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491 Uppsatser om Dead trees - Sida 30 av 33
Markberedning i blockrik terräng : en jämförelse mellan grävmaskin och harv
Runt 70 % av skogsföryngringen i Sverige utförs genom plantering efter maskinell markberedning. På de flesta marker uppnås tillräckligt antal godkända planteringspunkter men vid riklig förekomst av block som hindrar eller stör markberedningsaggregatet blir det problem. En annan komplikation i samband med markberedning på blockrik mark är att där till följd av tidigare brukningshistorik och ålder ofta finns rikligt med död ved i form av lågor. Vid markberedning ska hänsyn tas till att dessa inte skadas, eftersom död ved är viktig för den biologiska mångfalden.
Huvudsyftet med denna studie var att jämföra resultatet av markberedning med grävmaskin respektive harv på blockrik mark, vad gäller planteringspunkter och skador på lågor. Även användbara planteringspunkter innan utförd markberedning samt skador på lågor orsakade av maskiner i samband med avverkningen studerades.
Hägn i skogsbruket :
This survey was made during the autumn of 2002 and the beginning of 2003, on commission
from the National Board of Forestry. The purpose with the survey was to gather experience
and knowledge in the organisation about fencing and this was made through interviews. The
ambition was also to get knowledge from people outside the organisation that have great
experience of forestry and fencing.
The interviews were based on questions that have been composed by the author with help
from the supervisors. The questions were the same to both the personal from the National
Board of Forestry and to the foresters. Interviews were also made with private landowners, gamekeepers, game researcher, the County Administrative Board, the National Road Administration, pole and net retailers and contractors.
The target group for this work is the National Board of Forestry to be forwarded to persons interested in forestry with the ambition to spread knowledge about how to prevent damage on the forest by browsing animals.
The deer populations are big in the south of Sweden and growing populations have increased the damage on plantations of broadleaves of the most species.
Påsköns stenstatyer, moai : Vilket genus representerar de?
Abstract.The question in this analysis is which gender moai, the big statues on Rapa Nui, represent. My hypothesis is that they have developed from visual symbols to metaphores in mythologies from an polynesian context. That these statues were symbols for human origin and creation of ancestors ideological power, and gods in consideration male gender. In the long isolation, in both time and space, the mytologies in Rapa Nui was changed, and the pictures got a new meaning. These changes depended on clearing of wood and big trees and the following difficult situation in farming.
Ahmed, Adam och de asatroende : En undersökning av två samtida skildringar av offer i den fornnordiska religionen
This essay takes its start in the problematic situation concerning source material in the study of the Norse religion before the Christianization of Scandinavia. There is a lack of written sources from the time when the religion was still practiced. There are plenty of archeological sources economic situation than their religious beliefs. The Icelandic stories written in the 13th and 14th centuries give us a broad pictureof the Norse mythology, but the writers were Christians which makes their reliability questionable.The focus of this essay is therefore on two texts written during the time when the Norse religion was still in practice. The first source is the travel notes written in 922 by the Muslim scholar Ahmad ibn Fadlan who met a group of the Rus? people.
Rhododendron ur undersläktet Vireya - något om dess karakteristika och användning i nordiska vinterträdgårdar :
Present essay aims to introduce the reader to central topics regarding Rhododendrons of subgenus Vireya. As a result of a donation, the Swedish University of Agricultural Sciences, received a collection of Vireya from a local amateur grower, Kurt Myllenberg. Since the subgenus Vireya is uncommon in Scandinavian horticulture, the study tries to establish conditions for successful growing.
The subgenus Vireya differ from the other Rhododendron species through mainly three characteristics: the presence of two tails, attached to each end of the seed; the ovary-style junction is tapering and the pedicels arises directly from a dome-like base and form an umbel and not a raceme. The subgenus is distributed mostly in the islands of Indonesia and New Guinea, but also from Malaysia to Nepal and in Australia.
Since Vireya species mainly grows as epiphytes in the tree canopies, they need high drainage and not too much water.
Handen bakom Vegeholms engelska park - en studie av parken och dess uppkomst
A boom in horticulture characterized the 18th century in Sweden and Skåne. Parks and gardens were gradually built out to become, at the end of the 18th century, large and comfortable facilities which responded to European parks. During the late 1700s the new fashion came to Sweden. In Sweden it was named ?the English style? which directly refers to the English expression ?Romantic style?.
Mekaniserad ungskogsbehandling för röjning och skörd :
Earlier attempts at mechanising pre-commercial thinning have been met with varying degrees
of success. Most attempts have been based on techniques where residual stems are straddled.
Early treatment is essential to limit damage on residual trees. One part of the present study is an evaluation of mechanised pre-commercial thinning using the new Vimek 404R. Vimek 404R is a fairly small machine that permits selective removal of stems, making it potentially suitable also for areas overdue for pre-commercial thinning. The study established the level of performance for the machine, as well as the improvement needed to make it an economically viable option.
Däck-mark Interaktion hos skogsmaskiner
The most predominant method for forest harvesting in Sweden is the cut-to-length method based on two-machines, a harvester that fells trees and cut them in a predefined length, and a forwarder which transports logs to a landing area for further transport to a processing facility. New machine solutions have to be much gentler to the ground than today?s machines. To be able to develop a forestry machine that preserves the terrain requires a proper understanding of the interaction between tire and soil.The goal of the project is to contribute to the existing knowledge of forest machine tire-soil interaction and to develop a tire-soil model that enables dynamic simulations of forest machines operating in rough terrain. The modeling has especially been focused on the interaction between tires and soft ground.A comparison of theoretical data of different WES-based terrain interaction models and a comparison test data from a full scale field test is presented.
Löslighet och metylering av kvicksilver i en förorenad sjö (Ala-Lombolo) i Kiruna kommun :
Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) is a biotic process that is proposed to be conducted primarily by sulphate reducing bacteria (SRB). The formation of MeHg is of great interest because it is the mercury species that biomagnifies to the greatest extent in the aquatic food webs; about 90 % of all Hg in fish is MeHg. Our understanding of factors involved in the production of MeHg is very important for making a reliable risk assessment. The purposes of this study were to investigate the different factors that control the solubility of Hg and the production of MeHg in a contaminated lake sediment.
The lake Ala-Lombolo, Kiruna municipality, is well-known to be contaminated by mercury from different sources. Sediment cores were sampled at three different locations (N, SW and SE) in the lake and divided in three different layers; 0-5, 5-10 and 10-15 cm.
Utveckling av gran, Douglasgran, bok och tall under skärm av hybridlärk :
?Development of Norway spruce, Douglas fir beech and Scots pine with a larch
shelter wood? is a report written by Per-Olof Magnusson. The thesis is a
compulsory part of forest engineer program at ?Skogsmästarskolan?, SLU,
Skinnskatteberg, Sweden.
The purpose of this report is to describe and evaluate an experiment with hybrid
larch (Larix x eurolepis) as shelter wood, and different tree species growth and
survival depending on the density of the shelter wood. The experiment is
conducted by southern Swedish forest research centre, faculty of forestry, SLU in
Alnarp.
The hybrid larch ought to be an interesting alternative to birch (Betula sp.) as
shelterwood on suitable sites in southern Sweden.
Är förekomst av knäckesjuka i tallföryngringar mindre på stora naturvårdsaspar än på aspsly?
Pine twisting rust (Melampsora pinitorqua) is a parasitic rust fungus found all across Sweden causing damage resulting in lower quality and reduced tree growth in pine stands. In Sweden, the fungus is dependent on two alternate hosts; European aspen (Populus tremula) and Scots pine (Pinus sylvestris). Pine twisting rust has five different spore stages, two of them (uredinio- and teliospores) on the leaves of aspen. Injures on aspen caused by pine twisting rust is not extensive. On the other hand, when it infects the annual shoots of Scots pine it often results in a bent steam or even a top shoot breakage.
Användning av lekplatser : en fallstudie i Vänersborgs kommun
The aim with this report is to investigate what influence the way playgrounds are used throw the case study in Vänersborg, and also to find methods for municipalities to collect information about how playgrounds are used.
The methods were observations, interviews with parents and children, a questionary with questions about what playgrounds they used, how often and why they used them and what the children used to do there. There was also a demographic investigation and documentary research.
The most popular playground, Skräcklan, gets visitors from all parts of the municipality. It is located in a park with a view over the lake Vänern, there is a parking place and a café and it has furthermore a large area and many play equipments. Many of the families make shorter trips and picnics to this place. In exception of this playground, the families almost always go to the playground in their neighborhood and their part of the town.
Betula : arter och sorter
As birch is one of the most common trees in Sweden, and probably one of the easiest for
someone who lives here to identify, it is interesting to note that most people do not know
how variable the genus is and how widely it is distributed across the northern hemisphere.
One can find birch growing at both high and low elevations, demanding different soil
conditions and preferring varying amounts of sunlight. Many people may also be surprised to
hear that the colour of the bark can vary from bight white to almost black, and different
shades of pink, orange and red can also be displayed. This, together with the astonishing
beauty of the genus, the important role as a pioneer in many ecological systems and the
difficulty in sorting out the taxonomy of the genus, constitutes the background of this thesis. The thesis is written at the Department of Landscape Development in Alnarp, Sweden with Kenneth Lorentzon, researcher at the Swedish University of Agriculture as a supervisor. The aim of this thesis is to highlight which species and cultivars within the genus Betula could be appropriate for horticultural use in Sweden.
Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden
Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.
Habitat preference and foraging behaviour in adult red-tailed monkeys (Cercopithecus ascanius)
The red-tailed monkey (Cercopithecus ascanius) is a small, alert and active animal inhabiting forests with dense vegetation and as such hard to observe in its natural habitat. The principal aim of this study was to scrutinize whether the methods, previously used in a behavioural study of the blue monkey (Cercopithecus mitis) can be applied in studies of the red-tailed monkey?s behaviour as well. Additionally, habitat preference and foraging behaviour of the red-tailed monkey were examined. The study was carried out between the 16th and the 22nd of March 2009 in the Sabaringo forest, located on the western border of the Masai Mara National Reserve.