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Volumn 43, Issue 3, 2009, Pages 411-431

Sawn timber properties of scots pine as affected by initial stand density, thinning and pruning: A simulation based approach

Author keywords

Knots; Pinus sylvestris L.; Sawing simulator; Shading; Three dimensional modeling

Indexed keywords

DENSE STANDS; INTEGRATED MODELS; KNOTS; LIGHT CONDITIONS; MODEL DEVELOPMENT; PINUS SYLVESTRIS; PINUS SYLVESTRIS L.; SAWN TIMBERS; SCOTS PINE; SELF-PRUNING; SHADING; SIMULATION-BASED; STAND DENSITIES; STAND MANAGEMENT; STEM VOLUME; THREE-DIMENSIONAL MODELING; THREE-DIMENSIONAL STRUCTURE; VALUE OPTIMIZATION;

EID: 70349491218     PISSN: 00375330     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article
Times cited : (20)

References (53)
  • 1
    • 0030617080 scopus 로고    scopus 로고
    • Simulated stand characteristics and wood product yields from Douglas-fir plantations managed for ecosystem objectives
    • Barbour, R.J., Johnston, S., Hayes, J.P. & Tucker, G.F. 1997. Simulated stand characteristics and wood product yields from Douglas-fir plantations managed for ecosystem objectives. Forest Ecology and Management 91: 205-218.
    • (1997) Forest Ecology and Management , vol.91 , pp. 205-218
    • Barbour, R.J.1    Johnston, S.2    Hayes, J.P.3    Tucker, G.F.4
  • 2
    • 2642659407 scopus 로고    scopus 로고
    • The interior knot structure of Pinus sylvestris stems
    • Björklund, L. 1997. The interior knot structure of Pinus sylvestris stems. Scandinavian Journal of Forest Research 12: 403-412.
    • (1997) Scandinavian Journal of Forest Research , vol.12 , pp. 403-412
    • Björklund, L.1
  • 4
    • 0021541565 scopus 로고
    • Competition within stands of Picea sitchensis and Pinus contorta
    • Cannell, M.G.R., Rothery, P. & Ford, E.D. 1984. Competition within stands of Picea sitchensis and Pinus contorta. Annals of Botany 53: 349-362.
    • (1984) Annals of Botany , vol.53 , pp. 349-362
    • Cannell, M.G.R.1    Rothery, P.2    Ford, E.D.3
  • 5
    • 0033707126 scopus 로고    scopus 로고
    • Validation of a CT-based simulator against a sawmill yield
    • Chiorescu, S. & Grönlund, A. 2000. Validation of a CT-based simulator against a sawmill yield. Forest Products Journal 50(6): 69-76.
    • (2000) Forest Products Journal , vol.50 , Issue.6 , pp. 69-76
    • Chiorescu, S.1    Grönlund, A.2
  • 6
    • 0000706934 scopus 로고
    • Branchiness of Norway spruce in northeastern France: Predicting the main crown characteristics from usual tree measurements
    • Colin, F. & Houllier, F. 1992. Branchiness of Norway spruce in northeastern France: predicting the main crown characteristics from usual tree measurements. Annals of Forest Science 49: 511-538.
    • (1992) Annals of Forest Science , vol.49 , pp. 511-538
    • Colin, F.1    Houllier, F.2
  • 8
    • 0001953152 scopus 로고
    • Investigations on the basic density of Finnish pine, spruce and birch wood
    • Hakkila, P. 1966. Investigations on the basic density of Finnish pine, spruce and birch wood. Communicationes Instituti Forestalis Fenniae 61(5). 98 p.
    • (1966) Communicationes Instituti Forestalis Fenniae , vol.61 , Issue.5 , pp. 98
    • Hakkila, P.1
  • 9
    • 0003265552 scopus 로고
    • Puun rungon luontaisesta karsiutumisesta. Summary: On natural pruning of tree stems
    • Heikinheimo, O. 1953. Puun rungon luontaisesta karsiutumisesta. Summary: On natural pruning of tree stems. Communicationes Instituti Forestalis Fenniae 41(5). 39 p.
    • (1953) Communicationes Instituti Forestalis Fenniae , vol.41 , Issue.5 , pp. 39
    • Heikinheimo, O.1
  • 10
    • 0003264596 scopus 로고
    • On the relations between the development of the early age and thickness of trees and their branchiness in pine stands
    • (In Finnish with English summary.)
    • Heiskanen, V. 1965. On the relations between the development of the early age and thickness of trees and their branchiness in pine stands. Acta Forestalia Fennica 80(2). 62 p. (In Finnish with English summary.)
    • (1965) Acta Forestalia Fennica , vol.80 , Issue.2 , pp. 62
    • Heiskanen, V.1
  • 12
    • 0028833994 scopus 로고
    • Linking growth modelling to timber quality assessment for Norway spruce
    • Houllier, F., Leban, J.M. & Colin, F. 1995. Linking growth modelling to timber quality assessment for Norway spruce. Forest Ecology and Management 74: 91-102.
    • (1995) Forest Ecology and Management , vol.74 , pp. 91-102
    • Houllier, F.1    Leban, J.M.2    Colin, F.3
  • 13
    • 0037450695 scopus 로고    scopus 로고
    • Linking tree stem properties of Scots pine (Pinus sylvestris L.) to sawn timber properties through simulated sawing
    • Ikonen, V.-P., Kellomäki, S. & Peltola, H. 2003. Linking tree stem properties of Scots pine (Pinus sylvestris L.) to sawn timber properties through simulated sawing. Forest Ecology and Management 174: 251-263.
    • (2003) Forest Ecology and Management , vol.174 , pp. 251-263
    • Ikonen, V.-P.1    Kellomäki, S.2    Peltola, H.3
  • 14
    • 49749108551 scopus 로고    scopus 로고
    • Modelling the distribution of wood properties along the stems of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) as affected by silvicultural management
    • doi:10.1016/j.foreco.2008.06.039
    • Ikonen, V.-P., Peltola, H., Wilhelmsson, L., Kilpeläinen, A., Väisänen, H., Nuutinen, T. & Kellomäki, S. 2008. Modelling the distribution of wood properties along the stems of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) as affected by silvicultural management. Forest Ecology and Management 256: 1356-1371. doi:10.1016/j.foreco.2008.06.039
    • (2008) Forest Ecology and Management , vol.256 , pp. 1356-1371
    • Ikonen, V.-P.1    Peltola, H.2    Wilhelmsson, L.3    Kilpeläinen, A.4    Väisänen, H.5    Nuutinen, T.6    Kellomäki, S.7
  • 15
    • 0030357146 scopus 로고    scopus 로고
    • Timber quality after thinning from above and below in stands of Pinus sylvestris
    • Jäghagen, K. & Lageson, H. 1996. Timber quality after thinning from above and below in stands of Pinus sylvestris. Scandinavian Journal of Forest Research 11: 336-342.
    • (1996) Scandinavian Journal of Forest Research , vol.11 , pp. 336-342
    • Jäghagen, K.1    Lageson, H.2
  • 16
    • 70349555981 scopus 로고    scopus 로고
    • Simulated yield and quality distribution of sawn timber from final felling in a Norway spruce (Picea abies [L.] Karst.) stand with varying thinning regimes - A case study
    • Doctoral thesis. University of Helsinki, Department of Forest Ecology
    • Kantola, A., Song, T., Usenius, A. & Heikkilä, A. 2008. Simulated yield and quality distribution of sawn timber from final felling in a Norway spruce (Picea abies [L.] Karst.) stand with varying thinning regimes - a case study. In: Kantola, A. 2008. The structure of Norway spruce (Picea abies [L.] Karst.) stems in relation to wood properties of sawn timber. Doctoral thesis. University of Helsinki, Department of Forest Ecology.
    • (2008) Kantola, A , pp. 2008
    • Kantola, A.1    Song, T.2    Usenius, A.3    Heikkilä, A.4
  • 17
    • 5044221574 scopus 로고
    • Nuorten mäntyjen laatuun vaikuttavia tekijöitä
    • (In Finnish.)
    • Kärkkäinen, M. & Uusvaara, O. 1982. Nuorten mäntyjen laatuun vaikuttavia tekijöitä. Folia Forestalia 515. 28 p. (In Finnish.)
    • (1982) Folia Forestalia , vol.515 , pp. 28
    • Kärkkäinen, M.1    Uusvaara, O.2
  • 18
    • 0028978977 scopus 로고
    • A model for the structural growth of young Scots pine crowns based on light interception by shoots
    • Kellomäki, S. & Strandman, H. 1995. A model for the structural growth of young Scots pine crowns based on light interception by shoots. Ecological Modelling 80: 237-250.
    • (1995) Ecological Modelling , vol.80 , pp. 237-250
    • Kellomäki, S.1    Strandman, H.2
  • 19
    • 0344585242 scopus 로고
    • Effect of stand density on branchiness of young Scots pines
    • (In Finnish with English summary.)
    • Kellomäki, S. & Tuimala, A. 1981. Effect of stand density on branchiness of young Scots pines. Folia Forestalia 478. 27 p. (In Finnish with English summary.)
    • (1981) Folia Forestalia , vol.478 , pp. 27
    • Kellomäki, S.1    Tuimala, A.2
  • 20
    • 5344246568 scopus 로고
    • Effect of stand density and site fertility on the branchiness of Scots pines at pole stage
    • (In Finnish with English sum, mary.)
    • Kellomäki, S. & Väisänen, H. 1986. Effect of stand density and site fertility on the branchiness of Scots pines at pole stage. Communicationes Instituti Forestalis Fenniae 139. 38 p. (In Finnish with English summary.)
    • (1986) Communicationes Instituti Forestalis Fenniae , vol.139 , pp. 38
    • Kellomäki, S.1    Väisänen, H.2
  • 21
    • 0024887108 scopus 로고
    • Structural development of Scots pine stands with varying initial density: Effect of pruning on branchiness of wood
    • Kellomäki, S., Oker-Blom, P., Valtonen, E. & Väisänen, H. 1989. Structural development of Scots pine stands with varying initial density: Effect of pruning on branchiness of wood. Forest Ecology and Management 27: 219-233.
    • (1989) Forest Ecology and Management , vol.27 , pp. 219-233
    • Kellomäki, S.1    Oker-Blom, P.2    Valtonen, E.3    Väisänen, H.4
  • 22
    • 0345425073 scopus 로고    scopus 로고
    • Modelling the structural growth of Scots pine with implications for wood quality
    • Kellomäki, S., Ikonen, V.-P., Peltola, H. & Kolström, T. 1999. Modelling the structural growth of Scots pine with implications for wood quality. Ecological Modelling 122: 117-134.
    • (1999) Ecological Modelling , vol.122 , pp. 117-134
    • Kellomäki, S.1    Ikonen, V.-P.2    Peltola, H.3    Kolström, T.4
  • 23
    • 0005647651 scopus 로고    scopus 로고
    • Linking models for tree growth and wood quality in Norway spruce. Part I: Validation of predictions for sawn board properties, ring width, wood density and knottiness
    • 26-31 August 1996, Kruger National Park, South Africa. Edited by Gérard Nepveu, INRA-Nancy
    • Leban, J.M., Daquitaine, R., Houllier, F. & Saint-Andre, L. 1996. Linking models for tree growth and wood quality in Norway spruce. Part I: Validation of predictions for sawn board properties, ring width, wood density and knottiness. In Proceedings of the 2nd Workshop on Connection between Silviculture and Wood Quality through Modelling Approaches and Simulation Software, 26-31 August 1996, Kruger National Park, South Africa. Edited by Gérard Nepveu, INRA-Nancy. p. 220-229.
    • (1996) Proceedings of the 2nd Workshop on Connection between Silviculture and Wood Quality through Modelling Approaches and Simulation Software , pp. 220-229
    • Leban, J.M.1    Daquitaine, R.2    Houllier, F.3    Saint-Andre, L.4
  • 25
    • 10344228287 scopus 로고    scopus 로고
    • Relationships between stem size and branch basal diameter variability in Norway spruce (Picea abies (L.) Karsten) from two regions of France
    • DOI: 10.1051/forest:2004047
    • Loubère, M., Saint-André, L., Hervé, J.-C. & Vestøl, G.I. 2004. Relationships between stem size and branch basal diameter variability in Norway spruce (Picea abies (L.) Karsten) from two regions of France. Annals of Forest Science 61: 525-535. DOI: 10.1051/forest:2004047
    • (2004) Annals of Forest Science , vol.61 , pp. 525-535
    • Loubère, M.1    Saint-André, L.2    Hervé, J.-C.3    Vestøl, G.I.4
  • 26
    • 0035165812 scopus 로고    scopus 로고
    • Vertical structure of Scots pine crowns in different age and size classes
    • Mäkelä, A. & Vanninen, P. 2001. Vertical structure of Scots pine crowns in different age and size classes. Trees 15: 385-392.
    • (2001) Trees , vol.15 , pp. 385-392
    • Mäkelä, A.1    Vanninen, P.2
  • 27
    • 0001583737 scopus 로고    scopus 로고
    • An application of process-based modelling to the development of branchiness in Scots pine
    • Mäkelä, A., Vanninen, P. & Ikonen, V.-P. 1997. An application of process-based modelling to the development of branchiness in Scots pine. Silva Fennica 31(3): 369-380.
    • (1997) Silva Fennica , vol.31 , Issue.3 , pp. 369-380
    • Mäkelä, A.1    Vanninen, P.2    Ikonen, V.-P.3
  • 28
    • 0033055810 scopus 로고    scopus 로고
    • Growth, suppression, death, and self-pruning of branches of Scots pine in southern and central Finland
    • Mäkinen, H. 1999. Growth, suppression, death, and self-pruning of branches of Scots pine in southern and central Finland. Canadian Journal of Forest Research 29: 585-594.
    • (1999) Canadian Journal of Forest Research , vol.29 , pp. 585-594
    • Mäkinen, H.1
  • 29
    • 0032216353 scopus 로고    scopus 로고
    • Predicting branch angle and branch diameter of Scots pine from usual tree measurements and stand structural information
    • Mäkinen, H. & Colin F. 1998. Predicting branch angle and branch diameter of Scots pine from usual tree measurements and stand structural information. Canadian Journal of Forest Research 28: 1686-1696.
    • (1998) Canadian Journal of Forest Research , vol.28 , pp. 1686-1696
    • Mäkinen, H.1    Colin, F.2
  • 30
    • 0033305911 scopus 로고    scopus 로고
    • Predicting the number, death, and self-pruning of branches in Scots pine
    • Mäkinen, H. & Colin, F. 1999. Predicting the number, death, and self-pruning of branches in Scots pine. Canadian Journal of Forest Research 29: 1225-1236.
    • (1999) Canadian Journal of Forest Research , vol.29 , pp. 1225-1236
    • Mäkinen, H.1    Colin, F.2
  • 32
    • 0005824192 scopus 로고    scopus 로고
    • Models of knot properties for Norway spruce and Scots pine
    • In Doctoral thesis, Uppsala, Sweden
    • Moberg, L. 1999. Models of knot properties for Norway spruce and Scots pine. In Doctoral thesis. Swedish University of Agricultural Sciences, Uppsala, Sweden. 24 p.
    • (1999) Swedish University of Agricultural Sciences , pp. 24
    • Moberg, L.1
  • 33
    • 0034128422 scopus 로고    scopus 로고
    • Models of internal knot diameter for Pinus sylvestris
    • Moberg, L. 2000. Models of internal knot diameter for Pinus sylvestris. Scandinavian Journal of Forest Research 15: 177-187.
    • (2000) Scandinavian Journal of Forest Research , vol.15 , pp. 177-187
    • Moberg, L.1
  • 34
    • 0035973417 scopus 로고    scopus 로고
    • Models of internal knot properties for Picea abies
    • Moberg, L. 2001. Models of internal knot properties for Picea abies. Forest Ecology and Management 147: 123-138.
    • (2001) Forest Ecology and Management , vol.147 , pp. 123-138
    • Moberg, L.1
  • 35
    • 33644611953 scopus 로고    scopus 로고
    • Predicting knot properties of Picea abies and Pinus sylvestris from generic tree descriptors
    • Moberg, L. 2006. Predicting knot properties of Picea abies and Pinus sylvestris from generic tree descriptors. Scandinavian Journal of Forest Research 21(7): 48-61.
    • (2006) Scandinavian Journal of Forest Research , vol.21 , Issue.7 , pp. 48-61
    • Moberg, L.1
  • 36
    • 33644616303 scopus 로고    scopus 로고
    • Predicting lumber volume and grade recovery for Scots pine stems using tree models and sawmill conversion simulation
    • Moberg, L. & Nordmark, U. 2006. Predicting lumber volume and grade recovery for Scots pine stems using tree models and sawmill conversion simulation. Forest products journal 56: 68-74.
    • (2006) Forest products journal , vol.56 , pp. 68-74
    • Moberg, L.1    Nordmark, U.2
  • 37
    • 0027951064 scopus 로고
    • Development of growth and stand structure in Norway spruce stands planted withdifferent initial densities
    • Nilsson, U. 1994. Development of growth and stand structure in Norway spruce stands planted withdifferent initial densities. Scandinavian Journal ofForest Research 9: 135-142.
    • (1994) Scandinavian Journal ofForest Research , vol.9 , pp. 135-142
    • Nilsson, U.1
  • 38
    • 0027836787 scopus 로고
    • Changes in growth and allocation of growth in young Scots pine and Norway spruce due to competition
    • Nilsson, U. & Gemmel, P. 1993. Changes in growth and allocation of growth in young Scots pine and Norway spruce due to competition. Scandinavian Journal of Forest Research 8(2): 213-223.
    • (1993) Scandinavian Journal of Forest Research , vol.8 , Issue.2 , pp. 213-223
    • Nilsson, U.1    Gemmel, P.2
  • 39
    • 70349557529 scopus 로고
    • Grading rules for pine (Pinus sylvestris) and spruce (Picea abies) sawn timber
    • Nordic timber grading rules, Föreningen Svenska Sågverksmän (FSS)/Suomen Sahateollisuusmiesten Yhdistys (STMY)/Treindustriens Tekniske Forening (TTF)/Markaryds Grafiska, Sweden/Finland/Norway/Markaryd (printing)
    • Nordic timber grading rules. 1994. Grading rules for pine (Pinus sylvestris) and spruce (Picea abies) sawn timber. Commercial Grading Based on Evaluation of the Four Sides of Sawn Timber. Föreningen Svenska Sågverksmän (FSS)/Suomen Sahateollisuusmiesten Yhdistys (STMY)/Treindustriens Tekniske Forening (TTF)/Markaryds Grafiska, Sweden/Finland/Norway/Markaryd (printing). 80 p.
    • (1994) Commercial Grading Based on Evaluation of the Four Sides of Sawn Timber , pp. 80
  • 40
    • 6344241904 scopus 로고    scopus 로고
    • Prediction of board values in Pinus sylvestris sawlogs using X-ray scanning and optical three-dimensional scanning of stems
    • doi: 10.1080/02827580410030172
    • Nordmark, U. & Oja, J. 2004. Prediction of board values in Pinus sylvestris sawlogs using X-ray scanning and optical three-dimensional scanning of stems. Scandinavian Journal of Forest Research 19: 473-480. doi: 10.1080/02827580410030172
    • (2004) Scandinavian Journal of Forest Research , vol.19 , pp. 473-480
    • Nordmark, U.1    Oja, J.2
  • 42
    • 36448965589 scopus 로고    scopus 로고
    • Effects of early thinning regime and tree status on the radial growth and wood density of Scots pine
    • Peltola, H., Kilpeläinen, A., Sauvala, K., Räisänen, T. & Ikonen, V.-P. 2007. Effects of early thinning regime and tree status on the radial growth and wood density of Scots pine. Silva Fennica 41(3): 489-505.
    • (2007) Silva Fennica , vol.41 , Issue.3 , pp. 489-505
    • Peltola, H.1    Kilpeläinen, A.2    Sauvala, K.3    Räisänen, T.4    Ikonen, V.-P.5
  • 43
    • 0031881579 scopus 로고    scopus 로고
    • Prediction of branch variables related to timber quality in Pinus sylvestris
    • Petersson, H. 1998. Prediction of branch variables related to timber quality in Pinus sylvestris. Scandinavian Journal of Forest Research 13: 21-30.
    • (1998) Scandinavian Journal of Forest Research , vol.13 , pp. 21-30
    • Petersson, H.1
  • 44
    • 31144447380 scopus 로고    scopus 로고
    • Simulated and realized industrial yields in sawing of maritime pine (Pinus pinaster Ait.)
    • doi: 10.1007/ s00107-005-0042-3
    • Pinto, I., Knapic, S., Pereira, H. & Usenius, A. 2006. Simulated and realized industrial yields in sawing of maritime pine (Pinus pinaster Ait.). Holz als Rohund Werkstoff 64: 30-36. doi: 10.1007/ s00107-005-0042-3
    • (2006) Holz als Rohund Werkstoff , vol.64 , pp. 30-36
    • Pinto, I.1    Knapic, S.2    Pereira, H.3    Usenius, A.4
  • 45
    • 0030821828 scopus 로고    scopus 로고
    • Crown profile models based on branch attributes in coastal Douglas-fir
    • Roeh, R.L. & Maguire, D.A. 1997. Crown profile models based on branch attributes in coastal Douglas-fir. Forest Ecology and Management 96: 77-100.
    • (1997) Forest Ecology and Management , vol.96 , pp. 77-100
    • Roeh, R.L.1    Maguire, D.A.2
  • 46
    • 0003225892 scopus 로고
    • The effect of fertilization on the basic density of Scots pine (Pinus sylvestris L.). A densitometric study on the X-ray chart curves of wood
    • Saikku, O. 1975. The effect of fertilization on the basic density of Scots pine (Pinus sylvestris L.). A densitometric study on the X-ray chart curves of wood. Communicationes Instituti Forestalis Fenniae 85(3). 49 p.
    • (1975) Communicationes Instituti Forestalis Fenniae , vol.85 , Issue.3 , pp. 49
    • Saikku, O.1
  • 48
    • 0008406586 scopus 로고
    • Kasvupaikan viljavuuden ja puuston tiheyden vaikutus nuorten mäntyjen oksien läpimittaan
    • (In Finnish.)
    • Turkia, K. & Kellomäki, S. 1987. Kasvupaikan viljavuuden ja puuston tiheyden vaikutus nuorten mäntyjen oksien läpimittaan. Folia Foretalia 705. 16 p. (In Finnish.)
    • (1987) Folia Foretalia , vol.705 , pp. 16
    • Turkia, K.1    Kellomäki, S.2
  • 49
    • 5044234978 scopus 로고    scopus 로고
    • The effect of two bucking methods on Scots pine lumber quality
    • Uusitalo, J., Kokko, S. & Kivinen, V.-P. 2004. The effect of two bucking methods on Scots pine lumber quality. Silva Fennica 38(3): 291-303.
    • (2004) Silva Fennica , vol.38 , Issue.3 , pp. 291-303
    • Uusitalo, J.1    Kokko, S.2    Kivinen, V.-P.3
  • 51
    • 0002308356 scopus 로고
    • The quality and value of sawn goods from plantation-grown Scots pine
    • Uusvaara, O. 1985. The quality and value of sawn goods from plantation-grown Scots pine. Communicationes Instituti Forestalis Fenniae 130. 53 p.
    • (1985) Communicationes Instituti Forestalis Fenniae , vol.130 , pp. 53
    • Uusvaara, O.1
  • 52
    • 70349540850 scopus 로고
    • Pystykarsituista männiköistä valmistetun sahatavaran laatu ja arvo. Summary: Quality and value of sawn goods from pruned Scots pine stands
    • Uusvaara, O. 1993. Pystykarsituista männiköistä valmistetun sahatavaran laatu ja arvo. Summary: Quality and value of sawn goods from pruned Scots pine stands. Folia Forestalia 816. 26 p.
    • (1993) Folia Forestalia , vol.816 , pp. 26
    • Uusvaara, O.1
  • 53
    • 0000905242 scopus 로고
    • Structural development of Pinus sylvestris stands with varying initial density: A preliminary model for quality of sawn timber as affected by silvicultural measures
    • Väisänen, H., Kellomäki, S., Oker-Blom, P. & Valtonen, E. 1989. Structural development of Pinus sylvestris stands with varying initial density: a preliminary model for quality of sawn timber as affected by silvicultural measures. Scandinavian Journal of Forest Research 4: 223-238.
    • (1989) Scandinavian Journal of Forest Research , vol.4 , pp. 223-238
    • Väisänen, H.1    Kellomäki, S.2    Oker-Blom, P.3    Valtonen, E.4


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