Forest Ecology and the Forest Ecosystem

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					Forest Ecology and the
  Forest Ecosystem

The ecological interactions within and
between groups of individuals. In
essence, the ecology of populations,
communities, and ecosystems.
              Stand Structure
   The physical and temporal distribution of
    plants in a stand.

   The horizontal and vertical distribution of
    components of a stand including the
    height, diameter, crown layers, and stems
    of trees
What controls community

    Site factors

    Biota available

    Competition
   “Survival of the Fittest”

   As individuals grow, more space is
    required, some must die.
   Competition within species yields no change in
    the species present and thus no change in
    community composition.

   Competition between species yields a change
    in the species present and a change in
    community composition

   This change is termed succession.

   The replacement of the biota of an area
    by different species. Primarily based on
    shade tolerance.

   The process of change, over time, leading
    to climax vegetation.
   Primary Succession - starts from bare

   Secondary Succession – succession
    resulting from setback or disturbance.
          Xerarch Succession
Primary succession beginning on solid rock
  and with minimal water holding capacity
         Hydrarch Succession
Primary succession beginning on or in water
(think pond or lake)
         Mesarch Succession
Primary succession beginning on a substrate
  other than solid rock or water
(think mudflow or glacial moraine)
   Interrupts primary succession, leading to
    secondary succession
        Types of Disturbance
1.   Windthrow
2.   Fire
3.   Insects
4.   Disease
5.   Wildlife
6.   Human activity
Human Activity - Forest Management
  Management often seeks to duplicate
  natural patterns of disturbance or

     1. Intolerant – Large openings
     2. Mid-tolerant – Small openings
     3. Tolerant – Individual trees
    A Second Look: Composition
Species composition
     a. Pure – usually intolerant, early
     b. Mixed – more tolerant, later

Density – reflects stocking, occupancy
          (how much is there)
      A Second Look: Structure
Age of trees (think crown layers too)
    a. Even-aged – usually intolerant
                (early successional)

    b. Uneven-aged – mixed tolerance
            (later successional)
               Habitat Typing
   Identifying a successional pattern

   Developed by John Kotar for the Lake
    States Region

   Relies on ground flora to identify habitat
                Size Classes
Related   to merchantability and structure
     a.   Seedling
     b.   Sapling
     c.   Poletimber (Pulpwood)
     d.   Sawtimber

Can discuss composition of each
Sampling Forest Resources
   Diameter (in.) at breast height

   Outside bark diameter measured 4.5 feet
    above ground
Measured with a DBH tape, calipers, or
 perhaps a Biltmore Stick
   Watch out for leaning trees!

   Measure perpendicular to the lean
   Watch out for deformities at 4.5 feet
    above ground!
   Watch out for slopes!
               DBH Classes
   “The name of the class is the center of
    the class”

1 inch classes
     go down to the 0.6 and up to the 0.5

       example: 7.6” – 8.5” is the 8 inch class
               DBH Classes
   “The name of the class is the center of
    the class”

2 inch classes (typically even numbered)
     go down to the 0.1 and up to the 0.0

       example: 7.1” – 9.0” is the 8 inch class

   Seedling   (less than 4.5 feet tall)

   Sapling    (0” < DBH ≤ 5.5”)
   Pole or Pulpwood (paper products)
       Hardwood     5.6” ≤ DBH ≤ 11.5”
       Softwood     5.6” ≤ DBH ≤ 9.5”

   Sawtimber (sawn products)
       Hardwood       DBH ≥ 11.6”
       Softwood      DBH ≥ 9.6”
         Other “Types” of Trees
   Cull: a non-merchantable living tree

   Snag: a standing dead tree