Sök:

Sökresultat:

99 Uppsatser om Stems - Sida 2 av 7

Effects of ten year old enrichment plantings in a secondary dipterocarp rainforest : a case study of stem and species distribution in Sabah, Malaysia

Large areas of forests in the tropical region have during the last decades been lost and converted to new land uses while other areas have been degraded into secondary forests. These secondary forests need to be restored and rehabilitation through enrichment planting and liberation may help to speed up the recovery process. The objective of this thesis was to evaluate a rehabilitation method that includes enrichment planting, slashing of weeds and girdling of unwanted trees. The site for the project is situated in Sabah, Borneo in a secondary forest which had been logged and burnt by a wildfire. The project?s goal is to rehabilitate and increase biodiversity through enrichment planting of seedlings mainly belonging to the family Dipterocarpeaceae (dipterocarps).

Gallringsprioritering av contortabestånd :

Extensive planting of the tree species lodgepole pine (Pinus contorta var. latifolia) during the 1970s and 80s has resulted in large areas now being available for commercial thinning. However, the varying quality of the stands creates a problem. The purpose of this study was to investigate, at the Torsby district of the Stora Enso forest company, how well the present computer records of the stands correspond to reality and determine which stands are, from a qualitative perspective, suited for timber production. Finding variables that indicate better stands would give Stora Enso the possibility of selecting qualitative stands which are more profitable to thin. The study included 32 stands containing at least 70 % Pinus contorta.

Utvärdering av flygbildstolkning för uppskattning av beståndsvariabler och åtgärdsförslag i ungskogar : en studie på Korsnäs Skog och Bergvik Skog AB i västra Dalarna

In Korsnäs district Dala Väst there were problems with information concerning their younger forests, mainly those in pre-thinning stage. They were divided into large, heterogeneous stands with often poor stand data quality. In 2006 an aerial photo interpretation of the young forests was conducted to fix these problems. Necessary information to get from the interpretation were silvicultural management suggestions, new stand delineation and new stand data. This thesis is supposed to evaluate the quality and usability of the interpreted data. To evaluate the interpretation an objective control inventory was conducted in 60 stands, either through callipering or counting Stems.

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.

Analys av data från flyglaserscanning :

In forestry there are always needs of forest data to make good strategic decisions of different actions and economic winning. Usually this data gets from field-estimations made by forest workers with expensive costs and sometimes unsatisfied quality. StoraEnso Skog is a great forest company in Sweden and they have part of the responsibility of the forest own by Bergvik Skog. Bergvik Skog is owner of 1, 9 million hectares productive forest land. Both Bergvik and StoraEnso have great interest in new inventory techniques to get the important forest data. The company Foran Remote Sensing offers the opportunity with airborne laserscanning of forest and forest land. Foran got the mission of Bergvik and StoraEnso to laser scan Bergviks possession in Älvdalen, Dalarna.

En undersökning av Bergvik skogs och Skogsstyrelsens gallringsmallar mot en gallringsoptimering på simulerade typbestånd

The purpose of this study was to analyze the two thinning models: Bergvik Skog´s thinning model, which is based on total Stems and dominant height, And Swedish forest agency´s thinning model which is based on basal area, habitat index, dominant height and recommended number of Stems at final felling in Heureka´s StandWise and PlanWise. The data we chosen for our study were taken from the Swedish National Forest Inventory and we were creating a simulated stand based on a great number of sample plots in Region three from The Swedish National Forest Inventory. We had chosen to create one stand with low habitat index (T20) and one with high habitat index (T24). Our purpose were to come as close as possible to a natural stand in central Sweden. We performed the thinning in StandWise and analyzed the data I Excel files. Our thinning optimizing´s were performed and analyzed in PlanWise. There wasn´t any big differences between the thinning on the lower habitat index.

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.

Lövskogens förändring i eklandskapet söder om Linköping : 1927 jämfört med 2013

The forests of Sweden are constantly changing. Map studies indicate that the amount of deciduous trees in Sweden has decreased in recent years in favor of the coniferous trees. The National Forest Inventory has since the early 1920s monitored the Swedish forests and in recent years has made the old data digitally available. In the present project, we have investigated how the numbers of Stems in different diameter classes have changed for birch and other deciduous trees. The inventory was conducted in the same manner as in the first forest inventory.

Vad orsakar skador på kvarstående träd vid mekaniserad gallring - en intervjustudie

This thesis includes a review of scientific studies of tree injuries following mechanized thinning. Interviews have been made with drivers of single grip harvesters and forwarders in forest thinning and a number of essential factors have been identified as the most important to take into account in order to minimize and/orprevent injuries to Stems and roots of remaining trees..

Vad är egentligen en muta?

Bribery is a concept which has appeared quite frequently in the media recently, but what constitutes a bribe and what factors can be used in determining if an individual case is actually a bribe? The purpose of this essay is to try and answer these questions through a study in which respondents were presented with different scenarios and were asked to determine whether a bribe had occurred and explain their reasoning. In the study, it was evident that the amount of money involved in a given case had a large impact on respondents? determination of whether a bribe had occurred or not. The grey area that seems to exist between what is appropriate and inappropriate most likely Stems from ambiguousness in Swedish law..

Viking center

My diploma thesis has focused on creating a proposal for a Viking center in Stockholm that meets the international interest. A building dedicated solely to the Viking heritage. My ambition has been to give the Viking center an architecture that can serve as scenography for its exhibitions and to give the visitors a feel for the Vikings that they have been craving.  A boat-shaped building in tribute to the Vikings boat building skills with curved Stems of equal height that gives a familiar silhouette to the city.  A wood building constructed of curved beams and wood columns painted with tar..

Bedömningsmatriser : En studie av lärares och elevers uppfattningar

This paper reports from a study looking at teacher?s and student?s apprehensions regarding rubrics. The idea to research this specific subject Stems from our interest in this phenomenon due to our education and curiosity about how rubrics are apprehended and not about how they are used or described. To explore this area we have used empirical material compiled through interviews. The analysis is done by creating categories containing various apprehensions expressed in the material through different characterizations of the phenomenon called rubrics.

Utvärdering av produktionsrapporterad volym för contorta

The background to this study is that the forest company, Holmen, has found large discrepancies between harvested volume and the measured volume at the industry. Factors like bark features, breakage, double tops, bends and stem damages was noted, and all Stems were measured manually. Hypothesis testing with the method "random in pairs" were used to examine whether the harvester measured values significantly differed from the manually measured. The result of a properly calibrated harvester shows in average underestimation of the volume with Skogforsk Pine as a bark function. This means that the harvester isn´t the reason why the volume measured in the industry is lower, the fault is elsewhere. The study also indicates a need for a unique bark function for logepole pine..

Plantinventering och plantkontroll med digitala bilder från helikopter :

This study was carried out as a commission from Holmen Skog, district ?Egen skog? in Norrköping. During October 2006 several stands were inventoried by aerial photos from helicopter. The stands were those for which the next action proposed was plant inventory or plant check. The photos were interpreted and the number of Stems was calculated.

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.

<- Föregående sida 2 Nästa sida ->