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681 Uppsatser om Soil moisture gradient - Sida 36 av 46
Silver och vismut i plaster och färger : Källor till förhöjda halter i slam?
Chemical substances are spread diffusely and uncontrollably as a result of the increased consumption of goods. REVAQ is a certification system that works to reduce the flow of hazardous substances to Swedish treatment plants and to create a sustainable nutrient recycling. According to REVAQ, the yearly accumulating rate of metals should not exceed 0.2% in soil per year. Silver and bismuth are two metals that do not fulfill this requirement. The silver concentration in sludge decreased during the last decade, however the last few years, it has leveled off.
Kvalitetsarbete i grotskotning
This study was carried out at the request of the Swedish forest company Sveaskog which is an important producer of logging residues (branches and tops) intended for energy production. The company wanted to increase the average dry content to 60 percent in their delivered logging residues. At the time when this study was initiated, the dry content in the chipped logging residues originating from the Bergslagen district was at 52 percent. The aim of the study was to find out how windrows of logging residues could be arranged in order to help obtain desired properties such as increased dry content. Sveaskog had developed a system for evaluation of windrows and a standardized form was utilized to describe different properties of the windrows.
Pottaskeframställning och tjärbränning i Femsjö socken från år 1700 till 1900 :
Femsjö is a small parish situated in Hylte municipality, Växjö diocese. The parish has a total area of 8230 ha of which 5000 ha are covered with forest. There have not been any large industries in the parish offering work opportunities for the inhabitants, so they have had to generate income from their land and the forest. Instead of going to the bank to get a bank loan the people of Femsjö parish went out in to the forest and harvested trees for timber and extra cash revenue. Production of pine tar and potash were two other ways that the residents of Femsjö parish could earn extra money for the household in order to keep starvation away.
OMBYGGNAD AV TRAFIKPLATS : Ekhagsmotet i Jönköping
We have the tradition in Sweden to build villas and houses with a wooden framework. It has become natural for us because we have so much forest in our country. Building with wood has advantages, it is easy to process, but also disadvantages, as it is sensitive to moisture.Finland has long made use of the thermal blocks to build villas. It is a type of bricks that are a bit like a sandwich element, with a core of EPS and concrete on both sides of the core material. The concrete is hollow, so that after the walls has been bricked up you pour concrete into the hollow bricks.The issue of this report is to find out if concrete can be an alternative to wood as framework material in villas.
Säsongsvis avverkning : det operativa traktvalets påverkan på den säsongsmässiga uthålligheten i ett bolagsdistrikts traktbank
Due to soft grounds in combination with seasonal variation in soil humidity, there is a lack of stands that are possible to cut during spring and autumn in some geographical regions. For Holmen Skog this sometimes means that a large proportion of the contracted private forest is cut during the winter when the ground is frozen. One consequence of this is that the proportion of winter stands in the stand bank of own forest increases while spring and autumn stands becomes a scarcity. This in combination with milder winters, especially when there is a long period of reduced bearing capacity in spring or autumn, means that the situation rapidly can become critical.
The overall goal with this study was to generate basic data for decision support in the work to achieve a sustainable distribution between own forest and contracted private forest in the stand bank.
The study took place at Holmen Skog, district of Umeå, during autumn 2007 and was based on interviews and an analysis of harvest planning and delivery data.
The study showed that there is a problem with how the cutting is distributed between own and contracted private forest during the year and that it foremost is the proportion of winter thinning of own forest that has increased in the stand bank.
Trädplantering i stadsmiljö : exempel i Uppsala och Stockholm
Syftet med denna uppsats är att undersöka hur
olika potentiellt skadliga faktorer påverkar
nyetablerade stadsträd. För att göra detta
utvecklas en metod för inventering av träd och
ståndort, som sedan appliceras på ett urval på 94
stadsträd fördelade på 11 anläggningar i
Uppsala och Stockholm. Faktorerna som
framkom som resultatet av studien jämförs med
skadliga och gynnsamma faktorer enligt
uppgifter från trädexperter och litteratur.
Uppsatsen inleds med en beskrivning av
stadsträds situation idag och historiskt, samt
nuvarande kunskapsläge. Därefter följer ett
metodkapitel som beskriver metodutvecklingen.
Metoden bygger på inventering och analys av
ett antal punkter. Exempelvis behandlas vilken
information stamomfång kan ge och hur det
inventerats under rubriken Stamomfång.
Trädföryngring i låga gropar uppkomna vid brand i boreal naturskog :
This study was conducted in the "Kåtaberget" forest reserve in Västerbotten in the summer of 1999. In the summer of 1995, a prescribed burning was performed in the reserve. In some places where coarse dry woody debris (logs and stumps) was present, the fire consumed the wood, as well as parts of the humus layer, creating deep-burned patches. The low intensity ground fire also created dead woody debris by burning off living trees with open fire scars, as well as standing dead trees.
In this study, the post-fire tree seedling establishment was examined, with special attention given to the former presence of woody debris. The study also includes a survey of the areal extent of deep-burned patches, as well as an examination of tree seedling establishment in these patches, compared to other burnt ground.
Diversitet hos jordlöpare (Col: Carabidae) i hävdade strandnära gräsmarker :
Diversity of ground beetles (Col: Carabidae) in managed riparian grasslands.
The carabid community in moist seminatural grasslands was studied at three different sites in mid-Sweden. Pitfall trapping was carried out during six weeks in spring and early summer 2003. Eight transects, each containing seven pitfall traps, were placed in three different management regimes, either late or continous grazing, or meadow.
The species composition was analysed by ordination analyses, i.e. DCA and CCA.
Effekt av överlast på förstärkt jord : FEM- analys för att visa överlastens verkningsgrad på krypsättningar i kalkcementpelarförstärkt lös jord
Applicering av överlast på kalkcementförstärkta jordar är ofta förekommande idag, forskning indikerar dock på att överlasten här, inte ger samma effekt som på oförstärkta jordar. Med grund i uppmätta värden i fält, visas i denna rapport, sättningsdifferenser mellan att använda överlast jämfört med att endast applicera brukslast. Resultat av analyserna visar på sättningsbeteende observerat i fält. Om erforderlig liggtid för brukslast finns, uppstår endast små sättningsdifferenser mellan att använda överlast eller inte.Genom att utföra sensitivitetsanalys i FEM- programvaran PLAXIS studeras kryputvecklingen i den förstärkta jorden. Effekten av att applicera en överlast visas för krypsättningar över lång tid.Inget resultat från de numeriska FEM- analyserna visade att märkbart gynnsam effekt uppstår på grund av överlastens applicering, med avseende på krypsättningar.De numeriska analyserna utförs i 2 och 3 dimensioner för att belysa effekt av förenkling av ett lastfall som inte uppfyller krav för oförstärkta jordar i plant töjningstillstånd.Utöver detta ges efter en litteraturstudie, förslag på hur vissa indataparametrar kan utvärderas från empiriska relationer.
Olika typer av täckning och samodling och dess påverkan på antalet skadegörare i en Pak choi odling :
The purpose of this report is to examine the possibilities to decrease the number of insects and other pathogens in a crop of pak choi (Brassica rapa), grown with different types of cover and living mulches. Included in the report is a study of literature where amongst others, a summary on the vegetable pak choi and theories of living mulches and different kind of covers are to be found. To examine the amount of predators in the field, traps were used.
During the autumn 2002 the tests were conducted in Alnarp. The pak choi and the living mulches were planted/sawn at the same time, the different covers were also applied at this time. The total experiment was divided into six different treatments (plus control) of which three were with covers and three were with living mulches.
Once a week the number of leaves, the height and damages were read on ten of the plants from each parcel.
Numeriska simuleringar av betongplattor på mark med gradientkrympning och sprickfördelande armering
Betongplattor på mark är en ofta använd grundläggningsmetod. Trots detta är sprickbildning ett vanligt problem där kraven på maximala sprickvidder ofta inte uppfylls. De sprickor som bildas i plattorna uppkommer bl.a. till följd av dess uttorkning, och då olika fuktförhållanden råder på var sida om plattan utvecklas en krympning som varierar med en gradient över tvärsnittet. Vid dimensionering av armeringen för denna inre last och sprickbildningen den orsakar, finns endast otillräckliga analysermetoder att tillgå i normer.
Fosforförluster från lantbruket och dess bidrag till övergödning av sjöar och vattendrag i Växjö kommun
The possibility for plants to utilize phosphorus in soil is a prerequisite for conducting agricultural production, both small scale and professional. Spreading of phosphorus fertilizers and manure is therefore seen as a necessity in today's agriculture in order to achieve high yield. Manure management, livestock farming and manure storage could contribute to the eutrophication of lakes and rivers. For instance, when the ground becomes saturated, phosphorus leakage could be seen in surface runoff or in point sources resulting from inadequate manure storage management.In the municipality of Växjö there is still many bodies of water that do not reach the Swedish environmental water quality standard of "good ecological status". This thesis has therefore analyzed the manure management and storage on agricultural farms which may have contributed to eutrophication in the municipality.The method for this thesis was a literature study, a questionnaire survey with 820 receivers and a summary of issued inspection reports from 2013.The results highlight the ways in which agriculture may have contributed to the eutrophication of lakes and streams in the municipality of Växjö.
Stommaterial för villor - trä eller betong?
We have the tradition in Sweden to build villas and houses with a wooden framework. It has become natural for us because we have so much forest in our country. Building with wood has advantages, it is easy to process, but also disadvantages, as it is sensitive to moisture.Finland has long made use of the thermal blocks to build villas. It is a type of bricks that are a bit like a sandwich element, with a core of EPS and concrete on both sides of the core material. The concrete is hollow, so that after the walls has been bricked up you pour concrete into the hollow bricks.The issue of this report is to find out if concrete can be an alternative to wood as framework material in villas.
Do retention trees affect the composition of ectomycorrhizal fungi? : a comparison between clear-cuts areas with and without retention trees in pine forests
Under det senaste årshundradet har de svenska skogarna genomgått en omfattande förvandling, från mer eller mindre naturligt dynamiska till hårt brukade skogar bestående av monokulturer av tall eller gran. Denna förändring har lett till en minskning av den biologiska mångfalden, att många arter som är beroende av skog har minskat radikalt och hotas av utrotning. Som ett försök att främja variation, biologisk mångfald i allmänhet och förhindra minskningen av rödlistade skogsarter introducerades i början av 90-talet en viss naturvårdshänsyn i brukade skogar. I den här studien utvärderas den påverkan som kalavverkning har och den betydelse hänsynsträd har på artsammansättningen och förekomsten av ektomykorrhizasvampar (EMF) under de första 20 åren efter kalavverkning. Studien utfördes genom extrahering och identifiering av svamp-DNA från jordprover tagna på kalavverkade ytor, nära hänsynsträd och i gammal skog i ett begränsat geografiskt område i norra Sverige.
Marknaden för skogsvårdstjänster : en undersökning bland privata markägare inom en region i Värmland
This work broadly illuminates the conditions for increasing the commissions of forestry services within the whole, or parts of, the western regions of Stora Enso?s operating area. Through a questionnaire, a survey was made examining whether the owners of the forests themselves do the forestry on their woodlands. This foremost concerns the pre-commercial thinning, but also planting and soil scarification. The survey also shows who are buying the most part of their forestry services and who are carrying it out themselves.