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355 Uppsatser om Trees - Sida 7 av 24

Restaurerade ängs- och betesmarker : restaureringseffekten på växter och insekter

Semi-natural grasslands have a high biodiversity and host ecologically and economically valuable ecosystems and species. Restoration on these types of land is often done by removing Trees and scrubs, mowing, grazing, changing the soil by removing nutrition or changing the structure of the ground. Another way of restoration is planting seeds of common grassland plants. By comparing 18 scientific publications I investigated if the restoration was affecting the plants in a positive way and if the effect was similar for insects. By comparing the publications, time seemed to have an important effect on insects. They needed time to recolonize restored areas.

Liv i d?d ved: En unders?kning av f?rh?llningss?tt till d?d ved p? ?ppeltr?d i tr?dg?rdshandb?cker och bland yrkesverksamma tr?dbesk?rare

In this essay, several factors in apple tree care (specifically in relation to whether dead wood should be kept or removed) are highlighted for example, aesthetics and biodiversity. To present some background, the essay begins by introducing some previous literature on dead wood. This leads into how dead wood is treated within forestry. Next, previous research on dead wood in fruit Trees is mentioned. Cultural and historical management methods are also highlighted.

Granproduktion på tallmarker! : är produktionen hållbar?

The aim of this report was to investigate the hypothesis that Norway spruce (Picea abies L. Karst), planted on poor ?Scots pine? stands will not have sustained growth during the whole rotation, due to water deficit in the closed stands. In order to investigate this hypothesis, data from 10 Norway spruce stands in southern-eastern Sweden were collected. In 10 plots in each stand, diameter and breast heights were measured on every tree.

Tillväxtreaktion på kvarlämnade träd i Hagners "Naturkultur" försök :

The primary goal of this study was to investigate how the radial growth of retained Trees responds after thinning-from-above. The National Board of Forestry which initiated this study, was interested in whether there were differences in the growth-response between the tree species Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Another question of issue was if there were differences in the growth response between Trees of different sizes. It is within the framework of the National Board of Forestry?s, Continuous Forests Project that these urgent questions are to be answered.

Habitat preferences and reproductive success forthe threatened longhorn beetle Plagionotusdetritus

Plagionotus detritus is a threatend longhorn beetle that only exists at one site in Sweden. It is saproxylic and depending on recently dead coarse oak wood for its larval development. Trees at Djurgården, Stockholm that have been colonized by Plagionotus detritus has been studied to find out the habitat preferences of the species and to see what affects the density of beetles in a tree. The bark of some Trees and wood from the breeding project at Nordens Ark has also been studied to find out what affects the species reproductive success. The reproductive success was measured in two ways, the larval mortality and the size of the hatching holes.

Subjektiv och objektiv bedömning av underlag på svenska hopptävlingar på elit- och nationell nivå

Bark-stripping by red deer (Cervus elaphus) cause extensive damage to economically valuable spruce Trees (Picea abies) in Swedish forests. The underlying causes for bark-stripping are not fully understood, and the frequency and severity of damage unpredictably differ between regions. In this study, I investigated if landscape structure (e.g. agricultural dominated landscape opposed to forest dominated landscape), forage availability, population density and disturbance (e.g. roads and settlements) affect bark-stripping frequency.

Nyckelbiotoper - urskogsrester eller kulturprodukter? : beståndshistorik i tolv nyckelbiotoper i Lycksele kommun

Since 1993 the Swedish Forestry Administration conducts a nation-wide inventory of wood-land key habitats covering all forest land in Sweden. The inventory aims at mapping and describing habitats where redlisted species occur or can be expected to occur. According to the inventory stand history is crucial to the presence of red-listed species. However, the current knowledge of stand history in woodland key habitats is very limited. The purpose of this work is to describe stand history in woodland key habitats, i.e. fire history, human activities - mainly cuttings - and structural changes.

Fukthaltsförändringar för skogsbränsle : En jämförelse av torkförloppet i grönrisskotade och brunrisskotade vältor

In 1994 a new Forestry Act was accepted in Sweden. One of the aims of the law is to raise consideration forpreservation of biodiversity. Since the new law got accepted and some time has passed, there now lie someinterest in examining whether the law has been effective towards its purpose. Methods suitable for analysishave been examined during this study. The content of this pilot study is based around five parameters whichcan be used to validate the effects of the new law.

Introduktion av buskskikt i ungskogar

Young stands in urban forests often lack a shrub layer, though shrubs play an important structural and biological role in forests. All layers interact with one another to form a multilayered stand, in which shrubs have a vital role.In this diploma thesis, theoretical models for forest dynamics are compared with four reference stands to detect factors, and principals for introduction of shrubs in young stands. In these stands four different ways of introduction were found. In one Trees and shrubs were planted together at the same time. Shrubs spontaneous spread under a canopy of mature forest, in another.

Skogseldens påverkan på epifytiska trädlavar på tall i relation till brandintensiteten :

Not much is today known about how epiphytic lichens are effected by fire. A considerable part of the fires in Sweden today are prescribed fires for the purpose of environmental conservation. How these fires affect lichens is largely unknown. The aim of this study is to find out how epiphytic fruticose and foliose lichens on Scots pine are affected by fire, and to elucidate the relationship between fire intensity and the survival of lichens and later re-colonization. The study was performed at three locations just outside Umeå in Västerbotten that were burned 5-7 years earlier. In all locations there were larger groups of surviving Scots pines with varying amount of fire-damage in the crown, which enabled a reconstruction of fire intensity.

Samverkan på svenska mötesdestinationer.

Not much is today known about how epiphytic lichens are effected by fire. A considerable part of the fires in Sweden today are prescribed fires for the purpose of environmental conservation. How these fires affect lichens is largely unknown. The aim of this study is to find out how epiphytic fruticose and foliose lichens on Scots pine are affected by fire, and to elucidate the relationship between fire intensity and the survival of lichens and later re-colonization. The study was performed at three locations just outside Umeå in Västerbotten that were burned 5-7 years earlier. In all locations there were larger groups of surviving Scots pines with varying amount of fire-damage in the crown, which enabled a reconstruction of fire intensity.

Jordbruksverkets nya definition av betesmark : Effekter och reaktioner hos lantbrukarna. Intervjuundersökningar från Skåne och Örebro län.

Wooded pastures are common in the agricultural landscape in Sweden, often rich in naturaland cultural values. It is not a well confined biotope but consist of a semi-open landscapewith a complex pattern and wide variation of tree and shrub coverage. The values in thewooded pastures have been created through a long history of management.One major threat to wooded pastures is ceasing management. Yearly and intensive grazinghas been demanded for several years in order to receive economical support. At the sametime Trees and bushes have often been regarded as vegetal invasion.

Kan biologisk mångfald ökas i ett avsatt skogsområde? : skötselplan för Storskogsberget på Holmen skogs marker, distrikt Umeå

The biodiversity of the Swedish forest has degenerated since the beginning of the 19th century when fire suppression and large scale logging first occurred. Together with a changed land use, these actions today have had a negative influence on many forest dwelling species, due to gradual reduction of natural processes, successions and different structures from the forest ecosystem. The Swedish Forest Act, together with different environment certifications, have today encouraged private persons and forest companies, among them Holmen Skog, to work actively to improve nature conservation. The aim of this study was to, by field inventories of already existing nature values, literature studies, recommendations from scientific reports and ecological gap analysis as a basis, make a management plan, for a non-production area, to conserve or improve the prerequisites for biodiversity. ?Storskogsberget? is located in the coastal area of Västerbotten County, 35 km from the city of Umeå.

Factors affecting bark-stripping by red deer (Cervus elaphus) : the importance of landscape structure and forage availability

Bark-stripping by red deer (Cervus elaphus) cause extensive damage to economically valuable spruce Trees (Picea abies) in Swedish forests. The underlying causes for bark-stripping are not fully understood, and the frequency and severity of damage unpredictably differ between regions. In this study, I investigated if landscape structure (e.g. agricultural dominated landscape opposed to forest dominated landscape), forage availability, population density and disturbance (e.g. roads and settlements) affect bark-stripping frequency.

Datering av röta i hålekar :

I have chosen in this work to examine which factors are affecting the artificially creation of a tree cavity containing decomposed wood. The purpose of the work is to find out which factors are affecting the most when a tree cavity is created, and to apply these results when you artificially try to create a tree cavity. The need to create tree cavities comes from the situation where many tree cavity living beetles finds themselves today. When existing Trees are to pass out there will be no suitable inheritors yet. The work was initially to focus on cavities created from cut branches.

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