APES UNIT 04
Energy, Succession & Biomes
Chapter 8
Biomes
Earth’s Biomes
• The Earth has 17 major biomes, each with
its own characteristic dominant shapes
and forms of life.
• Most biomes have been heavily altered
by human action.
• People have introduced exotic species
(invasive species) to new habitats –
sometimes creating benefits, most often
creating problems.
Earth’s Biomes
Biome Handout
• Please use the biome handout with your text
to help you to understand and memorize
the characteristics of each biome.
Remember to color/mark where each
biome is on the world map.
• Please also make sure that you also
research at least TWO human impacts on
each biomes as well as endangered species
in each area.
• This will replace questions 8 & 9 in your study
guide.
Chapter 9
Biological Productivity
and Energy Flow
Biological Production
• Biomass - the total amount of organic matter on
Earth or in any ecosystem. Measured in terms of
mass per unit of space. Examples: kg/hectare or MT
(metric tons)/hectare or g/m2(square meter).
• Biological Production- the capture of usable
energy from the environment to produce organic
compounds in which that energy in stored. Two
types. Measured by the amount of food produced
per area per time period. Examples: gram/m2/day
or kg/ hectare/day.
Two Kinds of Biological
Production
1. Primary Production
•
•
•
Make their own organic matter from a source
of energy and an inorganic compound
Carried out by autotrophs and
chemoautothrophs
Examples: photosynthesis & chemosynthesis
2. Secondary Production
•
•
Cannot make their own organic compounds
and therefore must feed on other living things
Carried out by heterotrophs
Respiration
Respiration:
– the use of biomass to release energy that can
be used to do work
– In other words, the use of energy from organic
matter by most heterotrophic and autotrophic
organisms is accomplished through respiration.
– An organic compound such as sugar is
combined with oxygen to produce carbon
dioxide and water.
– Compare to photosynthesis. Do you remember
the formula for photosynthesis and the formula
for respiration?
Energy Lost as Heat
Gross and Net Production
•
The production of biomass and it’s use as a
source of energy by autotrophs includes
three steps:
1.
Gross Production: An organism produces organic matter within
it’s body
It uses some of this new organic matter as a fuel in respiration
It stores some of the newly produced organic matter for future
use
2.
3.
•
The amount left over after utilization is called Net Production
Net Production (NPP) = Gross Production (GPP)- Respiration (Ra)
Energy Flow
• Ecosystem Energy Flow
– The movement of energy through an
ecosystem from the external environment
through a series of organisms and back to the
external environment
The Laws of Thermodynamics
• 1st Law of Thermodynamics
- (the law of conservation of energ y)
-Energy is neither created nor destroyed. It is
merely changed from one form to another
• 2nd Law of Thermodynamics
- Energy always changes from a more useful,
higher quality from to a less useful, lower quality
form
•Thermodynamic System
- Formed by an energy source, ecosystem and
energy sink, where the ecosystem is said to be an
intermediate system between the energy source
and the energy sink (degraded heat energy)
Energy Efficiency and
Transfer Efficiency
Energy Efficiency
-the ratio of output to input, or the amount of useful
work obtained by some amount of available
energy.
Trophic-level efficiency
- Also known as food chain efficiency.
- It is an ecological measure of energy efficiency
- the ratio of production of one trophic level to the
production of the next lower trophic level
Energy Pyramid of Trophic- Level Efficiency
•10 percent of the energy at one level of a food web is transferred to the
next, higher, level.
•The other 90 percent of the energy is used for the organism's life processes
or is lost as heat to the environment.
Question: How many kcals would transfer to the 4th order consumer if there
was one?
QUESTION: Why are there so few organisms at the top of the pyramid?
See page 173
http://www.mlms.logan.k12.ut.us/~mlowe/EnergyPyramid.gif
Energy Pyramids Continued
• The organisms at higher feeding levels of an energy
pyramid do not necessarily require less energy to
live than organisms at lower levels. Since so much
energy is lost at each level, the amount of energy in
the producer level limits the number of consumers
the ecosystem can support. As a result, there
usually are few organisms at the highest level in a
food web and increasingly more organisms as you
move down the energy pyramid to successively
lower feeding levels.
Critical Thinking Questions
Apply what you have learned:
Please read the article on page 173
and answer the 5 critical thinking
questions.
Chapter 10
Ecological Restoration
The Balance of Nature
– An environmental myth that states that
the natural environment, when not
influenced by human activity, will reach a
constant status, unchanging over time.
– Biomes have reached some consistency
and this is known as a climax community,
but this is different from climax state,
which according to the Balance of
Nature would continue indefinitely.
– In truth ecosystems do change – think
about the biomes that require fire.
What needs to be restored?
As we have been studying, biomes and the ecosystems
within have been undergoing degradation and are in
great need of restoration. Examples from your text:
1. Wetlands, Rivers and Streams
(Ex: Kissimmee River, Everglades National Park)
2. Prairie Restoration
(Ex: Allwine Prairie)
When Nature Restores Itself:
The Process of Ecological Succession
Ecological Succession:
The process of the development of an
ecological community or ecosystem.
Two Types:
1. Primary Succession: The initial
establishment and development of an
ecosystem. No previous life exists.
Pioneer species are the first.
2. Secondary Succession: The
reestablishment of an ecosystem where
there are remnants of a previous
biological community
Which is which and why?
Patterns in Succession
1.
2.
3.
4.
An initial kind of vegetation specially adapted to
the unstable conditions
Small plants and other early-successional species
grow and seeds spread rapidly.
Larger plants and other late successional species
enter and begin to dominate the site.
A mature forest develops.
Examples of Succession:
Dune Succession, Bog Succession, Old-Field Succession
Bog Succession
Reproductive Strategies
• R-strategists
– Many offspring, low parental care, reproduce rapidly
– Read reproductive age early, low survival rate, short lifespan,
short generation time
– Seen in unstable environments – often pioneer species
– ________ successional species, opportunists, type _______
– Generalists, Also prone to population crashes when competitive
species move in.
– Example: dandelions
• K-strategists
–
–
–
–
–
–
–
–
–
Few offspring, reproduce late
Mature slowly
High survival rate
High parental care
Seen in stable environments
Specialists
__________ successional species
More prone to extinction
Example: gorilla
Survivorship curve
Survivorship Curve
• Type I survivorship curves are for species that have
a high survival rate of the young, live out most of
their expected life span and die in old age.
– Humans are a good example of a species with a Type I
survivorship curve.
• Type II survivorship curves are for species that have
a relatively constant death rate throughout their life
span. Death could be due to hunting or diseases.
– Examples of species exhibiting a Type II survivorship curve
are coral, squirrels, honey bees and many reptiles.
• Type III survivorship curves are found in species that
have many young, most of which die very early in
their life.
– Plants, oysters and sea urchins are examples of species that
have Type III survivorship curves.
Species Change in Succession
Earlier and later species in succession may
interact in three ways:
If they do not interact, the result is termed
chronic patchiness – where the species
that enters first remains until the next time
the ecosystem is disturbed.
1. Facilitation
• During succession, one species
prepares the way for the next (and
may even be necessary for the
occurrence of the next)
• Example: The pine tree provides the
shade to allow the oak to grow.
2. Interference
• During succession, one species
prevents the entrance of a later
species into an ecosystem.
• Ex) Some grasses produce dense and
thick mats so the seeds of trees cannot
reach the soil to germinate
Life History Difference
• The difference in the life histories of the
species allow some time to arrive first
and grow quickly, while others arrive
late and grow more slowly.