TEKS 7.12D
observe and describe
the role of ecological
succession in
ecosystems
Overview
Ecosystems are constantly changed.
Different organisms are adapted to certain
conditions. After an event that can change
the ecology of an area, the flora and fauna
also changes. Students will look at what
happens after several such changing
events such as a fire or glacier movement.
Misconception
As plants grow back after a disturbance, the
same plants that were there previously
grow back. They are just shorter because
they are growing back.
Science Concept
Certain types of plants and animals are
better adapted to grow in certain
environments. There is a natural
succession of life that grows back after a
disaster.
Rebuild
• Allow students to explore the online field
trip about the natural succession in a
national park.
• And/or view Yellowstone Aflame
Misconception
Fires are bad.
Science Concept
Fires are natural occurrences and are
necessary for maintaining a balance and
clearing out plant debris. When fires can
become bad is when humans prevent fires
for long periods of time, allowing debris to
build up. The debris acts as fuel to
intensify the fire. If the fire gets to big,
then we see the major fires that we have
become accustomed to hearing about in
the news.
Rebuild
• Allow students to explore some of the
positive impacts fires have.
• The virtual field trip does a great job of
reinforcing that fires are neither good nor
bad, just a part of the natural cycle of
things.
Prior Knowledge
• While the idea of succession is a new one to students,
the following TEKS should be covered in the 7th grade
prior to lessons on ecological succession. Background
on ecosystems is imperative to understanding
succession.
• 7.12) Scientific Concepts. The student knows that
there is a relationship between organisms and the
environment. The student is expected to:
• identify components of an ecosystem;
• observe and describe how organisms including
producers, consumers, and decomposers live
together in an environment and use existing
resources;
• describe how different environments support
different varieties of organisms
Teacher Background
• Succession is the process by which
communities are established.
• The end result is a climax community. A
climax community is the combination of
flora and fauna that use the land and its
resources most effectively.
• There are 2 types of ecological succession:
primary and secondary.
• Primary Succession occurs on inorganic material
such as rock. The start of primary succession
can occur with events such as a volcanic
eruption, rock exposed by retreating glaciers.
• In order for suitable soil to be made, primary
succession must begin with a pioneer species,
or soil forming species. One common such
species is the lichen.
• Secondary succession begins with organic
material in the soil.
Engage
• Show a video clip of a forest fire such as
the one found at
http://video.google.com/videoplay?docid=9
039257627990588050&q=forest+fire&hl=e
n
• Have student make a T-chart in their
notebook or journal. On one side have
them list possible causes of the forest fire.
On the other side have students
brainstorm effects of a forest fire.
• Alternative to a fire video would be a
volcano or earthquake.
• One reason for this is that we will be using
a fire a lot as the catalyst for starting
succession. We don’t want to lead
students to believe that this is the only way
to begin succession.
Explore
• Virtual Field Trip: If you have access to a
computer lab, students can go through the
field trip at their own speed. If not, the
field trip can be taken as a class with a
projector.
• The field trip is located through the
Yellowstone National Park website.
http://www.windowsintowonderland.org/fire
/index.html
Explore alternative/addition
• View last two chapters of Yellowstone
Aflame DVD (Firestorm and Aftermath)
• Firestorm shows more of the actual fire
and what firefighters went through in
fighting it. The images are amazing and
students will likely get into it. (approx 5 min)
• Aftermath is more of the succession
aspect of what happened after the fire.
(approx 3 min)
Explain
• The Heathland Project site at the
Woodland Education Centre
• http://www.countrysideinfo.co.uk/successn
/second.htm
1993
• In 1993 the land here
was cleared
purposefully and then
treated with Roundup
to clear the site of all
plants. The purpose
was to observe the
natural succession.
1998
2002
2004
Elaborate
• Students will make a film strip of what
might happen to an area after an
ecological changing event. Each frame will
show the changes that are made over
time. Students will note pioneer species
and a climax community. See Black-Line
masters.
Evaluate
• Have students make a timeline of at least
4 steps leading up to a climax community.
• Timelines should be illustrated with 2
sentences about what is going on in their
pictures.