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524 Uppsatser om Thinning stands - Sida 6 av 35
Vedlevande lavar på döda grenar på levande träd i produktionsskog
Saproxylic lichens in managed forests have less substrate available than in unmanaged forests due to the shortage of dead wood. However, a suitable substrate for these lichens could be dead branches on living trees. To this date, there has not been any systematically collected data about theabundance of dead branches on living trees and the lichens growing on these branches in managed forests. The aim of this study was to see where dead branches were located on living trees of Pinus sylvestris and Picea abies, how large the surface area of these branches was and what lichens grewof wood on these branches. The study was made in Finspång, Sweden, where 11 forest stands of P.sylvestris and P.
Nyttjande av det digitaliserade stickvägsnätet vid skogsgödsling med traktor
Forest fertilization had its peak in the late 60´s, when almost 200 000 ha was fertilized annually. The silviculture of today has high demands for timber production at the same time as the demand for nature conservation increases. It means that it?s necessary to produce more volume in smaller areas in the future. The use of DGPS equipment has in modern forestry in Sweden become more and more common.
Klibbalens gödslingseffekt på volymproduktionen i ett blandbestånd av gran och klibbal : en simulering i Heureka
A secondary and a pioneer tree species can with advantage be included in a mixed stand to increase the use of sunlight. Nitrogen-fixing plants have been shown to increase the supply of nitrogen in the soil by, for example, litter fall. This deposition acts as a biological fertilization, which may be used by non-fixing plants. Alder is a nitrogen-fixing, pioneer tree species that loses its nitrogen-rich leaves late in the autumn. The aim of this study was to examine the effect on the total volume of production, when different proportions of nitrogen-fixing Alder were part of spruce stands.
Skötsel av älgskadade bestånd :
Sweden has today the highest moose (Alces alces) population in the world. The population has been very high since the late seventies and in the beginning of the eighties there was a big ?moose explosion?. The main food source for moose during the winter is young pine (Pinus sylvestris) and birch (Betula spp.). The high moose population has therefore lead to high damage on pine forests over big areas.
Jordlöparfaunan i bestånd av contortatall (Pinus contorta) och svensk tall (P. sylvestris) 1987 och 2010
In the 1970´s the North American lodgepole pine (Pinus contorta) was introduced to Sweden in large scale. The lodgepole pine affects its new environment different from Scots pine (P. sylvestris), leading to a change in biological diversity.
Forestry today affects the ground beetle fauna (Carabidae). Habitat specialists associated with older forests are first affected. When the canopy closes again after a clear-cutting species that prefer open habitats reduces and those who prefer mature/closed forests increase.
In this study we compare differences in diversity and community structure of ground beetles in stands of lodgepole pine and Scots pine.
Pinus contorta susceptibility to Heterobasidion spp. : a study of stumps, roots and artificial spore infections of stumps
The Lodgepole pines susceptibility to Heterobasidion spp. was investigated in three parts ofthis study. In the first part, discs from freshly cut stumps were collected and analyzed to seeif the fungi can spread and grow naturally in Lodgepole pine stands. In the second part, rootsamples were collected from Lodgepole pines planted in former infected Norway sprucestands to see if the fungi can spread through root contacts. For the third part, new stumpswas created and artificially infected with spores of both the S?type (H.
A comparison of methods to assess site index in young Norway spruce stands
This study investigates whether the site index curve method (SICM) and the growth intercept method (GIM) can be used for site index predictions in younger Norway spruce (Picea abies (L.) Karst.) stands than recommended by current guidelines. For SICM it was thus investigated whether the method could be used for stands younger than ten years, and for GIM it was tested whether a starting point for the intercept measurements could be used below the recommended
2.5 meter. This was tested based on measurements taken from experimental stands in Tönnersjöheden Research Forest.
For GIM it was found that the method can only be used when the TH-trees of a stand have five complete intercepts above 2.5 meters. For the method to be applicable beyond this, it will be necessary to adapt the underlying equations, perhaps following the Canadian example where a 1.3 meter intercept start is used. In conclusion it is not currently possible to apply the approach beyond the current recommendations.
For SICM, SI predictions are accurate for the study area already form year three.
Påverkan från den förväntade klimatförändringen på tillväxten i norra Sveriges skogar : En litteraturanalys
This is a literature review of how the climate change affects the forest growth innorthern Sweden. The temperature will rise about 5 °C with the largest increase in thewinter season (December - February) and the CO2level in the atmosphere is expected tobe doubled. Precipitation patterns will change and increase with 25-35 % and theprecipitation will be in form of rain rather than snow. Today the forests in northernSweden are entirely dominated by coniferous stands. This may shift with the climatechange and results in a larger number of deciduous trees, preferably birch will becomestronger and grow better and faster.
Skogsentreprenör 2007 : en kvantitativ studie av organiserade skogsentreprenörer i Sverige
SMF Skogsentreprenörerna is a nationwide organisation for Swedish forestry contractors. It has about 750 organised companies with somewhere around 1500 logging machines. These machines perform well over 50% of all yearly landed wood in Sweden. The members of SMF also performs more and more of other functions in Swedish professional forestry, such as soil scarification, planting and pre-commercial thinning of younger stands.
In order to determine what major priorities SMF should focus on in the future a member survey was initialised and carried out by SMF together with Daniel Larsson-Snygg, student at the swedish university of agricultural sciences SLU.
This report presents the result of this survey sent out to all members of SMF. It is intended to answer a number of questions about their entrepreneurship such as:
What different kinds of work do these companies perform? How many machines and employees do they have? How old are the company owners and their employees? What are their thoughts about the future of their business? How well does SMF serve their members needs?.
Skötselns och ståndortens betydelse för kärnvedsbildningen i tall
Heartwood has always been a desirable part of the tree, due to it?s superior decay qualities com-pared to the sapwood. How the formation of heartwood works has been known for a long time, but which factors that initiates and stimulates the production are poorly understood. This case study presents the results of a study in which silvicultural treatments and site properties had a key position as factors to the formation of heartwood. According to the hypothesis the amount of sapwood is directly controlled by the size of the crown.
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.
Stubbehandling med pergamentsvamp och urea mot sporinfektioner av rotticka i bestånd av hybridlärk
Root rot is a big hurter and a huge economic problem for the Swedish and European forestry. The severest hurter is Heterobasidion annosum (Fr.) Bref and it occurs as two different species in Sweden. Commonly referred to as the P-type (Heterobasidion annosum s.s. (Fr.) Bref.) and the S-type (Heterobasidion parviporum Niemelä & Korhonen). Therefore a lot of research has been carried out in this topic to find a solution and reduce this problem, one alternative that have shown to be profitable is stump treatment in thinnings.
Höjdtillväxt, överlevnad och skador i praktiska etableringar av hybridaspbestånd i södra Norrland, anlagda 2004-2011
Hybrid aspen is a crossbreed between European and North American aspen. It is a fast growing tree species that has shown strong growth in the South of Sweden. The follow-ups that have been made on hybrid aspen stands, have mainly been done on plant material in the South of Sweden. In the North of Sweden, only occasional studies have been made, and the knowledge of Northern hybrid aspen stands is, thus, unsatisfactory.In the South of Norrland, land owners have planted hybrid aspen, but what kind of plants it is, and how well these stands have established, is not ascertained, since data has not been compiled on the subject.The objective of this study is to evaluate practical plantations of hybrid aspen in the South of Norrland regarding height growth, survival and damages. The ambition is to increase the knowledge about practical plantations regarding height growth, survival and damages, and from the conclusions thereof, give recommendations for future establishments of hybrid aspen in the area.For the study, eight hybrid aspen stands in the South of Norrland were localised.
Skötselmetoder för bestånd med produktions- och naturvårdsmål :
This study is made on assignment by the local board of forestry in Skåne,
Blekinge and Halland.
The change of the forest law 1994 brought a new type of management plan.
A more active planning was introduced in order to equate the environment goal
with the production goal. The purpose with this study is to give a better picture of
how planning for nature conservation in production forest is made and to develop
support for selection of silviculture methods for stands with combined goals. With
combined goals means production forestry with a reinforced consideration to both
nature and culture, called PF-classified stands. This was done by:
? Describing silviculture models from the literature that are possible to use
for stands with combined goals.
? Describing silviculture models that is used in practice in stands with
combined goals.
? Describing how the classification of stands with combined goals is used.
Which means, were in the terrain, with which frequency and in which type
of forest PF-classification is used.
? Comparing differences and similarities of theoretical and practical used
models.
The study was done partly as a literature study and partly as an interview study of
forest planners.
Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris :
The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) (?C?) which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) (?S?).But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed.