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494 Uppsatser om Excavated soil - Sida 30 av 33
Vildsvinsskador inom jordbruket : hur stora är förlusterna?
Problems with wild boars are increasing in Sweden and some people argue that the wild boar population must decrease. This is mostly the opinion by farmers, while the hunters want more wild boars in Sweden. Today the population is the strongest in the south of Sweden and in the eastern parts of the country. However the population is growing stronger in other parts of Sweden as well. The population origins from these areas where they escaped from pens around 1970.
Produktionseffekter och behov av dikesrensning i Sveaskogs skogar :
Ökad efterfrågan på virke har lett till ett ökat intresse för och användande av olika produktionshöjande åtgärder. En sådan åtgärd är dikesrensning som innebär att befintliga diken eller dikessystem rensas för att de skall bibehålla eller återfå sin ursprungligt avvattnande och produktionshöjande funktion. Sveaskog avser att öka omfattningen av dikesrensning. Därför behövs en kartläggning av behovet på deras marker. På samma gång behöver produktionseffekterna och livslängden på dikena utrönas.
Studien genomfördes via en studie av befintlig litteratur om skogsproduktionseffekter efter dikesrensning och dikning samt förfall och livslängd hos diken.
Modell för ett integrerat skärgårdsskogsbruk : en fallstudie på Kallsö
The forests in the unique archipelago of the Baltic Sea is housing many and high values. For the resident population, which has a central role in sustaining a living archipelago, the forest can contribute to the outcome. The forest also contributes to turn the archipelago into one of Sweden?s most attractive recreational areas. Furthermore, these forests exhibit very high environmental values, and they are an element in the traditional cultural landscape.
Skogsbruksplanens betydelse för aktiviteten hos privata skogsägare i Älvdalen :
The purpose of Älvdalens besparingsskog is to develop the district and most of all the forestry in Älvdalen. It's owned by about 2 300 private forest owners who's landed properties are located in Älvdalen. Every year the besparingsskogen gives out a lot of its profit in form different types of subsidies for agriculture and forestry. The owners can apply for subsidies for several of the costs that occur in forestry. During the period 2000-2003 the owners are offered forest management plans and pcSKOG-gård at no cost for their private forest properties.
The purpose of this master's thesis was to find out if the activity in the forestry changed when the forest owners got new forest management plans and the computer program pcSKOG-gård.
Stem injection of different nitrogen forms into young Norway spruce
This master thesis has been a pilot study preceding a forthcoming project of a larger scale with the long term objective to separate the direct effect of added nitrogen on soil processes from indirect effects via trees. The aim of this study has been to investigate the allocation of nitrogen following direct injection of liquid solutions into the xylem of 40 year old Norway spruce. The field site is located at Flakaliden (64°07?N, 19°27?E), approximately 60 km northwest of Umeå, Sweden. A total of 18 trees were selected for treatment, equally divided between three treatments, potassium nitrate, glutamine and water (control).
Aspekter på flyttkostnader, fastighetsbildning och fastighetstorlekar :
This master thesis has three purposes. The first purpose is to give a theoretical background of how to divide up forest estates and to study how the legal system for these matters works.
A literature study has been carried out to give the background and a theoretical model has been made for analysing the law cases. The first purpose also partly touched the decision process in dividing up forest estates from point of view of the law of land parcelling (FBL), point of view.
The second purpose is to examine effects of a change of production requirements in 3 cap.7 § FBL as regards dividing up forest estates of private forest owners.
Bredspridning av grönmassa :
There are a great possibility to shorten the time between mowing and preservation by spreading of ley crops in connection to the conditioning. In this case the cellular respiration (the plants breeding that consume sugar until the crop is ensiled) should not continue as long and the forage will perhaps get a higher nutritional value. The capacity of the next machine could also be higher because the rake gives swaths with a lot of material. There is also a possibility that spreading of ley crops gives the material a more homogeneous content of dry matter and that gives a reduced growth of clostridium. This is particularly important when the method of harvest doesn?t include any mixing of the material like it does with a round baler or silagewagon.
?Rätt avlopp på rätt plats? : ? Livscykelanalys av tre enskildaavloppsanläggningar
?Rätt avlopp på rätt plats? ? Livscykelanalys av tre enskilda avloppsanläggningarProblemen med övergödning i Östersjön och i Sveriges insjöar är stort och enskildaavlopp pekas ut som en central aktör, framförallt beträffande fosforutsläppen. I Sverigefinns det ungefär en miljon enskilda avloppssystem och nästan hälften av dessa har enså pass bristande vattenrening att de inte uppfyller gällande lagstiftning. Utvecklingenav nya tekniker för rening av avloppsvatten har länge strävat efter att minska utsläppenav övergödande ämnen, detta ibland på bekostnad av andra utsläpp, så somväxthusgaser och försurande ämnen.Det här examensarbetet har därför med hjälp av metodik från livscykelanalys (LCA)utvärderat tre enskilda avloppssystem med tanke på deras utsläpp av växthusgaser,försurande gaser samt övergödande ämnen. Då misstanke också fanns att de lokalaplatsegenskaperna påverkar de enskilda avloppssystemens totala miljöpåverkan,utfördes även en intervjustudie med ett antal av landets kommuner.
En jämförelse av sitkagranens (Picea sitchensis) och den vanliga granens (P. abies) produktion :
Sitka spruce (Picea sitchensis) is a tree species that have its natural distribution along the
West Coast of North America, from Alaska in the north to northern California in the south.
Sitka spruce is a typical coastal tree species that can reach heights up to 85 meters and occurs
in single pure as well as in mixed stands.
The main purposes of this study were to describe the Sitka spruce growing characteristics and
the volume production in comparison to spruce (Picea abies). The possibility to predict future
volume production by using prognosis tools designed to be used on spruce were also studied.
The material that has been used in this study are permanent sitka trials established by the
Faculty of Forestry fixed Sitka trials and also material gathered in this study.
A literature study was also carried out in order to determine the Sitka spruce growing
characteristics.
Sitka spruce has a high adaptation and a high volume production on a broad scale of soil
types. The tree species is a pioneer species that has a fast early growth and in combination
with sharp needles it is less susceptible to animal browsing than spruce. The factor that is the
single most limiting factor for where the Sitka spruce can be planted is frost. This factor can
be limited by using plant material with a well-suited provenance.
According to the literature, the Sitka spruce has an average total volume production that is
between 20-40% higher than spruce.
Geosynteter för hållbara vägar : Modell för jämförelse av vägöverbyggnader med eller utan geotextiler och/eller geonät
The different material layers as part of a road construction fill all a function so theroad becomes durable, safe, comfortable and aesthetically pleasing. Recently, anew group of construction materials started to play an important role in roadconstruction ? geosynthetics.This thesis addresses the two most common types ofgeosynthetics used in modern road construction, namely geogrids and geotextiles.The most common use of geogrids is reinforcement of poor subgrade by usinggeogrid soil reinforcement, which occurs when road material particles wedge inthe geogrid?s mesh. Geotextiles act partly as a barrier that prevents the finermaterial in the below ground from being mixed with coarser upper material andalso act as a load spreader.Road contractors often face a choice of whether geogrids and/or geotextiles areappropriate in a particular road project and also how much profit the choice mightbring. This phase in the tender calculation process is the intended scope of thisthesis.The thesis deals with both the "hard" cost-function aspects and the "softer" values e.g.
Removal efficiency of perfluoroalkyl substances (PFASs) in drinking water : evaluation of granular activated carbon (GAC) and anion exchange (AE) using column tests, and the effect of dissolved organic carbon
Poly- and perfluoroalkyl substances (PFASs) are a group of environmental contaminants that have gained increasing attention due to their potential to bioaccumulate, environmental persistence and potential toxicity. PFASs have been found in surface water, sediment, air, soil, sludge and ice caps globally, as well as in wildlife and humans. Furthermore, PFASs have also been detected in drinking water, leading to raised concerns for human health, since drinking water is one of the most significant sources of PFASs for the general population. Conventional water treatment techniques have shown to be ineffective removing PFASs, highlighting the importance for further research to develop efficient removal techniques.
The aim of this study was to investigate the removal efficiency of PFASs in water using two treatment techniques; granular activated carbon (GAC), type Filtrasorb 400®, and anion exchange (AE), type Purolite A-600. Additionally, the effect of dissolved organic carbon (DOC) on removal efficiency was studied.
Skånes gröna guld : anläggning, odling & mossarter i mossträdgården
This is a 15 hp (10 p) thesis in biology at the programme for Horticulture Management at the Swedish University of Agricultural Sciences, Alnarp. In this literature study we have processed, reviewed and arranged facts and research, to make it more available for those who want to know more about establishment or cultivation of mosses. Our client is Fredriksdal?s Museums and Gardens in Helsingborg who are planning to establish a moss garden. The information is meant to be used by Fredriksdal and other similar facilities.
Karaktärisering av Gremmeniella-skadade bestånd inom Holmen Skog AB :
Since the end of the eighteenth century forest damage caused by the pathogen Gremmeniella abietina has been observed and documented. During the latest epidemic in Sweden more than 480 000 hectares forest land have been injured and this has lead to considerable economic losses. For the pathogen to succeed with infection, spore dispersal and colonization the right environmental conditions is required. The aim of this paper is to describe the diseased stands using site and stand characteristics and to evaluate the effect of these variables on the disease incidence. Further, the thinning performed during the time for spore dispersal and its relationship to injured stands is examined.
Monitoring and pest control of Fruit flies in Thailand : new knowledge for integrated pest management
Fruit flies (Tephritidae) are serious pests that cause enormous losses for farmers in many countries. The frequent use of insecticides in controlling fruit flies in fruits and vegetable has not resulted in sustainable management of the pest. Problems associated with this complete reliance on chemical control are many residues of insecticides in crops, health problems for farmers, contamination of water and soil, insecticide resistance development and decrease in natural enemy populations. The implementation of control measures that do not imply an added burden to the environment and/or the farmers is urgent. More knowledge about the ecology of fruit flies is the basis for finding new and better ways to control this pest.
Trädslagsinverkan på markvegetationens utveckling i odlingsförsök med tall och contorta :
In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.