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224 Uppsatser om Seed viability equation - Sida 15 av 15
Flygbildsanalys av trädskiktets status efter brand : en metodstudie
During the past years fire has been identified as an important factor for nature conservation in the forest landscape. To accurately quantify the size of a burnt area is obviously important, but also to quantify the degree of fire damage to the tree canopy. Such data are important for assessing the conservation value, and to support planning and management of the burned area in the future.
I have examined how to estimate the status of tree crowns after fire from interpretation of aerial photographs. This is possible because fire changes the structure of tree crowns and this influences the colours in aerial photographs by spectral reflection.
Included in the study are four areas, three of which burned in 2005 and one in 2006.
GIS och statistik vid dräneringsområdesvis kväveläckagebeskrivning i Halland
The last decades have shown increased nitrogen leeching from soil to water recipients. This is inSweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and thedeclining extent of wetlands. The accumulated amount of nitrogen in water doesn?t only make itunsuitable for use by humans and cattle, but also decreases the biological diversity as well as negativelyaffect tourism and fish industry. In the most severe cases shallow maritime grounds can be completelydepleted of oxygen due to decomposition of the increased amount algae and plankton growth.This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainagebasin, located in southern Halland, Sweden.
Den relativa viktens (kalv/ko) inflytande på kalvningsegenskaperna hos SRB och SLB :
Difficult calvings and stillbirths are problems in Swedish dairy production that result in large expenses for the farmers and welfare issues concerning the animals. A common opinion is that the live weight of SRB and SLB is increasing, and whether increased weights have caused the increase in calving problems has been discussed. The aim of this study was to investigate the relationship between the relative birth weight (calf/cow) and calving difficulty and stillbirth, respectively. The importance of breed and parity for the relative weight has been investigated, and comparisons with previous studies have been made to evaluate whether the relative weight has changed over the last decades or not.
The study was based on 807 calvings, registered during the period 1993-2003 in the experimental dairy herd of the Swedish University of Agricultural Sciences (Jälla).
Zonerat skogsbruk - en möjlighet för Sverige
Trakthyggesbruk är det skogsbruk som i över ett halvt sekel dominerat i Sverige. På senare år har dock detta skogsbruk ifrågasatts gällande främst den naturhänsyn som det lämnar samt att trakthyggesbruket bedrivs på i princip all skogsmark som brukas. Detta leder till liten variation bland de uppväxande skogarna, och flera myndighetsutredningar och rapporter hävdar att Sveriges nationella mål för bevarande av natur och miljö inte kommer att nås om inga omfattande förändringar görs i sättet att bruka skogarna på.
I denna rapport undersökte jag om zonerat skogsbruk, s.k. triadskogsbruk, är ett bra alternativ till dagens traditionella skogsbruk i Sverige i syfte att uppnå hög virkesproduktion och biologisk mångfald på landskapsnivå.
Svensk utsädeproduktion : en kvalitativ intervjustudie om beredning av vete och korn
I denna kvalitativa intervjustudie tittar jag närmare på hur anläggningarna fungerar och vilka olikheter som finns hos Sveriges utsädesproducenter. Efter att så många anläggningar som möjligt hittats och intervjuats, så jämfördes detta antal anläggningar med en lista hos
Jordbruksverket. Undersökningen visade sig vara gjord på 15 av 22 anläggningar som producerar certifierat utsäde i Sverige. Dessa 15 anläggningar var jämnt spridna över landet
och av varierande storlek. Resultatet av studien visar att min undersökning representerar stora delar av Sveriges utsädesproducenter.
Stress test methods : a potential approach to hurry up shelf-life tests on oat products
The aim of this Master?s thesis was to find out more about the delimiting quality- and shelf-life parameters over time for liquid oat-based products. According to that, to present applicable subjective and objective shelf-life test approaches at accelerated conditions. The study aimed to gain a deeper knowledge concerning the general and accepted way of performing accelerated storage tests. This study focused especially on products, which suffer from quality failure caused by oxidation, such as liquid oat-based products.
Willingness to pay for improved maize seeds among smallholder farmers : a study of the input factor market in Kenya
Kenya is considered to be a developing country. This means that basic needs such as nutrition are not met for an extended period of time (www, Sida 1, 2012). Approximately half of the population is living under the poverty line (www, CIA 1, 2012). Agriculture is the largest sector in the country, employing 75% of the population. These are thereby directly dependent on the sufficiency of outputs received.
Optimalt råvarulager för biobränsleföretaget :
This report was written as a final thesis within the Department of forest economics at the Swedish University of Agricultural Sciences as a completion of the M.SC Forestry programme. The aim of this study was to create a model that, with respect to given stock levels, temperature, fuel usage and fuel price, would identify the optimal levels for purchase of bio fuels, optimal levels of incineration of bio fuels and the sum of the present values of all costs. The model would be applicable for a larger district heating plant.
Data regarding temperature were received from SMHI. Information considering fuel prices was taken from the Swedish Forest Agency and the facts about fuel usage were collected from a large district heating plant, located in the southwest of Sweden. For the temperature, a sinus curve was adapted to describe the temperature over a year.
Nyckelbiotoper - urskogsrester eller kulturprodukter? : beståndshistorik i tolv nyckelbiotoper i Lycksele kommun
Since 1993 the Swedish Forestry Administration conducts a nation-wide inventory of wood-land key habitats covering all forest land in Sweden. The inventory aims at mapping and describing habitats where redlisted species occur or can be expected to occur. According to the inventory stand history is crucial to the presence of red-listed species. However, the current knowledge of stand history in woodland key habitats is very limited.
The purpose of this work is to describe stand history in woodland key habitats, i.e. fire history, human activities - mainly cuttings - and structural changes.
The effects of mother trees and site conditions on the distribution of natural regeneration establishment in a Bornean rainforest disturbed by logging and fire
In the tropics, logging and wild fire can result in degraded secondary forests with lower biodiversity than in the natural forest. One way to limit forest degradation is to rehabilitate the present large areas of secondary forests. However, there is a lack of knowledge concerning the ecology of tropical tree species and further studies would be advantageous for future rehabilitation efforts of degraded rainforest. The objective of this study was to investigate how mother trees in secondary forest and different site factors affect the abundance and spatial distribution of natural regeneration of non-pioneer tree species in a tropical rainforest in Sabah, Malaysia.
The study took place in the INIKEA Forest Rehabilitation Project area, which suffered from wild fire in 1983 and has been selectively logged over both before and after the fire. Natural regeneration and site variables were inventoried in plots, while mother trees were inventoried in the whole survey area.
Neonicotinoids and honeybee health : the effect of the neonicotinoid clothianidin, applied as a seed dressing in Brassica napus, on pathogen and parasite prevalence and quantities in free-foraging adult honeybees (Apis mellifera)
Sub-lethal doses of neonicotinoids have been shown to negatively impact the health of honeybees. However, most studies to date have exposed bees only artificially to these pesticides under laboratory conditions. There have been just a few well designed and replicated studies of the
impacts of realistic neonicotinoid exposure on honeybees foraging under field conditions. In order to close this knowledge gap, and to test the influence of the neonicotinoid clothianidin on honeybees, we used a study system of 16 paired, spatially separated (>4 km) spring oilseed rape fields in the south of Sweden. The fields were paired according to land use, the surrounding landscape and
geographical proximity, using GIS.
Renkavlens biologi - möjligheter till kontroll
Renkavle har under lång tid varit ett stort problem för lantbrukare i stora delar av norra Europa och har etablerat sig på större arealer även i Sverige. Genom sin bio-logi är renkavle mycket väl anpassad till odling av höstsådd spannmål, speciellt i kombination med reducerad jordbearbetning. Det finns en ökande trend av både höstsådd spannmål och reducerad jordbearbetning som talar för att problemen med renkavle kommer att öka framöver. Även den pågående klimatförändringen mot ett varmare klimat i Sverige förbättrar förutsättningarna för att renkavle ska etablera sig längre norrut. Renkavle är ett ogräs som kräver en mycket hög grad av kontroll för att inte öka kommande år eftersom fröproduktionen hos renkavle kan vara mycket stor.
Att identifiera lovande affärsidéer: en förbättring av
urvalsprocessen i ett entreprenörsdrivet Venture Capital-
bolag
I dagens snabba, globala och föränderliga omvärld anser allt fler att innovation är en viktig och nödvändig faktor för ekonomisk tillväxt. Entreprenörer har därför en betydande roll för samhället i jakten på nya innovationer och start av nya företag. På samma sätt har även riskkapitalister en lika betydande roll då staten, banker och andra institutioner sällan vågar satsa på nya riskfyllda affärsidéer. För affärsidéer i tidiga faser, som kanske ännu inte blivit företag med intäkter, är Venture Capital-bolag den vanligaste och största form av riskkapitalister som är villiga att ta en sådan investeringssrisk. Affärsidéer i tidiga faser är mycket riskfyllda då det kan vara svårt att förutse marknaden eftersom det ännu inte finns ett företag.
Undersökning av självspridning av contortatallen i norra Sverige
Over the past 40 years 600 000 ha of lodgepole pine (Pinus contorta ssp. latifolia (Engelm.) Critchf.) has been planted in Sweden (280 000 ha on SCA's forest land alone which represents about 15% of the company's total forest land area). In the early 70's SCA situated a number of experimental stands in order to investigate different aspects of the exotic tree, primarily growth rate. To be able to compare the two species plots with scots pine (Pinus sylvestris L.), this species was also planted at the same time and under the same conditions.
A number of questions should always be raised when exotic species are introduced in an ecosystem. Invasiveness, the pathogen situation and purely ethical issues should be discussed.