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408 Uppsatser om Hardwood tree - Sida 6 av 28

Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden

Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.

Artificiella EkosystemSom Artificiell Intelligens I Actionrollspel : En jämförelse av algoritmer och deras anpassning till realtids-spel

Artificiella ekosystem är en tillämpning av artificiell intelligens som har funnits länge. Användningsområden för artificiella ekosystem innefattar främst biologiska simulationer men även andra typer av simulationer förekommer. Genom att simulera individuella djur blir den artificiella intelligensens uppgift att styra djurens beslut utifrån dess individuella förutsättningar och kamp för överlevnad. Detta arbete behandlar frågeställningen vilken beslutsalgoritm som är bäst lämpad att för att använda till ett artificiellt ekosystem i ett spel. Två beslutsalgoritmer jämförs, en dynamisk som bygger på maskin inlärning och en statisk som inte är kapabel att lära eller minnas.

Identifiering av gallringsbehov med hjälp av flygburen laserskanning :

Thinning is one of the most important silvicultural activities in middle aged forests, partly to minimize damages and partly because it leads to earlier harvesting revenues and increases the value of the remaining trees. There are many different indices used to describe stand density and thereby the need of thinning in forests today. Studies have shown that forest variables can be estimated with high accuracy using airborne laser scanning and it is likely that the method could also be used to estimate forest density indices. In this study, the possibility of using the forest density index ?H² to determine and map priorities for thinning operations for a forest area was examined.

Trädföryngring i låga gropar uppkomna vid brand i boreal naturskog :

This study was conducted in the "Kåtaberget" forest reserve in Västerbotten in the summer of 1999. In the summer of 1995, a prescribed burning was performed in the reserve. In some places where coarse dry woody debris (logs and stumps) was present, the fire consumed the wood, as well as parts of the humus layer, creating deep-burned patches. The low intensity ground fire also created dead woody debris by burning off living trees with open fire scars, as well as standing dead trees. In this study, the post-fire tree seedling establishment was examined, with special attention given to the former presence of woody debris. The study also includes a survey of the areal extent of deep-burned patches, as well as an examination of tree seedling establishment in these patches, compared to other burnt ground.

Vetlandas gatuträd : analys av trädens upplevelsekvalitéer

Street trees have had a prominent role in Vetlandas history from the turn of the century up to present day. Many trees have unfortunately been taken away through the ages, but most of them luckily remains and most of the streets in central Vetlanda are still tree lined. The comprehensive inventory that has been made shows that lime is the dominant species in Vetlanda with no less than 62 %. The age division is quite even with one peak at the turn of the century, one during the ?60s and another during the ?90s.

Influence of prescribed burning and/or mechanical site preparation on stand stem density and growth of Scots pine stands above the Arctic Circle : results 9-19 years after stand establishment

Prescribed burning was commonly used for site preparation in Sweden to establish new forests until the 1960?s, when mechanical scarification was introduced. During recent decades the interest in prescribed burnings has increased again, mainly due to certifications of forestry stating that 5% of the regeneration areas should be burned on dry and mesic soils. The objective of the study was to evaluate actual influence of prescribed burning compared to other site preparation on stand stem density, growth parameters and tree damages for Scots pine (Pinus sylvestris L.) after direct seeding and planting. The study also attempts to simulate growth until first thinning.

Spaljerad frukt på Trädgårdens skola. Rapport från ett praktiskt trädgårdsmästararbete

Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Trädgårdens hantverk och design, 21 hp, 2010.

Torrefaction of biomass : a comparative and kinetic study of thermal decomposition for Norway spruce stump, poplar and fuel tree chips

Stump biomass is energy rich and stump harvesting for use as fuel become more and more interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump harvesting in Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of stump are probably of great importance to make it accepted as fuel. It is therefore rewarding to carry out an investigation in this area for stump. This report represents results from a diploma project, which was aimed to develop a fixed bed reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic modelling employing Ozawa method and different kinetic models including one-step and three-pseudo-component models.

The major food trees of the Angola black-andwhitecolobus (Colobus angolensis palliatus)in Diani Forest, Kenya

The Angola black-and-white colobus (Colobus angolensis palliatus) is a subspecies of Colobus angolensis inhabiting fragmented forests in coastal Kenya and Tanzania. C. angolensis is regarded as Least Concern in the red list of IUCN because its populations are abundant. However, the populations of C. a.

Höjdtillväxt, överlevnad och skador i praktiska etableringar av hybridaspbestånd i södra Norrland, anlagda 2004-2011

Hybrid aspen is a crossbreed between European and North American aspen. It is a fast growing tree species that has shown strong growth in the South of Sweden. The follow-ups that have been made on hybrid aspen stands, have mainly been done on plant material in the South of Sweden. In the North of Sweden, only occasional studies have been made, and the knowledge of Northern hybrid aspen stands is, thus, unsatisfactory.In the South of Norrland, land owners have planted hybrid aspen, but what kind of plants it is, and how well these stands have established, is not ascertained, since data has not been compiled on the subject.The objective of this study is to evaluate practical plantations of hybrid aspen in the South of Norrland regarding height growth, survival and damages. The ambition is to increase the knowledge about practical plantations regarding height growth, survival and damages, and from the conclusions thereof, give recommendations for future establishments of hybrid aspen in the area.For the study, eight hybrid aspen stands in the South of Norrland were localised.

Effekterna av urbanisering, barksprickedjup och solexponering på lavfloran i sydöstra Sverige

Studies have shown that air pollution, as well as bark fissure depth and sun exposure of a tree can have an effect on lichen growth as well as abundance of lichen species. The aim of this study was to find out the relative importance of these factors. 211 oaks in south eastern Sweden were surveyed for presence of 17 lichen species, as well as the total number of lichen species. Half of the trees were situated in urban areas and half in the countryside. For each tree the bark fissure depth was measured and the sun exposure of the trunk was estimated.

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.

Att täcka en obekant yta med Spanning Tree Covering, Topologisk Täckande Algoritm, Trilobite

Det har blivit mer och mer vanligt med ny, datoriserad teknik i hemmen. Fler människor har ett allt stressigare liv och inte längre samma tid att ta hand om det egna hemmet. Behovet av en hjälpande hand med hushållsarbete har blivit allt större. Tänk själv att komma hem från jobbet eller skolan och så har golvet blivit skinande rent utan att Ni knappt har behövt göra någonting! Det finns idag flera olika robotar på marknaden för detta ändamål. En av dessa är den autonoma dammsugaren, som är det vi inriktat vår uppsats på.

Productivity of integrated harvesting of pulpwood and energy wood in first commercial thinnings

The aim of this study was to quantify the productivity and the costs of different harvesting systems (teams), containing harvesters equipped with accumulating harvester heads and forwarders, in first commercial thinnings were an integrated harvest of pulpwood and energy wood were performed. In the beginning the plan was to study and measure 20 sites before and after harvest. Due to storms during the summer of 2010, complete data could only be obtained from 8 of these 20 sites. Seven of these sites were privately owned and one was owned by UPM, all of the sites had been pre-commercially thinned. The mean stem density before harvest was 2578 stems per ha and the mean stem volume was 0.074 m3solid over bark.On average 1518 stems/ha was harvested.

Där jag aldrig varit

The sites I visit turned into routines a long time ago. Everywhere someone has decided what should be there and what will not fit. I retreat into my daydreams, away from everyday life. A longing for something different, something wonderful. I decided to go where I've never been, searching for something unknown.

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