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What is this activity?
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Purpose: The purpose of this model
is to help you understand the stages of the Southern Pine Beetle and Southern Pine Beetle (SPB) population dynamics. |
  The
Southern Pine Beetle (SPB) is an ever-present threat to the
health of pine forests in the South. During
1999 and 2000, the SPB infestation in the pine forests of Tennessee reached epidemic proportions. Move your
mouse over the lush, green
pine forest photo to see how areas have been reduced to barren wastelands. |
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Several factors have caused the increase in SPB
populations.
- In
recent years, Morgan County, Tennessee and the surrounding counties have had
several severe ice storms that caused extensive damage to the yellow pine
forests. This made the tree
more susceptible because the tree used its resources to repair the damage
and therefore could not defend against the SPB attacks.
- Tennessee
has had a decrease in rainfall over the past several years causing a drop in
the water table. As the water
table decreased, the pine trees had less access to water necessary to
produce resin (pitch) that is the trees’ natural defense mechanism to
force the attacking beetles out of the tree.
- The
winters have not been harsh enough to decrease the population of the SPB.
Temperatures need to be in the single digits for about a week to
control the population growth of the SPB.
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