The cut-to-length (CTL) har­ves­ting met­hod ser­ves to directly pro­duce high-qua­lity tim­ber cut to the requi­red length based on demand. It is based on users’ actual needs – only the trees requi­red are har­ves­ted.

Assort­ment refers to the dif­fe­rent types of pro­ducts cut from a single fel­led stem, inclu­ding
sawn wood, plywood and small logs, pulpwood, and wood used to gene­rate bio­energy. In CTL har­ves­ting, we are tal­king about a mac­hine chain, con­sis­ting of a har­ves­ter and forwar­der.

The har­ves­ter fells, delimbs, mea­su­res, opti­mi­ses and cuts stems directly into the assort­ments orde­red by the user, nor­mally a forest com­pany. In the CTL met­hod, trees are proces­sed in the forest into dif­fe­rent assort­ments, based on the reques­ted pur­pose of use. All the assort­ments requi­red are pro­duced from each stem by proces­sing it once – in the same place in which it was fel­led. The forest com­pany sends its raw mate­rial needs, i.e. places its order, directly to the har­ves­ter, detai­ling the assort­ment, length and qua­lity requi­re­ments. The har­ves­ter recei­ves cut­ting instruc­tions from the forest com­pany and helps the ope­ra­tor pro­duce the assort­ments orde­red. In addi­tion, the har­ves­ter opti­mi­ses each stem based on the order and cuts them to the speci­fied lengths. As a result, the valuable raw mate­rial can be used as fully as pos­sible, wit­hout gene­ra­ting any waste. The volume of the assort­ments pro­duced can be moni­to­red auto­ma­tically in real time.

The forwar­der car­ries the assort­ments to the side of the forest road, placing each assort­ment into a sepa­rate pile. A tim­ber truck will then trans­port the assort­ments to the mill for furt­her proces­sing. Each assort­ment is trans­por­ted directly to its cor­rect des­ti­na­tion: logs to saw­mills; plywood logs to the plywood mill; and pulpwood to the paper or pulp mill. They will then con­ti­nue their jour­ney to ful­fil various pur­po­ses in buil­dings, fur­ni­ture and various bio­pro­ducts.

The aim of har­ves­ting is to mini­mise mac­hine trails. Eight-whee­led PONSSE forest mac­hi­nes have a balanced weight distri­bu­tion, and cor­rectly selec­ted tracks can have a sig­ni­ficant impact on mac­hine trails. Forwar­ders have the grea­test impact on trails because they drive over the same path mul­tiple times. As it moves and works in the forest, the PONSSE har­ves­ter spreads delim­bed branc­hes and tree­tops over trails. This dec­rea­ses sur­face pres­sure and reduces soil damage. In addi­tion, the nut­rient-rich lea­ves, need­les, limbs and tops remain in the forest for the next tree gene­ra­tion. A large load space also helps reduce soil damage, as fewer runs are requi­red.

Ten­ded forests grow more quickly and pro­duce hig­her-qua­lity wood

Forests seques­ter car­bon dioxide from the atmosp­here and slow the progress of the green­house effect. This is why forests are car­bon sinks. Forests are kept healthy through well-execu­ted thin­ning, which inc­rea­ses the amount of car­bon dioxide they seques­ter. Furt­her­more, cor­rectly timed thin­ning reduces the risk of snow and storm damage, wild­fi­res and insect damage. Mana­ged forests grow more quickly and pro­duce hig­her-qua­lity wood. A fully-grown forest keeps the car­bon dioxide it has seques­te­red, but can­not seques­ter more
car­bon dioxide as effec­ti­vely as a young, growing forest. Sys­te­ma­tic and long-term forest mana­ge­ment pro­duces the best results.

The more sus­tai­nable pro­ducts are made from wood, the more slowly the car­bon dioxide seques­te­red in trees is relea­sed. Durable wood pro­ducts such as tim­ber buil­dings and woo­den fur­ni­ture can be regar­ded as small car­bon stocks. When a lar­ger part of fel­led trees is used in these pro­ducts with a slow car­bon cycle, the amount of car­bon dioxide in the atmosp­here dec­rea­ses. In the CTL met­hod, the lar­gest pos­sible part of fel­led trees can be proces­sed into valuable and durable logs and sub­sequently into pro­ducts with a slow car­bon cycle.

CTL forest mac­hi­nes can be used in all har­ves­ting met­hods, from first thin­ning to con­ti­nuous cover fore­stry and rege­ne­ra­tion fel­ling. The fast and reliable rege­ne­ra­tion is addres­sed in all har­ves­ting met­hods. After all, only the healthy growth of the next tree gene­ra­tion enables the con­ti­nua­tion of the forest cycle and the rege­ne­ra­tion of the raw mate­rial. To enable dif­fe­rent har­ves­ting met­hods, mac­hi­nes must be balanced and strong so that they can use their long crate reach on thin­ning sites, for example. PONSSE forest mac­hi­nes ope­rate effec­ti­vely in all con­di­tions – regard­less of the weat­her, time of year or ground sur­face. The advanced com­pu­ting capacity of forest mac­hi­nes allows the best pos­sible value to be ext­rac­ted from forests. This means more than financial gain. By opti­mi­sing the yield and proces­sing value of the raw mate­rial, the maxi­mum amount of sawn tim­ber with a long-term car­bon seque­stra­tion capacity can be pro­duced.

Cut-to-lenght VS tree-length met­hod

Where the CTL met­hod is not yet used in mec­ha­ni­sed har­ves­ting, the tree-length met­hod is usually used. Com­pa­red to the tree-length met­hod, CTL is a more effec­tive and envi­ron­men­tally friendly met­hod as a result of such fac­tors as fuel eco­nomy and the proces­sing times and work sta­ges requi­red. In addi­tion, less cut­ting damage and tim­ber con­ta­mi­na­tion, com­bi­ned with fewer top breaks, mean that the tim­ber qua­lity is hig­her.

In the CTL met­hod, the mac­hine chain usually con­sists of a har­ves­ter and a forwar­der, whe­reas the tree-length met­hod requi­res up to four mac­hi­nes. In the tree-length met­hod, all stems are deli­ve­red as whole stems to the road­side sto­rage, from where they are usually trans­por­ted first to a saw­mill or inte­rim sto­rage. There, the stems are unloa­ded and cut for sawing. In other words, stems are not proces­sed into assort­ments until they have been deli­ve­red to the saw­mill or inte­rim sto­rage. After this, the stems are loa­ded once again for trans­port to various pro­duc­tion faci­li­ties. The same stems go through seve­ral proces­sing cycles, each resul­ting in more costs and adverse envi­ron­men­tal impacts. In the CTL met­hod, stems are already proces­sed into assort­ments in forests based on their inten­ded use, and logs are trans­por­ted directly from forests to their cor­rect des­ti­na­tions, wit­hout any inte­rim sto­rage or back-and-forth dri­ving. While CTL is the most com­mon har­ves­ting met­hod in the Nor­dic count­ries, the tree-length met­hod is still used widely in other parts of the world, inclu­ding Canada, the Uni­ted Sta­tes and Italy.

Glo­bal CTL recig­ni­tion to Chile

The Einari Vidgrén Foun­da­tion awar­ded the Huequecura com­pany from Chile the first-ever Glo­bal CTL recog­ni­tion. With the recog­ni­tion, the Einari Vidgrén Foun­da­tion seeks to encou­rage and pro­mote sus­tai­nable sil­vicul­ture and the diverse uses of valuable wood raw mate­rials using the cut-to-length (CTL) met­hod.

“The com­pany has been enga­ged in sys­te­ma­tic high-qua­lity har­ves­ting in Chile. It’s impor­tant to see how the Nor­dic CTL met­hod is sprea­ding across the world,” says Juha Vidgrén, Chair of the foun­da­tion.

Radiata pine accounts for some 60 per cent and various euca­lyp­tus species for 22 per cent of all plan­ted forests in Chile. Around 40–45 mil­lion cubic met­res of wood are har­ves­ted per year. In Chile, the tree-length met­hod is more com­mon, whe­reas only about 15 per cent of forest cont­rac­tors use the CTL met­hod. CTL forest mac­hi­nes were int­ro­duced to the Chi­lean mar­kets in the 1990s.

Establis­hed in 2002, Con­struc­tora Huequecura Ltda. pro­vi­des ser­vices in forests and civi­lian areas. The company’s foun­ders have more than 40 years of expe­rience in the forest industry.