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132 Uppsatser om Thinning - Sida 4 av 9
Förändrad aptering av massaved från 3- till 4-meterslängder vid gallring inom Södra : en systemanalys av effekter från avverkning till levererad virkesråvara
The costs of logging and of transportation with truck are dominating the total cost of wood delivered at industry. To support the profitability for the members' forestry the processing and handling with the timber has to be as efficient as possible. Increased length of pulpwood in Thinning is one conduct that can result in higher productivity and/or lower costs. The study is scaled as a system analysis with the aim to exemplify the differences between working with 3- and 4-meter as standard length of pulpwood, related to biological aspects, timber receipts, cost of logging and cost of transportation with truck. Important aspects are if the change is technically and biologically feasible and economically profitable.
Medlemsundersökning SÖDRA Skog
This report is prepared in cooperation with Södra, Norra Halland SBO. The survey gives the members an opportunity to influence the services and also gives the staff at Södra a hint of the member?s demands.Södra is the largest co-operative forest company in Sweden with over 50 000 members and is divided into 31 areas. Norra Halland SBO is one of them.A questionnaire was sent to the members and 516 (or 53 %) of them answered. Of the respondents 68 % were between 60 and 69 years of age.
Skattningar i gallringsskog med hjälp av flygburen laserskanning : beräkningar med massaslutenhet
This master?s thesis is a remote sensing study of an area-based method used to detect forest in need of Thinning by use of laser data and field samples. Only pine-dominated forest has been included in the study and height limits were set to match empirical restrictions. The study area was in the municipality of Älvsbyn (Latitude 65° 40´ N, Longitude 21° 00´ E), in northern Sweden.The Swedish authority Lantmäteriet is currently laser scanning most parts of Sweden, providing new opportunities and applications. The primary aim of the national laser scanning is to create a new elevation model, useful in consequence analysis of climate changes.
Vilka faktorer avgör då skogsägaren söker samarbetspartner för planering och genomförande av skogsvård?
Silviculture in young stands in Sweden is below the mark concerning what has to be done in the forest, and it is time to solve the problem. The problem will not be solved only by the private forest owners, professional help is needed.
Skogsägarna Mellanskog is one of four forest unions in Sweden who wants to play a role and take responsibility for forestry in the middle of Sweden. This academic essay is based on a market survey sent to 350 forest owners in the Örebro district. 186 of them answered the questions, giving a response frequence of 53 percentage.
The purpose of the essay is to find the determining factors which will make a forest owner to find a collaborator when planning and carrying out the silviculture measures in young stands.
The result of the survey shows that the forest owners are anxious about the price and the costs. The costs have a severe effect if the silviculture measures in young stands will be carried out or not.
Produktivitet och lönsamhet vid skogsbränsleuttag i klena gallringar : en tidsstudie av Vimek 608 BioCombi i contortabestånd
The annual demands for forest fuels increases in Sweden. At present, large unutilized biomass resources is found in young, dense forests from which about five million oven-dry tonnes (ODt) (23 TWh) could annually be extracted as forest fuel. But harvesting small trees give high logging costs and new cost-efficient harvesting techniques are therefore required. The aim was to study the productivity of Vimek 608 BioCombi in forest fuel Thinning of Lodgepole pine and to calculate the economy of the harvesting and estimate the Thinning quality. The time study was performed in Åmarken in the county of Västerbotten.
Gallring med vinkelkran : en jämförande studie av skördarkran med och utan horisontellt ledad vipparm
One of the most important components of a harvester is the crane. Most harvester cranes are only possible to pivot (or horizontally rotate) at the crane pillar. Cranab in Vindeln, Sweden, has developed a new type of harvester crane which has an extra pivot point on the outer boom. This makes it possible to reach around residual trees, easing Thinning work in dense stands.
The aim of the study was to analyze if the use of a pivoting outer boom (POB) crane gave an increase in Thinning production and if there were any differences in time consumption between the work elements for the POB crane and a conventional crane. A Valmet 911.3 equipped with a POB crane was used in the study.
Föryngringsresultat och beräknad virkesproduktion i naturligt föryngrade tallbestånd i Västerbotten under mitten av 1990-talet :
According to the Board of Forestry, in Västerbotten, many natural regenerations of Scots pine (Pinus sylvestris) carried out on privately owned forest in the middle of 1990 in Västerbotten have rendered a bad regeneration outcome and will provide a low future forest production. The Board of Forestry believes that the negative result can be explained by the fact that the regeneration has been carried out in wrong locations and that scarification failed to work as planned. In order for an accepted rate of regeneration the guidelines of the Forrest Act require, not less than 10 years after final cutting at natural regeneration, that there should be at least 1300 (site indices 16 m) - 1700 (site indices 20 m) main crop stems per hectare. Main crop stems are defined as stems according to the place of growth and appropriate tree type, in addition with regard to quality, stage of development and damage risk have a prospect of succeeding. In addition main crop stems should be separated by surface so that the proportion sample plots with 3 meters radius, and lack main crop stems, are not more than 10 % of site indices 14 meters or higher.
Gremmeniella abietina-epidemin 2001 : har skogen återhämtat sig?
The fungus Gremmeniella abietina causes damage to conifers that can lead to tree death. In 1999 and 2001 the pathogen caused severe attacks in Sweden, where about 500 000 ha of pine forest were affected. Trees of all ages were attacked, but mainly forests between 30-60 years that were ready for their first commercial Thinning. After recommendations from the forest agency, sanitary fellings were made to trees that had more needle loss than 85%, a total of about 50 000 ha. Economic losses have been estimated to more than one billion SEK.
Tillväxtreaktion på kvarlämnade träd i Hagners "Naturkultur" försök :
The primary goal of this study was to investigate how the radial growth of retained trees responds after Thinning-from-above. The National Board of Forestry which initiated this study, was interested in whether there were differences in the growth-response between the tree species Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Another question of issue was if there were differences in the growth response between trees of different sizes. It is within the framework of the National Board of Forestry?s, Continuous Forests Project that these urgent questions are to be answered.
Kronandelsrelaskopering, en ny metod för att fastställa gallringsbehov?
In today´s forestry, assessments of needs for Thinning are based on basal area measurements. This is an indirect measurement. The approach and the developed assessment tables are based on an assumed production forest, which implies that management proposals in stands that deviate from the basic model may be misleading. Since Walter Bitterlich in 1948 launched the idea of the relascope, several modifications have been developed for different purposes. In common is that all are based on a certain angle measurement principle.
Skogsbruksplanens betydelse för aktiviteten hos privata skogsägare i Älvdalen :
The purpose of Älvdalens besparingsskog is to develop the district and most of all the forestry in Älvdalen. It's owned by about 2 300 private forest owners who's landed properties are located in Älvdalen. Every year the besparingsskogen gives out a lot of its profit in form different types of subsidies for agriculture and forestry. The owners can apply for subsidies for several of the costs that occur in forestry. During the period 2000-2003 the owners are offered forest management plans and pcSKOG-gård at no cost for their private forest properties.
The purpose of this master's thesis was to find out if the activity in the forestry changed when the forest owners got new forest management plans and the computer program pcSKOG-gård.
Röjningsformen och stamantalets effekt på höjd- och diametertillväxt i toppröjda och konventionellt röjda tallbestånd.
Topping is a precommercial Thinning (PCT) method where secondary stems are cut higher above the ground compared to conventional PCT. The secondary stems continue to live for a period and are supposed to compete with the main stems and promote their quality.The objective of the study was to compare the effect of PCT on height and diameter growth between topping and conventional PCT. The study also analysed the relationship between height and diameter growth and the number of stems after PCT.Nine topped stands and six conventional precommercially thinned stands were visited between February 28th and March 5. One sample plot per hectare was laid out in the investigated stands. In every sample plot the number of stems was counted and five main stems were measured for height, height growth since PCT, diameter and diameter growth since PCT.The results showed significantly higher effect on height growth after topping as compared to conventional PCT but no significant difference in the effect of diameter growth between topping and conventional PCT.
Biomassauttag vid delkvistat sortiment i klen gallring
The purpose of this study was to estimate the removal of biomass in connection with Thinning operations in young stands that are dominated by small diameter trees. The economy of such operations depends on the products generated as well as the performance of the harvesting systems. Conversion tables designed to predict the outcome based on harvesting method was another goal of this study. Removal of biomass affects the nutrient composition of the site. Therefore it is a purpose that this study will provide researchers with some variables that can be utilized when studying this aspect.
Trees were harvested and divided into bunches based on diameter.
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.
Gallringsinventering från helikopter utrustad med profilerande laser och kamera för låghöjdsfotografering
Today Holmen Skog finds and selects suitable Thinning stands using data on upper height and basal area. These figures are often based on basic forest data that has been updated with the help of growth prediction models. The problem is that these figures are not always correct. The aim of this study was to investigate if a combination of data from a profiling laser and a digital camera for low elevation photography, can be used for collecting data on number of stems per ha, tree species mixture as well as basal area weighted mean height and upper height for stands. The possibility to use these data to assess the need for Thinning cutting was also investigated.Laser data and aerial photographs were collected from a helicopter operating at an approximate height of 100 meters.