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766 Uppsatser om Soil conservation - Sida 45 av 52

Gröna broar : ekologiska, sociala och estetiska tillgångar

The visions of the United Nations concerning sustainable development and conservation of biodiversity can only be realized if the human population succeeds in creating coexistence between human and wildlife. Landscape architects are able to influence on how landscapes are to be maintained and developed. The negative impact of infrastructure on wildlife has become a critical problem in Sweden and other parts of Europe. Wildlife crossings has been developed as a solution for the problems of road barriers in the landscape. The crossings are made to give animals a better opportunity to cross roads.

Trädens utveckling efter att de har lämnats som naturhänsyn : tillväxt, mortalitet och strukturell förändring 6-18 år efter avverkning

Today green tree retention, together with leaving dead wood, is a common practice with the aim to reduce negative impacts on biodiversity and environment due to clear-felling. To better understand whether this conservation practice also makes a long-term difference, it is important to know what happens to these trees after harvest. Few studies have made an assessment of what happens to retention trees over a longer time period. In this study I inventoried retention trees that were left at clear-cuts six, twelve and eighteen years ago. I carried out a re-inventory of 57 retention patches (divided into free-standing tree groups, small swamp forests and edge zones) and free standing dead trees, spread over 25 previous clear-cuts in central Sweden.

Årstidsdynamik för kvicksilver i ett sövattensediment :

The limit for mercury in fish, set by health authorities, is exceeded in about half of the lakes in Sweden. Methyl mercury (MeHg) is the most toxic form of mercury and accumulates in fish. Therefore transformation of inorganic mercury (Hg) to methylmercury (MeHg) is an important process that we need to understand in order to possibly counteract the negative effects of mercury in the environment. The seasonal dynamics of mercury biogeochemistry is likely of great importance for the accumulation of MeHg in the aquatic food web. In thesis the chemical speciation and transformations of Hg and MeHg in bottom waters and sediments is followed in Ängessjön, a small lake located on the east coast in the middle of Sweden. The lake is not directly affected by any industrial pollution and concentrations of Hg in the sediment reflect the atmospheric deposition in this area, as well as processes taking place along the hydrological pathways from soil to lake. Samples from sediment, bottom- and streamwater were collected in average every second month during the period Feb.

Interactions between some plant-parasitic nematodes and Rhizoctonia solani in potato fields

The pathogenic fungus Rhizoctonia solani causes major economic losses for potato producers in Sweden. The producers, as well as advisors, have reported possible increases in severity of R. solani when free-living plant parasitic nematodes are present and active. There are several examples in the literature of interactions between pathogens where one, or both species, support or increase the damage made by the other organism. These complexes are important to investigate and to be able to forecast, since even low incidences of fungi or nematodes may result in an interaction of significance.

Design Program for Dessie Campus, Wollo University, Ethiopia

A geographical position and its social, cultural and political context as well as climate and specific physical characteristics define the scope for a landscape design project. This has become clearer for us in our master project where we have made a Design Program for the outdoor environment of Wollo University in Dessie, Ethiopia and analysed and reflected on the work and process. The aim for the project has been to design an attractive and functional outdoor environment for the Campus, based on the inventories and the needs and wishes of clients and users. But, the aim has also been for us as landscape architect students to gain a greater knowledge about landscape architecture and the design process by position ourselves outside our usual context. The method has been open and seeking where the site, literature studies, dialogues with people and our own experiences from the field study in Ethiopia has influenced the work. Wollo University is situated 400 kilometers north of Addis Ababa, in a mountainous landscape. It faces problems of heavy rainfall during the summer, soil erosion, a lack of essential facilities, and is still a construction site with empty spaces in-between buildings and infrastructure.

Viltanpassad röjning längs skogsbilvägar som en foderskapande åtgärd för älgen

The moose is a keystone species in the boreal forest ecosystem, but the dense Swedish population do cause some serious problems. From a forestry perspective, their browsing on young Scot pine (Pinus sylvestris) causes extensive losses of revenue. Adjusting the cleaning along roadsides of low trafficked forest roads can favour the production of plant species preferred by the moose. This is thought to redirect the moose´s browsing to the roadsides and thereby decrease the damages on commercial forest.The aim of this study has been to present a first evaluation of the vegetation in roadsides, one year after wildlife-adapted roadside clearing has been undertaken. In the wildlifeadapted clearing operation, the roadside was widened by removal of some trees in the forest edge whereupon a complementary clearing with a conventional chain flail was conducted.

Smart seed : fördröjd groning hos raps : försök med frö-coating samt litteraturgenomgång om frögroning, coating och praktisk tillämpning i reläodling

Oilseed rape constitutes a good break crop within a cereal dominated cropping system. The normal sowing time for winter rape in Sweden is August. It's a time in the cropping year characterized by a heavy work load, such as harvest and soil management. In addition, it is often a period with large precipitation. Thus, it is sometimes problematic for the farmer to do the sowing of winter rape at the optimal time.

Effekter av predationsrisk på sånglärkors (Alauda arvensis) habitatval på åkermark

Along with other European farmland birds, the skylark (Alauda arvensis) has declined rapidly since the 1970?s. Between 1975 and 2003, the Swedish population of skylarks declined with 64 %. In Britain, the decline is often explained by alterations in farming practices in general and the shift from spring-sown to winter-sown cereals in particular. The dense vegetation structure of winter cereals is limiting the number of breeding attempts possible, causing the entire population to decline.

Volume and taper equations for Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst.) and White spruce (Picea glauca (Moench) Voss) in Iceland

The aim of this study was to evaluate different types of volume and taper equations that can be used to predict single-tree stem volume and stem diameter at any given height along the tree stem for plantation grown Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst) and White spruce (Picea glauca (Mounch) Voss) in Iceland. A number of published tree volume equations were tested and modified to predict the total stem volumes over bark but three logarithmic equations were taken for more in-depth analysis. Three taper equations were tested. Two variable-exponent equations (Kozak 1997, Kozak 2004) and one exponential equation described by Biging (1984). Data from a total of 617 sample trees were used in this study, collected from stands in various parts of the country and present different types of stands growing in different soil types and cover most of the site conditions suitable for forestry in Iceland.

In search for sustainable alternatives to lawns : connecting research and landscape design

A large part of Sweden?s green, urban landscape is covered by lawns. Approximately 80 000 ha of maintained grass lawns are part of public courtyards, schoolyards, parks, golf courses, sport fields and traffic environments. Beyond this figure, the lawn is also an essential element in most private villa-gardens. Lawns have become a universal phenomenon through the dispersion of landscape aesthetics from the Western world.

Daily rests of wild boar Sus scrofa sows in southern Sweden

For a few decades, the wild boars are established over large areas in southern and centralSweden. Where they cause problems in terms of damage to crops in the agriculturelandscape, where rooting, browsing and trampling, but also damage to the crop when wildboars chosen daily rest in the cultivated fields. Along with the growing number of wildboars the rate of car accident with wild boars has also increased.Here I examined the daily rests of wild boar (Sus scrofa) sows in southern Sweden, todetermine the factors which the wild boars sows choose for daily rest. By determining whatfactors are important in this selection of daily rests, we may be able to make managementmeasures to reduce the damage wild boars make in the agriculture landscape by attractingthem to places where they do less economic damage and accidents on roads.In this study I have examined 123 daily rest positions from 14 different individual wildboar sows fitted with GPS collared in Southern Sweden, Skåne County in Christinehof,Högestad Kronovalls estate. Data was collared over the years 2004-2006 during the periodfrom June 1 to September 30.

Retention of stumps on wet ground at stump-harvest and its effects on saproxylic insects

Low stumps represent on their own up to 80% of the dead wood remaining on clear cuts and therefore supply suitable habitat for saproxylic insects i.e. insects depending on dead wood for their survival. Recent stump harvesting activities threaten this substrate of ecological importance and increase the anthropogenic negative impacts on these species. Because of technical and environmental reasons (nutrient leakage, erosion) guidelines for stump harvesting recommend to retain stumps standing in wet parts of clear cuts. However, stumps in wet positions might not be a satisfactory substrate for saproxylic insects and therefore might not be as much used as stumps in dry positions.

Fastighetsbildning inom strandskyddat område : En studie av tillämpningen i två kommuner

Stränder och strandnära områden utgör i många avseenden en värdefull miljö som i Sverige skyddas tack vare vår strandskyddslagstiftning. Strandskyddslagstiftningen är en naturvårdsföreskrift som syftar till att trygga allmänhetens tillgång till stränder och bevara goda livsvillkor för växt- och djurlivet. Skyddet är generellt, dvs gäller alla stränder i Sverige och innebär bl a ett förbud mot uppförande av ny bebyggelse. Fastighetsbildning inom strandskyddat område utgör en åtgärd där hänsyn måste tas till strandskyddsbestämmelserna. Åtgärden kräver en bedömning där förrättningslantmätaren, efter vederbörligt samråd med kommunen eller länsstyrelsen, avgör om strandskyddets syfte motverkas eller inte.

En analys av SCA Skog AB's metod för egenuppföljning av gallringar :

A high quality is highly requested in today?s thinnings, since these are the base for continued value development of the forests. Thinning quality often means a minimization of damages on soil, stems and roots during the cutting. One way to reach a high quality is to set up goals that will be followed up after the cutting is made. Self-checking gives information of the machine drivers work and guarantees the customers a good quality of work.

Småskalig livsmedelsförsörjning av mjölk :

During the last year?s Swedish agriculture have had difficult times, with decreasing prices and at the same time increasing production costs, which has led to bad profitability and faith in the future. The dairies in Sweden have also had a rough time and there have been large rationalizations during the years. In the beginning of the 20th century there were almost 1700 diaries in the Swedish countryside. There has been a large technical development during the 20th century resulting in a decrease in diaries to only 46 in the whole country today. They are owned by 15 diary companies, of which 7 large and dominate on the market and the rest are small-scale companies. With this development the confidence and feeling for the diary companies also has decreased.

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