forestry: envirothon

FORESTRY: ENVIROTHON

About 30% of the world is forested today, but the ratio between forest and population varies immensely.

More than one half of the world's softwood timber (the major forest product) comes from North America and Europe—an area with only a fourth of the world's population.

The forested area of the United States has shrunk in 300 years from about one half to one third of the total land acreage.

The United States and Canada share 16% of the world's forests; the former Soviet Union contains 21%, Africa has 20%, and Latin American has 24%.

FOREST PRODUCTS

FORESTS: ASSESSINGTHE RESOURCE

Depending on “what you want” from a forest will determine what you will and won’t do to it……

Minimally even if you were to preserve the forest you have to know what’s there. That inventory could be the trees (and all other life and non-life there: smaller plants, animals, bacteria, fungi, soils, hydrology, etc.)

WHAT SPECIES?Measuring the diversity or species composition of your forest isalmost always a basic and prime concern. One way to identify treesparticularly if the species are new to you is to use a KEY. Some itemsthat appear in keys that are useful to know are:Leaf shape Branching pattern

Leaf type

WHAT SPECIES?

Other useful characteristics to help identify trees are:

Bark characteristicsFruits

Flowers

WHAT SPECIES?

Tree form Smell (leaves, bark)

Leaf tips

Leaf bases

Site

Buds, twigs

ETC…….

Tree diameter and heights usingBiltmore stick/Merritt hypsometer

TREE DIAMETER (DBH):

D-tapemeasure at4.5 ft fromground….

TREE HEIGHT (TOTAL):

Suunto ClinometerTwo measurements:-One at ground level-The other the very top of the tree

HEIGHT=TOP MEASUREMENT – BOTTOM MEASUREMENT(BE CAREFUL: THERE ARE + and – READINGS YOU CAN GET!)

TREE AGE (at breast height):

Increment corer

TREE AGE (at breast height) CONT’D:

We bore the tree at breast height4.5 feet from the ground….

You can bring the cores back to the lab, mount and sand them and do some DENDROCHRONOLOGY (study of tree rings)..

TREE AGE (at breast height) CONT’D:

POINT SAMPLING

SILVICULTURE“the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society on a sustainable basis through the application of silvics”

SILVICS:….the life history and general characteristics of forest trees

and stands, with particular reference to environmental factors….

SILVICULTURE CONTROLS:

Stand composition

Stand density

Restock underproductive areas

Protection and salvage

Control rotation length

Facilitate the harvest, management, and use of the forest

Protection of the site and indirect benefits

SILVICULTURAL SYSTEMS

REGENERATION SYSTEMS

Even-aged systemsClearcut systemsCoppice systemsSeed tree systemsShelterwood systems

Uneven-aged systems Group or Individual Selection systems

CAN BE DIVIDED INTO THREE BROAD GROUPS:

INTERMEDIATE CUTSThinnings, cleanings

SALVAGE/PROTECTION

Clearcut-usually INTOLERANTtrees regenerated-create or promote even-aged stands-best with light seeded spp.-trees are overmatureBE CAREFUL:-Can promote shrubs-can overexpose sensitivesites -slash can impair regeneration.-erosion on steep slopes

CLEARCUTS

In strips…..

or patches:

Jack pine clearcutin Manitoba tomimic natural firepattern

Coppice

You are ASEXUALLYreproducing the forest: stump sprouts

Seed TreeThe trees you leave as seed sources should represent the species you want and are the‘best’ there….

What are the dangers to this process?

Shortleaf seed tree (15 per acre)

SHELTERWOOD Preparatory cuts

These may be one or several light cuts to improve the vigor and wind firmness of potential leave-trees to prepare for the next cuttings. Establishment, regeneration or seeding cut Establishment, regeneration or seeding cut This cutting, which may be the first cutting in some unmanaged stands, is to provide growing space for establishing regeneration while maintaining shelter for developing seedlings. Trees chosen to be retained after this cut should be vigorous and wind firm.

Overstory removal cut(s) Once regeneration is established and stocking is acceptable, removal of the sheltering overstory is a common option. Alternatively, all or some of the sheltering residual overstory can be permanently or temporarily reserved from future cutting to satisfy management objectives.

SHELTERWOOD

Shelterwood on Douglas fir in West (note slope of land)

SELECTIONsingle tree

Usually this and group are for TOLERANT trees and uneven-aged stand

SELECTIONsingle tree

Single tree selection : red spruce,hemlock, and balsam fir

SELECTIONgroup

Group selection: old growthspruce fir forest

INTERMEDIATE CUTSTreatment of stand during part of the rotation not includedin regeneration period….

Intermediate cuts are used for: -improve existing stand -regulate growth -provision for early financial returns

If regulate growth then called thinningsIf regulate species composition: young stands: release cuttings

old stands: improvement cutsIf take branches off: pruning

INTERMEDIATE CUTS

Many types of thinnings:

Low (German)Crown (French)SelectionGeometricFree

CROWN CLASSIFICATION

Low ThinTrees are removed from thelower crown classes

Mimics natural mortality

You can work in a range ofThinnings:

A-B thin without risk ofreducing wood production

C-D stimulate growth ofremaining trees (not just salvage)

CROWN THINRemove trees in middle andupper crown classes

Most trees cut are Codominantbut can take out interferingIntermediates or Dominants

Crown thinning favors nearly thesame trees as Low thins but removes a few strong competitors rather than eliminatethe weak (As Low thin does)

Crown thin is more flexible butdemands greater expertise…

SELECTION THIN

-Dominant trees are removed to stimulate lower crown classes-Vigorous trees favored in Crown and Low are the very ones likely to be cut here-Be careful: limited use, could become High grading!

MECHANICAL THIN

Aspen stand in which 5 meter wide strips are removed to thin…

PRUNING

Very expensive and intensive BUT incertain circumstances you could get moremoney for the wood (no knots)

RELEASE CUTS/TREATMENTDone when stand is young to remove species not desired…..

Pine stand above – releasingpines by using brush saw onundesirable species- the final resultis the bottom picture

IMPROVEMENT CUTS

BEFORE (LEFT) and AFTER (RIGHT) of HARDWOOD STANDIn Mississippi- get rid of poorly formed species or undesirable species and shrubs…