Sök:

Sökresultat:

703 Uppsatser om Species richness - Sida 24 av 47

Gallringsprioritering av contortabestånd :

Extensive planting of the tree species lodgepole pine (Pinus contorta var. latifolia) during the 1970s and 80s has resulted in large areas now being available for commercial thinning. However, the varying quality of the stands creates a problem. The purpose of this study was to investigate, at the Torsby district of the Stora Enso forest company, how well the present computer records of the stands correspond to reality and determine which stands are, from a qualitative perspective, suited for timber production. Finding variables that indicate better stands would give Stora Enso the possibility of selecting qualitative stands which are more profitable to thin. The study included 32 stands containing at least 70 % Pinus contorta.

Utvärdering av flygbildstolkning för uppskattning av beståndsvariabler och åtgärdsförslag i ungskogar : en studie på Korsnäs Skog och Bergvik Skog AB i västra Dalarna

In Korsnäs district Dala Väst there were problems with information concerning their younger forests, mainly those in pre-thinning stage. They were divided into large, heterogeneous stands with often poor stand data quality. In 2006 an aerial photo interpretation of the young forests was conducted to fix these problems. Necessary information to get from the interpretation were silvicultural management suggestions, new stand delineation and new stand data. This thesis is supposed to evaluate the quality and usability of the interpreted data. To evaluate the interpretation an objective control inventory was conducted in 60 stands, either through callipering or counting stems.

?Tillvaron [...] vidgar sig? : Alberte ? en Ny kvinna i genusomskapandets tid

This essay examines the Alberte triology, by the Norwegian writer Cora Sandel, from a gender/feminist perspective. Taking Yvonne Hirdman's theory about the gender system as a starting point I will show how the living conditions and the different roles of men and women are represented in the novel and how they are changing during the centuries before and after the First World War.I am particularly interested in Alberte, the main character, what attitude she takes to her position in the gender system and in what way she differs from the traditional female model. Is she a New Woman, a different ?species?, who doesn't fit into the rigid gender system? Does the New Woman have a male counterpart, and is he to be found in the novel? Does the novel give a positive vision of a future where men and women can meet as equals?.

Föryngring i stormfälld rekreationsskog : en jämförelse mellan föryngring i produktions-, rekreation/produktion och rekreationsskog.

When the storm Gudrun hit Sweden on the 8th and 9th of January, many recreational forests in southern Sweden blew down. For this reason there is a demand for new regeneration methods as to how these storm-felled areas should be regenerated and with what species. In this study the forest is divided into three areas: production, recreation/production and recreation. The first area is a forest with production as main goal and these kinds of forests are located a bit from the city. The second type ? recreation/production forest ? has two equal goals: production and recreation, and is located close to the city.

Potentiella virala zoonoser hos apor på svenska djurparker år 2008

This paper is a compilation of some of the important viral zoonosis that can be passed from apes and simians (simian and prosimian) to man. Viral zoonoses are viral diseases that can be passed from animals to humans. The paper will also provide a better insight of the risks workers and visitors to the zoo can be exposed to. The viruses that this paper is focused on is herpes Bvirus, simian T-lymphotropic virus type 1 (STLV), simian immunodeficiency virus (SIV), Ebola virus, Marburg virus, yellowfever virus, monkeypoxvirus and hepatitis B virus. The choice of viruses is based on how infectious they are and how pathogenic they are.

Skötselmetoder för bestånd med produktions- och naturvårdsmål :

This study is made on assignment by the local board of forestry in Skåne, Blekinge and Halland. The change of the forest law 1994 brought a new type of management plan. A more active planning was introduced in order to equate the environment goal with the production goal. The purpose with this study is to give a better picture of how planning for nature conservation in production forest is made and to develop support for selection of silviculture methods for stands with combined goals. With combined goals means production forestry with a reinforced consideration to both nature and culture, called PF-classified stands. This was done by: ? Describing silviculture models from the literature that are possible to use for stands with combined goals. ? Describing silviculture models that is used in practice in stands with combined goals. ? Describing how the classification of stands with combined goals is used. Which means, were in the terrain, with which frequency and in which type of forest PF-classification is used. ? Comparing differences and similarities of theoretical and practical used models. The study was done partly as a literature study and partly as an interview study of forest planners.

Vanliga helminter hos hund, katt och häst i Sverige : artbeskrivning och laboratoriediagnostik

This report includes common helminths, symtoms, routes of infection, diagnostic laboratory techniques and prophylactic methods to prevent infection. We have pointed out where there is a risk of zoonotic transmission and how to avoid contamination and infection. We have restricted the number of species to the most common helminths. Some of these helminths do not naturally occur in Sweden (yet) but are nevertheless of current interest when we travel across borders with our horses, dogs and cats. The diagnostic part of our report tells about different techniques to find an occurance of helminths in samples of faeces, blood, urine or saliva from a horse, dog or cat. We also write about some recommendations on treating parasitic infections and the development of anthelmintic resistant helminths that originates from incorrect use of anthelmintic drugs .

Fredningseffekter och rekryteringsproblem hos abborre (Perca fluviatilis) i Stockholms skärgård

Effects of fishery closure on perch was detected as female perch was on average 5 cm longer in closed areas compared to non-closed areas. This could be a result of larger individuals surviving as an effect of reduced fishing. No effect was detected on the reproduction rate of YOY (young of the year) perch.A zooplankton survey revealed less amounts of the most important plankton groups for YOY perch in areas with failed reproduction, though the difference was statistically insignificant.The distribution of YOY perch and YOY/adult stickleback differed completely in this study with no area where the two species are both present. It is sketchy to draw any conclusions from this data but it remains a field for further investigation.The reproduction problem is concentrated to the outer parts of the archipelago which confirms previous studies of the geographic extension..

Bottensubstratets inverkan på föryngring av Flodpärlmussla

The freshwater pearl mussel (Margaritifera margaritifera) is threatened throughout its range. There has been a substantial decline of the species and one major reason is habitat degradation. We investigated how the substrate composition of the bottom floor affects the regeneration of the mussel by analyzing data from the Västerbotten County Board?s inventory of the freshwater pearl mussel. The results implied that fine material such as fine sediment and sand might be detrimental to regeneration whereas gravel and boulders and in particular stone seem to be beneficial.

Skånes gröna guld : anläggning, odling & mossarter i mossträdgården

This is a 15 hp (10 p) thesis in biology at the programme for Horticulture Management at the Swedish University of Agricultural Sciences, Alnarp. In this literature study we have processed, reviewed and arranged facts and research, to make it more available for those who want to know more about establishment or cultivation of mosses. Our client is Fredriksdal?s Museums and Gardens in Helsingborg who are planning to establish a moss garden. The information is meant to be used by Fredriksdal and other similar facilities.

Trädens betydelse för gatan :

?The trees importance to the street? discusses just that, the trees importance to the street. The purpose of this paper has been to examine what influence the trees have on streets. By writing about good examples of how trees can add good qualities to a street I wish to inspire to more use of trees in future city-planning. I have examined three streets in Malmö and three streets in Berlin and analyzed the trees influences there through the help of literature by three authors: Great Streets (1993) and The Boulevard Book (2002) by Allan B. Jacobs, Trees in Urban Design (1993) by Henry F.

Stadsodling : möjligheter och begränsningar

Urban farming can be viewed in several contexts. The first part of this work brings up the beneficial effects of farming on our physical and mental health, knowledge as well as on social life in cities. The introduction of gardening in schools can contribute to an increased awareness on both agricultural practices and importance as well as ecological processes. It can also be used in teaching of other subjects. Farming can also contribute to improving the household economy, and the economy on a municipal or national level.

Preparatanvändning och ogräsförekomst på gårdar med olika jordbearbetningsstrategier

Reduced tillage has increased in Sweden during several years, primarily to decrease costs andincrease efficiency in crop production. Despite this, mouldboard ploughing is still the mostcommon primary tillage method on most farms. The aim with this thesis was to compare theuse of pesticides and the occurrence of weeds on ten farms in Skåne and ten farms inMälardalen that use different soil tillage systems. The object of the study was also to clarifywhy the farms had chosen their specific soil tillage system and the consequences it has had onweed occurrence and use of pesticides. The result showed a slightly higher use of pesticideson the farms that use reduced tillage.

Dolls 4R: Ett mått på kunskapsutveckling? : En studie om bedömning av studentens kunskapsutveckling

Aim: The aim of this study was to examine a way to measure students? knowledge development by using a self-made measure instrument based on William Doll?s postmodern curriculum.Question: Is it suitable to use an self-made measure instrument based on William Doll?s post-modern curriculum theory to measure development of knowledge?Methods: The study was based on process-hermeneutics and was focused on analysingcollege students? written and oral reflective thoughts. The data was collected over three lessons, where six students? written reflective thoughts were handed in. An observation was carried out each lesson for an extra control of validity.

Apparently obscure

Through wing pattern, posture and movement, a harmless moth of the family Brenthia imitates an eight-eyed jumping spider. When an octopus of the species Thaumoctopus mimicus sense danger it can alter its appearance to that of a venomous sea snake. They are both drawing attention to themselves. Nevertheless, and because of this, they are protected. The mechanism is called mimicry.

<- Föregående sida 24 Nästa sida ->