Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization
Individual-tree-selection (ITS) is a continuous cover forestry method that aims to utilize the uneven-sized stand structure through optimized individual tree selections. ITS is an interesting management alternative to rotation forestry in terms of production of multiple benefits and forest owner pro...
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Linnéuniversitetet, Institutionen för skog och träteknik (SOT)
2022
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-116633 https://doi.org/10.15626/LUD.467.2022 |
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ftlinnaeusuniv:oai:DiVA.org:lnu-116633 2024-04-07T07:52:24+00:00 Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization Fagerberg, Nils 2022 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-116633 https://doi.org/10.15626/LUD.467.2022 eng eng Linnéuniversitetet, Institutionen för skog och träteknik (SOT) Växjö Linnaeus University Dissertations 467 orcid:0000-0001-7731-1593 http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-116633 urn:isbn:9789189709478 urn:isbn:9789189709461 doi:10.15626/LUD.467.2022 info:eu-repo/semantics/openAccess continuous cover forestry selective cutting Picea abies uneven-aged single-tree-selection growth model knot size model Forest Science Skogsvetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2022 ftlinnaeusuniv https://doi.org/10.15626/LUD.467.2022 2024-03-13T03:16:54Z Individual-tree-selection (ITS) is a continuous cover forestry method that aims to utilize the uneven-sized stand structure through optimized individual tree selections. ITS is an interesting management alternative to rotation forestry in terms of production of multiple benefits and forest owner profitability. With regard to Fennoscandia, ITS is currently only practiced to a limited extent, partly because of a scarcity in knowledge and skills among all stakeholders, but also due to the shortage of scientific guidelines for how optimized tree selections are performed in practice. Thus, the aim of the thesis is to develop tools for optimizing practical ITS recommendations for Norway spruce. Tree position data for model fitting were collected from five trial sites in southern Sweden, one of which was documented with terrestrial laser scanning to get crown shape data for knot size modelling. A method that optimizes the target diameter dependent on the discount rate and the degree of the local competition exposed to the subject tree, was developed. Technically, a defined adaptive control function was optimized with full system stochastic simulation and with expected present value as the objective function variable. Since the quality of the optimization is dependent on the quality of the models in the simulation, priority was given to the evaluation and development of the central models. Available individual tree growth models were tested and evaluated with tree data from long term uneven-sized trial plots. Furthermore, new individual-tree distance-dependent growth models were developed for uneven-sized Norway spruce. A modelling framework, for prediction of the largest knot size per stem height section, was developed to provide means of simulating log quality depending on impact from local tree competitors. The results indicated that the thinning intensity in uneven-sized stand structures may be used to actively control the transition point where smaller diameter classes are subjected to suppressed growth. The ... Doctoral or Postdoctoral Thesis Fennoscandia Linnaeus University Kalmar Växjö: Publications (DiVA) Norway |
institution |
Open Polar |
collection |
Linnaeus University Kalmar Växjö: Publications (DiVA) |
op_collection_id |
ftlinnaeusuniv |
language |
English |
topic |
continuous cover forestry selective cutting Picea abies uneven-aged single-tree-selection growth model knot size model Forest Science Skogsvetenskap |
spellingShingle |
continuous cover forestry selective cutting Picea abies uneven-aged single-tree-selection growth model knot size model Forest Science Skogsvetenskap Fagerberg, Nils Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
topic_facet |
continuous cover forestry selective cutting Picea abies uneven-aged single-tree-selection growth model knot size model Forest Science Skogsvetenskap |
description |
Individual-tree-selection (ITS) is a continuous cover forestry method that aims to utilize the uneven-sized stand structure through optimized individual tree selections. ITS is an interesting management alternative to rotation forestry in terms of production of multiple benefits and forest owner profitability. With regard to Fennoscandia, ITS is currently only practiced to a limited extent, partly because of a scarcity in knowledge and skills among all stakeholders, but also due to the shortage of scientific guidelines for how optimized tree selections are performed in practice. Thus, the aim of the thesis is to develop tools for optimizing practical ITS recommendations for Norway spruce. Tree position data for model fitting were collected from five trial sites in southern Sweden, one of which was documented with terrestrial laser scanning to get crown shape data for knot size modelling. A method that optimizes the target diameter dependent on the discount rate and the degree of the local competition exposed to the subject tree, was developed. Technically, a defined adaptive control function was optimized with full system stochastic simulation and with expected present value as the objective function variable. Since the quality of the optimization is dependent on the quality of the models in the simulation, priority was given to the evaluation and development of the central models. Available individual tree growth models were tested and evaluated with tree data from long term uneven-sized trial plots. Furthermore, new individual-tree distance-dependent growth models were developed for uneven-sized Norway spruce. A modelling framework, for prediction of the largest knot size per stem height section, was developed to provide means of simulating log quality depending on impact from local tree competitors. The results indicated that the thinning intensity in uneven-sized stand structures may be used to actively control the transition point where smaller diameter classes are subjected to suppressed growth. The ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Fagerberg, Nils |
author_facet |
Fagerberg, Nils |
author_sort |
Fagerberg, Nils |
title |
Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
title_short |
Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
title_full |
Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
title_fullStr |
Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
title_full_unstemmed |
Individual-tree-selection in uneven-sized Norway spruce stands in southern Sweden : Developments of tools for simulation and optimization |
title_sort |
individual-tree-selection in uneven-sized norway spruce stands in southern sweden : developments of tools for simulation and optimization |
publisher |
Linnéuniversitetet, Institutionen för skog och träteknik (SOT) |
publishDate |
2022 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-116633 https://doi.org/10.15626/LUD.467.2022 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_relation |
Linnaeus University Dissertations 467 orcid:0000-0001-7731-1593 http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-116633 urn:isbn:9789189709478 urn:isbn:9789189709461 doi:10.15626/LUD.467.2022 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.15626/LUD.467.2022 |
_version_ |
1795667716837736448 |