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544 Uppsatser om Tree mortality - Sida 11 av 37

Svartgran ? ett alternativ när allt ser mörkt ut? : en kartmodell för att visa lämpliga ståndorter för odling av svartgran

A common problem in forestry is plant death caused by frost. The risk of frost is highest on wind protected, flat or low-lying areas in the terrain. Here you often have regeneration problems with Norwegian spruce which is especially sensitive to spring frost. Swedish tree experiments have shown that the black spruce can be a suitable alternative on these areas, for example on moisture frost prone areas. The species originates from North America and its pioneer tree characteristics make it more frost hardy than Norwegian spruce.

Alnarps rehabiliteringsskog : ett gestalningsförslag

The understanding of the role of nature for rehabilitation of both physical and psychological afflictions has greatly increased in the last few years. There?s a lot of science that describes the healing effects of nature. The rehabilitation garden in Alnarp has contributed with very positive results from the treatments of patients with burnout syndrome. In the first stages of rehabilitation, the need for calm is very important and a demand-less and stress-free environment is of essence.

Liv i d?d ved: En unders?kning av f?rh?llningss?tt till d?d ved p? ?ppeltr?d i tr?dg?rdshandb?cker och bland yrkesverksamma tr?dbesk?rare

In this essay, several factors in apple tree care (specifically in relation to whether dead wood should be kept or removed) are highlighted for example, aesthetics and biodiversity. To present some background, the essay begins by introducing some previous literature on dead wood. This leads into how dead wood is treated within forestry. Next, previous research on dead wood in fruit trees is mentioned. Cultural and historical management methods are also highlighted.

Hybridlärkens tillväxt i Snogeholm : hur påverkas produktionen i blandbestånd jämfört med trädslagsrena bestånd?

The hybrid larch (Larix x eurolepis Henry) is a fast growing tree species and was introduced in Sweden for about 50 years ago. The high growth and expected resistance to diseases are probably the main reasons of introducing the tree species into the Swedish forests. The purpose of this thesis was to document the production of hybrid larch planted in the Snogeholm landscape laboratory and to compare the production in the pure hybrid larch stand with the mixture together with pedunculate oak (Quercus robur). The data collection in Snogeholm since the establishment has been carried out by the Swedish University of Agricultural Science (SLU). The fieldwork for the thesis was carried out in 3 stands, containing hybrid larch, pedunculate oak and a mixture of hybrid larch and pedunculate oak, in order to be able to compare the total stand production of the areas. The results show that the total production of hybrid larch in the mixed stand only is 35 % compared with the total production of hybrid larch in the pure stand. Therefore, the hypothesis that the total production of hybrid larch is equal to the planted mixture with pedunculate oak was rejected. The other hypothesis that the total production of a 2 hectare large stand containing a mixture of hybrid larch and pedunculate oak would be greater than the total production of two pure stands of 1 hectare containing hybrid larch and oak each was also rejected. In the studied case the total production was 45 % greater if hybrid larch and pedunculate oak was planted in pure stands. The results from the case-study only indicate that the total production of hybrid larch and oak under the investigated conditions can be higher when planting the two species in pure stands compared with a mixture of the two species.

Vattensork och åkersork - skadegörare i svensk fruktodling

There are two species of voles that cause damage in Swedish fruit production: the water vole (Arvicola terrestris) and the field vole (Microtus agrestis). Both species make the most damage during the winter season. The water vole makes subterranean burrows and cause serious damage by gnawing on the tree roots. The field vole seldom makes burrows and gnaws the bark at the base of the tree trunk. In recent years there have been several reports about increasing vole damage.

Parametriserad 3D-modell av cyklon : Parametrisering av en 3D-modell av ett cyklonfilter i SolidWorks för snabb framtagning av nya konstruktioner till Outotec Skellefteå

This bachelor thesis project has been executed at Outotec Sweden AB in Skellefteå. Outotecs main business focus is selling mineral and metal processing technologies. A rest product from the metal process is particle-polluted gas and cyclone designs are today the most commonly used abatement device for particle control. A cyclone provides a simple design with high efficiency particle percolation by using air streams.The purpose of this work is to reduce the time it takes create new cyclone designs in Outotecs projects. An extensive construction work is needed for every new cyclone order due to new designs.

Användning av satellitdata för lokalisering av skogsområden där lövröjning bedöms angelägen : en analys av användbarheten med fjärranalys som hjälpmedel till röjningsrådgivning

This master thesis project is a part of a project called ?Järboprojektet? at the regional board of forestry, the district of Gästrikland. The project will give answers to questions regarding if an analysis of satellite images can be used to contact and inform landowners of the located areas where precommercial thinning is useful. The whole project is a part of the National Board of Forestrys IT-stake where the analysis of satellite images will, at the latitudes possible, be adapted to each district in purpose to identify these areas in need of precommercial thinning. This master thesis project is based on a field inventory of identified objects where precommercial thinning is useful.

Viltets inverkan på vegetationsutvecklingen i en Sydsvensk skogsföryngring :

Herbivore impact on the Swedish forest has under a long time been a common subject of debate. There are many different opinions depending on what direction the forest owner has with his/her forest. Populations of moose and roe deer have increased significantly in Sweden during the last decades. The purpose of this study is to get a full picture of the herbivore impact on the regeneration areas. The field work was done once a year for seven years (1999?2005).

Where has the fertilizer gone? Closing the nutrient budget for a eucalyptus fertilization experiment in southern China

An increasing demand for wood products in China has resulted in large areas invested in fast-growing tree plantations of eucalyptus. Eucalyptus plantations are often associated with an intensive management including fertilization. By understanding the effects of fertilization and where in the ecosystem nutrients are accumulated a more sustainable forest management could be achieved. In this study, a nutrient budget including all biomass and soil components was created for Eucalyptus urophylla. The examined nutrients were nitrogen, phosphorus and potassium.

Leaf area index in Vittelaria Paradoxa parklands in Burkina Faso estimated by light interception and leaf sampling

Burkina Faso as well as most sub-Saharan African countries struggle with providing food for a fast growing population. The dominating farming system is agroforestry parklands. Agroforestry parklands can broadly be defined as areas where scattered trees occur on farmlands as a result of selective clearing. The presence of trees in crop fields may in the long term have a positive effect on the production of annual crops. It is commonly discussed, but not proven, that the presence of trees leads to increased groundwater recharge due to higher infiltration capacity of the soil.

Akut hjärtinfarkt : En litteraturstudie om patienters emotionella upplevelser vid en akut hjärtinfarkt

Background: Heart ischemia is a disease affected by behaviour, lifestyle and heredity. The disease is more common in the western world and the number of those who suffer increases. The mortality has reduced thanks to that medical resources and knowledge have approved. Purpose: The purpose of this study of the literature was to find out what patients experienced emotionally at an acute heart attack. Methods: A study of literature where scientific articles has been refereed and analyzed, then resulted into five categories presented in the result.

Hur kopplad är asp till tidigare jordbruksmark? : en studie av aspförekomst och tidigare markanvändning i fem län i Mellansverige

Aspen (Populus tremula) is a tree that is important for biodiversity. It is a pioneer tree that is favored by much light. It is possible that aspens that regenerated on agricultural land have a different importance for biodiversity than aspens that regenerated in forests, since their conditions have been different. By studying how the land use have changed you can see how many of today?s aspens regeneretad on agricultural land.

Outbreaks of African swine fever in domestic pigs in Gulu district, Uganda

The demand for animal products has increased in the last decades, especially for poultry and pork. Pork production has increased drastically globally, and also in Uganda. Thirty-one percent of Uganda´s population lives in poverty. Pig production is believed to play a crucial role in poverty alleviation, because of the ability to convert low quality feed into high quality protein together with high reproductive potential. African swine fever (ASF) is a lethal disease of domestic pigs often characterized by haemorrhagic fever and with mortality rates up to 100%. The disease is endemic in most sub-Saharan countries and since 2007 in the Russian Federation and Caucasus area.

Kronandelsrelaskopering, en ny metod för att fastställa gallringsbehov?

In today´s forestry, assessments of needs for thinning are based on basal area measurements. This is an indirect measurement. The approach and the developed assessment tables are based on an assumed production forest, which implies that management proposals in stands that deviate from the basic model may be misleading. Since Walter Bitterlich in 1948 launched the idea of the relascope, several modifications have been developed for different purposes. In common is that all are based on a certain angle measurement principle.

Skötselåtgärder vid nyetablering av skyddszoner vid bäckar i södra Värmland :

Buffer zones play an important role for the water quality in our watercourses. When harvesting a forest close to a watercourse a buffer zone should be left. When it's not left, it will lead to radical changes in the environment for the water organisms. The overall purpose of this thesis was to illuminate the production- and environmental thinking when establishing new buffer zones in south of Värmland. The partials goals were to determine choice of tree species, ways of regenerate, occurrence of soil scarification and the occurrence of machine tracks in newly established buffer zones.

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