Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris
The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) ("C") which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylves...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Forest Ecology and Management
2008
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| Materias: |
| _version_ | 1855572001249296384 |
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| author | Persson, Cecilia |
| author_browse | Persson, Cecilia |
| author_facet | Persson, Cecilia |
| author_sort | Persson, Cecilia |
| collection | Epsilon Archive for Student Projects |
| description | The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) ("C") which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) ("S").But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed. To establish a better comparison between the coniferous species initiated SCA in 1970 new experimental stands where C and S were planted under the same conditions. These experimental stands were measured 1979, 1984 and 1991 and the data were used for development of growth models.
The purpose of this study was to follow up growth- and saw timber quality development in SCA´s experimental stands with C and S. On the basis of previous comparisons of the species the following hypothesis were formulated:
• The total growth is up till now 50 % superior in C than in S
• The dominant height in studied stands is developing according to height curves both for C and S
• The "future stems" have almost the same saw timber quality in C and S
Nine experimental stands from Åsarna in Jämtlad to Vilhelmina in Lapland (middle north Sweden) were visited in autumn 2007. In every experimental stand ten permanent plots were examined, five in C stands and five in S. On those plots all trees with dbh > 5 cm were callipered and height was measured on sample trees. About 20 "potential final cut trees" were appointed within a radius of 10 m and the criterion for those trees was that they visually showed on good saw timber quality.
The total growth, including thinned trees for C was as a mean value 53 % higher than for S. The average growing stock was 179 m3sk/ha in C and 134 m3sk/ha in S. The development of C follows the yield models as predicted. Until 1991 C had a higher survival rate than S. Three C stands were tinned (9064, 9066 and 9072) in the beginning of 2000. Those stands had a higher natural mortality.
The top height development the last 16 years followed the height development curves. For C the top height in average followed the curve for site index T27 and S top height is increased with the curve for T24.
Of the "potential final cut trees" 21 % of C were straight and with no spike knots and for S the corresponding figure was 30 %. In the C stands a larger amount of the future stems had a bend while the S stands had more future stems with spike knots. |
| format | L3 |
| id | RepoSLU12105 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2008 |
| publishDateSort | 2008 |
| publisher | SLU/Dept. of Forest Ecology and Management |
| publisherStr | SLU/Dept. of Forest Ecology and Management |
| record_format | eprints |
| spelling | RepoSLU121052017-11-07T12:20:14Z Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris Growth and potential saw timber quality in comparison plantations with Pinus contorta and P. sylvestris at the stage of first thinning Persson, Cecilia Pinus contorta Pinus sylvestris jämförelse produktion kvalitet The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) ("C") which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) ("S").But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed. To establish a better comparison between the coniferous species initiated SCA in 1970 new experimental stands where C and S were planted under the same conditions. These experimental stands were measured 1979, 1984 and 1991 and the data were used for development of growth models. The purpose of this study was to follow up growth- and saw timber quality development in SCA´s experimental stands with C and S. On the basis of previous comparisons of the species the following hypothesis were formulated: • The total growth is up till now 50 % superior in C than in S • The dominant height in studied stands is developing according to height curves both for C and S • The "future stems" have almost the same saw timber quality in C and S Nine experimental stands from Åsarna in Jämtlad to Vilhelmina in Lapland (middle north Sweden) were visited in autumn 2007. In every experimental stand ten permanent plots were examined, five in C stands and five in S. On those plots all trees with dbh > 5 cm were callipered and height was measured on sample trees. About 20 "potential final cut trees" were appointed within a radius of 10 m and the criterion for those trees was that they visually showed on good saw timber quality. The total growth, including thinned trees for C was as a mean value 53 % higher than for S. The average growing stock was 179 m3sk/ha in C and 134 m3sk/ha in S. The development of C follows the yield models as predicted. Until 1991 C had a higher survival rate than S. Three C stands were tinned (9064, 9066 and 9072) in the beginning of 2000. Those stands had a higher natural mortality. The top height development the last 16 years followed the height development curves. For C the top height in average followed the curve for site index T27 and S top height is increased with the curve for T24. Of the "potential final cut trees" 21 % of C were straight and with no spike knots and for S the corresponding figure was 30 %. In the C stands a larger amount of the future stems had a bend while the S stands had more future stems with spike knots. SCA har idag 280 000 ha skogsmark planterad med contorta (Pinus contorta var. Latifolia) (”C”) vilket motsvarar ca 14 % av det totala skogsmarksinnehavet. Contortan har i tidigare försöksplanteringar visat på en högre tillväxt än tall (Pinus sylvestris L.) (”S”) men jämförelserna kunde kritiseras eftersom tallbeståndens historik var okänd och åldersskillnader mellan tall och contorta förekom. För att få en bättre jämförelse mellan contorta och tall lade SCA ut ett antal försöksodlingar i början av 1970 talet där contorta och tall odlas under lika villkor. Dessa bestånd är inmätta tre gånger tidigare och ligger till grund för produktionsmodeller. Syftet med detta arbete var att följa upp och jämföra produktion och kvalitetsutveckling i SCA:s odlingsförsök med contorta och tall. På grundval av tidigare contortastudier formulerades följande hypoteser: • Totalproduktionen har hittills varit ca 50 % högre i C än i S • Övre höjden har utvecklats enligt SI-kurvorna för både C och S • Framtidsträden har nästan lika god timmerkvalitet hos C som hos S Nio lokaler besöktes från Åsarna i Jämtland till Vilhelmina i Lappland under hösten 2007. I varje lokal fanns tio permanenta försöksytor, fem i contortabeståndet och fem i tallbeståndet. På varje provyta klavades alla träd med dbh > 5 cm och höjd mättes på provträden. Cirka 20 potentiella slutavverkningsträd utsågs inom en radie på 10 meter. Kriteriet för dessa träd var att de bedömdes vara mest lämpade för god tillväxt och timmerproduktion (vitala, raka, sprötoch klykfria). På framtidsträden bedömdes kvalitet uppdelat på tre bedömningsgrunder, krök, spröt och dubbeltopp. Resultaten visar att contortan har under ca 40 år i snitt inklusive gallring och naturlig avgång producerat 53 % mer än tallen. Den stående volymen i contortabestånden var i snitt 179 m3 sk/ha och i tallbestånden 134 m3 sk/ha. Fram till 1991 hade contortabestånden högre överlevnadstakt än tallbestånden. Tre contortabestånd var gallrade (9064 9066 and 9072) och dessa bestånd hade en hög andel avgångar i form av vindfällen och toppbrott. Överhöjdsutvecklingen de senaste 16 åren för contorta följer höjdutvecklingskurvan för T27 medan tallen följer kurvan för T24. Av de utvalda potentiella slutavverkningsträd var 21 % av contortaträden helt raka och utan spröt. För tallen så var 30 % av stammarna fina timmerträd. Contortan hade större andel av framtidsstammarna med krök medan tallen hade fler stammar med spröt. SLU/Dept. of Forest Ecology and Management 2008 L3 swe eng https://stud.epsilon.slu.se/12105/ |
| spellingShingle | Pinus contorta Pinus sylvestris jämförelse produktion kvalitet Persson, Cecilia Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title | Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title_full | Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title_fullStr | Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title_full_unstemmed | Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title_short | Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris |
| title_sort | tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med pinus contorta och p. sylvestris |
| topic | Pinus contorta Pinus sylvestris jämförelse produktion kvalitet |