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Silva Fennica vol. 42 no. 5 | 2008

Category: Research article

article id 467, category Research article
Annika Kangas, Ruut Haapakoski & Liisa Tyrväinen. (2008). Integrating place-specific social values into forest planning – Case of UPM-Kymmene forests in Hyrynsalmi, Finland. Silva Fennica vol. 42 no. 5 article id 467. https://doi.org/10.14214/sf.467
In participatory forest management planning, the perceived values of local inhabitants concerning the area under planning are collected. The results may, however, depend on the methods used. In this study, values of residents of Hyrynsalmi municipality concerning the nearby forests owned by UPM-Kymmene Ltd. were evaluated with a questionnaire consisting of general value questions and mapping of social values of forests. The data was collected from a public meeting and from a mailed survey from randomly sampled people and from members of municipal council. The aims of the study were to 1) test the social value mapping method in commercial forests in a rural-urban interface as well as to examine the benefits and drawbacks 2) in place-specific and non-specific data collection, and 3) in different data collection methods, from the viewpoint of forest management planning. We noted that while all respondents can claim to represent local values, different data collection methods produced statistically significantly different local values. This needs to be accounted for when planning a participatory process. In operational forest planning, place-specific information is more useful than questions concerning the general values, while the latter may help in defining forest policy goals. The social values mapping method is also relatively easy for the participants. However, in the studied case about one fifth of the area was delineated by the participants per each positive value. The answers were quite scattered, suggesting that most of the area had some social values for local people. This indicates that utilising a social values mapping method in planning needs further development in rural areas, where distinctive patches can not be easily detected.
  • Kangas, University of Helsinki, Department of Forest Management, P.O. Box 27, FI-00014 University of Helsinki ORCID ID:E-mail: annika.kangas@helsinki.fi (email)
  • Haapakoski, University of Helsinki, Department of Forest Management, P.O. Box 27, FI-00014 University of Helsinki ORCID ID:E-mail:
  • Tyrväinen, Finnish Forest Research Institute, P.O. Box 16, FI-96301 Rovaniemi, Finland. ORCID ID:E-mail:
article id 466, category Research article
Ilkka Korpela, Tuukka Tuomola, Timo Tokola & Bo Dahlin. (2008). Appraisal of seedling stand vegetation with airborne imagery and discrete-return LiDAR – an exploratory analysis. Silva Fennica vol. 42 no. 5 article id 466. https://doi.org/10.14214/sf.466
The potential for combined use of airborne discrete-return LiDAR and digital imagery in the classification and measurement of common seedling stand vegetation was examined in southern Finland (61°50’N, 24°20’E). Classification was based on spectral and textural image features in addition to geometric and radiometric features of the LiDAR. The accuracy of leaf-on, LiDAR-based terrain elevation models was tested as well as the accuracy of LiDAR in the measurement of vegetation heights. LiDAR-based canopy height and the range-normalized intensity of the LiDAR were strong explanatory variables in vegetation classification. Interspecies variation was observed in the height measurement accuracy of LiDAR for different tree, shrub and low vegetation canopies. Elevation models derived with 1–15 pulses per m2 showed an inherent noise of app. 15–25 cm, which restricts the use of LiDAR in regeneration assessment of very young stands. The spatial pattern of the competing vegetation was reproduced in classification-based raster surfaces, which could be useful in deriving meaningful treatment proposals.
  • Korpela, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail: ilkka.korpela@helsinki.fi (email)
  • Tuomola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
  • Tokola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
  • Dahlin, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
article id 465, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Målfrid Toeneiet & Erlend Rolstad. (2008). Effect of logging on the threatened epiphytic lichen Usnea longissima: a comparative and retrospective approach. Silva Fennica vol. 42 no. 5 article id 465. https://doi.org/10.14214/sf.465
Usnea longissima is a conspicuous circumboreal “beard lichen” draping tree canopies in moist coastal and mountainous forests. It is extirpated in many European and North-American localities, presumably due to industrial forestry and air pollution, but still has a stronghold in parts of Scandinavia and U.S. and Canadian Pacific Northwest. Using a retrospective approach, we reconstructed the stand histories in 24 plots (0.1 ha) of mature Norway spruce (Picea abies) forest stands in Lillehammer, Norway, of which 21 was selected due to the presence of U. longissima. Number of trees with U. longissima present within plots varied from 4 to 37 and number of visible thalli from 12 to 469. The detailed stand reconstructions were done by means of tree-ring analysis of 517 living trees and the size and decay stage of 1423 stumps from logging and 467 dead trees. Total harvested volume during the last 100 years ranged 100–370 m3ha–1 (representing 40–350% of the present-day standing volume), and present amount of dead wood ranged 2–87 m3ha–1 (1.0–37% of the standing volume). All stands had been selectively logged 2–4 times during the last 100 years, of which 5 stands almost to a clearcut appearance. We used a variety of present-day and historic forest structural variables, both at the scale of study plots and individual trees, to predict the occurrence and abundance of U. longissima. Although most forest stand variables failed in this respect, there were indications of a certain negative influence of the historic logging activity. Number of thalli present on trees showed a unimodal relationship to present-day tree density, indicating that medium dense forest stands are most favorable for U. longissima. We tentatively suggest that selective logging, securing lichen-rich trees, may be a viable management option to keep tree density at a moderate level in the long run, thereby enhancing growth and establishment of U. longissima.
  • Storaunet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: ken.storaunet@skogoglandskap.no (email)
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Toeneiet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
article id 227, category Research article
Ola Lindroos. (2008). The effects of increased mechanization on time consumption in small-scale firewood processing. Silva Fennica vol. 42 no. 5 article id 227. https://doi.org/10.14214/sf.227
Firewood, which is mainly processed by the consumer, is still an important source of energy for heating houses in industrialised countries. Possibilities to compare the mechanization’s impact on efficiency of firewood processing are limited, due to variations between working conditions in previous studies. Therefore, the objective was to compare time consumption for two small-scale firewood processing systems with different levels of mechanisation under identical conditions. The systems were tested on two classes of wood: one with a homogeneous and medium-sized diameter of logs and one with a mixture of small and large-diameter-logs. Differences in time consumption were analysed for correlations with physical workloads, deviations to routine operations, operator influences and operator perceptions. Twelve operators (60–79 years old) were studied and they showed large variation in time consumption. However, the within-operator time consumption patterns were consistent. In other words, operators all responded similarly to the different combinations of systems and wood classes, but at different absolute levels. The time required to process a unit volume of wood was 25–33% lower when the more highly mechanised system was used, and the time required was 13–22% lower for the homogeneous wood class. Physical work load, deviations and perceptions of the work varied between operators, but were weakly correlated with time consumption. The results’ implications for analyses of investments in equipment for firewood-processing for self-sufficiency purposes are discussed.
  • Lindroos, Swedish University of Agricultural Sciences, Department of Forest Resource Management, SE-901 83 Umeå, Sweden ORCID ID:E-mail: ola.lindroos@srh.slu.se (email)
article id 226, category Research article
Anneli Viherä-Aarnio & Pirkko Velling. (2008). Seed transfers of silver birch (Betula pendula) from the Baltic to Finland – effect on growth and stem quality. Silva Fennica vol. 42 no. 5 article id 226. https://doi.org/10.14214/sf.226
Silver birch (Betula pendula Roth) seed origins from the Baltic countries, Finland and Russia were compared for survival, growth and stem quality, and the effect of latitudinal seed transfer distance examined in two provenance trials. The trials were located on moist upland forest soils at Tuusula (60°21’N) in southern Finland and at Viitasaari (63°11’N) in central Finland. The material consisted of 21 stand and single tree origins ranging from latitudes 54° to 63°N. Survival, height, dbh, relative stem taper, stem volume/ha and the proportion of trees with a stem defect (vertical branch or forked stem), were assessed when the trees were 22 years old. Significant differences were detected among the origins regarding all the measured traits in both trials. Southern Finnish origins produced the highest volume per unit area in central Finland, whereas Estonian and north Latvian stand seed origins, as well as the southern Finnish plus tree origins, were the most productive ones in southern Finland. The more southern the origin, the higher was the proportion of trees with a stem defect in both trials. The latitudinal seed transfer distance had a significant but relatively small effect on survival, stem volume/ha and proportion of trees with a stem defect. The proportion of trees with a stem defect increased linearly in relation to the seed transfer distance from the south. The relationship of both survival and stem volume/ha to the seed transfer distance was curvilinear. Volume/ha was increased by transferring seed from ca. 2 degrees of latitude from the south. A longer transfer from the south, as well as transfer from the north, decreased the yield.
  • Viherä-Aarnio, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: anneli.vihera-aarnio@metla.fi (email)
  • Velling, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail:
article id 225, category Research article
Johan Bergh, Urban Nilsson, Harald Grip, Per-Ola Hedwall & Tomas Lundmark. (2008). Effects of frequency of fertilisation on production, foliar chemistry and nutrient leaching in young Norway spruce stands in Sweden. Silva Fennica vol. 42 no. 5 article id 225. https://doi.org/10.14214/sf.225
Keywords: sludge; wood-ash; boreal; N; P; K
There is a great need to increase the production in Swedish forests to meet future demand from the forest industry and the bio-energy sector. One option to increase the production is to supply nutrients to young stands of Norway spruce. For the practical application it is important to develop and optimise fertilisation regimes in terms of production, economy and leaching of nutrients. The frequency of fertilisation is one important variable in the fertilisation regime, and this study aimed to study effects of different fertilisation frequencies on production and leaching of nitrogen. In 2001, five field experiments were established in southern, central and northern Sweden. Young stands of Norway spruce were fertilised every year, every second year and every third year. In addition, fertilisation with sludge pellets and wood-ash combined with nitrogen was investigated. The current annual increment after five years of treatment was significantly larger in fertilised than in unfertilised treatments. The difference in production between fertilisation every year and every second year was insignificant, while fertilisation every third year resulted in lower production. Sludge pellets and wood-ash fertilisation gave significantly lower production than fertilisation every second year even though approximately the same amount of nitrogen was applied. There was relatively little leaching of nitrate to ground water in all treatments; 0.6–1 kg N ha–1 a–1 from plots with fertilisation every year or every second year; and 2.7 kg N ha–1 a–1 from plots with fertilisation every third year. Most of the leaching was after the first fertilisation, in all treatments at all sites.
  • Bergh, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: johan.bergh@ess.slu.se (email)
  • Nilsson, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Grip, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Hedwall, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Lundmark, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
article id 224, category Research article
Xiangwen Xiao, Xiao Xu & Fan Yang. (2008). Adaptive responses to progressive drought stress in two Populus cathayana populations. Silva Fennica vol. 42 no. 5 article id 224. https://doi.org/10.14214/sf.224
The young, vegetatively propagated cuttings of Populus cathayana Rehder were exposed to a progressive drought stress for 12 weeks in a greenhouse to characterize the physiological and biochemical basis of drought adaptation in woody plants. Two contrasting populations were employed in our study, which were from the wet and dry climate regions in western China, respectively. The results showed that the adaptive responses of P. cathayana to drought were affected by drought intensity and poplar genotype (population). The progressive drought stress significantly inhibited plant growth, increased carotenoid contents and, at the same time, accumulated soluble sugars and free proline in the plants of both populations tested. On the other hand, the gradually increasing drought also induced antioxidative systems including the increase of the activities of superoxide dismutase (SOD) and guaiacol peroxidase (POD). Moreover, there were different responses to progressive drought stress between the two contrasting populations. Compared with the wet climate population, the dry climate population had lower shoot height and growth rate, higher free proline content, and more efficient photoprotective system (such as higher carotenoid content and Car/Chl) and antioxidant system (such as higher POD activity), as a result of drought stress. These results suggest that the dry climate population possesses better drought tolerance than the wet climate population. The differences in drought tolerance may be closely related with efficient photoprotective system, accumulation of the osmoprotectant proline as well as the increased capacity of the antioxidative system to scavenge reactive oxygen species, and the consequent suppressed level of lipid peroxidation under drought conditions.
  • Xiao, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, P. R. China ORCID ID:E-mail: xiaoxw@cib.ac.cn (email)
  • Xu, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, P. R. China ORCID ID:E-mail:
  • Yang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, P. R. China ORCID ID:E-mail:

Category: Research note

article id 228, category Research note
Aku Riihelä & Terhikki Manninen. (2008). Measuring the vertical albedo profile of a subarctic boreal forest canopy. Silva Fennica vol. 42 no. 5 article id 228. https://doi.org/10.14214/sf.228
The validation of airborne and satellite-derived albedo measurements suffers from the fact that the surface albedo of forest is difficult to measure in-situ over large areas. The goal of this study is to examine whether or not the estimation of the surface albedo of a forest stand from ground level measurements is possible. In addition, knowledge about the vertical behavior of albedo, and therefore transmitted solar radiation, is important in the modeling of interactions of sunlight with the forest canopy. Such modeling is useful for forest growth estimations among other things. To achieve these goals, an albedometer set-up capable of vertical albedo profiling has been used to obtain data from a boreal forest stand in Northern Finland during periods in summer 2006 and winter 2007. The results show a strong relationship between the data and fitted power-law regression curves. Power-law regression fits best likely because of the radiation transmission characteristics of boreal forest.
  • Riihelä, Finnish Meteorological Institute, P.O. Box 503, FI-00200 Helsinki, Finland ORCID ID:E-mail: aku.riihela@fmi.fi (email)
  • Manninen, Finnish Meteorological Institute, P.O. Box 503, FI-00200 Helsinki, Finland ORCID ID:E-mail:

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