Introduction to Forestry

1
Introduction to Forestry

• Hoyt Ponder
• Submitted October 20, 2005

2
Objectives

• Upon completion of this course, the student
  should be able to
• Describe the forest resources of Louisiana and
  our region.
• Explain primary and secondary growth of a tree.
• Define and explain techniques used for the
  management of a forest including soil, water,
  and wildlife.
• Understand basic economic concepts of the
  forestry industry.

3
What makes up forest?

• In terms of woody plants, the two main types are
  trees and shrubs.
• What are the main differences in a tree and a
  shrub?

4
Trees and Shrubs

• A tree is a woody plant, typically large with a
  well-defined stem and a more or less defined
  crown.
• A shrub is a woody plant, seldom exceeding 10 ft.
  in height, usually having several persistent
  woody stems branching from the ground.

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Types of Seeds

• Angiosperms trees which produce seeds that are
  encased in a hull, shell or fruit. (Oaks, Fruit
  Trees, and Grasses)
• Gymnosperm trees which produce seeds that are
  naked. (Pines)

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Types of Seeds (cont.)

• Angiosperms (two kinds)
• Monocotyledons-embryo with one leaf.
• Palm trees and grasses
• Dicotyledon-embryo with more than one leaf.
• Oaks, maples, and magnolias
• Broadleaved or hardwoods
• Gymnosperms
• Conifers-pines, junipers, spruces, firs, and
  cypress
• Softwoods

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Types of Trees

• Evergreens
• Retains leaves year round
• Often a synonym for conifers (except cypress)
• Deciduous
• Trees that loose their leaves every year
• Often a synonym for hardwood (oaks)

8
Energy/Food

• 2 Types of Sugars
• Starch source of energy, excess is converted
  into wood
• Cellulose structural, makes up 70 of wood

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Energy/Food

• Photosynthesis
• Co2 water in the presence of light sugar

• Respiration
• Oxidation of Carbon
• Sugar in the presence of Oxygen CO2

10
Secondary Chemicals

• Lignin functions as a glue that glues cells
  together, second most abundant chemical in wood
• Tannins, terpenoids, and alkinoids all protect
  trees from insects, fungi and bacteria

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Three Types of Tissue

• Ground biochemistry
• Dermal epidermis or skin
• of plant (bark)
• Vascular transport system
• Xylem transports water
• and mineral salts
• Phloem transports
• organic food and sugars

12
Growth

• Primary Growth elongation (height)
• Secondary Growth diameter (width)
• Each year a tree gets
• a new growth ring
• The growth ring can
• tell you a great deal
• about a tree

13
Growth (cont.)

• Meristems
• Refers to points of growth that are actively
  dividing
• Apical meristems tips of limbs and trunks
  (primary growth deals with elongation)
• Cambium meristems single cell layer wide
  (secondary growth gets bigger in diameter)

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Plant Hormones

• Auxins
• Hormones that are made in the shoot tips, and
  controls phototropism (ability to grow towards
  the light)
• Apical Dominance
• Control of auxins in the tips of the limbs and
  shoots
• Suppresses elongation of lateral branches

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Symbiosis with Fungi

• Symbiosis both plant and fungi benefit
• Mycarhizae fungi that surround the roots
• increases uptake of nutrients, increases the
  surface area of the roots
• Rhizobium bacteria that is symbiotic with
  legumes (mimosa, black locust) and
• fixes atmospheric nitrogen

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Tolerance

• Tolerance is the ability to grow in low light
  conditions

17
Tolerance

• Intolerant grow best in full sunlight (bald
  cypress, pines, oaks)
• Tolerant has relatively equal growth with
  different levels of sunlight (southern magnolia,
  beech)

• Many of the important commercial and wildlife
  species are intolerant trees. Much of forest
  management has focused on maintaining communities
  of intolerant species.

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Gap Dynamics

• Small scale disturbances small openings in a
  forest where advanced regeneration occurs
• Fugitive easily distributed seeds (pines)
• Buried seeds seeds remain viable for a long
  time (oaks)
• Sprouting roots and stumps sprout to form a new
  forest

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Competition through Chemistry

• Allelopathy condition when some plants produce
  chemicals that inhibit, retard, or kill other
  plants
• The black walnut produces juglone which is a
  phenolic compound that kills most plants.

20
Prescribed Burning

• Uses
• Reduction of logging debris
• Preparation of seed beds
• Reduction of fuels in forests
• Control understory vegetation
• Improvement of wildlife habitat
• Improvement of forage for livestock

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Prescribed Burning

• Limitations
• Must be controllable (fuels, weather, topography)
• Preparation of fire breaks
• Smoke management (air quality, liability)
• Cost 7-20 per acre

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Let It Burn Policy

• Managing Natural Fires
• Put out the fire or let it burn?
• Yellowstone Park is this policies biggest
  challenge (contains 2.2 million acres)

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Let It Burn Policy

• In 1988 45 of Yellowstone burned (approx. 1 mil.
  Acres)
• ½ were only surface fires
• 25-30 burned under constant suppression
• Much of the problem was caused by fuel build up
  due to prior fire suppression

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Regeneration

• Follows harvesting or small scale disturbance
• Natural Regeneration seeds produced in area
  sprout and regenerate.
• Artificial Regeneration can be accomplished by
  either Direct Seeding or Planting nursery grown
  seedlings

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Natural Regeneration

• Advantages
• Usually produces a thick stand
• No bed preparation is required
• Requires no costs

• Disadvantages
• Unknown species
• Unknown genetics
• Bad seed year
• Drought
• Seeds may be eaten by rodents

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Natural Regeneration

• Methods
• Seed tree method superior trees are left to
  provide seed and are removed after regeneration.
• Shelter wood method similar to seed tree
  method, but deals with species where shelter is
  required
• Coppice method using stump and root sprouts.

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Artificial Regeneration

• Advantages
• Control seed supply
• Increases prompt reforestation
• Greater control over species and genetics
• Control tree spacing
• Regenerate in optimal weather conditions

• Disadvantages
• Can be costly
• Bed prep
• Cost of seedlings
• Cost of planting

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Succession

• The orderly replacement of species through time
  in a given location eventually leading to a
  stable community
• Two types of Succession
• Primary initial invasion of a bare site
• Secondary orderly replacement of species over
  time

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Harvesting Timber

• 2 Main ways
• Clear cutting all trees are removed at one time
• High grading best quality and largest trees are
  removed, only poor quality and small trees are
  left
• Thinning age, corridor

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Clear Cutting

• Advantages
• Easy site preparation
• Max profits
• Natural and artificial regeneration can be used

• Disadvantages
• Soil erosion
• Takes time to regenerate
• Negative view

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High Grading

• Advantages
• Biggest tallest trees are harvest
• Species can be selected for a market
• Highest dollar per board foot

• Disadvantages
• Appearance
• Smaller trees and poorer quality is left
• Regeneration has genetics that are inferior

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Siviculture

• Manipulation of forest vegetation to accomplish a
  specific set of objectives controlling forest
  establishment, composition and growth
• Even aged stand stands in which relatively
  small differences exist between individual trees
• Usually develop after a large scale disturbance
  (intol.)
• Un-even aged stand lack of disturbance (tol.)

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Un-even Aged Stand

• Dominant project above canopy, direct sun from
  above and part of the sides
• Co-dominant top of canopy, direct sun from
  above only
• Intermediate crowded into canopy, sun only
  directed to the top of the crown
• Suppressed completely overtopped,no constant
  direct sun (some plants will die)

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Review

• What is the difference between a tree and a bush?
• How does fungi work together with trees?
• What is the controversy over the Let it burn
  policy?
• What are advantages and disadvantages of clear
  cutting and high grading?

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Tomorrows Lesson

• Commercial Forest Land
• NIPF Non-industrial Private Forests
• Land Expectation Value (LEV)
• Mean Annual Increment (MAI)
• Harvest Scheduling