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455 Uppsatser om Basiphilous pine forests - Sida 20 av 31

Epiphytic lichens associated with different traffic intensities along the highway E4

Inventories of epiphytic lichens on Scots pine (Pinus sylvestris) were conducted at three sites in east central Sweden: along the newly build motorway (Road E4), along the old road (Road 600) and in a reference site, to compare the effects of traffic pollution on lichen diversities. At each site, species richness, lichen mean sensitivity value (MK), air quality index of the forest stand/sample plot (LKI) and nitrogen impact value (N) were calculated and it was tested if there was any difference between the sites. Twenty-four species were observed in total, and Parmeliopsis ambigua and Hypogymnia physodes were the most common species at all sites. At Road E4, fewer lichen species were observed than at the other sites and this might be due to the impact of air pollution. The species richness at Road 600 was similar to that of the reference site, which might be explained by the improved air quality.

Habitat diversity and composition among growing wild boar (Sus scrofa L.) populations in Sweden

The wild boar (Sus scrofa L.) has expanded across Europe and Sweden in the last decades. It is a generalist species which utilizes a variety of habitats, and its presence has been shown to have both positive and negative effects for people and the landscape they are in. The abundance and increase of wild boar has previously been shown to differ between counties in Sweden, but there have been few explanations as to why. In this study, I investigated correlations between the per capita rate of change (r) among wild boar populations in Sweden and a variety of different habitats on the county level. I also investigated if fragmentation per se or in certain habitats could be associated with the wild boar?s per capita rate of change. My results show that fragmentation/diversity per se was not correlated with wild boar r.

The distribution of Moose (Alces alces) during winter in southern Sweden : a response to food sources?

The traditional Swedish way of dealing with browsing damages made by moose, is to reduce the moose population. However, a growing way of dealing with damages made by several ungulate species, including wild boars in particular is to redistribute them with supplementary food sources. Attracting them to settle in habitats less vulnerable to damages made during foraging. This study we tracked collared moose in southern Sweden from January throughout April in the year of 2009. From the tracking data their ?favourite? positions was selected and visited in order to study the features that attracts moose during winter.

Cassava as an additive in biomass fuel pellet production :

In this study, the effects of using fine milled cassava stems as an additive in biofuel pellet production was compared to the effects of refined starch addition. The bulk biomass fuel raw material, to which the additive was added, was a blend of spruce and pine sawdust. An experimental design in the factors cassava/starch content, moisture content and material temperature was used. Measured responses were pellet bulk density, pellet durability, amount of fines, pelletizer motor current, pellet temperature, die temperature and CV for pelletizer motor current (a measure of process stability). Each response was modeled by multiple linear regression (MLR).

Återförvilda Sverige?: En studie av rewilding som strategi för att bevara kulturlandskapet och gynna biologisk mångfald

Through millennia, humans have shaped the European landscapes. Agriculture, hunting andforestry have influenced virtually every ecosystem on the continent and formed what we todaythink of as the cultural landscape; a mosaic pattern of cropland, fields, pasture and forests. Thepast two centuries, globalization, industrialization and urbanization have come to pose a threatto the existence of these landscapes. European farmlands are now being abandoned at analarming rate, and the associated loss of landscape preservation, biodiversity and ecosystemservices is a concern to the scientific community and public alike.This thesis studies if the implementation of the relatively new conservation strategy rewilding(recreating self-sustaining ecosystems and reintroducing keystone species) can be a part of thesolution to preserve cultural landscapes and biodiversity in Sweden. Through interviewssupplemented with studies of published works, expertise from different fields has beencompiled to provide an overall picture of the capacity of rewildings as conservation method.

Skogsbolagens syn på vindskadeförebyggande åtgärder efter stormen Dagmar

On the night of the 26th December 2011, large parts of southern Norrland were struck by the storm ?Dagmar? that caused serious damage to the forests. In the past 10 years wind damage has become a hot topic after several major storms. Forest companies own 25% of the Swedish forest and thus influenced largely by wind damage. The main purpose of this study was to examine whether forest companies attitude towards preventive wind damage actions were changed after the storm ?Dagmar?. The result was developed by doing interviews with two forestry companies.

Förutsättningar för återintroduktion av stora gräsätare i Sverige

Biodiversity is under threat in Sweden and many species are on the brink of extinction. This is mainly due to the large-scale drainage projects during the 19th and 20th century and the increasingly intensive land use in agriculture and forestry. The intensive land use with sharply defined boundaries between the production units has in many cases led to either overgrazing or overgrowing. As a result many species have been pushed back to "leftover" habitats like shooting ranges, power line corridors, roadsides, dumps, embankments and other similar areas. Therefore the question has been raised, wether or not it is needed to re-introduce large herbivores into the wild in order to maintain the biodiversity that is related to the extensive land use.This study has been conducted as a literature review and will focus on the European bison?s (Bison bonasus) impact on other species and biodiversity; conditions for reintroducing large herbivores in Sweden are also discussed.Free roaming populations of large herbivores have a positive impact on plants, insects and many other groups of organisms.

Varför är Bivarödsånsvatten så brunt?

The river Bivaröd is one of the river Helgeån tributaries which has the highest and the fastest increase in water colour. The reason behind this increase is unclear but several factors have been suggested to affect this pattern. In this work, I studied the role of land use, iron and precipitation for water colour increase in river Bivaröd for the period 1976 -2011. Data from a field study along with data from SRK for river Helgeån were used for the analyses. The results showed that both water colour and iron concentration increase and that there is a strong correlation between these two variables.

Tillvaratagande av GROT i skärgårdsnära miljö :

The main aim of this study was to investigate and compare different methods for the extraction of forest fuel from environments close to an archipelago. The study was based on relevant literature and published reports as well as personal communications. Forestry has traditionally been characterized by intense efforts to rationalize and mechanize the cutting technique used for timber and pulpwood. In line with the increasing importance of forestry, more concentrated efforts can be expected in the area of techniques and methods, especially for the above-mentioned product lines. In Sweden, forestry is of major importance and the Swedish economy and standard of living have mainly been created based on the revenues generated from it. Thus, it is vital that Swedish forests are harvested in an efficient and responsible manner. The demand for biofuel is growing and today accounts for 15% of total Swedish energy production, a share that will probably increase. This study is based on three research questions, which are described under the heading of Aim. The results reveal that the most profitable method for handling forest fuel is the traditional one, which is also the most commonly used method in southern Sweden, namely the stockpiling of logs in a clearing by means of forwarders followed by splintering at the place from where they will be distributed. Today, the high cost of barge transport required for the extraction of forest fuel in an archipelago environment renders such operations unprofitable.

Realisering av en modulär skogsmaskin - En skalmodell

Wood for commercial use is harvested from forests using forest machines like harvesters which folds, branches and cuts trees and forwarders which transports logs to a landing area for further transport to a processing facility. Future forest machines have to be much gentler to the machine operators and forest soil than today's machines. Hence new machine solutions must be developed and tested. A practical way is to develop a physical scale model which can be used as a test-bed to incorporate different types of solutions for suspensions, cabin damping, tires and tracks, crane and overall architecture. The aim of this project was to develop such a 1:5 scale model of a forest machine, named as ?Skogbil.A scaling strategy was employed to arrive at important scale dimensions and specifications ofSkogbil which would be comparable to the full scale model.

Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd

The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth. Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.

Skogsägarenas inställning till markberedning i västra Värmland

According to a press release from the Swedish forest agency in May 2014, western Värmland has the worst regenerations of forest result in the whole of Sweden. The scarification frequency is low in the area. AB Hilmer Andersson want´s to know if the private forest owners want to scarify more than is done today. Good regeneration is important for private forest owners so they can have a long term forest management and economics of their forests. This academic study is done as an opinion poll. The purpose of the study is to see how big the interest of scarification among the private forest owner is.

Naturupplevelse och psykisk hälsa : Hur påverkar naturupplevelser människor med stress- och utmattningssymtom

Stress-related diseases in Sweden have doubled since 1997. Even longterm sickness related tostress has increased over the last decade. In future there is a need of alternative methods todecrease the amount of people being affected to gain a better population health. Natureassisted therapy (NAT) was shown to be a successful method as part of the therapy of stressand burnout likewise was nature an important factor to prevent people from mentaldisorders. The aim of this study was to analyse the latest research concearning nature and itshealth effects with focus on stress and burnout patients in order to plan health promotingactivities outdoors for these patients.

Minskad trädtillväxt under Lilla sitiden? : En dendroklimatologisk jämförelse mellan nutid och 1600-talet invid trädgränsen i norra Skandinavien

During the period called Little Ice Age (1400 ~ 1900) the climate of northern Europe was in an annual year-basis overall colder than it was before and after that period. The numbers of short, cold and rainy summers and long, bitter-cold winters where often repetitive under the approximately 500-years the period lasted. In Scandinavia, the coldest time during this period is estimated to have started around the end of the 16th century and lasted to the beginning of the 18th century. Trees growing at the tree-line are limited by temperature for their annual growth and hence showing differences of growth during changes in the climate,  a method called dendroclimatology. The variations of growth can be read in the tree-rings either by analyze the width of the ring or by look into the density of the wood and is used to reconstruct past climates.

Export of wood pellets from British Columbia : a study about the production environment and international competitiveness of wood pellets from British Columbia

The global wood pellet market has seen a rapid growth after the adoption of the Kyoto protocol and the renewable energy incentives created within the European Union. The global consumption of wood pellets reached 13,5 million tonnes in 2010 and several experts estimate the consumption to be between 35-50 million tonnes by 2020. These forescasts raise the questions which regions that can supply this vast amount of wood pellets and what the conditions are for producing it. This study evaluates the conditions for wood pellet production and export from British Columbia, on Canada?s west coast, focusing on existing industry structure, raw material supply and the distribution chain.

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