Sök:

Sökresultat:

745 Uppsatser om Threatened species - Sida 49 av 50

Om att skapa en databas över Enaforsholms fjällträdgårds 60-åriga växtförsök

Enaforsholms mountain garden is situated in the western parts of the Swedish province Jämtland. This means a maritime climate. After a donation made by wholesaler A. W. Bergsten the country estate became KSLA property in 1937.

Vattendragsrestaurering i teorin och fiskinventering i praktiken : en litteratur respektive metodstudie

Running water-pathways have played an important roll in Sweden and frequently been manipulated. One profound change was made during the period of logging when streams were cleared from obstacles as big boulders, sharp bends and side-streams. Dams and different constructions gave control of the stream water and the streams became channel-like with a homogen structure. This interference gave problems for many fish populations and resulted in a shortage of feeding habitat, over-wintering habitat, spawning habitat, unnatural flow regimes, sedimentation, unnatural temperature fluctuations. Many of these historical changes of the watersheds are now subjects for restoration, ie., bring back the streams to what we believed it was before the change. However, what once existed in terms of complexity is now gone and difficult toreplace.

Metoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket, efter den senaste skogsvårdslagenMetoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket, efter den senaste skogsvårdslagen.

In 1994 a new Forestry Act was accepted in Sweden. One of the aims of the law is to raise consideration forpreservation of biodiversity. Since the new law got accepted and some time has passed, there now lie someinterest in examining whether the law has been effective towards its purpose. Methods suitable for analysishave been examined during this study. The content of this pilot study is based around five parameters whichcan be used to validate the effects of the new law.

Utvärdering av skördetidsprognoser i vall :

Sammanfattning Ensilerat vallfoder är ett av de absolut viktigaste fodermedlen för att förmå korna att producera en stor mängd högkvalitativ mjölk. En hake är dock att ensilaget ska vara av god kvalitet och med bästa möjliga näringsvärde, samtidigt som man även vill ha volymmängder. För att få detta gäller det att skörda vid rätt tidpunkt, vilket kan vara svårt att veta när det infaller. Till detta finns ett hjälpmedel som kallas skördetidsprognos. Detta går ut på att man klipper prover i vallen upp till tre gånger innan första skörden för att analysera gräset och därigenom kunna avgöra när bästa tiden är för att skörda för att få den mest optimala kombinationen av mängd och näringsvärde. Syftet med detta arbete är att undersöka hur bra hjälpmedel jordbrukare i norra Sverige tycker att skördetidsprognosen är för att få en ökad kvalitet på ensilaget, samt att jämföra variationen i näringsvärde och mängd biomassa inom och mellan olika fält.

Naturligt föryngrade huvudstammar i röjda bestånd etablerade efter plantering på SCAs mark

Dagens dominerande föryngringsmetod i Sverige är plantering som utgör 75 procent, därefter kommer naturlig föryngring som utgör 18 procent. Anledningen till att plantering är den dominerande föryngringsmetoden är att ofta används förädlat material vid tillverkning av plantor vilket ökar tillväxten och överlevnaden samt minskar omloppstiden. Föryngringsperioden är kortare hos plantering jämfört med naturlig föryngring. Röjning är en beståndsvårdande utglesning som ska gynna stammar med bra egenskaper. Faktorer som kan påverkas med röjning är trädslagsblandning, tillväxt och kvalitet.

Alternativa skogsbruksmetoder i Norden : ett välbehövligt komplement?

Clearcutting systems have been the dominating silvicultural approach during the last decades in the Nordic countries. While economically rational, it is also leading to a trivialisation of the flora and fauna, and may result in negative reactions of people in urban settings. As a consequence of this, and a more diversified view on which goods and services forests should deliver, there is an increasing interest in broadening the range of silvicultural methods that are used. The term continuous cover forestry (CCF) represents a suite of methods that have gained increasing interest in the Nordic countries. In CCF a considerable amount of the trees are left after harvest to favour values that require a continuity of tree-covered areas. There are thus hopes that this method will meet the needs for maintaining biodiversity and satisfy social and cultural values.

Utveckling av en diameterklassmodell för grandominerade bestånd i Sverige :

Growth models are very useful tools for forestry to predict growth and yield. With growth models and optimising tools you can manage forest stands in a way that maximize benefit and income. There are three major types of growth models. Stand models; stage structured models and single-tree models. The most advanced models give the most accurate forecasts.

Vattendraget på Kåbo golfbana : en kartläggning som ett steg i golfklubbens miljöarbete

This degree project studied surface waters on Kåbo Golf Course in Uppsala, Sweden, with the aim of determining the status of the water and how it is affected by the activities of the golf club, and to obtain suggestions of measures to create better conditions for the water environment on and around the golf course. The project forms part of the environmental protection work of Kåbo Golf Club, which is working towards achieving environmental certification from the Swedish Golf Association (SGF). The study is based on literature studies and quantitative and qualitative field studies of water on the golf course, with the focus on environmental factors identified as being important for the golf industry and on strategic environmental goals developed by SGF. The number of open water bodies in the Swedish landscape has substantially declined during the past 200 years, so it is important to save those that remain. This study showed that the surface water at Kåbo Golf Course is an important element in the surroundings since the area contains few wetlands, which can be a habitat for large numbers of species. The stream and ponds on Kåbo Golf Course also have the important function of serving as water hazards in the game and adding difficulty and variety to the course. Since Kåbo Golf Club wants its surface waters to look aesthetically appealing, extensive algal growth and drying up of ponds during parts of the year are regarded as problems.

Anlockning och gnag av snytbaggar (Hylobius sp.) : effekt av plantstorlek och behandling med metyljasmonat

Two field experiments were conducted in central Sweden in order to: 1) Determine a relationship between the number of approaching pine weevils (Hylobius sp.) and the number of attacks by pine weevils, in relation to the size of seedlings of Scots pine (Pinus sylvestris). 2) Determine if application of methyljasmonate (MJ) on seedlings of Scots pine will result in higher resistance towards attacks by pine weevils and/or have any effect on the number of approaching pine weevils. The field experiments were designed with two separate parts in close vicinity on the same clear cuttings: a) pitfall traps placed in patches of scarified soil that caught approaching pine weevils at 2.5 cm from the bait, which consisted of different sized seedlings of Scots pine some of which were subjected to application of MJ and b) the same type of seedlings planted out in patches of scarified soil. The first field experiment was conducted on a 1-year old clear cutting outside Uppsala in east central Sweden and the trapping part of the experiment consisted of 8 blocks with 6 treatments: 1) control, 2) small over-wintered seedling, 3) medium sized seedling, 4) medium sized seedling treated with 0.5 ml 100 mmol MJ 4 days prior to start of experiment, 5) large seedling, 6) vial with 9.5 ml of ?-pinene. The trapping experiment lasted for 6 weeks in the early summer.

Utvärdering av DGT-tekniken (Diffusive Gradients in Thin film) samt jämförelse mellan DGT-tekniken och ultrafiltrering

Rapporten baseras på genomförd litteraturstudie samt provtagningar som genomfördes i Kamlungeforsen, nära utloppet på Kalixälven i norra Sverige under första halvåret 2002. Proven togs dels med hjälp av DGT-tekniken och dels med ultrafiltrering för att bestämma koncentrationen av lösta element. Metallspeciering innebär att man tar reda på i vilken fas spårmetallerna befinner sig i ? lösta joner och komplex, kolloider eller partiklar. Många spårmetaller är viktiga för liv, men kan också fungera som gifter beroende på koncentrationen.

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.

Dagvatten i Märsta : förslag till anläggning för ekologisk hantering samt metodöversikt

Stormwater in urban areas has been treated as a problem for a long time. The large proportion of impermeable surfaces inhibits the water from infiltrating in the ground to the same extent that it does in nature. This causes intensive surface flow during rain, which in turn causes inconveniences such as decreased accessability, floods and increased risk of desease spreading. Drainage through pipes is the traditional and usually functional metod for storm water disposal. That is as long as water flows are moderate. But precipitation varies naturally in amount and intensity and additional impermeable surfaces make some pipes insufficient for heavy or lasting precipitation.

Rekreation och utomhuspedagogik i tätortsnära skog : planering av skolskog och rekreationsanalys för Sätra, en stadsdel i Gävle

This Masters Thesis includes a survey of recreational habits and the attitudes towards forests of the people of Sätra, a suburb of the city of Gävle. The study also includes the planning and design of a forest suited for education in the same part of the city. The thesis is a part of a project called Tätortsnära skog, commissioned by the Swedish forest agency. The project aims to survey the recreational habits of the general public in the regions of Dalarna and Gävleborg. Tätortsnära skog is focused on cities with a population of more than 20 000 inhabitants, of which Gävle, Sandviken, Falun and Borlänge all fall within the category.

Till synes orörd skog : naturvärden och kulturhistoria i Rekdalen under 400 år

Nature conservation has for a long time been founded on the assumption that high ecological values depend on low human impact. In Sweden this has led to forests with these characteristics being strictly protected from human influences. However, it is also known that historical land-use can enhance ecological values in forests. Mountainous forests in Sweden, which have not been affected by modern forestry, have for a long time been considered as untouched by people. However, forest history research has in recent years shown that even these areas have been used by people for a long period of time.

Ligghall för utegångsdjur ? en sammanställning och analys av domar i djurskyddsärenden som handlar om ligghall till utegångsdjur åren 2007-2013

There is currently an ongoing discussion in Sweden about the need for weather shelter for farm animals being kept outdoors during the winter season. Currently, the national animal welfare legislation requires weather shelter providing the animals? with access to a dry and clean place to rest, but under certain conditions exemptions can be granted. The Swedish Board of Agriculture has put forward a hypothesis that there is a difference between judicial decisions in animal welfare cases dealing with weather shelters, as to whether the animal has shown to be suffering or not. The aim of the study was to highlight any weaknesses or difficulties when assessing animal welfare issues associated to the absence of or design of weather shelters.

<- Föregående sida 49 Nästa sida ->