Transcript energy in ecosystems

Chapter One Glossary
abiotic – non-living
albedo – percentage of light reflected from a material,
autotroph – producer or organism that produces its own
food
biodiversity - the number of species in an ecosystem
biomass – mass of dry biological matter
biotic - living
carnivore – an animal that feeds on other animals
community – collection of all populations in an
ecosystem
consumer – a heterotroph or an organism that eats other
organisms
decomposer – an organism that feeds on detritus
detritus – waste from plants and animals including their
dead remains
ecological niche – the place or role of a species within
an ecosystem
ecology – the study of the interaction of living things with
each other and with the abiotic factors in their
environment
ecosystem – the set of relationships between biotic and
abiotic factors in a defined area
ecotone – a transition area between two ecosystems
endangered – close to extinction
extinct – no longer exists
extirpated – no longer exists in one part of a range
food chain – a step by step feeding sequence
food web – a pictorial representation of feeding
relationships among organisms in an ecosystem
habitat – environmental conditions of a species
herbivore – an animal that eats plants
hetertroph – consumer or organism that eats other
organisms
omnivore – an animal that eats plants and animals
pest – an organism that people consider harmful or
inconvenient
population - all of the members of a species living in an
ecosystem
primary consumer – a consumer that eats producers or
autotrophs
producer – an autotroph or organism that makes its own
food
secondary consumer – an organism that eats primary
consumers
Thermodynamics – study of energy transformations
first law – energy cannot be created or destroyed, it can
only change form
second law – each time energy is transformed in a
system some of that energy is lost from the system
trophic level – feeding level
The Silence of the Frogs
pages 10-13
Ecology is defined as the study of the interaction
between living things with each other and with
abiotic factors in their environment. When one
considers the number of biotic and abiotic factors
on Earth one should realize that ecology is a very
complex area of study. The silence of the frogs
illustrates some of this complexity.
Read the Silence of the Frogs and make brief
notes. Generally this means one sentence per
paragraph.
Extinction in the Modern World p. 16-19
The evolution of the peppered moth over the last two
hundred years has been studied in detail. Originally, the
vast majority of peppered moths had light coloration,
which effectively camouflaged them against the lightcolored trees and lichens which they rested upon.
However, due to widespread pollution during the
Industrial Revolution in England, many of the lichens
died out, and the trees which peppered moths rested on
became blackened by soot, causing most of the lightcolored moths, or typica, to die off due to predation. At
the same time, the dark-colored, or melanic, moths,
carbonaria, flourished because of their ability to hide on
the darkened trees.
Since then, with improved environmental standards,
light-colored peppered moths have again become
common, but the dramatic change in the peppered
moth's population has remained a subject of much
interest and study, and has led to the coining of the term
"industrial melanism" to refer to the genetic darkening of
species in response to pollutants.
As a result of the relatively simple and easy-tounderstand circumstances of the adaptation, the
peppered moth has become a common example used in
explaining or demonstrating natural selection to
laypeople and classroom students.
The first carbonaria morph was recorded by Edleston in
Manchester in 1848, and over the subsequent years it
increased in frequency. Predation experiments,
particularly by Bernard Kettlewell, established that the
agent of selection was birds who preyed on the morpha
carbonaria morph.
Creationists such as Jonathan Wells have criticized the
use of peppered moth melanism as an example of
evolution in action. Wells alleges that peppered moth
studies, and in particular Kettlewell's experiments, were
erroneous and fraudulent in his book Icons of Evolution.
However, although various errors and oversights have
been found in early experiments on peppered moth
evolution, subsequent experiments and observations
have confirmed the phenomenon and its initial
explanation.
There are many reasons for species becoming extinct
or endangered. Read p. 16-19 and summarize the
natural reasons for extinction and the human made
reasons.
(go over diagram about extinctions or p. 17)
Thought Activity
You are shipwrecked on an island with
a chicken (hen) and a large sack of
bread crumbs. There is no food to
consume anywhere else on or around
the island. You have a plentiful amount
of freshwater. How should you utilize
your food sources so that you can
survive the longest and have the best
chance of being rescued alive?
ENERGY IN ECOSYSTEMS
p. 32 - 39
The source of all energy for ecosystems is
the Sun. Sunlight that reaches Earth has a
variety of outcomes (see p. 32). Energy first
begins to flow through living things when
photosynthesis occurs in plants.
Plants are called producers or autotrophs
and are the first trophic level. They provide
the first level of energy to an ecosystem by
converting the Sun’s energy to food.
Energy is transferred through the rest of the
ecosystem by feeding. Consumers or
heterotrophs cannot make their own food so
they obtain it from autotrophs or
heterotrophs. Consumers that feed on
producers are called primary consumers.
Heterotrophs that feed on other
heterotrophs are called secondary
consumers .
A food chain is a step by step sequence
linking organisms that feed on each other.
All food chains begin with a producer (plant,
algae, some bacteria). These organisms
form the first trophic level. Primary
consumers form the second trophic level
while secondary consumers form the third
trophic level. Higher trophic levels are also
possible (tertiary, quaternary consumers).
The consumer at the top of a food chain is
called the top carnivore. (Organisms may
change levels in different food chains.)
Each organism in an ecosystem is involved
in many food chains. A food web shows the
relationship of many food chains. Stable
ecosystems have the greatest biodiversity.
This biodiversity allows an ecosystem to
withstand variations from year to year within
an ecosystem.
Food Chain and Food Web Activity
Using the information contained on pages 40 and 41 of
the Insights 10 text book construct a food web with
about half of the organisms present. The food web
should be stopped when the number of lines present
begins to make the web look far to confusing. The
arrows on the food web (and food chains) point to the
organism getting the food energy. Using the food web
construct three food chains, one 3 member chain, one 4
member chain and a 5 member chain. The food web and
food chains should be neat and potentially “dressed up”
so a rough copy may be in order. This assignment can
be done individually or in pairs. This assignment is due
in two days.
Some organisms are numbered but cannot be found.
Food Chain
Secondary Consumer
Oak
leaf
Third trophic level
Caterpillar
Producer
First trophic level
Spider
Primary Consumer
Second trophic level
Eagle
Snake
Frog
Tertiary Consumer
Top Carnivore
Fourth trophic level
Quaternary Consumer
Sixth trophic level
Fifth trophic level
Food Pyramids
A useful tool to quantify the relationships
within a food chain is a food pyramid.
Quantifying energy, numbers or biomass
enables one to see how a food chain really
functions in an ecosystem. Figures 6-9
starting on p. 37 give examples. These
pyramids in general can only be 4 levels
high since we have run out of energy for a
higher consumer.
The energy pyramid is the most precise
relationship to be used but it is also the
most difficult to make.
The numbers pyramid is the easiest to
make but it often doesn’t make a pyramid
and show the proper energy flow.
The biomass pyramid is a very good
compromise between the two pyramids
above. It is not too difficult to make and it
generally mirrors energy flow very well.
Comparing Ecosystems, p. 28, 29
Ecology is about much more than recycling
or saying that everything should live in
harmony. Ecology is about biotic and abiotic
relationships and these relationships can be
measured (scientists like measurement!). In
this assignment you will answer questions
based on measurements of two
ecosystems.
In groups of 3 answer questions a-l and
question 1b (use full thorough sentences)
Roles in Ecosystems, p. 40-44
Each species in an ecosystem tends to
have a different role or ecological niche.
This helps reduce competition between
species for territory and resources.
Understand how hawks and owls occupy
different niches yet have a similar diet. Take
note how each species has adapted to its
role.
New species are constantly introduced to
ecosystems. This represents a disturbance
to the ecosystem and the ecosystem will
adjust to this disturbance. The new balance
or equilibrium that forms may be similar to
the old balance or quite different.
Understand the situation of the Zebra
Mussel and all of its consequences for Lake
Erie ecosystem.