Transcript Managing and Sustaining Forests

Chapter 11 Section 4
Ashley Zeigler & Jasaida Lajara
Old-growth Forest
Second-growth Forest
 Uncut forest or
 Stand of trees resulting
regenerated forest that has
not been seriously
disturbed by human
activities or natural
disaster.
 Store houses of
biodiversity
 Provides ecological niches
for multitude of wildlife
species
from secondary
ecological succession.
 When trees are removed
from an area by
humans(clear cutting) or
by natural disasters
second growth forms
Third type of
forests
Tree plantation
Tree farms
Uniformly aged trees
of one species that
are harvested by
clear cutting as soon
as they become
commercially
valuable.
They are replanted
and cut down.
Even-aged management
Uneven-aged
management
 Maintaining trees in a
 Maintaining a variety of
given stand the same age
and size
 Industrial forestryreplaces a biologically
diverse old-growth or
second-growth forest.
tree species in a stand at
many ages and sizes to
foster natural
regeneration.
 Selective cutting- intermediate-
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aged or mature trees in an unevenaged forest are cut singly or in
small groups
Advantages
reduces crowding of trees
encourages growth of new trees
Allows natural regeneration
Maintains uneven-aged stand of
trees
 Shelterwood cutting- removes all
mature trees in an area in two or
three cuttings over a period of
time.
 Seed-tree cutting- loggers harvest
nearly all of a stand’s trees in one
cutting but leave a few uniformly
distributed seed-producing trees to
regenerate the stand.
 Strip cutting- is clear cutting a strip
of trees along the contour of the
land, with the corridor narrow
enough to allow natural
regeneration.
Be selective or
chop them all
down
Clear cutting
removes all trees from
an area in a single
cutting
Things you
should know.
• Forests are used for:
1.
Housing- to build
2.
Medicines- plants
have special uses
3.
Fireplaces- burning
wood
•
Human activity has
reduced Earth’s
forests by one-fifth
Harvesting Trees
Fig. 11-10e p. 202
Road leads to forest degradation
 Increased erosion and runoff
 Habitat fragmentation
 Pathways for exotic species
 Accessibility to humans
Fig. 11-9 p. 201
Management Strategies: Rotation Cycles
Fig. 11-8 p. 201