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3373 Uppsatser om Fast growing tree species - Sida 2 av 225
Lämpliga främmande trädslag för Kalmar och Mönsterås kommuner
This report concerns the for Sweden foreign tree species hybrid larch, hybrid aspen and poplar, and focuses on the area Kalmar and Mönsterås municipalities. The report shows that there are not only advantages with these species. The larch, the most common of the alien tree species has the greatest problems due to that its timber is difficult to sell in the area but also the Larch´s poor pulp quality and is more likely to be damaged by wildlife than the spruce is. Hybrid Aspen is much easier to sell and is used like regular aspen for match wood and textile pulp. Its disadvantage is the high cost for plants and to prevent damage from wildlife.
Effekter av landskapets sammansättning på humlearters förekomst
The species in the genus bumblebees (Bombus) are important pollinators. In the world there are 250 bumblebee species and there are 34 species in Norway. The purpose of this study is 1) to assess changes in the species composition of bumblebees in twenty different places in Norway that have been inventoried first one time between 1939-1960 and the second time in 2012, and 2) to relate species richness and distributions to current landscape composition with the aid of orthophotos. In this study, I have used regression analyzes on the different bumblebee species that were present or absent at the inventory, using the premises of the following variables: low or high altitude, latitude, longitude and seven different types of land use (farmland, building/plots, open land/pasture, forest, wetland and open or snow-covered ground above the tree line) to see if there was any relationship between each species and the different variables.
I have not analyzed what the landscape looked like at the first inventories and therefore we cannot say whether it has changed and if that is why species number has decreased. This would be interesting to study further and to see if there is any relationship between landscape changes and bumblebee?s species decline.
Poppel - en möjlighet i norra Sverige?
The countries in the European Union have agreed to increase their percentage renewable energy sources to 20 %. To reach this goal an increase of biomass production needs to be made. One way of achieving this is by using nonnative species.
Poplar in Sweden produces biomass faster than the domestic trees. In the southern parts of Sweden plantations has been made with good results. In the northern parts survival is a problem that needs to be solved before plantations can be made for commercial use.
NATURMINNENS F?RVALTNING OCH SKYDD: Inventering i V?stra G?taland
Natural monuments are natural objects with special protection due to their high natural value or cultural significance. The natural value is determined by the occurrence of signal species found on and near the natural monument. The law surrounding natural monuments has evolved a lot since the first ones were declared, and today the title natural monument can be replaced with the title tree with high conservation value. The title has come later and can sometimes overlap natural monument. Some natural monuments lack the qualities required to be classified as a natural monument or a tree with high conservation value, but have a cultural importance.
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.
När trädens rotsystem får bestämma : En intervjustudie med en grupp yrkesverksamma inom anläggning av hållbara gröna miljöer.
ABSTRACTThis pilot study examines the knowledge about tree root systems amongst five treeplanting professionals. The aim is to find out the professionals? collective knowledge ofthe nature of root systems of various trees used in green areas. Furthermore; to explorehow the professionals adapt landscaped green areas to the tree root properties in asustainable manner. Questions: Which tree species have special root properties toconsider and how do the professionals utilize this knowledge? And: How do theprofessionals in general adjust planting according to the root systems of trees in areas tocreate sustainable green environments?Interviews with the professionals were performed.
Potentiella arealer för ökad virkesproduktion i norra Sverige genom skogsodling med Pinus contorta var. latifolia, Larix sukaczewii, Abies lasiocarpa, Populus × wettsteinii och Picea mariana
Sweden is a country with few native tree species. According to Govt. 2007/08: 108, exotic tree species may be seen as an opportunity to increase the growth of tree volume in Sweden. Potential areas where explored In this work for cultivation with Pinus contorta var. latifolia Engelm., Larix sukaczewii Dylis, Abies lasiocarpa (Hook.) Nutt., Populus × wettsteinii Hämet-Ahti (tremula x tremuloides) and Picea mariana (Mill.) Britton et.al.
Examination of mycorrhizal associations of Allanblackia stuhlmannii : a tree under current domestication
Allanblackia is a tree genus native to humid forests in West, Central and East Africa. Its fruits contain large seeds from which edible high-quality fat can be extracted. In order to create a sustainable supply chain of Allanblackia seeds, a domestication program has been initiated with the purpose to enable smallholder farmers to grow the tree as an agroforestry component and cash crop. More knowledge is required to understand the tree?s biology and possible symbioses involving soil microorganisms with plant growth enhancing poten-tial.
Retention of stumps on wet ground at stump-harvest and its effects on saproxylic insects
Low stumps represent on their own up to 80% of the dead wood remaining on clear cuts and therefore supply suitable habitat for saproxylic insects i.e. insects depending on dead wood for their survival. Recent stump harvesting activities threaten this substrate of ecological importance and increase the anthropogenic negative impacts on these species. Because of technical and environmental reasons (nutrient leakage, erosion) guidelines for stump harvesting recommend to retain stumps standing in wet parts of clear cuts. However, stumps in wet positions might not be a satisfactory substrate for saproxylic insects and therefore might not be as much used as stumps in dry positions.
Trädslagsinverkan på markvegetationens utveckling i odlingsförsök med tall och contorta :
In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.
Vad styr förekomsten av sälg och asp? : en studie av olika beståndstyper inom Hamra kronopark, Dalarna
Aspen (Populus tremula L.) and goat willow (Salix caprea L.) are two important tree species in the aspect of nature conservation. Due to the elimination of forest fires, a former negative attitude towards deciduous trees in forestry and a strong herbivore pressure, these tree species have been negatively affected during the last fifty years. The aim of this study was to investigate whether the occurrence of aspen and goat willow could be related to either human impact or to site properties, such as ground moisture and vegetation type. A side study included an inventory of a number of cyanobacterial tree lichens on aspen and goat willow in order to try to relate the occurrence of these lichens species to stand history and stand properties.
The study was performed in Hamra State Forest in northern Dalarna. Nature reserves were compared with stands in managed areas.
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.
Vad styr sortimentet hos svenska perennaodlare? : en studie baserad på sju företag i Sydsverige
The purpose of this study is to clarify the most important factors that affect Swedish perennial growers when designing their assortment. The study describes how herbaceous perennials are produced in Sweden today and try to give an answer to the question how growing method and choice of assortment are affecting the possibilities of Swedish producers to compete on the market.
Seven perennial growers in the southern and western parts of Sweden have been interviewed about their production methods and on what basis they design the assortment of perennials. During the interviews five factors seem to be the most important when the growers choose which species to grow ? profitability, the characteristics of the species, the sales channel/customer, the growing environment/growing facility and the grower?s interest and knowledge. It is often a combination of these five factors deciding if a cultivar will be grown or not.
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AHA in northern Sweden ? a case study : conservation values of deciduous trees based on saproxylic insects
AHA is a Swedish abbreviation of "reveal threatened park and avenue trees" and is a method to assess the conservation value of individual trees, mainly in the park environments but also in natural stands. This method has previously only been practiced in southern Sweden (Sörensson 2008). To see if this method could provide satisfactory results in northern Sweden, I have studied it in areas around the Umeå River. This was done by studying the relationship between trees with different classifications of conservation value (as classed by the AHA method) and their content of species (species richness and abundance). Insects were collected using trunk window traps in a period of 13 weeks during the summer of 2014.
Vegetationens roll i erosiva vattendrag : en review och fältstudie av två nyckelområden i Rönne å
The vegetation?s impact on erosion control is widely explored, even though research? results are scattered where it suggests a both positive and negative relationship between roots and erosion tendency. Research has measured the roots? impact on erosion by many different methods, hence the aim of this study is to offer a clearance of what factors play an important role in the choice of appropriate species controlling river bank erosion. I have therefore
studied 17 articles concerning vegetation and erosion control, which were found in different databases such as: Web of Knowledge, Biological Sciences, Academic Search Elite and Google Scholar.