Category :
Article
article id 7324,
category
Article
E. A. Martin Hagfors.
(1936).
Monographic studies on theory of forestry, part 1: G. König.
Acta Forestalia Fennica
vol.
42
no.
7
article id 7324.
https://doi.org/10.14214/aff.7324
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Studies by G. König are the main source for the profitability theories of forestry. He was one of the first economists developing the forestry practices more towards profitability aspects. His doctrine presented the first steps of current forest related trend of ideas and hence so significant in the later development of the discipline.
The article presents the life of G. König and two of his most important works: “Anleitung” (introduction) from the year 1813 and “Forstmathematik” (Mathematics of forest) from years 1835 and 1854
The PDF contains a summary in Finnish.
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Hagfors,
E-mail:
eh@mm.unknown
article id 7043,
category
Article
English title:
Studies on stump layers in peatlands in Finland.
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The investigations that have studied peat layers in peatlands have shown that the peatlands in several countries have layers containing tree stumps of different tree species. The stump layers have been explained by local hydrological changes that have caused paludification, or changes in climate.
Peat layers were studied in drained peatlands in Finland, and ditches were used to study the peat profiles. A peatland in Multia in Central Finland was studied in more detail. Tree stump layer patterns that would support the climate change explanation was not found in the Finnish peatlands. The peat changes usually gradually more oligotrophic towards the surface. The stump layers seemed to be caused by local drier periods. According to the layers of Sphagnum-peat near the bottom of the peatlands and the pollen studies indicate that the peatlands have been formed at different times. In South-West Finland, the peat profiles had more apparent layer patterns than in Central Finland, but these were not considered to be caused by changes in climate.
The PDF includes a summary in German.
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Lukkala,
E-mail:
ol@mm.unknown
Category :
Research article
article id 1283,
category
Research article
Ivana Bjedov,
Dragica Obratov–Petković,
Danijela Mišić,
Branislav Šiler,
Jelena M Aleksic.
(2015).
Genetic patterns in range-edge populations of Vaccinium species from the central Balkans: implications on conservation prospects and sustainable usage.
Silva Fennica
vol.
49
no.
4
article id 1283.
https://doi.org/10.14214/sf.1283
Highlights:
We studied fragmentary distributed range-edge populations of Vaccinium myrtillus, Vaccinium uliginosum and Vaccinium vitis-idaea from the Balkans using RAPDs; Low genetic diversities and high genetic differentiation were found in all species; The prevalence of clonal individuals was not observed; Past interspecific hybridization among V. vitis-idaea and the other two species was detected; Guidelines for conservation and sustainable usage were provided.
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Vaccinium myrtillus L., Vaccinium uliginosum L. and Vaccinium vitis-idaea L. are perennial, cold-adapted clonal shrubs distributed throughout Europe, northern Asia and North America. Due to their usage in food (berries) and pharmaceutical industry (berries and leaves), their natural populations are exposed to anthropogenic and other impacts that affect their genetic make-up. We analyzed 14 fragmentary distributed and small-sized peripheral populations of these species from the Balkans, which represents the southeastern-European marginal area of their wide European distributions, using RAPD molecular markers. The contemporary genetic patterns in all three species within the Balkans were generally similar, and in comparison to previous reports on populations of these species found in northward Europe, where they have a more continuous distribution, the levels of genetic diversity were more or less halved, genetic differentiation was several times higher, gene flow exceptionally low, and the expected prevalence of clonal individuals was lacking. The population dynamics of all three species within the Balkans was complex and distinct, and was characterized by a past admixture of individuals from discrete populations of the same species and interspecific hybridisation not only between V. myrtillus and V. vitis-idaea but also between V. uliginosum and V. vitis-idaea, the latter not being reported to date. Conservation measures suitable for preservation of presumably genetically distinct portions of the Balkans’ gene pools of studied species have been suggested, while the utility of interspecific hybrids in breeding programs and/ or in food/pharmaceutical industry is yet to be assessed.
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Bjedov,
University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia
E-mail:
ivana.bjedov@sfb.bg.ac.rs
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Obratov–Petković,
University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia
E-mail:
dragica.obratov-petkovic@sfb.bg.ac.rs
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Mišić,
University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia
E-mail:
dmisic@ibiss.bg.ac.rs
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Šiler,
University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia
E-mail:
branislav.siler@ibiss.bg.ac.rs
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Aleksic,
University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia
E-mail:
aleksic_jelena@yahoo.com.au
article id 460,
category
Research article
Hong Ling,
Sandhya Samarasinghe,
G. Don Kulasiri.
(2009).
Modelling variability in full-field displacement profiles and Poisson ratio of wood in compression using stochastic neural networks.
Silva Fennica
vol.
43
no.
5
article id 460.
https://doi.org/10.14214/sf.460
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Vertical and horizontal displacement profiles in compression parallel-to-grain in a 20 x 20 mm area (30 x 21 or 630 points) in the Tangential–Longitudinal (T–L) and Radial Longitudinal (R–L) sections of small wood columns were obtained from digital image correlation applied to simultaneously captured images of the two surfaces. These consisted of 21 displacement realisations of 30 points along the length of the specimen. They revealed considerable local variations. Stochastic neural networks were successfully developed to simulate trends and noise across and along a specimen in both displacements as well as Poisson ratios in T–L and R–L sections for two selected load levels of 20kN and 40kN. These networks specifically embed noise characteristics extracted from data to generate realistic displacement and Poisson ratio realisations with inherent variability. Models were successfully validated using independent data extracted based on bootstrapping method with high accuracy with R2 ranging from 0.79 to 0.91. The models were further validated successfully using a second approach involving Confidence Intervals generated from the data extracted from the models. Models and experimental results revealed that for 20kN load, both vertical and horizontal displacements in T–L section were less heterogeneous across the specimen (smaller vertical shearing and horizontal strain, respectively) than those in the R–L section. For the 40kN load, both displacement profiles in the T–L section were less noisy and more compact than those for the 20kN load indicating less heterogeneity due to compaction of structure. In the R–L section, larger vertical shearing and horizontal strains persisted at 40 kN load. Poisson ratio decreased with load and it was nonlinear in both sections but T–L section showed much less noise across the specimen than the R–L section.
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Ling,
Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand
E-mail:
hl@nn.nz
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Samarasinghe,
Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand
E-mail:
sandhya.samarasinghe@lincoln.ac.nz
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Kulasiri,
Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand
E-mail:
gdk@nn.nz
article id 170,
category
Research article
Ryoichi Doi,
Senaratne L. Ranamukhaarachchi.
(2009).
Community-level physiological profiling in monitoring rehabilitative effects of Acacia auriculiformis plantation on degraded land in Sakaerat, Thailand.
Silva Fennica
vol.
43
no.
5
article id 170.
https://doi.org/10.14214/sf.170
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This study was conducted to investigate the rehabilitative effects of planting Acacia auriculiformis trees on degraded land by observing variations in soil bacterial community profiles provided by community-level physiological profiling. Soil bacterial and physicochemical comparisons between an original evergreen forest and the Acacia plantation plot, established on an area severely degraded as a result of deforestation, showed that most soil characteristics were rehabilitated 18 to 19 years after the plantation of Acacia according to single variables, Shannon and Simpson diversity indices based on the community-level physiological profiles, principal component analysis and redundancy analysis. However, a more strict statistical comparison, discriminant analysis, completely discriminated between the Acacia plantation and the evergreen forest soils when the community-level physiological profiles were compared. Thus, the Acacia plantation soil was shown to still be in the process to full recovery. Here, we discuss the relevance of planting A. auriculiformis in land rehabilitation schemes in savanna regions.
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Doi,
AFE Building, School of Environment, Resources and Development, Asian Institute of Technology, Pathumthani 12120, Thailand
E-mail:
roird@aeiou.pt
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Ranamukhaarachchi,
AFE Building, School of Environment, Resources and Development, Asian Institute of Technology, Pathumthani 12120, Thailand
E-mail:
slr@nn.th
article id 261,
category
Research article
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This paper addresses tree crown envelope shape modeling from the perspective of optical passive remote sensing. The aims are 1) to review the specific requirements of crown shape models and ground measurement techniques in optical remote sensing, and 2) to present preliminary results from empirical, parametric crown shape and volume modeling of Scots pine and Norway spruce applicable in Finland. Results indicated that the basic dimensions (maximum radius, its height and crown length) of tree crowns were better predicted for pines, but the profile shape of the upper part of the crowns varied more than in spruce. Pine crowns were also slightly less concave than spruce crowns. No regularities were observed concerning the lower part of the crowns. The asymmetry of crowns increased as a function of tree age for both species, spruce crowns being more asymmetric than pine crowns. A comparison of measured crown volume with several simple geometrical crown shape envelopes showed that using a cone as a crown shape model for Scots pine and Norway spruce underestimates crown volume most severely. Other crown envelope shape models (e.g. ellipsoids) rendered crown volumes closer to the measured volume and did not differ considerably from each other.
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Rautiainen,
Tartu Observatory, 61602 Tõravere, Estonia, and Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland
E-mail:
miina.rautiainen@helsinki.fi
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Mõttus,
Tartu Observatory, 61602 Tõravere, Estonia
E-mail:
mm@nn.ee
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Stenberg,
Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland
E-mail:
ps@nn.fi
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Ervasti,
City of Vantaa, Land Use and Environment / Green Area Unit, Kielotie 13, FI-01300 Vantaa, Finland
E-mail:
se@nn.fi
article id 629,
category
Research article
S. Samarasinghe,
G. D. Kulasiri.
(2000).
Displacement fields of wood in tension based on image processing: Part 1. Tension parallel- and perpendicular- to grain and comparisons with isotropic behaviour.
Silva Fennica
vol.
34
no.
3
article id 629.
https://doi.org/10.14214/sf.629
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Displacement fields for tensile loaded rubber and wood in parallel- and perpendicular-to-grain were obtained from digital image correlation. The results showed that the digital image correlation can reveal fine details of the nature of displacements in both rubber and wood. It was found that when load is perpendicular-to-grain, the lignin matrix produces uniform displacement fields similar to that of isotropic rubber. Uniform displacement fields also observed when lignin is involved in contraction due to Poisson effect in parallel-to-grain tension. However, when tracheids carry the load in parallel-to-grain loading, or are compressed in perpendicular-to-grain loading, a complex displacement pattern distorted by internal shear stress and slippage is produced.
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Samarasinghe,
Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand
E-mail:
ss@nn.nz
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Kulasiri,
Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand
E-mail:
kulasird@tui.lincoln.ac.nz