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370 Uppsatser om Hollow trees - Sida 3 av 25
Odlingsmetodernas påverkan på vitaliteten hos Prunus avium :
The objective of this study was to get a better understanding of how the cultivation methods influence the vitality in Prunus avium. The purpose was also to examine if there was any differences in shoot growth and trunk expansion depending on the method of cultivation. To find the answer to this question a literature study and a case study has been done.
The literature study concerns the concepts vitality and stress. Different definitions of these concepts are shown and their connection whit establishment is explained. In the background the species Prunus avium, and the four method of cultivation that are included in this case study are described.
Measurements of the shoot growth and trunk expansion were made in this study, and as a complement to these methods, a visual estimate of the vitality was made.
Biomassauttag vid delkvistat sortiment i klen gallring
The purpose of this study was to estimate the removal of biomass in connection with thinning operations in young stands that are dominated by small diameter trees. The economy of such operations depends on the products generated as well as the performance of the harvesting systems. Conversion tables designed to predict the outcome based on harvesting method was another goal of this study. Removal of biomass affects the nutrient composition of the site. Therefore it is a purpose that this study will provide researchers with some variables that can be utilized when studying this aspect.
Trees were harvested and divided into bunches based on diameter.
Träd som berör : en intervjustudie om specifika träd i människors liv
There is no doubt about the significance of nature on the health of human beings. Not
only is the tree an element of nature that is of great value to our survival, it also serves as a valuable object and symbol of human beings? enjoyment and appreciation of the
environment. The purpose of this study is to present the relationship that a person may
have with a specific tree. Three women and two men are interviewed about their trees and
the places where they are located.
Betydelse av lövinslag, död ved och variation i träddiameter för artrikedomen hos småfåglar
Forest management contributes to the changes in forest structure by turning heterogenous forests of varied age into homogenous forests of similar age and thus affect bird species depending on different structures or habitats which are lost during forestry. In this report, a study was made to investigate how the amount of decidious trees, dead wood and variation in tree diameter affect bird diversity. The purpose of this study was to be able to give forest management guidelines to increase bird diversity. This study was conducted by investigating 65 transects in forests of different structure south of Linköping, Sweden. Along the 65 transects, birds were inventoried as well as the vegetation.
En inventering av säregna trädformer funna i Sverige
In Sweden and in Scandinavia the amount of tree species are rather few. However many different forms of trees arise due to mutations and gives rare appearances like cut-leaved and hanging forms. In some cases these trees are interesting as cultivars and a few of them have become popular garden trees. The knowledge of the original trees and early propagation is meagre.In this study a selected group of trees were found through search of literature. Eight tree forms were chosen and investigated in situ.
Provtagning av trädkärnor för att bedöma föroreningsgraden av klorerade lösningsmedel i grundvatten
Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.The aim of the study has been to investigate whether the CAH-concentration in tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons.
Prislisteoptimering för ett sågverk - Jarlträ AB :
This report is a thesis work for a B.Sc. in Forestry at the School for Forest Engineers, SLU. The work was an assignment from Jarlträ AB which is a privately owned sawmill located in southern Småland. The aim of the work was to investigate the economical result of different pricelists and how to adjust different parameters such as length correction to give an optimal result.
The pricelists was examined through a computer program (SilviA). The pricelists was made in the program and after that a simulation was preformed with a selection of random sampled trees gathered from the area nearby the sawmill.
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.
Betydelsen av taggbuskar, ljus och hävd vid föryngring av ek (Quercus robur)
Many species and hence biodiversity depend on old, large oaks (Quercus robur) with hollow trunks. The populations of oak-living organisms have to migrate to a nearby old oak in order to survive the death of the host. The oak district south of Linköping, Sweden, is unique in area and the number of old oaks. It is anyway doubtful whether regeneration of oak will secure future continuity. Oaks are light-demanding and thrive in open pastures.
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.