Most southern pine timber is harvested b y independent
logging contractors. Lesser amounts are harvested by logging
crews employed directly by larger corporate wood-using
organizations and by landowners themselves. Although the
chances are that you will not harvest timber yourself, an
understanding of what is involved in harvesting will better
enable you to deal with prospective timber purchasers and
work with the successful bidder for your timber.
The logging methods used and the logger's ability to carry
out your plans are critical to the overall success of forest
management. Well planned harvests ultimately determine the
financial success of the venture. The cash return immediately
available from the harvest is dependent upon the logger
producing the most valuable timber products possible. Site
preparation and establishment costs of the succeeding stand
are, to a large degree, dependent upon the completeness of
harvesting. Future productivity of the site will depend on how
well or how poorly the harvesting operations are carried out.
Finally, harvesting operations will influence both the
landowner's and the public's impression of the desirability of
producing timber for profit.
Harvesting includes as operations necessary to remove
timber from the forest and deliver it to the mill. These
operations are felling, limbing and bucking, skidding, loading,
and hauling. Alternate methods for accomplishing each of
these operations are available. The correct combination of
methods to use on a given site depends on tract size, timber
type, volume per acre, individual tree volume and see, type of
cut (clearcut, thinning, etc.), terrain, weather, soils, road
system, equipment availability, and landowner's desires.
Before cutting begins, a harvesting plan should be
developed for the entire tract. This plan will include:
- the landowner's management objectives;
- map of the area;
- legal property boundaries;
- description of trees to be removed;
- method of marking trees to be removed;
- method of harvesting;
- the placement of haul roads, skid trails and log
landings;
- placement and types of stream crossings;
- road and trail drainage structures;
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- soil conservation measures, including Best
Management Practices, to be used to protect water
quality;
- maximum height of stumps;
- slash d isposal methods;
- penalties for damaged fences, other man-made
structures and residual trees.
In addition, any other landowner or legal requirements
should be incorporated into the plan.
Next, a timber sale agreement or contract that incorporates
the essential elements of the logging plan should be
developed. It must be comprehensible, performable, and
enforceable by both the landowners and logger: For example,
if site preparation is to be the responsibility of the logging
contractor, this should be a part of the contract and should
stipulate the stocking level expected at termination of the
contract. A landowner shod realize that each additional
requirement is an expense to the contractor and will rest in a
reduction of the stumpage price received.
The following abbreviated descriptions of the harvesting
operations normally used for southern pines will help the
landowner understand the harvesting . process and assist
when negotiating with a contractor.
Felling
Felling is the act of severing standing trees from their
stumps. Felling is normally accomplished with a chain saw or a
hydraulic-powered felling head mounted on a self-propelled
machine. The chain saw is used for felling both sawtimber and
pulpwood, and is the primary tool used for cutting higher-value
products such as poles and sawlogs. (Figure 1)
There are several types of felling heads available. Mainly
used in cutting pulpwood, they have either one or two blades
and shear the tree from the stump. They can cause damage to
the butt log, thus limiting their use to pulpwood. Other heads
use various methods to saw the tree, thereby reducing log
damage. The felling head is mounted on a crawler tractor
(Figure 2), rubber-tired crier (Figure 3), excavator (Figure 41, or
specialized machine.
Delimbing and Bucking
This operation entails removing limbs from the trunk of the
tree up to a minimum top diameter and cutting it into logs or
bolts of predetermined lengths. Delimbing and bucking may
take place where the tree is felled, or the entire tree may be
skidded to a cleared area called a log landing for delimbing
and bucking. Equipment used
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includes chain saws or a variety of mechanized methods. In
pulpwood operations, the entire tree (minus limbs) is often
transported to the mill or concentration yard. In other pulpwood
operations, the entire tree (limbs and all) may be reduced to
chips at the log deck, with the chips blown into trailers for
transport to the mill.
Skidding
In the South, most movement of wood from the stump to the
landing is done with wheeled or tracked machines. Skidding, or
dragging logs, is accomplished with rubber-tired skidders
(Figures 5-6), crawler tractors (Figure 7), or even horses or
mules. Skidders and crawlers can be equipped with wire
nooses called chockers or grapples to secure the stems for
transport. Forwarding or prehauling involves carrying the wood
on a vehicle, from stump to landing. Skidder type machines,
equipped with bunks or trailers (Figure 8) are commonly used.
In mountainous areas, cable logging syste ms (Figure 9) are
sometimes used. These have a tower, yarder, and cables to
move the logs. Generally, there is less ground disturbance on
steep slopes with cable yarding.
Depending on sod properties, terrain slope and rainfall
patterns, ground skidding can sometimes cause unacceptable
levels of soil disturbance of forestland, resulting in reduced tree
growth and lower water quality through erosion. These impacts
can be reduced by a combination of minimizing the area in skid
trails and logging in dry weather: The location of skid tab
should be determined in the logging plan. They shod be
located in the field before logging begins.
Loading
Loading is the ink between logging and hauling operations.
Loading is performed from log deck located at the landing.
Several landings are often used on larger tracts so that
skidding distances are minimized. Loading is done with a
variety of machinery, rarely by hand. The most common
machines are hydraulic knuckleboom
loader (Figure 10), front-end loader (Figure 11), and big-stick
loader. If the end-product is wood chips, chippers are often
located at the landing, and the chips are blown into special
trailers.
Hauling
The final harvesting operation is the movement of belts, logs,
trees, or chips from the deck to a local concentration yard or mull
(Figure 12). All log decks should be located beside a haul road
system developed for the tract. This transportation network,
including deck and skid trail locations, shod be specified in the
harvesting plan to minimize skidding distances, haul-road
construction, maintenance costs, and soil and site disturbances.
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These publications developed jointly by.
Cooperative Extension Service
USDA Forest Service
Southern Region
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