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957 Uppsatser om Tropical rain forest - Sida 33 av 64
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.
Bokhögstubbar i Klåveröds strövområde : utbredning, egenskaper och betydelse för rödlistade vedlevande skalbaggar
Lack of dead wood is the main cause of decaying or loss of populations for many
forest species. To increase the amount of dead wood is a prerequisite to maintain
biodiversity in forests of northern Europe. In summer 2006 the recreation area
Klåveröd, at Söderåsen in Skåne, Sweden, has been inventoried for high stumps
(snags) of beech, (Fagus sylvatica). The result of the inventory has been compared
with data of the real estate and forest management directories from the owner,
region Skåne. The results have also been matched with the results from an
inventory of saproxylic beetles in 2005, performed with windowtraps on selected
snags both in the area and the adjacent national park Söderåsen.
594 snags were found on 747 ha.
Sortimentsinriktad avverkning
Forest enterprises have always searched for ways to improve efficiency. For the past few
years there has been an emphasis on stock-keeping levels. Increased demand for fresh
round timber and the need to decrease the amount of tied-up capital has made the forest
industry reduce its inventory levels. This has brought on a higher demand on the timber
supply from the forest management districts concerning both delivery in time and
assortment output. As a result, the flow of timber has fluctuated a lot with serious
consequence for the timber supply during 1994.
Spatiella mönster och lager av organiskt klor och klorid i barrskogsjord i sydöstra Sverige
The concentration and storage of organic chlorine and chloride were determined in soil, to a depth of 40 cm, in a coniferous forest in the Stubbetorp catchment area in south-east Sweden. Also, the spatial distribution of the two forms of chlorine was determined. Soil samples were collected at 49 of the nodes in a grid with approximately 105 m between the nodes. The analysis of spatial variability suggested that no spatial autocorrelation was present either within the variable organic chlorine or chloride. This means that no sample was more influenced by another nearby sample, as compared to other samples further away.
Stormskador i stickvägsgallrade bestånd i sydvästra Sverige :
A storm in January 2005 felled 75 millions cubic metres of forest in South Sweden. Previous studies of wind damage in thinned stands indicated the importance of early thinnings. The risks of wind throw increased by increasing age and height of the stands. Previous studies also indicated increasing risk of wind throw along the strip roads. The aim of the present study was to investigate wind damage in Norway spruce stands in South Sweden in relation to time of the first thinning and different pattern of strip roads (width, length and direction).
Fuktvandring i putsade lättbetong- och tegelfasader : En undersökning om hur fukt vandrar och beter sig mot en putsfasad av två olika material med olika porositeter.
I dagsläget finns en stor mängd byggnader i Sverige där fasaden består av puts direkt anliggande mot antingen lättbetong eller tegel. Dessa fasader kan skapa problem för brukaren p.g.a. fukttransport via putsen direkt in i konstruktionen. Problemen som kan uppstå som följd av dessa konstruktioner är inte bara estetiska utan kan även påverka inomhusmiljön. Syftet med detta arbete var att undersöka om det gick att med ny teknik visa de resultat som framkommit från erfarenheter från praktiskt arbete samt undersöka hur en renovering påverkar de fasader som består av puts direkt mot lättbetong eller tegel.
Lyviken : -bedömning av dagvattenkvalitet
AbstractStormwater is defined as rain- and melted water. Ludvika kommun had little knowledgde about the stormwater that reaches a specific recipient Lyviken. Therefore they intended to do an research of the stormwater that leads down to Lyviken. The aim with this study was to assess the quality of the contents in the stormwater based on pH, conductivity, phosphorous, nitrogen, bacterias, oil and one sample that meassured the value of several methals. Since the population has increased for decades, the area of hard surfaces and asphalts areas also has increased. This can increase the pollutions that finally ends up in the recipient.
Vart är naturen i skärgården på väg? : skogshistoria på Ängsön-Marskär i Stockholms södra skärgård
The following thesis is a study of the forest history on the island of Ängsön-Marskär concentrating on the last three hundred years. The island is located in the administrative province of Stockholm, the local community of Haninge and it is situated approximately seven kilometres east of the island Ornö in the south of the Stockholm archipelago. The questions this thesis attempts to answer are: How where the natural resources on Ängsön-Marskär used through the centuries? How has the state of the forests developed since the 16th century? How will the nature develop onwards? The thesis is based on archival sources for Ängsön-Marskär and the surrounding areas. A field study was conducted where the entire island was investigated using an objective forest inventory method.
The first map material existing over Ängsön-Marskär is from the year 1711.
Kvalitetssäkring av markberednings- och planteringsuppföljning hos SCA Skog AB Jämtlands skogsförvaltning :
Quality assurance means to systematically work for better understanding of the customers needs, demands and expectations. The goal for this study was to investigate how quality can be assured in the job follow up that is made by forestry contractors after soil scarification and planting. The study consisted of a description over the current follow up process at SCA forest AB Jämtlands forest administration, analysis of current follow up situation and an investigation of follow up process made by contractors in other line of business.
The first step was a statistical comparison where the own follow up made by contractors were compared with follow up made by SCA them selves over 100 stands. Two soil scarification contractors and two planting contractors carried out the silvicultural measures. The results showed that significant differences between a number of quality factors measured, for example number of approved plants or approved scarification points, average score on stand and number of totally planted plants.
Överlevnad, tillväxt och skador i planteringar av sitkagran (Picea sitchensis) efter stormen Gudrun
Sitka spruce (Picea sitchensis (Bong.) Carr) is just like Norway spruce (Picea abies) a species in thegenus picea. The natural range of Sitka spruce is a narrow strip along the west coast of North America. Itis the most coastal of all picea species, and very dependent on the mild and humid climate along thepacific coast.Sitka spruce has been grown a long time in the countries around the North Sea, particularly in GreatBritain where it currently is the most important species in British forestry. Sitka spruce has not beenplanted in Swedish forests to any large extent before the storm Gudrun in 2005. Several studies indicatethat the production of wood biomass is higher for Sitka spruce compared to Norway spruce.
Utvärdering av datorprogram för användning vid dagvattenutredningar
The main object of this diploma work thesis is about how computer programs can bea tool to use for work on stormwater investigations. The advantage of using acomputer program compared with calculations made by hand is evaluated anddiscussed. The computer programs that have been used for studies and a sequence oftesting of the possibilities are Autodesks Storm and Sanitary Analysis and DHIs MikeUrban.Focus on sustainable development now permeates the building industry. As a resultstormwater investigations have been conducted in an increasing extent the recentyears. Stormwater is water produced due to precipitation, such as rain and snowmelt.Stormwater investigations normally contain descriptions of existing land use, plannedland use and suggestions of measures and technical solutions for the future disposal ofstormwater.The initial part of the thesis consisted of literature studies on stormwater andstormwater investigations to understand the science.
Behandling av konfliktbestånd - problem och möjligheter :
Overdue cleanings have for a long time been an important topic of discussion within the forestry sector. When stands that have not been pre-commercially thinned are reaching the level of commercial thinning, many problems occur in terms of decision-making and economical outcomes. These types of stands are commonly known as conflict-stands.
The work was carried out partly as an interview survey towards representatives from the forest sector and the energy sector, partly as a case study of conflict-stands situated in Böksholm, north of Växjö and in Tönnersjö east of Halmstad. The criteria for the studied stands were that they had to be dominated by Norway spruce and be in a severe status of ?conflict?.
The aim of the interview was to get an overview of the situation today, and also analyse trends in terms of conflict stands.
Fjällfåglar : En jämförande studie från dal till topp i ett nordligt och sydligt svenskt fjäll
Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.
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.
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.