Sök:

Sökresultat:

912 Uppsatser om Tree species - Sida 7 av 61

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.

V?n eller Fiende? En Studie om Kommunalt Milj?ansvarigas Perspektiv kring Invasiva Fr?mmande V?xtarter

Invasive alien plant species have historically caused major damage to ecosystems and are considered to be amongst the greatest threats to biodiversity globally. The lurking threat of harm to well functioning ecosystems has led to the development of global and regional goals and regulations which seek to stop the spread of invasive species. The Swedish Environmental Protection Agency has proposed a list of species that are specifically harmful to the Swedish flora and fauna, which includes (amongst others) garden lupin. The management of invasive species is however largely dependent on local actions, making municipal public servants key players. This qualitative study uses interviews to investigate how municipal public servants who are responsible for managing invasive alien species view this work.

Julgransodlingar i Sverige : utbud, efterfrågan och lönsamhet

This thesis is about Christmas tree plantations in Sweden, and if its profitable to produce Christmas trees in Sweden. Sweden has 4,3 million households, 3 million of these households buys Christmas trees. 80 % of these Christmas trees are Norway Spruce (Picea abies), which is the most common Spruce in Sweden. Every year over 170 000 Christmas trees are imported to Sweden. The main import comes from Denmark.

Spatt relaterad till tarsalledens vinkel

The effectiveness of Phlebiopsis gigantea to prevent spore infections from Heterobasidionannosum and Heterobasidion parviporum on hybrid larch stumps were investigated in fivestands in southern Sweden. All sites are former forest land and the age of the trees wasbetween 9 and 13 years.The study was implemented in August 2010, a month where spore dispersal should be great.The five sites were located in previously un?thinned monocultures of hybrid larch. The sporeload in the air was studied with the help of spore traps from three different Tree species;Norway spruce, Scots pine and hybrid larch. A total of 146 spore traps, evenly distributed inall five sites were analyzed.

Tetratermmodellering och regressionsanalyser mellan topografi, tetraterm och tillväxt hos sitkagran och lärk : en studie i norra Island

This study was made in an attempt to give the forest research centre Mógilsá a producedtetratherm map and a better understanding of how topography and temperature influencethe growth of two Tree species. The digital tetratherm map model, covering the northernpart of Iceland, was developed to investigate the correlation between tetratherm and thegrowth of Picea sitchensis and Larix (sukaczewii + sibirica). The study confirms theusefulness of digital terrain models in providing data for a lot of different factors and forthe tetratherm model. Hopefully will this tetratherm map be used in future studies.Secondly, investigations were made correlating the growth of the two species againsttopographic factors representing height above sea level, distance to the sea, slope andtopex. Thirdly, investigations were made comparing the aspect and the ground shape tothe growth.The growth rate of Larix had strong significant correlations to the tetratherm and thedistance to the sea- factors.

Metoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket efter den nya skogsvårdslagen

In 1994 a new Forestry Act was accepted in Sweden. One of its aims was to raise the consideration for preservation of biodiversity. Since this happened over 15 years ago there is now an interest in analyzing if the law has been effective in its purpose. In this study methods suitable for analysis are being investigated. The study contents a pilot study of methods for five parameters that can validate if the law has been followed.

Does tree removal along railroads in Sweden influence the risk of train accidents with moose and roe deer?

After the storm Gudrun in 2005, the Swedish Transport Administration started clear-cutting of railroad corridors to reduce the risk of trees falling down on the tracks. Simultaneously, train accidents with moose and roe deer have become more frequent and the costs for consequent delays and repairs of engines are of growing concern. There is reason to assume that tree-clearance of railroad corridors may have contributed to an increase in number of accidents with moose and roe deer because the cleared areas provide attractive forage and thus may attract wildlife. The objective of my study was to investigate how clearing of trees affected the number of accidents with moose and roe deer. I compared deer-train collision frequencies before and after clearance of the selected railroads and compared these with uncleared control railroads in a BACI (before-after control-impact) approach.

Habitat preference and dispersal of a sandassociated beetle, Apalus bimaculatus

Species that have a high degree of specialization and poor dispersal ability can be more prone to extinction than more generalist species and good dispersers. How these species traits affect the viability of populations is dependent on landscape factors,such as isolation and connectivity. Additionally, interactions between species (e.g. symbiosis), and how these interactions vary spatially and temporally can have a large impact on populations. When the range and habitat areas of a species continuously decrease, management strategies are often needed if the species shall be able to survive.

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.

Efficacy of Phlebiopsis gigantea treatment on spore infections of Heterobasidion spp. on Larix X eurolepis

The effectiveness of Phlebiopsis gigantea to prevent spore infections from Heterobasidionannosum and Heterobasidion parviporum on hybrid larch stumps were investigated in fivestands in southern Sweden. All sites are former forest land and the age of the trees wasbetween 9 and 13 years.The study was implemented in August 2010, a month where spore dispersal should be great.The five sites were located in previously un?thinned monocultures of hybrid larch. The sporeload in the air was studied with the help of spore traps from three different Tree species;Norway spruce, Scots pine and hybrid larch. A total of 146 spore traps, evenly distributed inall five sites were analyzed.

Scilla-släktets användningsmöjligheter i Sverige : med utgångspunkt i ståndort, egenskaper och historia

This study investigates the main question ?How can the small, blue spring bulb genera Chionodoxa, Puschkinia and Scilla be used in Swedish outdoor settings, with main focus on the genus Scilla?? This is done by answering four sub-questions: Which of these Scilla-species are hardy in Sweden? Which are their characteristics and habitats? What does their history of application look like? What is commercially available today? The aim of the work has been to make a survey of hardy and available Scilla-species, their character-istics, field of application and history. The purpose is to create a tool in the work with geophytes in different outdoor settings in Sweden, and to contribute to the discussion of new fields of application for bulb plants, such as Chionodoxa, Puschkinia and Scilla. The questions are answered through literature studies and discus-sions with knowledgeable persons in the field. First, an investigation and a survey of Scilla-species hardy and commercially available in Sweden, will be presented, where information of appearance, charac-teristics, habitats, varieties and historical and present application of the species will be found. With this background, a discussion around all the questions, today?s use and also new fields of application, has been carried through. The conclusions made from this study, are that there are today 15 Scilla-species commercially available and hardy for the Swedish climate.

Osteometriska Mätningar : För artbedömning av får, get och svin utifrån mått av revben

Ribs from sheep, goat and pig are rarely assessed  to species due to the fact that they are very similar in their morphology and size. The ribs are instead considered unidentifiable although it is possible to see what kind of bone it is. If these ribs would be identified to species not only would species assessment degree of archaeological source material   increase, the relationship between meat-rich and meat poor regions would change.To find out whether there are morphologically measurable differences between sheep, goat and pig ribs, three measurement points on each rib has been defined and measured. At each measurement point two measurements were measured, one medial-lateral measurement and one cranial-caudal measurement. The ratio between the medial- lateral measurement and the cranial-caudal measurement was calculated for each point.

Sker rengöring av ögon, antenner och mun hos Odonata : Coenagrion larver med hjälp av borsten på framben och fötter?

Dragonflies are fascinating. The larvae stays larvae from a couple of weeks up to 5 years, it depends on the species (Hansen, 1981). The temperature, nourishment and time of the year also play a role for the growing factor for the larvae. Both Sahlén (1985) and Begon a.o (1990) say so. My report contains information about the branched setae on the front legs from the family damselflies (Zygoptera) and the species Coenagrion.

Goliatmusseron (Tricholoma matsutake) - kräver den en kontinuitet av träd? :

Modern forestry management may disadvantage some mykorrhiza forming fungi because; they are dependent on late successions and cannot survive the constantly recurring breaks in the continuity of their host tree. For this study the specie goliatmusseron (Tricholoma matsutake) was chosen to investigate this possibility. In Sweden T. matsutake is found in greatest amounts north of Örnsköldsvik on glacifluvial sandy soils in association with pine trees and reindeer lichens. Seventy two forest stands where the specie previously had been found were studied; 62 in the northern part of Sweden and ten in the southern. Several indicators were studied to find out if these stands have had a continuity of living trees.

Bevarande av naturvärdesträd i enlighet med FSC och Holmen Skogs naturvårdspolicy :

In the end of 1998 the company Holmen Skog AB was certified accordint to the FSC system with an area of 1 036 000 hectare. After that Holmen Skog AB has been working actively with the nature conservation in the forestry. In order to control the quality of the company?s nature conservation in final fellings they started a yearly inventory which is called BAKRUS (Judgement of ecological and culture care in relations to policies for a persevering silviculture). After 1999 the control was expended to include all actions in the forest.

<- Föregående sida 7 Nästa sida ->