The purpose of this study is to investigate whether it is possible for SCA to update their stand register with use of digital aerial photos photographed with a Zeiss/Intergraph DMC. ?Updating? in this study implies the delineation of stands and estimating stand variables such as average stand height, volume density, stand volume, and tree species composition in order to identify stands which can be of current interest for thinning. The study also includes how the aerial photo material and experience of the interpreter can influence the quality of the interpreted variables. The aerial photo interpretations were made by both experienced and inexperienced interpreters.

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.

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.

Ditch cleaning is increasingly important in Swedish forestry. This study compare different concepts concerning machinery, namely two general-purpose excavators of different sizes, 8 tonnes and 15 tonnes, versus a dedicated machine constructed solely to deal with ditch-cleaning. The machines were tested on rough as well as on gentle terrain and on open terrain as well as in young stands in connection with thinning. The conclusions were that the excavators are more versatile and have greater capacity than the dedicated machine, while the latter excels in quality of work. Interestingly, there was no significant difference in performance between the both excavators..

This thesis has focused on the possibility to use a satellite image method developed by Metria Mijöanalys to identify stands that are wrongly registered in Holmen Skogs database. The method is only intended for identifying stand with poor descriptions in Holmen?s database that needs to be updated and not for updating the stand information. The study area is located several km west of Hudiksvall on the borderline between Gävleborgs- och Västernorrlands län. The area is covered by a SPOT image from 2005. By which Metria Miljöanalys has made estimates of forest parameters for all stands in the area, and compared them with corresponding estimates according to the stand database.

Modern forestry management may disadvantage some mykorrhiza forming fungi because; they are dependent on late successions and cannot survive the constantly recurring breaks in the continuity of their host tree. For this study the specie goliatmusseron (Tricholoma matsutake) was chosen to investigate this possibility. In Sweden T. matsutake is found in greatest amounts north of Örnsköldsvik on glacifluvial sandy soils in association with pine trees and reindeer lichens. Seventy two forest stands where the specie previously had been found were studied; 62 in the northern part of Sweden and ten in the southern. Several indicators were studied to find out if these stands have had a continuity of living trees.

This survey was made during the summer of 2004 and the spring of 2005, on commission from the National Board of Forestry. The aim of this report was to investigate how often Norway spruce (Picea abies L. Karst), is planted on poor Scotch pine (Pinus Silvestries) sites and if it affects the yield of Norway spruce? In order to investigate this, data from 29 stands witch had a lower site index than T24 was collected. The investigated stands were situated in the southern-eastern Sweden. In 20 plots in each stand, the highest tree, age, number of seedlings, site index and tree species per stand were measured.

Plant survival, plant damage and height growth were studied in nine wild cherry (Prunus avium L.) plantations in southern Sweden established between 2000 and 2002. All stands were located to the county of Småland. The survey was conducted during May and June in 2007. During the survey the height, diameter and quality of the cherry trees were recorded. In one stand, red ? berried Elder (Sambucus racemosa L.) was a dominant species.

The storm Gudrun in 2005 led to massive windthow damage in forests in southern Sweden. Since then there has been a growing interest in factors influencing wind damage in above all Norway spruce (Picea Abies) stands. Although many other interesting areas still need to be examined. In 2005 there where a lot of stands that suffered different degrees of damage, a lot of these stands weren?t cut, but instead left to grow. The future development of these stands is uncertain and the guidelines are unclear.

The aim of this study is to investigate how multiple tree handling harvesters perform compared to earlier developed standards. The study shows that multiple tree handling harvesters are more efficient in thinnings stands with mean stock volumes less than 0,12 m3fub per stock. The increased efficiency is different for different mean stem classes. In stands with a mean stem volume of 0,04 m3fub per stock, the increase can be as high as 40 percent while it is about 10 percent in stands with a mean stem volume of 0,12 m3fub. Comparisons have been done between stands that are felled with partly limbed stands and stands without partly limbed assortments. The difference in performance is clear and shows that the partly limbed assortments strengthen the multiple tree handling harvesters positive effects in low dimension thinnings.

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.

In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.

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.

The purpose of this report was to investigate if there are any correlation between spruce medium height in young spruce stands and the number of birch stump shoots. The purpose was also to investigate if there are any correlation between the spruce height growth after clearing and the mean height of birch stump shoots. The reason for this investigation is that the problem with birch stump shoots after clearing can be expensive if there must be additional clearings before the first thinning. The study provides no apparent association and therefore no special clearance height is recommended. In the final stages of the work there are given some comments on the study´s weaknesses. Finally topics for further research are suggested..

Growth models are very useful tools for forestry to predict growth and yield. With growth models and optimising tools you can manage forest stands in a way that maximize benefit and income. There are three major types of growth models. Stand models; stage structured models and single-tree models. The most advanced models give the most accurate forecasts.