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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Naturhänsyn på slutavverkade hyggen i Östergötlands län.

Jonsson, Sofia January 2011 (has links)
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. On 18 of 20 felling sites nature consideration had decreased significantly from P1 inventory to re-inventory. Retention trees had declined the most, 7.9% of the total volume of retention trees was gone. Taking conservation in to consideration at final felling sites by retenetion of trees and habitats with high conservation value is an important step in preserving biodiversity and increasing the chances of survival for the species considered sensitive to forestry. In order to improve the consideration of nature and thereby increase the chances of species survival a functional follow-up of conservation efforts at the felling sites is required.
2

Naturhänsyn vid föryngringsavverkningar : En jämförelse mellan certifierade och o-certifierade hyggen / Nature conservation in regeneration fellings : A comparison between certified and non-certified forest clearings

Rylander, Anna January 2015 (has links)
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. In comparison to statistics of southern Sweden's average, the results also suggested that the certified clearings (from the county “Blekinge”) most of the time had a higher incidence of the investigated parameters, while the non-certified clearings most of the time had a lower incidence of the investigated parameters. The environmental considerations on neither the certified nor the non-certified clearings were found to be near the highest amount that could be required by the Swedish forestry act. This observation is interesting, especially since the certified clearings would be expected to maintain a consistently high level in relation to the law requirement.

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