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3373 Uppsatser om Fast growing tree species - Sida 10 av 225

Faderskapsanalys av tallfrö från Västerhus fröplantage : Skillnad i pollenkontaminering mellan öppen pollinering och pollinering inom ett avgränsat system

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree.

Vedrötor i stadsträd : biologi, detektionsmetoder och förebyggande åtgärder

Urban trees have very little in common with trees on natural sites, such as forests or pastures. Trees in urban environments are often planted in packed soil and in small volumes. This can lead to decreased availability of water and oxygen, as well as deteriorated ability for the soil to store nutritional elements. Also above ground the tree usually have limited space in cities. Regulations on free height over roads and cycle tracks demands high stems at an early stage of their development.

36 nyanser av torsk : en osteologisk analys av fiskben från Hemmor i Dalbo i När sn på Gotland

The purpose of this paper was to analyze fishbones from the Pitted Ware Culture settlement named Hemmor. in Dalbo, När parish on Gotland. The fishbones are unburnt and derive from one specific culture layer (c:6) in trench one VI:7, and radiocarbon dated to 2600-2300 BC cal.In this paper I wanted to answer these following questions:1. What kind of fish species did they eat in Hemmor?2.

Jordlöparfaunan i bestånd av contortatall (Pinus contorta) och svensk tall (P. sylvestris) 1987 och 2010

In the 1970´s the North American lodgepole pine (Pinus contorta) was introduced to Sweden in large scale. The lodgepole pine affects its new environment different from Scots pine (P. sylvestris), leading to a change in biological diversity. Forestry today affects the ground beetle fauna (Carabidae). Habitat specialists associated with older forests are first affected. When the canopy closes again after a clear-cutting species that prefer open habitats reduces and those who prefer mature/closed forests increase. In this study we compare differences in diversity and community structure of ground beetles in stands of lodgepole pine and Scots pine.

Status och hotbild för den oceaniska laven broktagel Bryoria bicolor i sydvästsverige :

Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline.

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.

Artrika vägkanter - hur påverkas de av slåtter och underhållsdikning?

ABSTRACT This study is an exam work at the Department of Ecology at the Swedish Agricultural University, Ultuna, Uppsala. The field work was performed in the counties of Uppsala and Västmanland. Grassland areas, exposed to annual mowing, are known to host a variety of rare and red-listed vascular species. The area of these grassland are, however, decreasing in the landscape due to modern farming. The fact that roadside verges maintain regular mowing has proven to be a successful concept for many rare vascular plant species in this habitat. Vascular plants along roadside verges at the State road network were inventoried due to a government mandate during 1995 and 1996. As a result ?Species rich roadsides? were pointed out.

Modeller för brösthöjdsålder för tall och gran :

The purpose of this study was to develop two types of prediction models for Scots Pine and Norway Spruce. The first type for calculation of the stump diameter under bark the year the tree reached breast height (Dstubh130). The second type for calculation of the annual difference, e.g. the number of growth years between stump height (0.2 m) and breast height (1.3 meters above ground level). The primary thought with these prediction models is to obtain the breast height age in the trees on basis of the number of annual rings at stump.

Isolating microorganisms from marine and marine-associated samples : a targeted search for novel natural antibiotics

The search for antibiotic compounds from the natural environment has been going on for seven decades, ever since penicillin entered the market and antibiotic treatments became routine. The evolutionary pressure put on the pathogenic microorganisms induced a rapid spreading of naturally occurring resistance genes, leaving only the option of finding new antibiotics to treat the resistant pathogens. Microorganisms have been extensively mined for their biosynthetic abilities to produce biologically active compounds. To date, more than 23 000 microbial natural products have been discovered. The Actinomycetales are ubiquitous bacteria that have been used for antibiotic discovery for more than half a century, and over 10 000 natural products have been identified from the order.

Hur bokskogslagen blev till ? konflikter och lösningar 1964-1974

During the early Middle Ages beech forests (Fagus sylvatica L.) spread out over large parts of southern Sweden. They had a crucial role in human survival for hundreds of years. For various reasons, the beech forest area has decreased since the 1600s. Spruce planted on former beech forest land was the primary reason for the decline during the second half of the 1900s, which made many worried about the future of the beech forests and led to a beech forest act in 1974. This study describes the background to the beech forest act based on parliamentary official documents.

Epixylic, forest-interior bryophytes in young stands : importance of local environmental variables, propagule sources, and distance to bordering woodland key habitats

The reduction of coarse, dead wood is considered to be the biggest threat to flora and faunain boreal forests. Extensive harvest of logging residues would increase this reduction evenmore. However, the role of dead wood created at final felling for boreal, epixylic species isstill largely unclear. It is therefore of interest to examine whether epixylic species inhabit thedead wood in young, boreal stands, especially species considered to be confined to forests inlate successional stages.The aim of this study was to investigate whether forest-interior species in fact can inhabitearly-successional forests arisen after logging. The study was conducted in young standsbordering dead wood rich woodland key habitats.

Laserdata i skogsbruket : - och möjliga tillämpningar för privata skogsägare

Data retrieved from airborne laser scanning represents a new source of forest data. Today, the technology has matured so that it can function in an operational environment. The aim of this study was to compile areas of application of laserdata in forestry. Moreover to analyze costs and accessibility of laserdata. The goal was to provide private forest owners information to support assessments of possible benefits of laserdata.

Short-term responses of the field layer vegetation in a south Swedish deciduous forest after establishment of wild boars (Sus scrofa)

Inside the south Swedish national park Dalby Söderskog, wild boars (Sus scrofa L.) have been visiting since 2010. The presence of wild boars has earlier been proven to impact both soil and vegetation characteristics, both positively and negatively. Still, there is a lack of knowledge regarding the rooting effect on the vegetation in deciduous forest within the native range. In this study, I have compared the field vegetation collected before and after the invasion of wild boars in 74 permanent experimental plots. More specifically, the study aimed to qualify the effect of wild boar rooting on cover ratio, species richness and species composition in a temperate deciduous forest.

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

Detta arbete har undersökt skillnaderna mellan den nuvarande skogsvårdslagen och den föregående. Undersökningen har bestått av två delar, där ena delen är en litteraturstudie av lagarna och den andra är en fältstudie av metoder för att mäta naturhänsynsförändring. Som komplement till fältstudien har en litteraturstudie av undersökningsparametranas naturvårdsnytta. Litteraturstudien av lagarna gick till på följande sätt, inledningen av båda lagarna och hänsynsparagraferna har lästs och jämförts. Fältstudie har gjorts efter metoder som har arbetats fram och sedan testats i fält.

Vivlar på prydnadsbuskar - nya arter eller förändringar i födopreferenser?

During the last couple of years leaf-edge-cuts, typical to Otiorhynchus wingless-weevils, have been discovered on ornamental shrubs, especially Syringa vulgaris lilac and Ligustrum vulgare privet. These plant species have not earlier been attacked by wingless-weevils and because of that, the aim of this study is to see if new species of weevils have been established in Sweden or if the domestic weevils have changed their food preferences. This work also includes a literature study of known weevil species in Sweden and their host plants, and of wingless-weevil species in Europe that could be invasive here. Locations, where damage to previously named plants has been reported, have been examined. The extension and appearances of the damages have been documented in order to study if different weevil species make different types of edge-cuts.

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