The main purpose of this study is to investigate the needs of pre-Commercial thinning on private owned forest properties, which is considered to be increasing. The reason is believed to be the high cost of labor that pre-Commercial thinning brings. Furthermore thinning is costly, the revenue created through pre-Commercial thinning are post-poned until the first thinning. The study was made through a survey among members of Mellanskog forest owners association. The survey was distributed by e-mail. The time to answer was set to two weeks. The answers indicate that the most common reason why the pre-Commercial thinning is delayed, or not done at all, is the forest owner?s lack of time.

This project was a request of Norrbodal´s Forestry Board, Västra Götaland. It was performed as a qualitative interview analysis of private forest owner?s deficient motivation regarding pre-Commercial thinning. The purpose of the project is to investigate what the Forestry Board can do to motivate private forest owners to do more pre-Commercial thinning. The results build upon 16 qualitative phone interviews with forest owners that have their forest within the district of Norrbodal. The owners are divided into two groups, the one who have performed the pre-Commercial thinning and the one that has possible pre-Commercial thinning needs on their properties according to the pre-Commercial thinning analysis ,which is the result of a satellite analysis.

The aim of this work is to demonstrate how the net present value (NPV) at the time of the first thinning depends on the spacing after pre-Commercial thinning, and show how net value from first thinning in same stand is influenced. This study is performed with models based on non-distant dependent growth models for single trees. Two different growth models have been used, one for cleaning (pre-Commercial thinning) and one for thinning. The first one yields stem density distributed over diameter classes. In the second one, (the thinning model), it is possible to choose when thinning should be done, the thinning method, thinning grade and numbers of thinning.

The purpose of this study was to examine how small-scale private forest ownersmake decisions regarding pre-Commercial thinning. In 2015 it is ten years agosince the storm Gudrun hit the southern parts of Sweden and now large areas arein need of pre-Commercial thinning. This study is built upon qualitativeinterviews with seven small-scale private forest owners with forest properties inthe county Kronoberg. The respondents were chosen by the modelSKOGSÄGARPROFILENTM (forest owner profile).The results of the interviews showed that five categories: ownership, the stormGudrun´s impact, silviculture, forestry contacts and driving force was important.How will their purpose and aim affect the pre-Commercial thinning? Personalinterests, and expectations of the next generation to take over, are purposes thisstudy has found.

The brown bear population in Alberta, Canada has been decreasing, while the Swedish has been increasing and all the affecting parameters are not known. This study examined the difference in these populations to see if an explanation could be found in differences between the forest management. The aim of the paper was to see if stand treatments had an influence of brown bears habitat selection in autumn in Sweden and how the results can be used in Alberta. This was done by analyzing bear positions in Sweden with forest data, and comparing forest management data for the study area in Sweden with forest management data for Alberta. The results displayed that mature forests over 60 years that have been commercially thinned are selected by bears rather than forests over 60 years that have not been commercially thinned in.

The purpose of this report is to investigate and compare the difference between stand-thinning machines and strip-road thinning machines, and how they affect the stand on behalf of future growth, theoretical economic result, wind impact, snow pressure and density of stand. The investigation is regarding the first Commercial thinning of pine stands, after pre-Commercial thinning that was well conducted. The investigation area was located near Katrineholm, Sweden. The measurements that were measured were strength of thinning and amounts of wind throws, snow-breaks and hauling damages. The results that emerged, was that thinning with strip-road machines had a significantly higher strength of thinning over all, as compared with the stand- thinning machines (45 percent versus 30 percent). Comparisons between wind-throws, snow-breaks and hauling damages of the stand could not establish any significant differences between the two methods that were investigated. Conclusions, over all, were that if forest owners want to have more timber volume left for second thinning and final cut of the stand, the forest owners should choose the method with stand-thinning machines. From the point of view of gentle treatment of the stand and ground damages the choice should be the same. However, the method with strip-road thinning machines is the most common and accessible method in Sweden. Most likely it is the most economical way to manage the stand for forest owners in present time. If the method with stand-thinning machines is becoming more common in Sweden, it is suggested for forest owners to consider the stand-thinning method as a candidate for treatment due to economic aspects..

Earlier attempts at mechanising pre-Commercial thinning have been met with varying degrees of success. Most attempts have been based on techniques where residual stems are straddled. Early treatment is essential to limit damage on residual trees. One part of the present study is an evaluation of mechanised pre-Commercial thinning using the new Vimek 404R. Vimek 404R is a fairly small machine that permits selective removal of stems, making it potentially suitable also for areas overdue for pre-Commercial thinning. The study established the level of performance for the machine, as well as the improvement needed to make it an economically viable option.

This report is a thesis work for a B.Sc. in Forestry exam at the School for Forest Engineers, SLU. The work was an assignment from Sydved and the aim of the work was to investigate the economical output of removing understorey trees before first thinning. Four treatments were studied. - no cleaning before thinning - cleaning of all trees less than DBH 5 cm before thinning - cleaning of all trees less than DBH 7 cm before thinning - cleaning of all trees less then DBH 9 cm before thinning The result shows a decrease of the cost per m3 for the harvester with about 38% if all trees less than DBH 9 cm was cleaned before thinning compared with the un-cleaned area. At the same time the total net revenue increases with about 22%. .

Thinning is the partial removal of trees in a forest stand prior to final harvest. The term can be divided in pre-Commercial thinning where little if any volume is removed from the stand and Commercial thinning where removals are intended to provide a positive economic result. From a silvicultural point of view, the goal of thinning is to enhance future crop tree quality by removing low-quality stems and providing sufficient space for the accelerated development of retained ones (Huuskonen & Hynynen, 2006). The goals of this study was to see if Commercial thinning could positively affect the short and medium term timber supply (MTTS) in the Interior regions of British Columbia (BC), and whether or not Scandinavian forestry practices could be adopted in the BC context. The mountain pine beetle (Dendroctonus ponderosae Hopkins) has created significant forest planning problems in BC. The annual allowable cut (AAC) was raised to capture beetle-killed timber while still merchantable.

Overdue cleanings have for a long time been an important topic of discussion within the forestry sector. When stands that have not been pre-commercially thinned are reaching the level of Commercial thinning, many problems occur in terms of decision-making and economical outcomes. These types of stands are commonly known as conflict-stands. The work was carried out partly as an interview survey towards representatives from the forest sector and the energy sector, partly as a case study of conflict-stands situated in Böksholm, north of Växjö and in Tönnersjö east of Halmstad. The criteria for the studied stands were that they had to be dominated by Norway spruce and be in a severe status of ?conflict?. The aim of the interview was to get an overview of the situation today, and also analyse trends in terms of conflict stands.

Successful forest regeneration is a prerequisite for sustainable forest management. Therefore, it is important to prevent browsing damage on the commercially important tree species Scots pine. In this study I have tested a new alternative way to increase the available amount of forage and increase the use of these resources by especially moose. The method is based on a slash treatment at harvest, where the accessibility of slash as forage is increased during final felling or Commercial thinning by gathering the slash and putting the Scots pine slash on top of the slash piles. This study has compared the availability of forage, the amount of browsed biomass and the number of fecal pellet groups between conventional and slash treated stands after final felling and Commercial thinning in southern Sweden.

Stands where pre Commercial thinning has been ignored or inadequate often tend to have high stem density and low average diameter when they reach heights of thinning. In such stands, it can often be expensive to do a conventional pulpwood harvest as a first thinning. This study investigates the development of the stands and the economic outcome of forest fuel extraction, or a combined harvest as alternatives to the ordinary pulpwood harvest. Simulations in Heureka StandWise were performed for two thin and dense stands, which were constructed by data from the Swedish National Forest Inventory. The simulations show that the extraction of forest fuel in first thinning at an early stage can provide higher net revenue compared to conventional pulpwood harvest at the same time or later.

Root rot causes large economical losses for Swedish forestry. The spread of root rot can partly be prevented by treating the spruce stumps in thinnings. Late pre-Commercial thinning (PCT) is one of the forestry measures where stump treatment is not used. Late PCT can be defined as: The act of cleaning the stand with the aim of improving accessibility and sight within the stand, and so to increase the mean stem´s volume during the first conventional thinning. The aim of this study was to examine how late PCT is performed, its spatial extent and if it aids the spreading of root rot. The study was limited to encompass late PCT before first conventional thinnings in spruce stands in southern Sweden. Samples of spruce stumps were taken from four stands where late PTC had been carried out.

I Sverige finns ca 1,2 miljoner hektar skog som bedöms ha omedelbart röjningsbehov. Skog där röjningen uteblir eller är svag kan komma att klassas som konfliktbestånd. I konfliktbestånd är stammarna många och diameterspridningen stor och dessa kan då behövas underröjas innan gallring. I denna studie jämfördes produktionen, kostnaderna och intäkterna från fyra olika underröjningsbehandlingar, oröjd, siktröjt, röjt allt upp till 5 cm i brösthöjd och röjt allt upp till 7 cm i brösthöjd. Behandlingen oröjd gav det bästa nettot och sämst hade upp till 5 cm efter gallring och uttransport av virke.

Each year, Heterobasidion spp. is a major cause of economic losses to forestry in the northernhemisphere, including Sweden. New results indicate that pre?Commercial thinnings could be at riskfor Heterobasidion spp. infections.