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524 Uppsatser om Thinning stands - Sida 8 av 35

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.

Inverkan av nederbörd, temperatur och frost på årsringens egenskaper hos boreal tall (Pinus sylvestris L.) :

The wide distribution range of our boreal pine (Pinus sylvestris L.) provides a great variation in growing conditions and climate/weather factors that influence the wood development of the trees. A great number of extensive studies have been conducted over the years in order to clarify growth trends of this and other species over more or less wide-ranging areas. In this thesis effects of weather factors were instead compared between different forest stands from the about same geographical location. The effects of precipitation, temperature and frost on the year ring characteristics of pine were studied in the research forest of Svartberget Vindeln, in northern Sweden. The stands differed in site index and silvicultural treatment; fertile ? high stem density, fertile ? low stem density, poor ? high stem density and poor ? low stem density.

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.

Produktivitet och lönsamhet vid skörd av skogsbränsle i klen björkgallring :

The aim of the study was to compare productivity in first thinning of birch stands, when either energy- or pulpwood was harvested. The systems total profitability was also compared by including forwarding and chipping costs. A Gremo 950 HPVR harvester was used and the same driver was used under the entire study. During the pulpwood harvest a Logmax 4000b harvester head was used and a feller buncher head made by Silvatec was used during the energy wood harvest. Six study unit pairs were located in a birch dominated stand outside Ängelholm in Skåne.

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.

Skogsbrukets erfarenheter av Poppel Populus sp. i Skåne :

In Europe poplar plantations has been planted for more than one hundred years. In the first plantation was made in 1940. The interest for poplars has since then shifted over the years and has for long periods been very low but is now slowly increasing again. The main reasons why poplars are becoming more interesting are because of their great production potential. Nevertheless, the knowledge of how to mange poplars in Sweden are very low and very little research has been done concerning management of the species. The objective for this study was to; 1) investigate and document experience and results obtained in practical Swedish forestry, 2) to give a fair picture of the perceived advantages and disadvantages that the poplars has for the forestry, 3) document what the foresters that has experience and those who has no experience of poplar plantations thinks about the potential of poplars.

Comparison of bird communities in stands of introduced lodgepole pine and native Scots pine in Sweden

The introduced lodgepole pine (Pinus contorta) occupies more than 650 000 hectares in Sweden. There are some differences between lodgepole pine and Scots pine (Pinus sylvestris) forests which could affect bird assemblages, for example differences in canopy density and ground vegetation. Birds were surveyed in 14 localities in northern Sweden, each characterized by one middle-aged stand of lodgepole pine next to a stand of Scots pine. The two paired stands in each locality were planted by the forestry company SCA at the same time and in similar environment to evaluate the potential of lodgepole pine in Sweden. In those 14 localities, one to three point count stations were established in both the lodgepole pine and the Scots pine stand, depending on the size of the area.

Föreställningar om naturfotografin En studie av naturfotografers syn på tendenser och förändringar inom naturfotografin

The purpose with this essay is to examine the role of landscape photography as a portrayer of nature. The study contains interviews with eight landscape photographers, to find out how they look at tendencies and changes in photography. The essay focuses on the discussion of authenticity and realism in landscape photography. Due to the requirement of nature as something natural and authentic, the landscape photography stands in a special position when it comes to matters of manipulation and influence. On the basis of certain analysis themes, the landscape photographers debate questions such as where landscape photography stands today, and how the future looks for the genre..

Naturhänsynen i FSC-standarden : vetenskap eller gissningar?

The Swedish FSC standard (Forest Stewardship Council) is a level standard used to certify forestry. All the major Swedish forest companies are using the FSC standard, and approximately 50% of the Swedish forests are FSC certified today. In the essay six items within the chapter on environmental issues and biodiversity are examined: the proportion of protected forest, the proportion of annually burnt clear-cut stands, the number of trees with large diameter, the amount of dead wood, the proportion of deciduous trees within a stand and the proportion of deciduous-dominated stands. The FSC standard states a level for all items, and the purpose of the essay is to analyse whether these levels are supported by research within the field of conservation biology. The validity of the levels of the six items is them discussed to evaluate whether changes are required to the next revision of the FSC standard.

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.

Hybridlärkens tillväxt i Snogeholm : hur påverkas produktionen i blandbestånd jämfört med trädslagsrena bestånd?

The hybrid larch (Larix x eurolepis Henry) is a fast growing tree species and was introduced in Sweden for about 50 years ago. The high growth and expected resistance to diseases are probably the main reasons of introducing the tree species into the Swedish forests. The purpose of this thesis was to document the production of hybrid larch planted in the Snogeholm landscape laboratory and to compare the production in the pure hybrid larch stand with the mixture together with pedunculate oak (Quercus robur). The data collection in Snogeholm since the establishment has been carried out by the Swedish University of Agricultural Science (SLU). The fieldwork for the thesis was carried out in 3 stands, containing hybrid larch, pedunculate oak and a mixture of hybrid larch and pedunculate oak, in order to be able to compare the total stand production of the areas. The results show that the total production of hybrid larch in the mixed stand only is 35 % compared with the total production of hybrid larch in the pure stand. Therefore, the hypothesis that the total production of hybrid larch is equal to the planted mixture with pedunculate oak was rejected. The other hypothesis that the total production of a 2 hectare large stand containing a mixture of hybrid larch and pedunculate oak would be greater than the total production of two pure stands of 1 hectare containing hybrid larch and oak each was also rejected. In the studied case the total production was 45 % greater if hybrid larch and pedunculate oak was planted in pure stands. The results from the case-study only indicate that the total production of hybrid larch and oak under the investigated conditions can be higher when planting the two species in pure stands compared with a mixture of the two species.

Gödslingsstrategins inverkan på Holmen Skog, Umeå distrikt

This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.

Metod för urval av bäriga bestånd längs med bäriga vägar i Sveaskogs planeringsområde Råneå och Överkalix :

With increased need for flexibility in timber deliveries, forest roads become an important factor. The disintegration of roads during the spring season can be avoided if it is possible to rule cutting areas to stands with good carrying capacity along roads with good carrying capacity. The goal with this work was to create a method to find the stands with high carrying capacity located near roads with high carrying capacity, and select them into a collection file. The method was based on Esri ArcGIS 9 and the tables that follow within that program. The method resulted in four different themes: 1. Collections with GYL 100 that cross the bufferzon for 0, 1, 2 and 3 class roads. Result 36 collections. 2. Collections with GYL 100 and 200 that cross the bufferzon for 0, 1, 2 and 3 class roads.

Introduktion av buskskikt i ungskogar

Young stands in urban forests often lack a shrub layer, though shrubs play an important structural and biological role in forests. All layers interact with one another to form a multilayered stand, in which shrubs have a vital role.In this diploma thesis, theoretical models for forest dynamics are compared with four reference stands to detect factors, and principals for introduction of shrubs in young stands. In these stands four different ways of introduction were found. In one trees and shrubs were planted together at the same time. Shrubs spontaneous spread under a canopy of mature forest, in another.

Exercise pens as an environmental enrichment for laboratory rabbits

This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.

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