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446 Uppsatser om Retention trees - Sida 1 av 30

Trädens utveckling efter att de har lämnats som naturhänsyn : tillväxt, mortalitet och strukturell förändring 6-18 år efter avverkning

Today green tree retention, together with leaving dead wood, is a common practice with the aim to reduce negative impacts on biodiversity and environment due to clear-felling. To better understand whether this conservation practice also makes a long-term difference, it is important to know what happens to these trees after harvest. Few studies have made an assessment of what happens to Retention trees over a longer time period. In this study I inventoried Retention trees that were left at clear-cuts six, twelve and eighteen years ago. I carried out a re-inventory of 57 retention patches (divided into free-standing tree groups, small swamp forests and edge zones) and free standing dead trees, spread over 25 previous clear-cuts in central Sweden.

Naturhänsyn på slutavverkade hyggen i Östergötlands län.

95% of the productive forest land in Sweden are now being exploited for forestry. The new Forestry Act of 1993 equate the goal of production and the environmental goal which means that the objective for forestry is a sustainable yield, while the biological diversity must be preserved. Recent years results from the inventories of the Board of Forestry show declining trends in how nature conservation aspects taken into consideration at the felling sites.The aim of this study is to investigate what happends with the nature consideration taken at felling sites in the long run. 20 final fellings in the county of Östergötland were re-inventoried 7-9 years after final felling. These felling sites had previously been inventoried before final felling (P0) and one year after final felling (P1) in the inventory Polytax by the Board of Forestry.

Har antalet naturvärdesträd i Sverige förändrats mellan 1999-2009?

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.

Naturhänsyn vid föryngringsavverkningar : En jämförelse mellan certifierade och o-certifierade hyggen

A growing number of Swedish forest owners are choosing to certify their forestry. However, there appears to be a lack of field surveys which describe differences between certified and non-certified forests concerning the degree of completed environmental considerations. In order to know to what extent certified forests contribute towards improved environmental consideration, we need studies on how large the difference is in relation to non-certified forests.Differences between certified and non-certified forest clearings were quantified through an inventory of the number of Retention trees, dead trees and snags. The result showed that the retained number of the investigated parameters varied greatly between individual clearings, regardless of certification status. However, the results suggested that the certified clearings had an average higher incidence ofthe investigated parameters.

Do retention trees affect the composition of ectomycorrhizal fungi? : a comparison between clear-cuts areas with and without retention trees in pine forests

Under det senaste årshundradet har de svenska skogarna genomgått en omfattande förvandling, från mer eller mindre naturligt dynamiska till hårt brukade skogar bestående av monokulturer av tall eller gran. Denna förändring har lett till en minskning av den biologiska mångfalden, att många arter som är beroende av skog har minskat radikalt och hotas av utrotning. Som ett försök att främja variation, biologisk mångfald i allmänhet och förhindra minskningen av rödlistade skogsarter introducerades i början av 90-talet en viss naturvårdshänsyn i brukade skogar. I den här studien utvärderas den påverkan som kalavverkning har och den betydelse hänsynsträd har på artsammansättningen och förekomsten av ektomykorrhizasvampar (EMF) under de första 20 åren efter kalavverkning. Studien utfördes genom extrahering och identifiering av svamp-DNA från jordprover tagna på kalavverkade ytor, nära hänsynsträd och i gammal skog i ett begränsat geografiskt område i norra Sverige.

Underröjning i förstagallring :

This report is a thesis work for a B.Sc. in Forestry exam at the School for Forest Engineers, SLU. The work was an assignment from Sydved and the aim of the work was to investigate the economical output of removing understorey trees before first thinning. Four treatments were studied. - no cleaning before thinning - cleaning of all trees less than DBH 5 cm before thinning - cleaning of all trees less than DBH 7 cm before thinning - cleaning of all trees less then DBH 9 cm before thinning The result shows a decrease of the cost per m3 for the harvester with about 38% if all trees less than DBH 9 cm was cleaned before thinning compared with the un-cleaned area. At the same time the total net revenue increases with about 22%. .

Bevarande av naturvärdesträd i enlighet med FSC och Holmen Skogs naturvårdspolicy :

In the end of 1998 the company Holmen Skog AB was certified accordint to the FSC system with an area of 1 036 000 hectare. After that Holmen Skog AB has been working actively with the nature conservation in the forestry. In order to control the quality of the company?s nature conservation in final fellings they started a yearly inventory which is called BAKRUS (Judgement of ecological and culture care in relations to policies for a persevering silviculture). After 1999 the control was expended to include all actions in the forest.

Våtmarker för näringsretention i Lillån : var bör de ligga och vilken effekt kan vi förvänta

Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.

Combining the Concepts of Fear Aroual and Customer Satisfaction & Retention - An Ethnographic Case Study on Krav Maga

The purpose behind this study is to explore and explain the role of fear arousal when combined with the concept of customer satisfaction and retention in one marketing strategy. The major theories applied are the concept of fear appeals and the concept of customer satisfaction & customer retention. We chose to conduct our research through an ethnographic case study of KM. We did a qualitative study where we collected 10 interviews and we conducted observations. Our empirical data consists of academic articles from scientific journals, interviews andobservations.

Bergviksäpplet och dess fruktsättning

Trees of Bergvik apple (Bergviksäpple) planted between 2001 and 2007 have shown varying harvest. This study investigates why some trees gets low or no harvest while others get significantly higher harvest. The aim is to identify some reasons why fruiting differs between the trees and if possible suggest and/or enlighten the tree owners what can be done to improve fruiting. The study includes 25 trees, mostly located in Hälsingland, Sweden. The tree owners have answered two questionnaires, first in the spring with questions regarding flowering and the second in the autumn, regarding harvest.

En studie av retentionen i floden Oder och dess avrinningsområden, Polen.

Nutrient enrichment is the main cause of the increasing eutrophication process in the Baltic Sea during last century. A prerequisite counteract this process the load of nutrients to the Sea must be investigated. The large contribution of nutrients to the Sea is caused by emission from the rivers within the drainage basin. For the total emission of nutrient into the Sea the retention process in the rivers has big influence. This process in the river system has been assumed as a not important part of the nutrient cycle.

Mortalitet av bok i Biskopstorp och Frodeparken naturreservat, Halland :

The aim with this study was to investigate mortality in older respectively younger beech stands (Fagus sylvatica), the different types of dead wood in the forest and the availability of coarse woody debris (CWD). The research was carried out in previously managed and seminatural stands in Biskopstorp and Frodeparken, located north of Halinstad in Halland,Sweden. Data were collected from 22 stands with at least 50 % beech and with a minimum age of 5 1 years, ranging in size from 0,67 to 19,9 ha. A transect was placed in each stand, in which the diaineter on both dead and living trees with a minimum diameter of 50 mm was recorded. On seven to 13 dead trees, depending on the size of each stand, decomposition stage, primary and secondary cause of death, amount of fungi and the type of the dead wood was noted.

Obalans mellan rot och krona skapar omplanteringschock i Prunus avium :

In this investigation has an attempt to find out whether so called transplanting shock depends on the moving and transplanting of trees, to other conditions, or if it is due to the imbalance between the root to shoot ratio. Seventy trees of Prunus avium have been part of the investigation and these trees have been divided into four different groups depending on methods of production, untouched on the field, trees still on the field but with root pruning, trees moved and planted into Root-Control-Bag, trees moved and planted into Spring-rings. To be able to answer the question, measurements of the length of the terminal shoots and the lateral shoots and the dimension of the stem growth have been done and also has a visual judgment of the trees vitality been performed. The result shows that it is not only the move of the trees that gives them transplanting shock, but rather the loss of roots which gives an imbalance between the root and crown..

Jätteträd ? inventering, bevaring, skötsel samt rekrytering :

During the summer of 2007 I was employed by Högestad Christinehofs Förvaltning AB. My main task was to make an inventory of giant trees at the estate. Högestad and Christinehof,which with their total possession of 13 000 ha of land is the biggest estate in Scania. A giant tree is a tree with a diameter in breast height more then 1 meter. Trees of these dimensions are registered by Swedish authorities. Landowners with a giant tree on their property can receive a subsidy for cutting trees that are in competition with the giant tree.(Levenskog, 2007) Giant trees are important for biodiversity in the landscape and there are important habitats for different insects, birds, bats, lichens and funguses.

Evighetsträd

FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation. This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.

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