TIMBER-harvesting.pdf

TIMBER HARVESTING LONG QUIZ REVIEWER Cutting- an operation of felling standing trees and bucking felled trees into logs. Gathering (minor transportation)- an operation of skidding or yarding logs from the stumpsite to the log landing. Transporting (major transportat...

TIMBER HARVESTING LONG QUIZ REVIEWER Cutting- an operation of felling standing trees and bucking felled trees into logs. Gathering (minor transportation)- an operation of skidding or yarding logs from the stumpsite to the log landing. Transporting (major transportation) an operation of loading logs to the trucks bunk and haul it to the mill site for processing. HISTORICAL BACKGROUND Pre- Spanish period (Before 1521) - During this period, axes were commonly used for felling trees. Carabao was used for skidding logs from the stumpsite to the market. Spanish Period (1521-1898) - There was little innovation on the system of logging employed during the Spanish time. However, the market expanded exceedingly due to high demand of materials used for ship building. American Period (1898-1935) - At this period, almost all logging operations were mechanized. Chainsaw was used for felling trees. Cable logging was employed. Tractors were used for skidding whereas military GI truck was used for hauling. Commonwealth period (1935-1945) - No improvement was introduced on the system of harvesting, but rather loggers adopted the entire system practiced by the Americans. Japanese Period (1941-1945) - There was wanton exploitation of timber in the forest and forest products were directly brought to Japan. Forest destruction was rampant particularly at the height of the war where trees were cut, damaged, injured and uprooted. Present Situation (1946 to the present) - Mechanized and systemic logging methods have been employed by the logging companies, with the adoption of selecting logging system (modified selection method) that in turn, applies and operationalize the principles of sustained yield. Importance of TIMBER HARVESTING Major source of revenue Stable Employment Provides growth of other allied industries like equipment manufacturing, etc. Improves transportation and communication facilities Facilitates settlement of communities Improves social conditions Major activities of timber harvesting Felling – severing the tree from its trunk to allow it to fall. Log preparation – preparing the log prior to processing. Minor transportation – initial movement of logs from the stumpsite to a temporary piling area, which could be along the roadside or in a log landing area. Major transportation – final movement of logs from the log landing to its final destination. Subsidiary activities in timber harvesting Development of road transport network Logging planning Scheduling and monitoring of harvesting operation Types of timber harvesting according to the mode of extraction Tractor Logging: This method involves using tractors equipped with specialized equipment to pull or drag logs out of the forest. Highlead Logging (or Highlead Yarding): This technique is used in steeper and more challenging terrain. Harvesting systems Types of timber harvesting according to preparation of logs produced Short wood systems Tree-length systems Full-tree systems Types of timber harvesting according to silvicultural system Clearcutting Selective Cutting (Selection System) Shelterwood Cutting Seed Tree Cutting SECTION 22. Silvicultural and Harvesting System (PD 705). For dipterocarp forest, selective logging. For pine, mangrove forest, the seed tree system. SECTION 23. Timber Inventory. The Bureau shall conduct a program of progressive inventories of the harvestable timber and young trees in all forest lands, whether covered by any license agreement, license, lease or permit, or not, until a one hundred per cent (100%) timber inventory thereon has been achieved. SECTION 24. Required Inventory Prior to Timber Utilization in Forest Lands. No harvest of timber in any forest land shall be allowed unless it has been the subject of at least least a five (5%) timber inventory, or any statistically sound timber estimate, made not earlier than five (5) years prior to the issuance of a license agreement or license allowing such utilization. Shortwoodsystems Shortwood (also known as cut-to-length): Trees are felled, delimbed, and bucked to individual product lengths directly in the stump area and then transported to the landing or roadside. Advantages Disadvantages Less adverse site impacts, Lower production Residues remain at the stump, Can't put on a heavy load on steeper slopes Less support equipment needed, Slash mat may be inadequate to fully support some equipment Smaller landings needed. Narrower skid trails needed. Tree-Length Systems Trees are felled, delimbed, and topped directly in the stump area and then transported to the landing. Advantages Disadvantages Branches remain at the stump Wood tends to be dirty Roadside slash is greatly reduced Landings are somewhat smaller FULL-TREE SYSTEM Full tree: Trees are felled and transported to the landing with the branches and top still intact. Advantages Disadvantages Maximizes volume recovery/unit Loss of high value may occur Less labor/unit volume Residues are not left at the stump Types of timber harvesting according to silvicultural system Clearcutting - is the simplest way of replacing an old stand. Advantages Disadvantages Cheaper in establishment Low aesthetics Ease in management Risks are high Ease in harvesting Uneven seedling distribution Less skills required Selection Method or Selective Logging - the only method used to regenerate uneven-aged forests. 3 Important phases of Forest Management in Selection Method Seeding or Establishment of Regeneration Tending and Caring or Timber stand improvement to include thinning, pruning, liberation cutting, fertilization if necessary. Harvesting End of Lecture I TIMBER RESOURCE INVENTORY - provide values for the birth, maturation, and death parameters for the healthy forest dynamics. Sampling Techniques – small portion of the forest which are considered representative of the whole forest that is selected. Advantages are Reduced cost, Greater speed, Greater scope. Sampling methods usually used in forest inventory Systematic sampling, stratified sampling, multi-phase sampling, multi-stage sampling, sampling for proportion/ratio. TERMINOLOGY IN TIMBER HARVESTING AAC - Annual allowable cut - The volume of timber that may be harvested from a particular area of forest in any one year. Animal Logging - skidding or yarding using animal power. Anvil - a fixed steel block that provides support for the cutting blade of a single-action tree shear. The hydraulic operated blade through the tree toward the anvil. Aspect - the direction toward which a slope faces. Backcut - the final cut made in a tree to remove or severe the wood on its back side and allow it to fall. Ball-Hooting - hand-skidding of logs down a slope too steep for animal skidding. Barber chair - a vertical split in a tree, generally caused by an insufficient undercut or neglecting to cut the sapwood on both sides of a heavy leaning tree before felling. Basal Area - (a) the area of ground surface covered by the stem or stems of a range plant, in contrast to the full spread of its herbage or foliage usually considered at one inch above the soil. Bastard-Sawn - wood so sawn that the annual rings form angles of 30 degrees to 60 degrees with the surface of the piece. Bayonet-Topped - A tree with a dead volunteer top noticeably offset from the axis of the main trunk. A multiple bayonet topped condition is sometimes referred to as candelabra topped. Beam - a large and relatively long piece of timber, usually greater than 8 x 8 inches in cross section: a main horizontal timber support for a building. Bed a Tree - to level or cushion the path in which a tree is to fall, so as to prevent shattering. Billet - a short log or bolt usually cut for pulp, shingles corporate stock or cordwood. Blaze - to mark trees with a shallow cut of an axe or other cutting tool, or with a daub of paint, to designate trees to be cut, or to mark the location of some point such as along a boundary, trail, survey line, etc. Block - (a) a pulley used in power logging to change the direction of haul, or to increase the pulling power. (b) An area to be logged, also a setting or strip. Board Foot - A standard unit of measure for standing timber, logs, and lumber equal to a board 1 foot wide, 1 foot long, and 1 inch thick. A unit usually of 1,000 board feet M is often used to indicate 1,000. Bob - A single pair of runners on which the forward ends of logs are loaded. Boom - Projecting arm of a log-loading machine which supports the log during loading. May be of either the swinging or the rigid type. Boom rat- one who works on a boom. Bottom Bind - One of the five basic conditions for the lay of a tree. It occurs when a tree is lying over some solid object. Bridle - A device for controlling the speed of logging.sleds. It consists of a chain of clevis placed around the forward end of the rear sked runners. Buck - To cut a felled tree into smaller segments, called logs, bolts, or if only the top of the tree is removed, tree- length logs. Bucking Chute - a short pole chute at a landing, in which multiple length logs are bucked before being loaded. Bullbuck - A cutting supervisor, a foreman of a cutting crew. Bull Block - A heavy block for use with large donkey engines, having a throat of sufficient width to allow ringing assembly to pass through it. Otherwise known as Butt chain block: lead block. Bulldozer - an earth-moving machine that is also used in constructing roads and fire-control lines; it consists of a standard Drawler tractor equipped with an earth-moving blade. Bummer - a smaller truck or dolly with two low wheels and a short pole, used in skidding logs. Otherwise known as Drag cart; self-loading skidder. Bunch - to skid logs together to form a load for subsequent hauled by other equipment. Bunk - The cross-member of a logs transportation vehicle on which the log rest. Bushel - to fell, buck or do any wood job on the bushel or volume rate of payment. A bushel is equal to 1,000 bd. ft. Busheler - a cutter who is paid by the total volume of timber felled or bucked during a given period at the bushel rate, volume is measured on the log scale used in the region. Butt Swell – increase diameter in the base of the tree. Butt - the base of a tree, the lower end of a log. butt rigging- It is a series of heavy steel links, swivels and shackles that connect the mainline and haulback line. Carriage - a frame on which are mounted the head blocks, set work, and other mechanisms for holding a log while it is being sawed, and also for advancing the logs toward the saw line after a cut has been made. Catamaran - a small raft carrying a windless and grapple, used to recover sunken logs. Check - a defect found in logs that have been exposed to sun or wind for a long period of time. Sun dries out the wood, causing deep checks on the ends of log. Chipper-and-Notcher - The chief of several saw screws. He notches the timber and keeps a tally of the number of logs cut by each saw screw. Choker - a noose of wire rope attached to log so that they can be yarded or skidded. One end of the choker is wrapped around the end of log while the other end is attached to winch line or directly to the skidding machine. Chock Block - any blocking device as a wedge, used to keep a log from rolling. Choker Hole - a hole dug under a log to allow placing of choker. Clean -Boled - free or cleared of branches; used to designate timber with a satisfactory length of clear bole. Clearcutting - an area on which the entire timber stand has been cut. Chute - a trough, often built of round timber, in which logs, bolts, etc. are transported up or down a grade, either by power Defect - tree injury in a stand of timber, such as stump rot, dead trees, and snags that decreases the volume of usable wood that can be recovered. Amount of defect also affect efficiency, costs and safety of a cutting operation. Directional Felling - felling trees in only one direction. In mechanized felling operations utilizing single-action shears, the angle of the cutting blade functions as a wedge and causes the trees to be felled in one direction. Dogs - a short heavy usually right-angled, steel hook, connected by a short length of chain with a center ring, used in skidding. Dogs may be driven into the log on opposite faces, or used to fasten logs together in strings. They are used for many purposes in logging, and are sometimes so shaped that a blow directly against the line of draft will loosen them. Dog Board - In sawing lumber on a head saw the last board in the log to which the carriage dogs are attached. Donkey - in logging, a portable engine mounted on a sled and equipped with drum and cable. Drag In - to drag logs from the place where they are cut directly to the skidway or landing. Dray - a single sled used in dragging logs. One end of the log rests upon the sled. Drive - (a) a body of logs or timbers in process of being floated from the forest to the mill or shipping point. (b) That part of logging which consists in floating of timbers., (c) Mechanical power application, such as chaining or rack- and-pinion drive. Double-Action Shear - a mechanized cutting tool for felling trees that works like a pair of scissors; one blade is slightly offset but both work against each other. Some double-action shears, however, work edge to edge. Corner - In felling timber, to cut through the sapwood on all sides to prevent splitting. Brosshaul - A method of loading log-transportation vehicle. One end of a line is passed over the load, around the log to be loaded and made fast to the load. Power applied to the other end of the line imparts a rolling motion to the log. Cross the Lead - to fell a tree at an angle across the established lead or felling pattern. Crotch - a small sled, without a tongue, often made from the natural fork of tree and used as an aid in skidding logs on stony and bare ground. Cull – a tree or log that is not merchantable because of defects. Cutter - a man who fells, bucks, and or limbs timber. Cutting Cycle - the planned interval between major felling operations in the same stand. Cutting Pattern - the pattern to which trees are felled during a cutting operation. Cutting Plan - is an overall operating plan for felling the timber on a given strip or cutting block. Lay Rate – a method of paying loggers by the day or hour instead of by the piece or bushel. Day Wages - compensation on a day rate. DBH - diameter of a tree at breast height. Dead-and-Down - all down timber and dead timber either standing or down. Debarking - the removal of barks of the felled trees. Fit - to notch a tree for felling and after it is felled to make into the log length into which it is to be cut. Forwarding - transporting trees from the felling area to a collection point by vehicle. Forwarding differs from skidding in that the logs do not come into contact with the ground. It is also called prehauling. Flume - a continuous trough-line device used for the transportation of logs or timber in flowing water. Gang - cutters working in combination with a skidding crew. Grade - the designated quality of log (based on its best end use) such as peeler, sawmill, etc. In the various species according to the official scaling and grading rules for a specific timber region. Includes permissible and non- permissible.