| 1. |
- Andersson, Solbritt, et al.
(författare)
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Effects of lime (CaCO3) on ectomycorrhizal colonization of Picea abies (L.) Karst. - seedlings planted in a spruce forest
- 1995
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 10:2, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- In two consecutive years, seedlings of Norway spruce (Picea abies) were planted in a 50-yr-old Norway spruce forest in limed (3.8 tons CaCO3 ha-1) and control plots. After 6 months they were harvested and the mycorrhizal status of the roots was analysed. Six types of mycorrhiza were distinguished. Three decreased after liming, two increased and one was not affected consistently by the liming. The effects on the total mycorrhizal colonization of the roots were opposite for the two years, indicating that the effects of liming are influenced strongly by other environmental factors. Statistical analysis also revealed pronounced natural variation in space. An inventory of the sporocarp-producing fungi showed that the number of saprotrophic species producing sporocarps was significantly higher in the limed plots whereas the number of ectomycorrhizal species was lower in the limed plots, compared with the control plots. It is concluded that more information is needed concerning the effects of liming on different soil types before any general conclusions can be made about its effects on mycorrhizal colonization.
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| 2. |
- Arnebrant, Kristina, et al.
(författare)
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Soil microbial activity in eleven Swedish coniferous forests in relation to site fertility and nitrogen fertilization
- 1996
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 11:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- The effect of forest fertilization on soil microbial activity and biomass was studied in 11 coniferous forests with different site fertility. Soil microbial activity was measured as respiration rate and the microbial biomass was estimated using ATP content and substrate-induced respiration rate (SIR). At all sites, except those with the highest site fertility, the microbial activity and biomass were reduced in the fertilized treatments compared with the control. The general trend indicated that the lower the site fertility, the more pronounced was the reduction of microbial biomass and activity. Some possible explanations for this effect are discussed.
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| 3. |
- Grundberg, Stig, et al.
(författare)
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Simulated grading of logs with an x‐ray log scanner‐grading accuracy compared with manual grading
- 1997
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 12:1, s. 70-76
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Tidskriftsartikel (refereegranskat)abstract
- Today sawmills have started to use automatic methods for log grading. The methods used are either optical or gamma–ray scanners. However, the signals from these scanners are too coarse for accurate log grading and for good control of the sawing process at the single log level. The objective of the present study was to determine the grading accuracy of a log–scanner with two industrial X–ray sources. The grading accuracy was compared with the accuracy of manual grading. The results showed that the manual grading of logs and boards is difficult. The accuracy of manual grading was low and the automatic grading systems were more reliable than manual ones. Possibilities for improving the automatic grading systems are discussed.
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| 4. |
- Jönsson, Anna Maria
(författare)
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Bark lesions on beech (Fagus sylvatica) and their relation to epiphytes and site variables in Scania, south Sweden.
- 1998
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 13:1-4, s. 297-305
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Tidskriftsartikel (refereegranskat)abstract
- Beech bark lesions, (Cryptococcus fagisuga), the most common lichen and fungi epiphytes on beech (Fagus sylvatica) stems were studied at 48 sites in Scania, south Sweden. Different site variables and the influence of nitrogen deposition were investigated. The field vegetation and lichens were used as biological indicators by calculating indices for nutrition status, toxicity, pH, light and moisture. Two sets of lichen indices, from Hultengren and Ellenberg, respectively, were calculated. Beech bark lesions were found at 25 sites and were more frequent at more polluted sites with much C. fagisuga and Lecanora conizaeoides, and on largish trees. Algae cover and C. fagisuga were positively correlated. Both preferred sites with no direct light exposure, high nitrogen deposition and low pH. The two sets of lichen indices were fairly comparable for toxitolerance, light and pH. In this investigation, Lepraria incana was the most frequent of all epiphytes, often determining the value of the lichen indices.
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| 5. |
- Oja, Johan
(författare)
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A comparison between three different methods of measuring knot parameters in Picea abies
- 1997
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 12:3, s. 311-315
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Tidskriftsartikel (refereegranskat)abstract
- Both foresters and sawmillers are interested in the knot structure of trees; in particular, position and number of knots, knot diameter, knot length and dead knot border. For research purposes, it is possible today to carry out non-destructive measurements using computer tomography (CT) and image analysis. The aim of this study was to measure knot parameters on Norway spruce (Picea abies (L.) Karst.) using a non-destructive method developed for Scots pine (Pinus sylvestris L.), and to compare the results of this method with the results of two different destructive methods. In order to do this, two Norway spruce stems were scanned by CT. Then five logs from one stem were cut into flitches 20 mm thick and the defects on the sawn surfaces were scanned manually. The other stem was cut just above every whorl and then each knot was split through its centre and the knot parameters were measured manually. The study showed that the CT method compares well with the destructive methods. It is a reasonably fast, non-destructive method which measures position and diameter of knots and detects larger knots with acceptable accuracy. The study also showed that a large number of smaller knots were not found by the CT method and that the CT method measured knot length and dead knot border with low accuracy. This means that the CT method has to be adjusted to Norway spruce in order to improve its ability to measure knot length and dead knot border and to detect smaller knots.
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| 6. |
- Oja, Johan, et al.
(författare)
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Measuring the outer shape of Pinus sylvestris saw logs with an X‐ray LogScanner
- 1998
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 13:1-4, s. 340-347
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Tidskriftsartikel (refereegranskat)abstract
- The accuracy of measuring the outer shape of Scots pine (Pinus sylvestris L.) saw logs with an X-ray LogScanner has been compared with the accuracy of using a 2-axis optical scanner, a 3-axis optical scanner and an ideal 3-D optical scanner. The different scanners were simulated using computed tomography (CT) data from the Swedish Stem Bank. The outer shape of 60 saw logs was measured every third centimeter. The error attributable to bark when using optical scanners was simulated separately. The results from the simulations showed that when measuring the outer shape on bark, the X-ray LogScanner facilitated measurement of the minimum shadow diameter with the same accuracy as with a 3-D optical scanner. The results also showed that the potential of combining the X-ray LogScanner with a 3-D optical scanner should be investigated
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| 7. |
- Simandl, Jiři, et al.
(författare)
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Spatial distribution of flying neodiprion sertifer (Hymenoptera, Diprionidae) males in a mature Pinus sylvestris stand as determined by pheromone trap catch
- 1995
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 10:1-4, s. 51-55
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Tidskriftsartikel (refereegranskat)abstract
- Field studies were conducted during three years to determine the vertical (height level) and horizontal (distance from stand edge) distribution of flying Neodiprion sertifer (Geoffroy) males in a non-outbreak population. Sticky traps baited with synthetic female pheromone (25, 35, 75-diprionyl acetate) were used in a mature stand of Scots pine (Pinus sylvestris L.) in Central Europe (southern Bohemia). The vertical distribution was distinct; more males were caught in traps at 9.0–12.5 m height (crown stratum) than in traps at 2.5 or 0.5 m above ground. The horizontal distribution was rather uniform inside the stand, with only small differences between catches near the stand edge (< 30 m) and inside the forest. These data show that the main flight of N. sertifer males in high pine stands takes place at the crown level. Implications for the use of pheromone traps in monitoring programs are discussed.
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| 8. |
- Öhman, Micael
(författare)
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Grade prediction of Pinus sylvestris logs with the aid of a radiograph image of the log
- 1998
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 13:1-4, s. 83-89
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Tidskriftsartikel (refereegranskat)abstract
- Today the internal structure of a log can be detected using X‐ray scanning technology. The objective of this study was to investigate the potential of grading a log by visual inspection of its longitudinal radiograph image (LRI). The grading accuracy of the LRI method was compared with the accuracy of a conventional manual log grading method. The grading accuracy was expressed as the ability to predict the grade of the centre planks of a log before the log was sawn. The grading results of the LRI method were determined by interviewing respondents connected with the wood and sawmill industry. The statistics of the conventional log grading method originate from the Swedish Stem Bank. The evaluation of the results was based on conventional statistical methods, unpaired significance tests and confidence intervals for means. This study shows that it is possible to grade logs by using LRIs. The grading accuracy is equal to, or better than, conventional log grading done by skilled graders from the Measurement Society of Sweden.
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| 9. |
- Jonsson, A, et al.
(författare)
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Interfamily variation in nitrogen productivity of Pinus sylvestris seedlings
- 1997
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Ingår i: SCANDINAVIAN JOURNAL OF FOREST RESEARCH. - : SCANDINAVIAN UNIVERSITY PRESS. - 0282-7581. ; 12:1, s. 1-10
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Open-pollinated families from 21 Pinus sylvestris L. clones from a seed orchard in central Sweden were cultivated in growth chambers in mineral wool for two growth periods. Two nitrogen treatments were applied: high N availability, free access to all nutr
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| 10. |
- Steenari, Britt-Marie, 1953, et al.
(författare)
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Long term leaching of stabilised wood ash
- 1998
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Ingår i: Scandinavian Journal of Forest Research. - 0282-7581. ; Suppl 2:1, s. 3-16
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Tidskriftsartikel (refereegranskat)
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