258 research outputs found
Modell för ett integrerat skärgårdsskogsbruk
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.
This work suggests a silviculture in the archipelago where environmental-, cultural-, recreational-, and economical values are integrated. With Kallsö, in the archipelago of S:t Anna, as example, seven habitats were identified as particularly important to distinguish when managing forests in the archipelago of Östergötland. The forest in the archipelago can be divided accordingly to these habitats into the following management classes:
Typical rocky grounds high up in the terrain
Periodically, very dry sites with shallow soil where almost exclusively pine is growing. The stands contain a great share of impediment. Only cautious selective cuttings are recommended.
Slopes and moraine grounds of medium heights
The largest management class and thereby also the most important for forestry on Kallsö. However, the silviculture must be flexible since the terrain is varying. Leaving shelterwoods and seedtrees, and gap-cuttings can be carried out in combination.
Valley bottoms and sediment grounds
Fertile sites, which often has been used for agriculture. If the location is not too exposed clearcutting can be used. The stands should be managed to maximise the volume production. Yet, some parts should be set aside for environmental consideration.
Forests along shores
Larger sites with the character of shore-forest, which often have long continuity. The stands are often dense and dominated by broadleaves. Should be set aside for environmental consideration.
Small islands
Minor forested islands that are suitable to set aside for environmental- and recreational values, either for free development or tending with focus on conservation.
Sites dominated with alder
Larger sites with alder by the sea, or alder swamps further up on the islands. These should be set aside for their highly environmental values.
Oak dominated sites with character of pastureland
Very important sites for the environment in the archipelago, which also have an aesthetic value in the scenery. Should be tended and grazed to accomplish a continuous oak succession.
The outcome of the suggested management has been compiled and indicates that there are potential for forestry in the archipelago. But it has to be carried out with great caution and consideration to other interests. The conclusion is that a small-scaled and well adapted forestry is most advisable in the archipelago, and that there are several advantages in choosing silviculture methods that implies that the land always is more or less forested.Skogarna i Östersjöns unika skärgårdslandskap hyser många och höga värden. För den bofasta
befolkningen, vilken har en central roll i bevarandet av en levande skärgård, kan skogen ge ett
viktigt bidrag till utkomsten. Skogen bidrar även till att göra skärgården till ett av Sveriges
attraktivaste rekreationsområden. Dessutom uppvisar skärgårdsskogen mycket höga
naturvärden, och ingår till viss del i det traditionella kulturlandskapet.
I det här arbetet föreslås en lämplig skötsel av skärgårdsskog efter att natur-, kultur-,
rekreations-, och ekonomiska värden integrerats. Med Kallsö, i S:t Anna mellanskärgård, som
exempel identifierades sju skogstyper eller ståndorter som särskilt viktiga att urskilja vid
förvaltning av skog i Östergötlands mellanskärgård. Utifrån dessa skogstyper kan
skärgårdsskog delas in i följande skötselklasser inom vilka liknande skötsel rekommenderas:
Utpräglade hällmarker högt upp i terrängen
Periodvis mycket torra partier med grunt jordlager där det växer nästan uteslutande tall.
Bestånden innehåller en stor andel impediment. Endast försiktiga plockhuggningar
rekommenderas.
Sluttningar och medelhögt liggande moränmarker
Den areellt största skötselklassen och därmed också den viktigaste för skogsbruket på Kallsö.
Terrängen är dock varierad varför skogsvården måste vara flexibel. Skärm- och
fröträdställning och luckhuggning kan kombineras.
Dalbottnar och sedimentmarker
Bördiga marker som i flera fall tidigare varit åkermark. Om läget inte är allt för exponerat kan
trakthyggesbruk bedrivas. Bestånden bör röjas, gallras och planteras så att volymtillväxten
maximeras. Vissa bestånd, eller delar av bestånd, väljs ut för förstärkt naturhänsyn.
Strandskog
Större partier med strandskogskaraktär som ofta är tämligen orörda. Bestånden är ofta
tätvuxna och lövdominerade med höga naturvärden. Lämnas för fri utveckling.
Småöar
Mindre skogsbevuxna öar som lämpligen avsätts av hänsyn till natur- och rekreationsmiljön,
antingen för fri utveckling eller med naturvårdsinriktad skötsel.
Aldominerade partier
Större partier med al vid vattnet, eller alkärr längre upp på land. Dessa bör lämnas för fri
utveckling för sina höga naturvärden.
Ekdominerade områden med hagmarkskaraktär
Mycket viktiga områden för skärgårdens naturvärden. De har även ett estetiskt värde i
landskapsbilden. Bestånden bör skötas och betas i syfte att skapa kontinuerlig eksuccession.
Utfallet av den föreslagna skötseln har sammanställts och visar att det finns potential att
bedriva skogsbruk i skärgården. Men det måste göras med stor försiktighet och hänsyn till
andra intressen. Slutsatsen är att ett småskaligt och ståndortsanpassat skogsbruk lämpar sig
bäst i skärgården, och att det finns flera fördelar med att välja skötselmetoder som innebär att
marken alltid är mer eller mindre beskogad
Technical efficiency and the relationship with result on equity : a efficiency study in Swedish dairy farms between 2009 – 2011
Syftet med den föreliggande studien är att med hjälp av jordbruksekonomiska undersökningen mellan 2009 – 2011 analysera hur teknisk effektivitet påverkar räntabilitet på eget kapital i svenska mjölkföretag. Mjölkföretagen i Sverige visade under 2011 sämre resultat, vilket förklaras främst av lägre avräkningspris på mjölk. Efter 2006 har avräkningspriset på mjölk fluktuerat kraftigt i Sverige. Avsalu priset på spannmål har efter 2007 fluktuerat kraftigt, vilket kan förklara ett högre pris på foder. Mellan 1990 och 2012 minskade antalet mjölkföretag i Sverige med 81 procent och under samma period ökade den genomsnittsliga besättningsstorleken från 22 mjölkkor till 70 mjölkkor. En slutsats är att mjölkföretagen blir färre men har större mjölkbesättningar.
Det finns olika metoder för att analysera hur framgångsrikt ett företag är. En metod är att utföra en benchmarkstudie, där till exempel mjölk per ko jämförs. Olika finansiella nyckeltal kan analyseras och jämföras inom branschen. Två metoder för att estimera ett företags förmåga att omvandla input till output är produktivitet och effektivitet. Produktivitet är relativt enkelt att beräkna när en output är producerad med en input, ett enkelt ofullständigt produktionsmått är till exempel output per hektar. Teknisk effektvitet tar hänsyn till företagets alla input och output. Teknisk effektivitet kan anta ett värde mellan noll och ett, där de fullt tekniskt effektiva företagen antar värdet ett.
I Sverige är studier på teknisk effektivitet få till antal. Den senaste studien på teknisk effektivitet i svenska mjölkföretag utfördes av Hansson et al (2010), data till studien är från jordbruksekonomiska undersökningen och är mellan åren 1998 – 2002. Det verkar således inte finnas några studier på teknisk effektivitet som är utförd med data från jordbruksekonomiska undersökningen efter 2002. Den föreliggande studien utförs med data från jordbruksekonomiska undersökningen mellan åren 2009 – 2011. I jordbruksekonomiska undersökningen från 2013 är det senast representerade året 2011.
Studier som undersöker vilka ekonomiska faktorer som påverkar teknisk effektivitet verkar vara få till antalet. Ekonomiska faktorer som påverkar teknisk effektivitet har tidigare varit en del av en större studie. Det innebär att det kan vara intressant att undersöka hur teknisk effektivitet påverkar räntabilitet på eget kapital i svenska mjölkföretag mellan åren 2009 – 2011.
För att beräkna teknisk effektivitet och undersöka om det påverkar räntabilitet på eget kapital används en tvåstegsmetod. För att beräkna teknisk effektivitet används metoden Data Envelopment Analysis (DEA), som är steg ett. Steg två är att utföra en regressionsanalys mellan teknisk effektivitet och räntabilitet på eget kapital. Resultaten tyder på att det finns ett svagt samband mellan teknisk effektivitet och räntabilitet på eget kapital i studien mellan åren 2009 – 2011.The aim of this study is to investigate how technical efficiency influence return on equity in Swedish dairy farms. Swedish dairy farm have faced volatile milk and feed prices since 2007. During the last two decades Swedish dairy farms have decreased with 81 percent. During the same period the quantity of dairy cattle in dairy farms have increased from 22 cows to 70. Between 2009 and 2011 Swedish farmers increased their debt with 34 millions Swedish kronor. There are several ways to investigate dairy farms and how successful they are. It can be done in a benchmark study, with financial key ratios, productivity or technical efficiency. Some of these methods don’t account for the whole dairy farm; they only explain a part of the success.
Studies on technical efficiency in Swedish dairy farms with data from the Farm Economic Survey, conducted by Statistics Sweden are few. The latest study on technical efficiency in Swedish dairy farms is from 2010, with data collected between the years 1998 – 2002. Recent studies have investigated various management, farm and economic determinants to technical efficiency. Studies on economic determinants are few, they are usually a part of one bigger study.
The results of this study imply that technical efficiency in Swedish dairy farms between 2009 – 2011 is 0,784. Which means that Swedish dairy farms in average can lower their cost with 21,6 percent. The result of regression between technical efficiency and return on equity, indicate a weak relationship between them
High levels of tissue plasminogen activator (tPA) antigen precede the development of type 2 diabetes in a longitudinal population study. The Northern Sweden MONICA Study
BACKGROUND: Impaired fibrinolysis is found in impaired glucose tolerance and type 2 diabetes, associated with components of the metabolic syndrome. There are no data concerning fibrinolysis in subjects with normal glucose tolerance that convert to diabetes. METHODS: We studied the activities of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) and the levels of tPA antigen (a marker of endothelial dysfunction) in 551 subjects with normal glucose tolerance in 1990 in relation to incident diabetes during nine years of follow-up. RESULTS: Subjects with diabetes at follow-up (n = 15) had significantly lower baseline tPA activity and higher PAI-1 activity and tPA antigen than non-converters. The risk of diabetes increased linearly across quartiles of PAI-activity (p = 0.007) and tPA antigen (p < 0.001) and decreased across quartiles of tPA activity (p = 0.026). The risk of diabetes with low tPA activity or high PAI-1 activity persisted after adjustment for age and sex but diminished to a non-significant level after further adjustments. The odds ratio of diabetes for high tPA antigen was 10.4 (95% confidence interval 2.7–40) adjusted for age and sex. After further adjustment for diastolic blood pressure, waist circumference, insulin, triglycerides, fasting and post load glucose the odds ratio was 6.5 (1.3–33, p = 0.024). CONCLUSIONS: Impaired fibrinolysis and endothelial dysfunction are evident in subjects with normal glucose tolerance who later develop diabetes. High tPA antigen is predictive of future diabetes independent from the metabolic syndrome
Parameter interactions and sensitivity analysis for modelling carbon heat and water fluxes in a natural peatland, using CoupModel v5
In contrast to previous peatland carbon dioxide (CO2) model sensitivity analyses, which usually focussed on only one or a few processes, this study investigates interactions between various biotic and abiotic processes and their parameters by comparing CoupModel v5 results with multiple observation variables.
Many interactions were found not only within but also between various process categories simulating plant growth, decomposition, radiation interception, soil temperature, aerodynamic resistance, transpiration, soil hydrology and snow. Each measurement variable was sensitive to up to 10 (out of 54) parameters, from up to 7 different process categories. The constrained parameter ranges varied, depending on the variable and performance index chosen as criteria, and on other calibrated parameters (equifinalities).
Therefore, transferring parameter ranges between models needs to be done with caution, especially if such ranges were achieved by only considering a few processes. The identified interactions and constrained parameters will be of great interest to use for comparisons with model results and data from similar ecosystems. All of the available measurement variables (net ecosystem exchange, leaf area index, sensible and latent heat fluxes, net radiation, soil temperatures, water table depth and snow depth) improved the model constraint. If hydraulic properties or water content were measured, further parameters could be constrained, resolving several equifinalities and reducing model uncertainty. The presented results highlight the importance of considering biotic and abiotic processes together and can help modellers and experimentalists to design and calibrate models as well as to direct experimental set-ups in peatland ecosystems towards modelling needs
Gender differences in trends of acute myocardial infarction events: The Northern Sweden MONICA study 1985 – 2004
<p>Abstract</p> <p>Background</p> <p>The registration of non-fatal and fatal MI events initiated 1985 in the WHO MONICA project has been ongoing in northern Sweden since the end of the WHO project in 1995. The purpose of the present study was to analyze gender differences in first and recurrent events, case fatality and mortality in myocardial infarction (MI) in Northern Sweden during the 20-year period 1985 – 2004.</p> <p>Methods</p> <p>Diagnosed MI events in subjects aged 25–64 years in the Counties of Norrbotten and Västerbotten were validated according to the MONICA protocol. The total number of events registered up to January 1, 2005 was 11,763: 9,387 in men and 2,376 in women.</p> <p>Results</p> <p>The proportion of male/female events has decreased from 5.5:1 to 3:1. For males the reductions were 30% and 70% for first and recurrent MI, respectively, and for women 0% and 40% in the 55–64 year group. For both sexes a 50% reduction in 28-day case fatality was seen in the 25–64 year-group. Mortality was reduced by 69% and 45% in men and women, respectively.</p> <p>Conclusion</p> <p>First and recurrent events of myocardial infarction was markedly reduced in men over the 20-year observation period, but for women the reduction was seen only for recurrent infarctions. Case fatality, on the other hand, was markedly reduced for both sexes. As a result of the positive effects on incidence and case fatality a substantial reduction was seen in total mortality, most pronounced for men.</p
Benthic organic carbon release stimulates bacterioplankton production in a clear-water subarctic lake
We carried out a set of experiments in a small clear-water lake in northern Sweden during summer 2010 to assess the effect of organic C (OC) released from epipelic algae on pelagic bacterial production (BP). The release rate of OC (dissolved and particulate) from epipelic algae was ,45.4 ng C m22 h21 . Bacterioplankton uptake of dissolved OC was P-limited, and pelagic primary production (PP) was colimited by N and P. Pelagic BP (3.2 6 6 mgCL21 h21 ) exceeded pelagic PP (0.012 6 0.008 mg C L21 h21 ). Pelagic BP was higher in lake water in contact with sediments and the epipelic algae growing on their surface than in water separated from the sediments. Epipelic algae release OC to lake water and potentially stimulate pelagic BP. However, exploitation of benthic OC probably is suboptimal because of nutrient limitation (primarily by inorganic P) of BP.Fil: Rodriguez, Patricia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina; Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina;Fil: Ask, Jenny. Umea University. Department of Ecology and Environmental Science; Suecia;Fil: Hein, Catherine L.. Umea University. Department of Ecology and Environmental Science. Climate Impacts Research Center; Suecia;Fil: Jansson, Mats. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina;Fil: Karlsson, Jan. Umea University. Department of Ecology and Environmental Science. Climate Impacts Research Center; Suecia
Landscape regulation of bacterial growth efficiency in boreal freshwaters
[1] Allochthonous organic carbon in aquatic systems is metabolized by heterotrophic bacteria, with significant consequences for the biostructure and energy pathways of freshwater ecosystems. The degree to which allochthonous substrates support growth of bacteria is largely dependent on bacterial growth efficiency (BGE), i.e., bacterial production (BP) per unit of assimilated carbon. Here we show how the spatial variability of BGE in the boreal region can be mediated by the distribution of the two dominating landscape elements forest and mires. Using an 11 days bioassay approach, the production and respiration of bacteria were measured in water samples from nine small Swedish streams (64°N 19°E), representing a gradient ranging from organic carbon supplied mainly from peat mires to carbon supplied mainly from coniferous forests. BP was positively correlated to forest coverage (%) of the catchment, while bacterial respiration was similar in all streams. Consequently, BGE showed a strong positive correlation with forest coverage. Partial least square regression showed that BGE was chiefly regulated by qualitative properties of the organic material, indicated by the absorbance ratio a254/a365 plus C/N and C/P ratios. The data suggest that a share of the organic carbon pool, drained mainly from forest soils, had a potential of being incorporated into bacterial biomass with great efficiency. Its potential for supporting growth was probably nutrient regulated as indicated by inorganic nutrient enrichment experiments
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