TITLE:  FOREST IN A JAR

AUTHOR:  Cindy Cook, Ririe Elementary, Ririe, Idaho

GRADE LEVEL/SUBJECT:  K-6, Science
  
OVERVIEW:  Succession is a term used to describe the ever-
changing environment and the gradual process by which one
habitat is replaced by another.  Many habitats that appear
to be stable are changing before us.  In this activity,
students will be able to see in miniature how a swampy area
can be succeeded by a forested habitat.

PURPOSE:  The major purpose of this activity is for students
to recognize the process of succession.

OBJECTIVES:  Students will be able to: 1) observe and describe
succession; and 2) summarize what they have learned about how
environments can change.

Method:  Students conduct an experiment using soil, water,
seeds, a plant, and a jar; and then draw a poster to represent
their observations and findings.

RESOURCES/MATERIALS:  Pint or quart jars (one per student or
small groups of students, or one for the entire class), water,
soil, aquatic plants (one per jar), two cups bird seed.

ACTIVITIES AND PROCEDURES:  
  1.  Place two inches of soil and three inches of water in a
jar.  Place the jar at a window, without a lid, and allow it
to settle overnight.
  2.  Plant an aquatic plant in the jar.  It should grow well
in this environment.  If your classroom has no windows,
substitute a grow-light.
  3.  Do not replace the water that evaporates from the jar.
  4.  Once or twice a week, have students add three or four
bird seeds to the jar.  While there is water in the jar, the
seeds should germinate and then rot.  Continue adding seeds
even after the water evaporates.
  5.  As the water evaporates down to the soil, the aquatic
plant will die.  The bird seeds will now find the environment
suitable for successful growth.  Sunflower seeds, which grow
large, can be added to represent forest trees.  You will now
need to add water, as a substitute for rainfall, to keep the
soil damp to keep things growing.
  6.  Have each student make a poster, drawing, or other visual
representation of what they saw happen to their "pond."  Ask
them to talk about what they have learned about how environments
can change.  Introduce the term, "succession," to older students.
  7.  OPTIONAL:  Take a field trip to a pond.  What plants are
growing in the water?  What plants are growing on the shore?
What parallels are there between this real pond and the "pond"
in the jar?  Make a second drawing of this real pond.  Compare
the similarities and differences between the two.

TYING IT ALL TOGETHER:  Describe three changes you saw happen to
what was inside the jar.