen sulfide
(hydrogen sulfide-bacterial breakdown of organic
matter in the absence of oxygen)

12.  Herbivore- plant eater
 Carnivore- animal eater
 Omnivore- eats both plants and animals
 Decomposers- decay, chemical breakdown of
organic matter
 Scavengers- animals that consume the
carcasses of other animals that have been
killed
 Detritivores- digest decomposers

13. Primary Consumers
Producers
Detritus Feeders
Producers
Primary Consumers
Secondary Consumers
Tertiary
Consumers
Decomposers

15.  Food Chain –
the path of energy
through the trophic
levels of an ecosystem
- all food chains begin
with a producer

16.  = a series of multiple
interconnected food chains.
 in most ecosystems, energy
doesn’t follow a simple path
 many consumers eat at
different trophic levels
 food webs are
representation of the
complex relationships
between organisms in an
ecosystem

18.  Biomagnification – the concentration of toxins as
they move through a food chain.
 Ecological succession – changes in the composition
of species found in a community over time
 Ecosystem – a community interacting with its
environment through a one-way flow of energy and
the cycling of materials
 Ecosystem stability – the ability of an ecosystem to
return to a state of equilibrium following a
disturbance

19.  Ecological pyramids: models that show the relative
amount of energy or matter contained within each
trophic level
 Symbiosis – an ecological interaction between two
organisms
 Trophic level – position that organism(s) occupy in a
food web, which is defined by its relationship to the
primary energy source
 Pioneer species – first species to populate an area
during succession

20.  Ecological succession: a series of more or less
predictable evens that occur in a community over
time
 Primary succession: begins in areas that have no
remnants of an older community
 Secondary succession: parts of old community
survive, and can regrow rapidly

21.  90% of the energy
available is lost as
energy is transferred
to the next trophic
level
- the energy is lost as
heat
 Only 10% is of
passed on to the
next level 100,000 J of sunlight
100 J Rats
10 J
Snakes
1,000 J Grasshoppers
10,000 J wheat

22. Pyramids of energy
show the relative
amount of energy
available at each
trophic level of a
food chain or food
web
Only 10% of energy
is transferred to the
next level

23.  Is the total amount of matter in the form of
living tissue within a given trophic level
 The amount of biomass a given trophic level
can support is determined by the amount of
energy available

24. A pyramid of
biomass is a model
that illustrates the
relative amount of
living organic
matter available at
each trophic level
in an ecosystem.

25.  Autotrophs (producers)
▪ Algae
▪ Phytoplankton
▪ Plants
▪ Cyanobacteria
▪ Mosses
▪ Some protozoa

26.  Heterotrophs (consumers)
▪ Primary
▪ Secondary
▪ Tertiary
▪ Herbivores
▪ Carnivores
▪ Omnivores

27.  Decomposers
▪ Fungi
▪ Protists
▪ Bacteria

28.  Detritivores (detrivores)
▪ Millipedes
▪ Wood lice
▪ Types of earthworms

29.  What happens to the biomass and numbers
as we move up trophic levels?
 How does energy move through an
ecosystem?
 What amount of energy is available to each
trophic level?