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132 Uppsatser om Precommercial thinning - Sida 2 av 9
Hur ska tall- och gran bestånd i Götaland gallras för att minska risken för vindskador?
With knowledge of how the southern Swedish forests have been affected by storms the past years, this study intended to find out which factors affect the storm firmness of a stand the most. The study was based on data from stands in the, by the storm Gudrun, affected area. The results of the analyses that tested the stand factors that influence the amount of storm damage to the greatest extent showed that the storm sensitivity of Norway spruce stands were largely due to previous management actions. The factors that could be controlled by thinning and had relevance of storm damage standpoint, according to the results were; the dominant height, volume, basal area weighted mean diameter and stand age at last thinning. In this study, these results are not as clear for Scots pine.
En undersökning av Bergvik skogs och Skogsstyrelsens gallringsmallar mot en gallringsoptimering på simulerade typbestånd
The purpose of this study was to analyze the two thinning models: Bergvik Skog´s thinning model, which is based on total stems and dominant height, And Swedish forest agency´s thinning model which is based on basal area, habitat index, dominant height and recommended number of stems at final felling in Heureka´s StandWise and PlanWise.
The data we chosen for our study were taken from the Swedish National Forest Inventory and we were creating a simulated stand based on a great number of sample plots in Region three from The Swedish National Forest Inventory. We had chosen to create one stand with low habitat index (T20) and one with high habitat index (T24). Our purpose were to come as close as possible to a natural stand in central Sweden. We performed the thinning in StandWise and analyzed the data I Excel files. Our thinning optimizing´s were performed and analyzed in PlanWise.
There wasn´t any big differences between the thinning on the lower habitat index.
Effekt av gödsling och gallring på mö?belvirke av furu
This thesis is about the effects of fertilizing and thinning on furniture timber from redwood. Interviews of furniture manufactures have been made and observing of timber from the Swedish fertilizing and thinning trails. The result from the interviews showed which properties that is important for the furniture manufactures and then the result from the observation showed which type of management of the forest that gave the most timber that had those properties. .
Hur väl skogsägare följer åtgärdsförslagen i skogsbruksplanen : en enkätundersökning
This rapport is about how often private forest owners follow the measures proposed in their forest management plan. The survey is made in cooperation with the forest-owners association Norrskog.
The private forest owners are relatively satisfied with the forest management plans and with the measures proposed. There are some differences between those who live on or near their property and those who live many miles away.
The forest owners who live on their property are those who follow the proposed measure of Precommercial thinning to the largest extent. That group also values precommercially thinned stands higher than thinned stands.
The complete opposite is the case for the group that lives far away from their property.
Almost all of the respondents thought that the forest management plan would be or had been a good help in the decision making about the forest..
Privata skogsägares benägenhet till röjning i Gudrunområdet : En kvalitativ intervjustudie
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.
Träddelsuttag eller massavedsuttag i förstagallring?
The purpose of this study is to compare the economic differences between withdraw of forest fuel and withdraw of pulpwood in first thinning, to see which method gives the maximum profitability (income - cost). Another purpose is to investigate the economic impact of the thicket cleaning.
The study compares four different methods: i) pulpwood output with thicket cleaning, ii) pulpwood output without thicket cleaning, iii) forest fuel output with thicket cleaning and iv) forest fuel output without thicket cleaning. The study was conducted in a 30-years old stand, dominated by spruce, outside Harg in Uppland.
The method that generated the best economic net income was pulpwood without thicket cleaning. It generated a positive net of 1,383 SEK per hectare. Forest fuel output without thicket cleaning also generated a positive net in 720 kronor per hectare.
Kvalitet och ekonomi i utförandet av förstagallring baserat på olika gallrings- och underväxtröjningsprogram :
Stora Enso Skog has a long term contract regarding felling rights and silvicultural activities on forest owned by Bergvik Skog. In the autumn 2006, Bergvik Skog proposed a new thinning program, ?Bergvikgallring?. The new program implied an increased focus on extraction of smaller trees compared to the present thinning program, Stora Enso Skog?s ?Kvalitetsgallring?.
Precommercial thinning stumps´susceptibility to Heterobasidion spp : a comparison between high and low Norway spruce and birch stumps : a measuring of the efficacy of Phlebiopsis gigantea stump treatment
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.
The influence of forestry stands treatments on brown bears (Ursus arctos) habitat selection in Sweden ? an option for Alberta forestry?
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.
Skogsbränsleuttag vid förstagallring och dess påverkan på beståndsutveckling : simulering i Heureka med olika skötselprogram
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.
Behandling av konfliktbestånd - problem och möjligheter :
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.
Lodgepole pine - stability after thinning
SCA has today almost 300 000 hectares of their forest land planted with lodgepole pine(Pinus contorta var. latifolia). Due to initial extensive planting in the 1970ies the area oflodgepole pine forests in the thinning age has grown rapidly from the end of the 1990ies.During the years 1996-2005 first commercial thinning of lodgepole pine at SCA took place.The goal of the hereby presented study was to investigate the growth and stability in thosefirstly-thinned lodgepole pine stands a few years after thinning. Furthermore, the objectivewas to investigate the relationship between stand stability and different stand parameters.Additionally, lodgepole pine stem quality was estimated.The study is mainly based on the data collected during an inventory project carried out atSCA in 2008. Altogether 91 lodgepole pine stands in northern Sweden were measured afterthe first thinning.
Identifiering av gallringsbehov med hjälp av flygburen laserskanning :
Thinning is one of the most important silvicultural activities in middle aged forests, partly to minimize damages and partly because it leads to earlier harvesting revenues and increases the value of the remaining trees. There are many different indices used to describe stand density and thereby the need of thinning in forests today. Studies have shown that forest variables can be estimated with high accuracy using airborne laser scanning and it is likely that the method could also be used to estimate forest density indices. In this study, the possibility of using the forest density index ?H² to determine and map priorities for thinning operations for a forest area was examined.
Stormskador i stickvägsgallrade bestånd i sydvästra Sverige :
A storm in January 2005 felled 75 millions cubic metres of forest in South Sweden. Previous studies of wind damage in thinned stands indicated the importance of early thinnings. The risks of wind throw increased by increasing age and height of the stands. Previous studies also indicated increasing risk of wind throw along the strip roads. The aim of the present study was to investigate wind damage in Norway spruce stands in South Sweden in relation to time of the first thinning and different pattern of strip roads (width, length and direction).
Underröjningsgradens påverkan på förstagallringsnetto med flerträdsaggregat
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.