Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia)
In Sweden, large scale planting of Lodgepole pine (Pinus contorta var. latifolia) started in the beginning of the 1970’s. At first, the aim was production of pulpwood, but later, also production of timber became considered realistic. Today, Sweden has more than 520 000 ha of Lodgepole pine. Vast are...
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| Formato: | Second cycle, A1E |
| Lenguaje: | sueco sueco |
| Publicado: |
2010
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| Acceso en línea: | https://stud.epsilon.slu.se/1092/ |
| _version_ | 1855570262270935040 |
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| author | Ledin, Johan |
| author_browse | Ledin, Johan |
| author_facet | Ledin, Johan |
| author_sort | Ledin, Johan |
| collection | Epsilon Archive for Student Projects |
| description | In Sweden, large scale planting of Lodgepole pine (Pinus contorta var. latifolia) started in the beginning of the 1970’s. At first, the aim was production of pulpwood, but later, also production of timber became considered realistic. Today, Sweden has more than 520 000 ha of Lodgepole pine. Vast areas are now ready for thinning. However, the knowledge regarding forest management practices are still relatively limited. Among other studies, a master thesis shows that many properties of quality are dependant on the initial spacing. Two 20 years old Swedish spacing trials were then studied; Långsjönäset in Jämtland and Ängomsåsen in Medelpad.
In this study, selected quality properties were again analysed on the same two spacing trials, now in an age of 41 years. The hypothesis was that butt logs with thinner branches, smaller relative branch diameter and smaller butt log taper are developed in more dense spacings. Another hypothesis was that initial spacing does not affect the frequency of basal- and bole sweeps and broken tops. Initial spacings of 1.60 m, 2.00 m, 2.85 m and 4.00 m were analysed. In total, 690 stems were included in the study. Butt log was identified as the first 4 m of the stem above height of the stump. Results from this study were also further compared with results from the above mentioned master thesis.
For the three properties; thickest branch diameter, relative branch diameter and butt log taper, trees growing in an initial spacing of 2.85 m were of statistically significant lower quality than trees growing in a 2.00 m spacing. Between the initial spacings 1.60 m and 2.00 m no statistically significant differences could be found regarding these three quality properties. These results indicates that spacings denser than 2.00 m does not produce significally higher quality in the butt log. Only the initial spacing of 4.00 m was of statistically significant lower quality than the more dense spacings with respect to basal- and bole sweeps and broken tops. The present age of the stands is suitable for evaluation of quality properties. The results can be used as decision support concerning future management practices for stands and further industrial use of the wood.
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| format | Second cycle, A1E |
| id | RepoSLU1092 |
| institution | Swedish University of Agricultural Sciences |
| language | swe swe |
| publishDate | 2010 |
| publishDateSort | 2010 |
| record_format | eprints |
| spelling | RepoSLU10922012-04-20T14:12:22Z https://stud.epsilon.slu.se/1092/ Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) Ledin, Johan Forestry production In Sweden, large scale planting of Lodgepole pine (Pinus contorta var. latifolia) started in the beginning of the 1970’s. At first, the aim was production of pulpwood, but later, also production of timber became considered realistic. Today, Sweden has more than 520 000 ha of Lodgepole pine. Vast areas are now ready for thinning. However, the knowledge regarding forest management practices are still relatively limited. Among other studies, a master thesis shows that many properties of quality are dependant on the initial spacing. Two 20 years old Swedish spacing trials were then studied; Långsjönäset in Jämtland and Ängomsåsen in Medelpad. In this study, selected quality properties were again analysed on the same two spacing trials, now in an age of 41 years. The hypothesis was that butt logs with thinner branches, smaller relative branch diameter and smaller butt log taper are developed in more dense spacings. Another hypothesis was that initial spacing does not affect the frequency of basal- and bole sweeps and broken tops. Initial spacings of 1.60 m, 2.00 m, 2.85 m and 4.00 m were analysed. In total, 690 stems were included in the study. Butt log was identified as the first 4 m of the stem above height of the stump. Results from this study were also further compared with results from the above mentioned master thesis. For the three properties; thickest branch diameter, relative branch diameter and butt log taper, trees growing in an initial spacing of 2.85 m were of statistically significant lower quality than trees growing in a 2.00 m spacing. Between the initial spacings 1.60 m and 2.00 m no statistically significant differences could be found regarding these three quality properties. These results indicates that spacings denser than 2.00 m does not produce significally higher quality in the butt log. Only the initial spacing of 4.00 m was of statistically significant lower quality than the more dense spacings with respect to basal- and bole sweeps and broken tops. The present age of the stands is suitable for evaluation of quality properties. The results can be used as decision support concerning future management practices for stands and further industrial use of the wood. I Sverige påbörjades storskalig plantering av Contortatall (Pinus contorta var. latifolia) i början av 1970-talet. Massavedsproduktion var ursprungstanken men med tiden fann man contortan även lämplig för sågtimmerproduktion. I Sverige finns idag drygt 520 000 ha contorta och stora arealer börjar nu bli gallringsmogna. Produktionskunskapen är dock fortfarande begränsad; men ett tidigare masterarbete på då 20-åriga försökslokaler, Långsjönäset i Jämtland och Ängomsåsen i Medelpad, visar att många kvalitetsegenskaper påverkas av planteringsförbandet. I denna studie studerades återigen utvalda kvalitetsegenskaper på ovan nämnda lokaler, nu när träden uppnått 41 års totalålder. Hypoteserna var dels att rotstockar med klenare kvist, mindre relativ kvistdiameter och mindre avsmalning utvecklas i tätare förband, dels att gällande basal- och stamkrökar samt toppbrott har förbandet ingen påverkan på skadefrekvensen. Förbanden 1,60 m, 2,00 m, 2,85 m och 4,00 m studerades. Totalt mättes 690 stammar, rotstock utgjordes av stammens första 4 m ovan stubbhöjd. Resultat jämfördes också med resultat från ovan nämnt masterarbete. För de tre kvalitetsegenskaperna grövsta kvistdiameter, relativ kvistdiameter och stammens avsmalning var förband 2,85 m av statistiskt säkerställd sämre kvalitet än förband 2,00 m. Däremot fanns inga signifikanta skillnader mellan förbanden 1,60 m och 2,00 m gällande dessa tre kvalitetsegenskaper. Detta indikerar att förband tätare än 2,00 m troligen inte genererar signifikant bättre kvalitet i rotstocken. För krökar och toppbrott var endast förbandet 4,00 m av statistiskt säkerställd sämre kvalitet än övriga förband. Nuvarande beståndsålder är lämplig för utvärderingar av kvalitetsegenskaper. Resultaten används med fördel som beslutsstöd för fortsatt beståndsskötsel och industriell virkesanvändning. 2010-04-23 Second cycle, A1E NonPeerReviewed application/pdf swe https://stud.epsilon.slu.se/1092/1/Ledin_J_100423.pdf Ledin, Johan, 2010. Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia). Second cycle, A1E. Umeå: (S) > Dept. of Forest Ecology and Management <https://stud.epsilon.slu.se/view/divisions/OID-241.html> urn:nbn:se:slu:epsilon-2-404 swe |
| spellingShingle | Forestry production Ledin, Johan Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title | Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title_full | Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title_fullStr | Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title_full_unstemmed | Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title_short | Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia) |
| title_sort | planteringsförbandets betydelse för kvalitetsegenskaper i contortatall (pinus contorta var. latifolia) |
| topic | Forestry production |
| url | https://stud.epsilon.slu.se/1092/ https://stud.epsilon.slu.se/1092/ |