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Introduction to Forestry Hoyt Ponder Submitted October 20, 2005.

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Presentation on theme: "Introduction to Forestry Hoyt Ponder Submitted October 20, 2005."— Presentation transcript:

1 Introduction to Forestry Hoyt Ponder Submitted October 20, 2005

2 Objectives Upon completion of this course, the student should be able to: 1.Describe the forest resources of Louisiana and our region. 2.Explain primary and secondary growth of a tree. 3.Define and explain techniques used for the management of a forest including: soil, water, and wildlife. 4.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.

5 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)

6 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

7 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

9 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

11 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)

14 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

15 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

16 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.

18 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

19 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

21 Prescribed Burning  Limitations: Must be controllable (fuels, weather, topography) Preparation of fire breaks Smoke management (air quality, liability) Cost $7-$20 per acre

22 “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)

23 “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

24 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

25 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

26 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.

27 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

28 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

29 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

30 Clear Cutting  Advantages: Easy site preparation Max profits Natural and artificial regeneration can be used  Disadvantages: Soil erosion Takes time to regenerate Negative view

31 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

32 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.)

33 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)

34 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?

35 Tomorrow’s Lesson  Commercial Forest Land  NIPF – Non-industrial Private Forests  Land Expectation Value (LEV)  Mean Annual Increment (MAI)  Harvest Scheduling

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