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745 Uppsatser om Threatened species - Sida 9 av 50
Planteringsförbandets inverkan på bestånd av contortatall (Pinus contorta var. latifolia) med avseende på volymtillväxt och virkesegenskaper
At the beginning of the 1970´s forestry feared an imbalance in the future wood supply. Because of this anticipated "timber slump" forest companies undertook a variety of measures to counter this. One of these measures was the introduction of exotic tree species. The choice finally ended up with lodgepole pines which were considered a fast growing tree species compared to our native tree species. Theambition for the new lodgepole pine stands were to run these with rotation periods of between 40-60 years, thus smoothing out the ?timber slump? that was anticipated.
Gäddan & fisket i Ringsjöholm : en osteologisk metodstudie i säsong & bevarande
This paper presents the results from an osteological method study of the Ringsjöholm fishbone material. Ringsjöholm is located in Scania, southern Sweden and is 14C dated to 5960-5200 B.P. The aim of this paper is to critically analyse methods used on fish bone material in estimations of season. Three different approaches were used to estimate the fishing season at the Ringsjöholm settlement; 1) identified species, 2) size estimations of the pike based on Enghoffs (1994-95) regression formulae of os dentale, and 3) growth rings of the pike vertebrae.The identified species and the size estimations of the pike points to the fishing being active both during spring and summer. Growth rings analysis of the pike vertebrae didn?t give any quantitative results because of fragmentation.
Hotbild för ädellav Megalaria grossa i Uppland och på Gotland :
Megalaria grossa is classified as Near treatened on the Swedish Red List. It is also a so called signals spieces, e. g. a spieces that function as an indicator, signalling a forest that is worthy of protection. The aim of this study was to clarify the status at selected localities in the province of Uppland and Gotland.
Vilken effekt har lärkrutor på ogräsfloran vid ekologisk höstveteodling? :
This study forms part of the R&D project "Improved survival of bird chicks in organic fields" managed by the Rural Economy & Agricultural society in Uppsala. The skylark (Alauda arvensis) is a species that has decreased drastically in Sweden as a consequence of more intensive cropping.
Studies in England have shown that skylark reproduction can be greatly improved within
conventional fields, at a low cost, by establishing patches of bare ground (skylark plots).
Within conventional farming, herbicides can be used in case a weed problem arises due to
implementation of these skylark plots, whereas this is not allowed in organic farming. This study examined the effects of skylark plots on the weed culture in organic autumn-sown (winter) cereals and whether weeds might cause long-term problems to farmers.
The study was conducted in two parts; a field study and a review of the literature regarding the weeds observed. The field study was carried out in 2007 during three weeks in June and three weeks in July, on eleven organic fields with winter cereal in the vicinity of Uppsala.
Klövviltets nyttjande av foderraps på viltåker och betespåverkan på angränsande skog
Today we have more game species than ever before in our landscape, both regarding number of species and number of individuals. The increasing number of wild species is an increase in game recourse for the countryside. The increase of game species, however, has negative effects on forests and agriculture land. The negative effects for forestry are damages on economic important trees, due to losses in production and quality. However there are ways to decrease the damage on valuable and important trees.
Effekter av upphörd hävd i Lurö skärgård : Har diversiteten av kärlväxtarter förändrats?
One of the main reasons for the massive loss in plant species diversity is the fragmentation of habitats. In Europe, open pastures and meadows are the habitats going through the most changes during the 20th century, according to the agricultural changes. In this study vascular plants were invented at five different islands in the Lurö archipelago, Vänern, Sweden. The aim of the study was to sort out whether the diversity of plants has gone through any changes in abandoned managed grasslands compared to continuous managed grasslands. The aim was also to study if a change in the landscape has made any differences for the species development or decline.
Leder ESBL-producerande bakterier till ökade samhällskostnader i Sverige?
Due to long time of overconsumption of antibiotic, the possibility of an effective infection treatment is now threatened. Bacteria have begun develop resistant against antibiotic, witch is most due to bacteria that do not normally develop resistant. These kinds of bacteria produce ESBL, and have made the healthcare costs increase around twice as much, as for bacteria that do not produce ESBL..
Threats and opportunities for the survival of the Yangtze finless porpoise
The Yangtze finless porpoise (Neophocaena phocaenoides asiaorientalis), is a small freshwater cetacean which has recently fallen dramatically in number. It is an endemic species for the Yangtze River and unless drastic action is taken, it risks the same fate as the now functionally extinct Yangtze river dolphin (Lipotes vexillifer). Threats to the porpoise are diverse but they have in common that they are caused by man. Development of the river has been made to supply a growing human population with food, hydropower, and to reduce the risk of flooding. These changes have resulted in a degraded habitat for the porpoise.
Vad styr sortimentet hos svenska perennaodlare? : en studie baserad på sju företag i Sydsverige
The purpose of this study is to clarify the most important factors that affect Swedish perennial growers when designing their assortment. The study describes how herbaceous perennials are produced in Sweden today and try to give an answer to the question how growing method and choice of assortment are affecting the possibilities of Swedish producers to compete on the market.
Seven perennial growers in the southern and western parts of Sweden have been interviewed about their production methods and on what basis they design the assortment of perennials. During the interviews five factors seem to be the most important when the growers choose which species to grow ? profitability, the characteristics of the species, the sales channel/customer, the growing environment/growing facility and the grower?s interest and knowledge. It is often a combination of these five factors deciding if a cultivar will be grown or not.
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Indirekta effekter på marklavars abundans och diversitet vid ökad kvävehalt i marken : en jämförelse mellan opåverkad och lågintensivt brukad mark
Lichens are adapted to bright and sparse forests on oligotrophic ground. Due to a slow growth rate and high light demand lichens will suffer from competition in eutrophic environments. Therefore, lichens have disappeared from managed forests where the forest industry has increased the productivity. A reduced abundance of lichens will affect both biodiversity of the forest and the reindeer winter graze lands. It is important to understand how and for how long fertilization affects the abundance and diversity of lichens in order to protect lichen rich ecosystems.
We have registered the biomass and number of lichen species in eight plots (four nitrogen rich and four nitrogen deficient) and compared fertilized Sami settlements with their oligotrophic surroundings in the nature reserves of Tjeggelvas.
Åre kommun och klimatförändringar : En studie kring hotet mot Åre kommuns vinterturism och dess anpassning till framtida klimatförändringar
Today?s climate research shows that the climate may increase its temperature. One sector that is being threatened by global warming is the winter tourism of the Swedish municipality A?re. Tourism is an important economical source of income in A?re and is now threatened by a shortened winter season.
Thuja plicata - etableringsförsök av jättetuja med fyra olika provenienser
Future climate changes may lead to an interest of alternative and foreign forest tree species in order to spread the risks in forestry. Douglas fir, Sitka spruce, Freemont cottonwood and hybrid aspen are examples of popular foreign tree species that along with western red cedar could have a future in the Swedish forests.Södra Skogsägarna and SLU have collaboration in establishment of foreign species in Swedish forests.The purpose of this study was to analyze and present the establishment of western red cedar, and to survey and illustrate injuries of freeze drying and other damages like deer browsing, vegetation and insect attacks. The study included four different provenances, and spruce as a reference, planted in two locations ? Asa and Släne.Western red cedar is despite its name a conifer of the cupressaceae family with defined secondary characteristic and gets along well with an overstory. Western red cedar grows often in mixed stands with similar conifers and its natural habitat is within and in the area near to British Columbia.The study included two series of field inventories, one made in the summer and one in the autumn 2013, three growing seasons after plantation.
Inokulering med två hjorttryfflar på arginingödslade täckrotsplantor i Gideå plantskola :
The effect of inoculation on containerized pine and spruce seedlings in a nursery with two
ectomycorrhizal fungi was investigated in regard to the development of mycorrhiza and plant growth. The fungi were Elaphomyces muricatus and Elaphomyces granulates and the inoculated seedlings were compared to an uninoculated control. These seedlings were all fertilized with arginine.
Five mycorrhiza species were found after DNA sequencing of the mycorrhizal root tips with different found morphotypes on seedlings from all treatments. Thelephora terrestris was the type which had the greatest distribution on pine seedlings and Tylospora asterophora was found at big extent on spruce seedlings. The inoculated species was not found, if it was due to the species hadn?t colonized the roots or if the DNA sequencing failed we can only speculate about.
Naturvärden i en värmländsk bruksskog : en skogshistorisk studie av Åbengtshöjden/Bogranghöjden
In this study I have analysed the history of a forest belonging to Saxåhyttan in Värmland. The study area is 448 hectares and has been used by iron industry since the 16th century. A forest that has been used by man during at least 400 years should have few ecological values. This inventory however shows the opposite.
The aim of the study is to interpret the history of the forest in the area, i. e.
Två år efter restaurering:Vad har förändrats i bottenfaunan?
The aim of the study was to examine if the benthos in a restored portion of a small lowland stream south of Linkoping differed from two non restored reference areas two years after restoration. The reference areas were one stretch downstream and one upstream stretches of the restored stream. The benthic invertebrates were collected using standardized kick sampling. In order to classify the communities and estimate any differences, three different indices were exercised. In addition rank-abundance curves and checklists were used to get a picture of species composition.