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83 Uppsatser om Pieca abies - Sida 3 av 6

Bok- och grankonkurrens i Sydsverige - markegenskaper och naturlig föryngring :

In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without natural regeneration of spruce.

Älgens barkgnag på granstammar : omfattning med avseende på geografisk utbredning, skadad volym och ekonomiska konsekvenser

In three areas in the province of Småland studies has been done to investigate how big damage the moose may do to P. abies. An inquiry examination and two different types of surveys were done to find out how big area, which volume and which financial consequences the moose debarking has had on the forest. When the volume was calculated the rot spreading was included. The area that was damaged was stipulated with the answers from the inquiry examination. 59 % of the asked forest owners answered the inquiry.

Samplanteringar med härdiga barrväxter i fokus : -Designförslag i tre tänkta miljöer

Denna uppsats presenterar tre designförslag på samplanteringar med barrväxter i fokus. Designförslagen är gjorda till tre fiktiva platser med olika ståndort i växtzon 5, en liten entréplantering i västerläge med kalkhaltig jord, en mellanstor plantering i söderslänt med sandblandad jord och en parkplantering med fuktig jord med ett lågt pH-värde. Platserna är valda med tanken att läsarna ska kunna inspireras att använda barrväxter i olika typer av planteringar och trädgårdar. Till grund för växtvalen har gjorts en litteraturstudie inom området barrväxter, med fokus på barrväxters ståndort och hur de fungerar i samplanteringar med perenner och lignoser. Bakom designförslagen ligger även en idé om att hitta lite nya sätt att använda barrväxter, detta för att inte göra upprepningar av de skötselfria planteringarna med barrväxter som blev så oerhört populära på 70-talet och som delvis givit barrväxter ett dåligt rykte.

Environmental variables determining the occurrence of Cladonia parasitica and Hertelidea botryosa, two boreal lichens confined to wood

Biodiversity is essential for human well-being and it is defined as the genetic variation within species and the variety of species and ecosystems. Biodiversity provides several ecosystem services which are necessary for human beings but there are different threats towards the biodiversity. The biodiversity linked to the forest in Sweden are threatened, about 50 % of the red-listed species in Sweden are associated with forests. This is linked to the commercial exploitation of the boreal forest in Sweden which started 200 years ago. The forestry the last 50 years, with clear-cuts, have contributed to a fragmented forest landscape.

Röjningsförbandets betydelse för avverkningsekonomin i södra Sverige :

The aim of this work is to demonstrate how the net present value (NPV) at the time of the first thinning depends on the spacing after pre-commercial thinning, and show how net value from first thinning in same stand is influenced. This study is performed with models based on non-distant dependent growth models for single trees. Two different growth models have been used, one for cleaning (pre-commercial thinning) and one for thinning. The first one yields stem density distributed over diameter classes. In the second one, (the thinning model), it is possible to choose when thinning should be done, the thinning method, thinning grade and numbers of thinning.

Analys av fiberlängdsfördelning hos gran (Picea Abies) och tall (Pinus Sylvestris)

Tree fiber lengths controls properties like strength and smoothness in paper and other wood products. For forest researchers it is of interest to be able to determine the fiber lengths in standing trees. Mo?rling et al. (2003), among others, have developed methods to estimate fiber length distributions in standing trees without damaging them.

Granvirkes permeabilitet beroende av dess fysikaliska utformning och applicerat färgsystem

Densitetsmätningar och permeabilitetstest enligt EN 927-5 har utförts för att studera huruvida granvirkes fysikaliska egenskaper i kombination med applicerat färgsystem påverkar permeabiliteten. De egenskaper som studerats är frod- och senvuxenhet, splint- och kärnved samt densitet. Aktuella färgsystem som studerats är alkyd, akrylat och linolja, vilka jämförts med omålad referens. Studien påvisar inget samband mellan virkets densitet och permeabilitet, bestruket eller ej. Det som istället tycks påverka vattenabsorptionen är närvaro av splint-/kärnved samt frod-/senvuxenhet.

Inventering av röjningsobjekt från helikopter :

In time with HolmenSkog district Egenskog Norrköping´s decreasing mountain of cleaning, the office started to look around for new alternative cleaning strategies to lower the costs connected with cleaning. One option was to make the inventory strategy more effective and after a phonecall with the head of the district, Jonnie Friberg, the planning started to try inventory in pictures taken from a helicopter. The pictures was at last taken from a digtal camera and the vegetationheight was mesured with a laser. The gear was supplied from Kallax Flyg AB, Luleå. In the trial 15 stands was selected depended on age and different mixtures between pine (Pinus sylvestris), spruce (Picea abies) and birch (Betula pubescense and Betula pendula).

Eld som naturvårdare : Kärlväxtflora och vegetationsutveckling efter naturvårdsbränning i två småländska naturreservat

This study has taken place in two nature reserves in the municipality of Uppvidinge in the Kronoberg region in southern Sweden. These have been chosen by the County Administrative Board to be part of a bigger landscape of fire affected nature, and prescribed fire has been implemented in these. The areas are called Ösjöbol and Berga fly and have been burned 2012 and 2013 respectively. Non-burned areas have been inventoried as well. Vascular plants and mineral soil have been inventoried with the Hult-Sernander-Du Rietz scale of five levels. Issues emanate from the County Administrative Board?s goals for prescribed fire: how sticks and herbs were affected, how much soil was uncovered, how the structure and fire favoured species were affected, and how deciduous trees and spruces (Picea abies) were affected. The study shows that the soil increased, as well as the fire favoured species.

Produktion och beståndsstruktur i fullskiktad skog skött med blädningsbruk

Denna studie behandlar tillväxt och beståndsstruktur samt sambandet mellan dessa i skog skött med blädningsbruk. Blädningsbruk förutsätter fullskiktad skog med fallande diameterfördelning, under nordiska förhållanden vanligtvis dominerad av gran (Picea abies (L.) Karst). Strukturen i fullskiktad skog är resultatet av tillväxt, skörd/mortalitet och inväxning. Kunskap om det komplexa samspelet mellan dessa faktorer ger skogsskötaren möjlighet att planera och sköta fullskiktad skog för en hög och uthållig produktion. Undersökningar och litteratur inom aktuella områden tas upp i en litteraturstudie. Ämnen som behandlas är: definitioner och begrepp, diameterfördelningen i fullskiktad skog och hur denna kan beskrivas, blädning och andra avverkningsstrategier samt tillväxt- och produktionsundersökningar i Norden, Europa och USA.

Plantering av gran (Picea abies) på kalhyggen och självföryngring under högskärmar av björk (Betula pendula och Betula pubescens) : föryngringsresultat 7-10 år efter avverkning

The aims of the silvicultural method natural regeneration of spruce (Picea abies L. Karst) in birch (Betula pendula and pubescens) shelterwoods are to establish a new stand of tree seedl-ings and to protect those from high groundwater levels, frost damages and grass competition during its first life years. The aim of this work has been to (i) describe how shelterwood and stand characteristics influ-ence the results from using natural regeneration of spruce protected by a shelterwood of birch, and to (ii) compare those regeneration results with planting of spruce after soil scarification in clear-cut areas. Totally 17 harvesting sites have been inventoried and 15 of those included natural regenera-tion in birch shelterwoods, and two were subjects to soil scarification and planting of spruce. The sites represented 7-10 year old final cuts and are located in the coastal (eastern) region of the province of Norrbotten in Sweden. In all areas shelterwood and stand characteristics, as well as the number of main crop seedlings and the height of the highest main crop spruce seedling, were estimated and registered in all areas.

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.

Lövsuccessioner i sluttningar längs nedre Umeälven :

Secondary deciduous forests, which have their origin in earlier pasture- and meadow-land in slopes along the lower reaches of the Ume river, are thought to contain high nature conservation values, in spite of a relatively low age. The aim of this study was to clarify how factors as historical use, exposition, disturbance dynamics and successional age influences the conservation values in these types of riparian forests and how this can be implicated in the practical work with conservation and management at Umeå municipality. Sample plots were placed in seven stands with a variation of their historical use, exposition, disturbance dynamics and age of succession. Conservation values as structure, tree-regeneration, abundance and composition of vascular plants, amount of dead wood and the abundance of signal-species were measured and registered. The species composition and especially the composition of tree species, differed between forests with different exposition and different historical use.

Dendrokronologisk undersökning av granbeståndet i Siggaboda naturreservat

Med hjälp av såg- och borrprover studerades åldern på 41 granar och en tall i Siggaboda naturreservat i sydligaste Småland, med syfte att undersöka granens etablering och döende på lokalen. Vidare har reservatet delats in i tre områden för att undersöka om några geografiska skillnader i granarnas etablerings- och dödsår förekommer. Analysarbetet utfördes på Nationella laboratoriet för vedanatomi och dendrokronologi vid Lunds universitet. På lokalen har tidigare bland annat en pollenanalys utförts (Björkman & Bradshaw 1996) samt en kombinerad pollenanalytisk och dendrokronologisk studie (Hannon et al. 2010).

Volymproduktion i fullskiktad granskog : Siljansfors försökspark, Dalarna

Blädningsbruk kan enbart bedrivas med sekundära trädslag i fullskiktade skogar. I Sverige är gran (Picea abies (L.) Karst) det dominerande trädslaget för denna form av skogsskötselsystem. Skötselsystemet har länge varit kontroversiellt på grund av missuppfattningen att det är synonymt med de dimensionshuggningar som i början på 1900-talet härjade de svenska skogarna. Denna studie inriktade sig mot att analysera den volymproduktionsökning som under de senaste 53 åren ägt rum på Siljansfors försökspark, blädningsyta 9082. Data bearbetades och variablerna som huvudsakligen analyserades var diametertillväxt, stamantal samt medelhöjd.

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