In the tropics, logging and wild fire can result in degraded secondary forests with lower biodiversity than in the natural forest. One way to limit forest degradation is to rehabilitate the present large areas of secondary forests. However, there is a lack of knowledge concerning the ecology of tropical tree species and further studies would be advantageous for future rehabilitation efforts of degraded rainforest. The objective of this study was to investigate how mother trees in secondary forest and different site factors affect the abundance and spatial distribution of Natural regeneration of non-pioneer tree species in a tropical rainforest in Sabah, Malaysia. The study took place in the INIKEA Forest Rehabilitation Project area, which suffered from wild fire in 1983 and has been selectively logged over both before and after the fire. Natural regeneration and site variables were inventoried in plots, while mother trees were inventoried in the whole survey area.

Many tropical rain forests has been lost or degraded as a result of human activities and environmental factors. Since the level of biodiversity is high in the tropics, maintaining these areas is of great importance. Forests like these are often assumed to benefit from forest restoration and rehabilitation. The INIKEA project area in Eastern Sabah, Malaysian Borneo, aims to improve biodiversity and/or species richness in the degraded forest through enrichment planting with indigenous species. The objective of this thesis was to evaluate how different treatments (liberation, gap-cluster planting and line planting) affect the biodiversity of Natural regeneration in different forest types in the Rain forest Restoration Experiment, located in the INIKEA project area.

According to the Board of Forestry, in Västerbotten, many Natural regenerations of Scots pine (Pinus sylvestris) carried out on privately owned forest in the middle of 1990 in Västerbotten have rendered a bad regeneration outcome and will provide a low future forest production. The Board of Forestry believes that the negative result can be explained by the fact that the regeneration has been carried out in wrong locations and that scarification failed to work as planned. In order for an accepted rate of regeneration the guidelines of the Forrest Act require, not less than 10 years after final cutting at Natural regeneration, that there should be at least 1300 (site indices 16 m) - 1700 (site indices 20 m) main crop stems per hectare. Main crop stems are defined as stems according to the place of growth and appropriate tree type, in addition with regard to quality, stage of development and damage risk have a prospect of succeeding. In addition main crop stems should be separated by surface so that the proportion sample plots with 3 meters radius, and lack main crop stems, are not more than 10 % of site indices 14 meters or higher.

The aims of the silvicultural method Natural regeneration of spruce (Picea abies L. Karst) in birch (Betula pendula and pubescens) shelterwoods are to establish a new stand of tree seedl-ings and to protect those from high groundwater levels, frost damages and grass competition during its first life years. The aim of this work has been to (i) describe how shelterwood and stand characteristics influ-ence the results from using Natural regeneration of spruce protected by a shelterwood of birch, and to (ii) compare those regeneration results with planting of spruce after soil scarification in clear-cut areas. Totally 17 harvesting sites have been inventoried and 15 of those included natural regenera-tion in birch shelterwoods, and two were subjects to soil scarification and planting of spruce. The sites represented 7-10 year old final cuts and are located in the coastal (eastern) region of the province of Norrbotten in Sweden. In all areas shelterwood and stand characteristics, as well as the number of main crop seedlings and the height of the highest main crop spruce seedling, were estimated and registered in all areas.

Forestry and forest products are vital components of the Swedish economy but the forest is also important for recreation, hunting, out-door life and conserving biodiversity. The Swedish Forest Act has two equally important objectives, production and environmental protection. Polytax is the Swedish Forest Agency´s inventory programme which monitors progress toward the two objectives in connection with regeneration fellings. It includes data on environmental protection measures taken in connection with regeneration fellings. 30 § of the Swedish Forestry Act and related regulations specify the demands for conserva-tion of nature.

Even though Sweden is a small country which has a low rate of inhabitants is it one of the worlds leading nations of exporting products from the forest industries. The Importance of a sustainable use of the Swedish forests has been known for many years. In 1903 the first law of forestry were establish. Today the National Board of Forestry carry out inventories of regeneration result. The result of the latest inventory showed that especially the non-industrial private forest owners did not full fill the regeneration work after a clear cut.

In January 2005 large forest areas in south Sweden were severely damaged by storm. This final thesis describes the work with creating an ecological and landscape-adapted regeneration plan for a severely storm damaged property in Kronobergs region in south Sweden. This regeneration plan, in difference to more regular plans, are focusing more on the owner?s use and goal?s for the property and seeing the property from a more comprehensive view in the regeneration process. Beside production and environmental values the plan also take in consideration other values as aesthetic, culture history, landscape picture and recreation values.

In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without Natural regeneration of spruce.

The freshwater pearl mussel (Margaritifera margaritifera) is threatened throughout its range. There has been a substantial decline of the species and one major reason is habitat degradation. We investigated how the substrate composition of the bottom floor affects the regeneration of the mussel by analyzing data from the Västerbotten County Board?s inventory of the freshwater pearl mussel. The results implied that fine material such as fine sediment and sand might be detrimental to regeneration whereas gravel and boulders and in particular stone seem to be beneficial.

This thesis is built on a field study that was carried out in two seed-tree stands near by Götbrunna in Uppland, Sweden. The aim was to examine if scarification carried out in spring time could generate a more dense seedling establishment when using natural generation, than scarification carried out in autumn. It was also investigated whether there were differences in mortality the first season between the two plot-types. Plots were established block-wise with 50 blocks (pairs) on each site. The spring scarification was made with a hoe during 22-23 of April.

How do you see on natural science within preschool? Does education and interest play a role for how the educationalist works with natural science? And is the children?s interest for natural science affected by the educationalist, what does the educationalist think himself? These questions have I under my teachers training and under deputyship in preschool asked myself and these questions lies to behalf for my investigation. I interviewed five educationalists on different preschools for my investigation.My investigation resulted in that I have been able to see a certain conjunction between how you work with natural science in preschool and the educationalist education or interest. What also plays a role is that you often associate natural science with knowledge of nature. The educationalist seems overall positive to natural science, but depending of a lack of knowledge it feels strange and difficult.

Many participants in the Swedish timber market procure raw material from private forest owners. They often also offer forest services to ensure reforestation after final felling. Selling silviculture services can be a part of creating a long term relationship with the landowner for future timber purchases. The Swedish Forest Agency monitors forest rejuvenation results in the entire country. In the latest survey (2006 - 2008) the proportion of approved regeneration area was 78%.

This case study is made on assignment of Södra, region Öst, as a part of a campaign promoting more active management of the oak forests in the region. Hardwood trees of good quality, especially oak, has a high value due to that the sawn material is highly estimated by the market. It is important that the Swedish oak forests are managed in a proper way in order to meet the future demand. Södra has therefore decided to increase the focus on oak in the Kalmar region and they would like to find out if continues cover forestry (CCF) under certain conditions can be an appropriate management model. The motive is to make use of the existing oak forests more efficient, not just considering well managed forests but also the more neglected oak forests, on poorer soils. Thus, the objective for this study is to examine if CCF is appropriate method in the three stand types; broadleaved mixtures oak forest, oak islet, and oak/spruce forest. Existing management models were surveyed in the literature.

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Fragmentation and reduction of forest area is a threat for many forest species and their habitat. Deficiencies in forest quality, such as lack of dead wood and old trees, are one explanation of the threat. The most important action to prevent the continued loss of forest types is to protect forest, but also to restore and to create areas that not previously had high nature values. Hence one of the key strategic roles for Fritid- och Naturkontoret, Uppsala municipality, is to monitor biodiversity in the context of urban planning. The majority of the Uppsala municipality residents live in urban areas and most of them spend some of their spare time in natural areas in cities and their immediate surroundings. Exploitation in and around Uppsala is high, but it is important that there is enough nature close to houses to meet the residents? needs of recreation.