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Silva Fennica 1926-1997
Acta Forestalia Fennica

Silva Fennica vol. 37 no. 3 | 2003

Category: Research article

article id 496, category Research article
Hampus Holmström, Hans Kallur & Göran Ståhl. (2003). Cost-plus-loss analyses of forest inventory strategies based on kNN-assigned reference sample plot data. Silva Fennica vol. 37 no. 3 article id 496.
The usefulness of kNN (k Nearest Neighbour)-assigned reference sample plot data as a basis for forest management planning was studied. Cost-plus-loss analysis was applied, whereby the inventory cost for a specific method is added to the expected loss due to non-optimal forestry activities caused by erroneous descriptions of the forest state. Four different strategies for data acquisition were evaluated: 1) kNN imputation of sample plots based on traditional stand record information, 2) imputation based on plot-wise aerial photograph interpretation in combination with stand record information, 3) sample plot inventory in the field with 5 plots per stand, and 4) sample plot inventory with 10 plots per stand. Expected losses were derived as mean values of differences between the maximum net present value and the corresponding value obtained when the treatment schedule believed to be optimal (based on data simulated according to method 1–4) was selected. The optimal choice of method was found to depend on factors such as stand maturity, stand area, and time to next treatment (thinning or clearcutting). In general, the field sample plot methods were competitive in large mature stands, especially when the time to the next (optimal) treatment was short. By in each stand (within an estate) employing the method with the lowest cost-plus-loss rather than choosing the method that performed best on average for the entire estate, the total cost for inventory at the estate level could be decreased by 15–50%. However, it was found difficult to identify what method should optimally be employed in a stand based on general stand descriptions.
  • Holmström, Regional Board of Forestry of Västra Götaland, P.O. Box 20008, SE-50420 Borås, Sweden ORCID ID:E-mail: (email)
  • Kallur, ÖKA Skogsplan, Kopparvägen 45 O, SE-90750 Umeå, Sweden ORCID ID:E-mail:
  • Ståhl, Swedish Univ. of Agricultural Sciences, Dept. of Forest Resource Management and Geomatics, SE-90183 Umeå, Sweden ORCID ID:E-mail:
article id 495, category Research article
Christopher Dean. (2003). Calculation of wood volume and stem taper using terrestrial single-image close-range photogrammetry and contemporary software tools. Silva Fennica vol. 37 no. 3 article id 495.
A method of estimating trunk and branch volumes of single trees is presented that uses a combination of elementary field measurements, terrestrial photography, image rectification and on-screen digitising using commercial software packages and automated volume calculation. The method is applicable to a variety of different sized trees in situations where the trunks are clearly visible. Results for taper measurement and wood volume calculation are presented for Eucalyptus regnans F. von Muell., Sequoiadendron giganteum (Lindley) Buchholz and Quercus robur L. Branch allometrics are provided for E. regnans. The largest errors arose from field observations. If the trees are asymmetrical in cross-section (e.g. due to irregular buttressing or forked stems), or if there is no vantage point perpendicular to the direction of lean, then photographs from more than one side are recommended. Accuracy and precision of geometric reproduction by the image rectification process, and the volume calculation, were tested using mathematically generated tree components. The errors in the branch volumes of the virtual tree showed complex trends due to interacting factors. Volumes were underestimated by an average 0.5% for stems and 4% for branches. Due to the area deficit resulting from non-circular cross-sections of the buttress, overestimation of stem volumes could be as high as 10% on average for mature trees. However, the area deficit was known for E. regnans and incorporated into the volume calculation. The underestimation of volumes would help counteract over-estimation due to the area deficit. The application of this method to carbon accounting in forests and woodlands is explained.
  • Dean, CRC for Greenhouse Accounting, The Australian National University, GPO Box 475, Canberra, ACT 2601, Australia ORCID ID:E-mail: (email)
article id 494, category Research article
Antero Varhimo, Soili Kojola, Timo Penttilä & Raija Laiho. (2003). Quality and yield of pulpwood in drained peatland forests: pulpwood properties of Scots pine in stands of first commercial thinnings. Silva Fennica vol. 37 no. 3 article id 494.
The inherent structural dynamics of drained peatland forests may result in a great variation in various wood and fiber properties. We examined variation in fiber and pulp properties i) among stands, ii) among trees within stands, and iii) within trees in young stands dominated by Scots pine (Pinus sylvestris L.). The stands, selected to cover a maximal range of the potential variation, were all at a stage of development where the first commercial thinnings would be feasible. Differences in the processability of the thinning removals were small. In similar kraft cooking conditions, a 5-unit variation in the kappa number of unbleached pulp was observed among the stands. Stand origin had no effect on pulp bleaching. The wood formed prior to drainage had a higher density, shorter fibers, was slightly slower delignified by cooking, and its yield was slightly lower than that of post-drainage wood. These properties, except for high density, are typical for juvenile wood in general, and at stand level they did not correlate with the proportion of pre-drainage wood. When the variation in fiber and pulp properties was broken down into its components, most of it was derived from tree-level in all the cases. On average, the fiber and pulp properties did not differ from those observed for first-thinning pulpwood from upland sites. Consequently, peatland-grown pulpwood may be mixed with other pulpwood in industrial processes. It would probably be best suited as the raw material for pulps with high bonding requirements, e.g. in the top ply of multi-ply board grades or in some specialty grades.
  • Varhimo, KCL, P.O. Box 70, FIN-02151 Espoo, Finland ORCID ID:E-mail: (email)
  • Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Laiho, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:
article id 493, category Research article
Göran Rune. (2003). Slits in container wall improve root structure and stem straightness of outplanted Scots pine seedlings. Silva Fennica vol. 37 no. 3 article id 493.
Root structure and basal sweep were measured on 6-year-old Scots pine (Pinus sylvestris L.) trees at two sites with different soil fertility. Each site was planted with seedlings of identical origin after nursery cultivation in either solidwall container types with vertical ribs or in slitwall container types. Neither container design nor container volume affected tree height or stem diameter on the two sites. The transversal area of lateral roots was larger than the transversal area of bottom roots for the two container types at both sites. The proportion of bottom root transversal area to the total root transversal area was larger in the seedlings growing on the low fertility site than in those growing in the high fertility site for both container types. Seedlings cultivated in slitwall containers had a larger root area in proportion to stem diameter and had less root spiralling compared to the trees cultivated in solidwall containers. At the high fertility site, trees from the slitwall container type had straighter stem bases than seedlings grown in solidwall containers. At the low fertility site, differences in basal sweep formation were small between the container types. Reasons for this are discussed.
  • Rune, Dalarna University, Department of Forestry and Wood Technology, SE-776 98 Garpenberg, Sweden ORCID ID:E-mail: (email)
article id 492, category Research article
Seppo Kaunisto & Tytti Sarjala. (2003). Foliar potassium concentrations of bilberry, bog bilberry and downy birch as indicators of potassium nutrition of Scots pine on a drained peatland. Silva Fennica vol. 37 no. 3 article id 492.
Leaves of bilberry (V. myrtillus), bog bilberry (V. uliginosum) and downy birch (B. pubescens) were collected five times during a growing season from 18 plots in a drainage area, and needles of Scots pine (Pinus sylvestris L.) once during the following winter from the same plots at Parkano, southern Finland. The aim was to study the potassium nutrition of the test plants and relationships between the foliar potassium concentrations of Scots pine and of the test plants. The estimation of the potassium nutrition of test plants was based on the accumulation of putrescine in foliage. Apart from single observations, elevated putrescine concentrations were found when the potassium concentrations were < 5 mg g–1 in bilberry, < 4 mg g–1 in bog bilberry and < 6 mg g–1 in downy birch, and the highest concentrations below the potassium levels of 3.0–3.5 mg g–1. At the concentrations of 2–3 mg g–1 the accumulation increased pronouncedly in bog bilberry but less in downy birch and only slightly in bilberry. The foliar potassium concentrations in test plants correlated closely with the concentrations in pine needles. The concentrations of all species in August were quite stable at the levels of the severe and slight potassium deficiency of pine (3.5 and 4.5 mg g–1 respectively) indicating that August would be suitable for collecting foliage. The concentrations in bog bilberry were very close to the concentrations in pine at the severe and those in bilberry at the slight deficiency level of pine. All test plants could be used for predicting the potassium nutrition of Scots pine, but additional research is needed for the practical application of the method.
  • Kaunisto, Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland ORCID ID:E-mail: (email)
  • Sarjala, Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland ORCID ID:E-mail:
article id 491, category Research article
Lars Rytter & Lars-Göran Stener. (2003). Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.). Silva Fennica vol. 37 no. 3 article id 491.
Differences in the nutrient concentrations and nutrient amounts of stems and branches amongst clones of hybrid aspen (Populus tremula L. x P. tremuloides Michx.) were investigated. Seven clones with superior and seven with medium growth rates were selected from a test of 119 clones in southern Sweden. Four trees per clone were randomly identified and harvested in dormant conditions. Sample discs from the stems and branches were collected and analysed for N, K, P, Ca, Mg, and S concentrations, as well as wood density. The analyses revealed significant genetic differences in wood density, K, P, and Mg concentrations in the stems. There were weak (non-significant) and negative genetic correlations between stem volume and concentrations of all the nutrients, except potassium, suggesting that nutrient-efficient clones could be selected without significantly sacrificing genetic gain for growth. In the branches K, Ca, and Mg concentrations differed significantly among clones. After selecting more nutrient efficient clones, the potential savings of nutrients compared with current hybrid aspen material was estimated to be around 5%, which seems fairly low, at least in a short-term perspective. However, the use of clones with different nutrient storage strategies may be regarded as a possible way in the long run to save nutrients in hybrid aspen ecosystems, or of removing them when sludge is applied.
  • Rytter, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden ORCID ID:E-mail: (email)
  • Stener, Forestry Research Institute of Sweden, Skogforsk, Ekebo 2250, SE-26890, Svalöv, Sweden ORCID ID:E-mail:
article id 490, category Research article
Veiko Uri, Hardi Tullus & Krista Lõhmus. (2003). Nutrient allocation, accumulation and above-ground biomass in grey alder and hybrid alder plantations. Silva Fennica vol. 37 no. 3 article id 490.
The aim of the present work was to investigate the nutrient (N,P,K) allocation and accumulation in grey alder (Alnus incana (L.) Moench) and hybrid alder (Alnus incana (L.) Moench x Alnus glutinosa (L.) Gaertn.) plantations growing on former agricultural land and to estimate the above-ground biomass production during 4 years after establishment. In August of the 4th year, when leaf mass was at its maximum, the amount of nitrogen accumulated in above-ground biomass of grey alder stand was 142.0 kg ha–1, the amount of phosphorus 16.3 kg ha–1 and the amount of potassium 49.5 kg ha–1. The amount of nitrogen accumulated in a hybrid alder stand totalled 76.8 kg ha–1, that of phosphorus 6.2 kg ha–1 and that of potassium 28.2 kg ha–1. The smaller amounts of N,P and K bound in the hybrid alder plantation are related to the smaller biomass of the stand. Still, the amounts of N,P and K consumed for the production of one ton of biomass were similar in the case of up to 4-year-old grey alder and hybrid alder stands. In the 4th year, the amount of nutrients consumed in one ton of biomass produced were: 16.0 kg N, 1.6 kg P and 5.4 kg K for grey alder and 14.6 kg N, 1.1 kg P and 5.2 kg K for hybrid alder. In the 4th year the total above-ground biomass (dry mass) of grey alder (15750 plants ha–1) amounted to 12.3 t ha–1, current annual increment being 6.7 t ha–1. In hybrid alder stands (6700 plants ha–1), the respective figures were 6.1 t ha–1 and 4.5 t ha–1. Comparison of the production capacity on the basis of mean stem mass in the 4th year revealed that the stem mass of grey alder exceeded that of hybrid alder (0.64 kg and 0.58 kg, respectively). Grey alder outpaced hybrid alder in height growth; in the 4th year after establishment, the mean height of the grey alder stand was 4.6 ± 0.9 m and that of the hybrid alder plantation 3.5 ± 0.9 m.
  • Uri, Institute of Silviculture, Estonian Agricultural University, Kreutzwaldi 5, 51014 Tartu, Estonia ORCID ID:E-mail: (email)
  • Tullus, Institute of Silviculture, Estonian Agricultural University, Kreutzwaldi 5, 51014 Tartu, Estonia ORCID ID:E-mail:
  • Lõhmus, Institute of Geography, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia ORCID ID:E-mail:

Category: Review article

article id 497, category Review article
Oili Kiikkilä. (2003). Heavy-metal pollution and remediation of forest soil around the Harjavalta Cu-Ni smelter, in SW Finland. Silva Fennica vol. 37 no. 3 article id 497.
Heavy metals and sulphur have been emitted from the Cu-Ni smelter at Harjavalta since 1945. This article reviews the work that has been published in scientific journals after 1975 concerning heavy metal deposition and the effects of pollution on forest ecosystem around Harjavalta. The pollution has had diverse effects on boreal forest ecosystem, e.g. vegetation, nutrient cycle mediated by microbiota and soil animals, herbivorous insects and pathogens, resistance mechanisms of vegetation, and birds. The deposition of heavy metals has increased up to 30 km distance from the smelter. At 8 km distance the ecosystem began to approximate an undisturbed ecosystem where only slight changes in the understorey vegetation were observed. At 4 km distance the species composition of different ecosystem components (vegetation, insects, birds, soil microbiota) had changed and the growth of trees was retarded. At 0.5–1 km distance, where the nutrient cycling was disturbed and only the most resistant organisms were surviving, the ecosystem had ceased to carry out its essential functions. Remediation through liming or mulching with organic matter, of forest soil has had some positive effects on the ecosystem.
  • Kiikkilä, Vantaa Research Centre, Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail: (email)

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