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355 Uppsatser om Trees - Sida 3 av 24
Vindfällning, tillväxt och plantuppslag i en 13-årig granskärm i Medelpad :
The interest for alternative forest regeneration methods increased significantly during the 1990´s after 50 years dominance of the clear-cutting system (Holgén & Hånell 2000). One reason for this was that clear-cutting was being more and more questioned by different envi-ronmental organizations and because the forest sector for economical reasons wanted to find cheaper ways to regenerate forests. In the beginning of the 1990´s two shelterwood experi-ments were established in a joint effort by Svenska Cellulosa Aktiebolaget (SCA) and the Dept of Silviculture, Swedish University of Agricultural Sciences (SLU). The experiments include various forms of cutting and shelterwood densities and represent productive spruce forests in central and north Sweden (Roggsjön in the province of Medelpad and Skikkis-jöberg in the province of Västerbotten, respectively ). The experiment next to Roggsjön has been reported earlier in three MSc theses, and is also the focus of this thesis.
Hur påverkar naturvårdsåtgärder mängden av vedlevande insekter : Manuellt dödade träd vs självdöda
Today?s forest managers implement a large number of methods to increase the amount of dead wood in Swedish forests. They use everything from high cutting of Trees to girdling Trees and burning forests. However, implementation of these measures without proper knowledge of their consequences is a common problem. This study has been performed to increase knowledge about two of these measures, girdling and high cutting, and how these actions affect the number of wood-living insects living on dead Trees.
Har antalet naturvärdesträd i Sverige förändrats mellan 1999-2009?
Forestry and forest products are vital components of the Swedish economy but the forest is also important for recreation, hunting, out-door life and conserving biodiversity. The Swedish Forest Act has two equally important objectives, production and environmental protection. Polytax is the Swedish Forest Agency´s inventory programme which monitors progress toward the two objectives in connection with regeneration fellings. It includes data on environmental protection measures taken in connection with regeneration fellings. 30 § of the Swedish Forestry Act and related regulations specify the demands for conserva-tion of nature.
När trädens rotsystem får bestämma : En intervjustudie med en grupp yrkesverksamma inom anläggning av hållbara gröna miljöer.
ABSTRACTThis pilot study examines the knowledge about tree root systems amongst five treeplanting professionals. The aim is to find out the professionals? collective knowledge ofthe nature of root systems of various Trees used in green areas. Furthermore; to explorehow the professionals adapt landscaped green areas to the tree root properties in asustainable manner. Questions: Which tree species have special root properties toconsider and how do the professionals utilize this knowledge? And: How do theprofessionals in general adjust planting according to the root systems of Trees in areas tocreate sustainable green environments?Interviews with the professionals were performed.
Inventering och klassificering av kvarlämnad virkesvolym vid slutavverkning :
This final thesis is performed on commission of Hargs Bruk Ltd. Hargs Bruk manages one of Sweden?s largest privately owned forests. A main part of the managed forest is situated in Roslagen in eastern Uppland. Since 1934 felling calculations have been performed within the estate every tenth year.
Produktivitet och lönsamhet vid skogsbränsleuttag längs skogsbilvägar :
With an increased demand for biomass based energy and with development of better technique harvest biomass, new possibilities open up. With the possibility to combine traditional cleaning of road?s right of way with biomass harvesting, the work of suppressing tree vegetation could become profitable or at least decrease the road maintenance cost. However, knowledge about productivity and profitability in mechanical biomass harvesting in roads? right of ways are still limited.
Hur ser lavars fördelning ut runt stammen på ek, och påverkas den av trädets storlek och dess närmiljö?
The aim of this study was to describe preferences of geographic direction of ten, oak-living epiphytic lichen species and how they responded to sun exposure, nearby bushes and Trees, bark fissure depth and circumference. The frequency of every species was recorded in arcs of ten degrees around the tree at a height of 130 to 180 cm above the ground. An estimation of the amount of every species in every arc was also recorded. To analyse how the distribution of the lichen species responded to the different factors their concentration for every tree was plotted against the four factors. The distribution of Cliostomum corrugatum had a positive response to high sun exposure and a negative response to a thick layer of bushes and Trees.
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.
Naturhänsyn på slutavverkade hyggen i Östergötlands län.
95% of the productive forest land in Sweden are now being exploited for forestry. The new Forestry Act of 1993 equate the goal of production and the environmental goal which means that the objective for forestry is a sustainable yield, while the biological diversity must be preserved. Recent years results from the inventories of the Board of Forestry show declining trends in how nature conservation aspects taken into consideration at the felling sites.The aim of this study is to investigate what happends with the nature consideration taken at felling sites in the long run. 20 final fellings in the county of Östergötland were re-inventoried 7-9 years after final felling. These felling sites had previously been inventoried before final felling (P0) and one year after final felling (P1) in the inventory Polytax by the Board of Forestry.
Stamprofiler : en jämförelse mellan två olika apteringslistor
This report is a thesis work for a B.Sc. in Forestry at the School for Forest Engineers, SLU.
The aim of the work was to compare two different pricelists with the actual output from a harvester. The results have also been compared with a volume estimate of standing Trees done by the Swedish Forest Agency and the ?true? value registered by the Wood Measurement Association.
The study confirms that the output calculated by the computer on the harvester is more reliable than the volume of standing Trees estimated by Swedish Forest Agency.
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Urskogen med de stämpelbleckade gammeltallarna : en skogshistorisk tolkning av Brännlidens naturreservat
People have used forest resources in northern Sweden for different purposes. Before the 20th century the forest was used for many different reasons, but during the past 200 years it has become an industrial raw material. The presence of people in the forest has left different kinds of traces in the forests. One example is culturally modified Trees (CMT´s). The aim of this study was to study and document how people have used the forest resources during the last centuries in Brännlidens nature reserve, and what kind of traces this land use has left.
Framtidens stadsträd för en fungerande grönstruktur
The effect of climate change places demands on how we build cities. Cities have to be built denser to meet the objectives of sustainability but as a result of this densification city green areas are at risk of exploitationand disappearing. The question this raises is whether there has to be an opposition between a dense and a green city?Urban Trees are playing a very important role in cities. They stand as the major part of the vegetation in citieswhich are otherwise dominated with concrete and stone.
Stamskador i gallringsbestånd
This study was conducted on a property with a thinning machine team. The purpose was to investigate in which machine, the harvester or the forwarder, that caused most damage to the Trees in six different stands. Different factors, related to the damage frequency in the stands, were checked out. For example: basal area per hectare, thinning strength, tree diameter and the rate of production.
The harvester drivers were also interviewed about how, when and why stem damages occur and how to minimize them.
The study stated that 4.3 percent of the Trees were damaged. Out of these 88 percent was caused by the harvester and the rest, 12 percent, by the forwarder..
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.
Jaktens betydelse för Södermanlands landskap : Hur viltvård kan påverka variationen av lövträd och buskar
The fragmentation and reduction of deciduous forests in Sweden is threatening many species. Particularity worrying is the loss of broad-leaf Trees, since a diversity of species is often associated to them. Today many deciduous Trees are situated along the border between forested and open areas, and these small fragments can be important for biodiversity.The aim of this study is to analyze if wildlife management can affect the variation of deciduous Trees and bushes in the landscape. In brochures and literature Svenska Jägareförbundet (the Swedish Association for Hunting and Wildlife Management) recommend hunters and landowners to promote deciduous Trees ? often broad-leaf Trees ? as wildlife management measures, while the Swedish forestry laws can be sensed as unclear regarding the treatment of these Trees.Five properties in Södermanland, Sweden, were chosen as study areas and inventoried in respect of Trees and bushes in September 2013.