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Articles containing the keyword 'aspen'.

Category: Research article

article id 9938, category Research article
Jyrki Hytönen, Egbert Beuker, Anneli Viherä-Aarnio. (2018). Clonal variation in basic density, moisture content and heating value of wood, bark and branches in hybrid aspen. Silva Fennica vol. 52 no. 2 article id 9938. https://doi.org/10.14214/sf.9938
Highlights: Hybrid aspen clones differed in their moisture content, ash content, basic density and heating value; Stem wood had lower ash content, basic density and effective heating value than stem bark; There was significant vertical variation in wood and bark along the stem in moisture content and basic density.

Hybrid aspen (Populus tremula × P. tremuloides) is one of the fastest growing tree species in Finland. During the mid-1990s, a breeding programme was started with the aim of selecting clones that were superior in producing pulpwood. Hybrid aspen can also be grown as a short-rotation crop for bioenergy. To study clonal variation in wood and bark properties, seven clones were selected from a 12-year-old field trial located in southern Finland. From each clone, five trees were harvested and samples were taken from stem wood, stem bark and branches to determine basic density, effective heating value, moisture and ash content. Vertical within-tree variation in moisture content and basic density was also studied. The differences between clones were significant for almost all studied properties. For all studied properties there was a significant difference between wood and bark. Wood had lower ash content (0.5% vs. 3.9%), basic density (378 kg m–3 vs. 450 kg m–3) and effective heating value (18.26 MJ kg–1 vs. 19.24 MJ kg–1), but higher moisture content (55% vs. 49%) than bark. The values for branches were intermediate. These results suggest that the properties of hybrid aspen important for energy use could be improved by clonal selection. However, selecting clones based on fast growth only may be challenging since it may lead to a decrease in hybrid aspen wood density.

  • Hytönen, Natural Resources Institute Finland (Luke), Natural resources, Teknologiakatu 7, FI-67100 Kokkola, Finland ORCID ID:E-mail: jyrki.hytonen@luke.fi (email)
  • Beuker, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 6, FI-57200 Savonlinna, Finland ORCID ID:E-mail: egbert.beuker@luke.fi
  • Viherä-Aarnio, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland ORCID ID:E-mail: anneli.vihera-aarnio@luke.fi
article id 1442, category Research article
Silva Šēnhofa, Mārtiņš Zeps, Roberts Matisons, Jānis Smilga, Dagnija Lazdiņa, Āris Jansons. (2016). Effect of climatic factors on tree-ring width of Populus hybrids in Latvia. Silva Fennica vol. 50 no. 1 article id 1442. https://doi.org/10.14214/sf.1442
Highlights: Hybrid poplar and hybrid aspen were sensitive to temperature in summer and dormant periods, but none of the tested factors were strictly limiting; Hybrid poplar was sensitive to a higher number of climatic factors than hybrid aspen; Temperature showed a negative correlation with tree-ring width.

Fast-growing hybrids of Populus L. have an increasing importance as a source of renewable energy and as industrial wood. Nevertheless, the long-term sensitivity of Populus hybrids to weather conditions and hence to possible climatic hazards in Northern Europe have been insufficiently studied, likely due to the limited age of the trees (short rotation). In this study, the climatic sensitivity of ca. 65-year-old hybrid poplars (Populus balsamifera L. × P. laurifolia Ledeb.), growing at two sites in the western part of Latvia, and ca. 55-year-old hybrid aspens (Populus tremuloides Michx. × P. tremula L.), growing in the eastern part of Latvia, have been studied using classical dendrochronological techniques. The high-frequency variation of tree-ring width (TRW) of hybrid poplar from both sites was similar, but it differed from hybrid aspen due to the diverse parental species and geographic location of the stands. Nevertheless, some common tendencies in TRW were observed for both hybrids. Climatic factors influencing TRW were generally similar for both hybrids, but their composition differed. The strength of climate-TRW relationships was similar, but the hybrid poplar was affected by a higher number of climatic factors. Hybrid poplar was sensitive to factors related to water deficit in late summer in the previous and current years. Hybrid aspen was sensitive to conditions in the year of formation of tree-ring. Both hybrids also displayed a reaction to temperature during the dormant period. The observed climate-growth relationships suggest that increasing temperatures might burden the radial growth of the studied hybrids of Populus.

  • Šēnhofa, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: silva.senhofa@gmail.com
  • Zeps, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: martins.zeps@silava.lv
  • Matisons, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: robism@inbox.lv (email)
  • Smilga, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: janis.smilga@silava.lv
  • Lazdiņa, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: dagnija.lazdina@silava.lv
  • Jansons, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: aris.jansons@silava.lv
article id 1135, category Research article
Matts Lindbladh, Per-Ola Hedwall, Ida Wallin, Annika M. Felton, Henrik Böhlenius, Adam Felton. (2014). Short-rotation bioenergy stands as an alternative to spruce plantations: implications for bird biodiversity. Silva Fennica vol. 48 no. 5 article id 1135. https://doi.org/10.14214/sf.1135
Highlights: There is a gap in knowledge regarding the biodiversity implications of replacing production forests with bioenergy stands; We compared the avian biodiversity of early rotation hybrid aspen stands and spruce plantations, the latter being the dominant production forest type in southern Sweden; Our results indicate that young hybrid aspen stands can support relatively diverse and distinctive bird communities.
Global efforts to decrease dependence on fossil fuels have increased interest in bioenergy production. One source of bioenergy is fast growing deciduous tree species, such as hybrid aspen (Populus × wettsteinii Hämet-Ahti). The majority of research on hybrid aspen which assesses biodiversity implications, has however primarily focused on agricultural lands as the reference condition. This has resulted in a substantial gap in our knowledge regarding the biodiversity implications of replacing production forest types with hybrid aspen, a form of reforestation taking place in northern Europe. In this study we address this knowledge gap by comparing the avian biodiversity of young hybrid aspen and spruce (Picea abies L.) plantations of similar age, the latter being the most prevalent forestry alternative in in southern Sweden. We found that hybrid aspen stands had higher bird species richness and abundance as well as a distinct community composition compared to the spruce stands. We suggest that the most likely driver was the greater structural and tree species complexity in the aspen stands, provided for by the fenced exclusion of ungulates from the regenerating hybrid aspen stands. Our results indicate that at least during early stages of regeneration, and in comparison to the dominating production forest type in the region, hybrid aspen stands can support relatively high levels of bird diversity, and a bird species composition more closely associated with broadleaf habitat types requiring restoration in this region.
  • Lindbladh, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: matts.lindbladh@slu.se (email)
  • Hedwall, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: per-ola.hedwall@slu.se
  • Wallin, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: ida.wallin@slu.se
  • Felton, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: annika.felton@slu.se
  • Böhlenius, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: henrik.bohlenius@slu.se
  • Felton, Southern Swedish Forest Research Centre, SLU – Swedish University of Agricultural Sciences, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: adam.felton@slu.se
article id 342, category Research article
Jaana Luoranen, Juha Lappi, Gang Zhang, Heikki Smolander. (2006). Field performance of hybrid aspen clones planted in summer. Silva Fennica vol. 40 no. 2 article id 342. https://doi.org/10.14214/sf.342
We investigated the possibility to plant clonal hybrid aspen (Populus tremula x tremuloides) during the summer of propagation when the plants are 20–25 cm tall and only a few months old. In four experiments carried out in years 1998–2001, survival of summer-planted hybrid aspens was at least as high as that of hybrid aspen planted in autumn and spring. In all experiments, compared to planting in September or the following May, height growth was greater with planting in July and early August. Root egress of hybrid aspens planted in July and August was also greater than that of aspens planted in autumn or the following spring. Summer planting was thus possible both with plants produced by micropropagation and with those produced from root cuttings.
  • Luoranen, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: jaana.luoranen@metla.fi (email)
  • Lappi, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
  • Zhang, College of Horticulture, Agricultural University of Hebei, Baoding, Hebei, China ORCID ID:E-mail:
  • Smolander, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
article id 521, category Research article
Gordon Nigh. (2002). Site index conversion equations for mixed trembling aspen and white spruce stands in northern British Columbia. Silva Fennica vol. 36 no. 4 article id 521. https://doi.org/10.14214/sf.521
White spruce and trembling aspen are two important commercial species in British Columbia. They often grow in association, particularly in the Boreal White and Black Spruce and Sub-Boreal Spruce biogeoclimatic zones. Site index conversion equations are useful for estimating the site index of one species from the site index of another species. This study fills a need for site index conversion equations for mixed spruce/aspen stands. Seventy 0.01 ha study plots were established in mixed spruce/aspen stands. One site tree of each species was selected from each plot. The height and breast height ages of the site trees were measured and the site index was estimated with these data. The correlation between the site index of spruce and aspen was 0.6. Geometric mean regression was used to estimate the parameters of a linear site index conversion equation. The analysis did not reveal any differences in the conversion equations across the three major biogeoclimatic units (BWBSmw1, BWBSmw2, and SBS) that were sampled. Therefore, only one conversion equation is required.
  • Nigh, Ministry of Forests, Research Branch, P.O. Box 9519, Stn. Prov. Govt., Victoria, BC, Canada V8W 9C2 ORCID ID:E-mail: gordon.nigh@gems2.gov.bc.ca (email)
article id 600, category Research article
Qibin Yu, P. M. A. Tigerstedt, Matti Haapanen. (2001). Growth and phenology of hybrid aspen clones (Populus tremula L. x Populus tremuloides Michx.). Silva Fennica vol. 35 no. 1 article id 600. https://doi.org/10.14214/sf.600
Height, basal diameter, diameter at breast height, bud burst, and leaf development were recorded in a 5-year-old hybrid aspen clonal trial. The field trial consisted of four aspen hybrid clones (Populus tremula x Populus tremuloides) and one local P. tremula seedling source. Phenological traits were observed in the 3rd year. Growth patterns were recorded during the 3rd and 4th years. Phenological traits were explored in relation to hybrid vigor expressed as growth traits. Differences were observed for phenological and growth traits among hybrid clones and P. tremula. The growth period varied from 143–158 days for the four hybrid clones, and was 112 days for P. tremula. The correlation between growth period and yield was highly significant. The annual growth rate of height for the hybrids was 4.2 cm per 7 days (2.4 for P. tremula) in the 3rd year and 6.4 cm per 7 days (2.9 for P. tremula) in the 4th year. After 5 years, mean estimated stem volume of the hybrids was 3.9 times that of P. tremula. Significant clone by year interaction was observed for height, diameter, and volume growth. The hybrid vigor seems to be mainly attributable to a longer growth period.
  • Yu, Department of Plant Biology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail: qibin.yu@helsinki.fi (email)
  • Tigerstedt, Department of Plant Biology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:
  • Haapanen, Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:

Category: Article

article id 5568, category Article
Tord Johansson. (1996). Site index curves for European aspen (Populus tremula L.) growing on forest land of different soils in Sweden. Silva Fennica vol. 30 no. 4 article id 5568. https://doi.org/10.14214/sf.a8503

Growth data were collected from 40 European aspen (Populus tremula L.) stands growing on eight localities in Sweden. The stands ranged in latitude from 56 to 66°N. The mean age of the stands was 32 years (range, 12–63), the mean stand density 1978 stems ha-1 (range, 300–6,000), and the mean diameter at breast height (on bark) 17 cm (range, 8–34).

Site index curves were constructed for total age. Curves for H40 (dominant height at 40 years total age) were made for total Sweden. Curves fitted for H40 total age have another shape than curves presented by other Nordic studies. The curves from the present study have slower growth for young aspens than curves from Norwegian and Finnish conditions. For 50–70-year-old aspen stands, curves from the present study indicate taller heights than from Nordic studies.

Classified soil types from the stands were grouped into three groups: sandy till (17), light clay (15) and medium clay till (4). As there was only one stand growing in the fine sand group and one stand in the heavy clay till group and two stands in the silty till group, these stands were not presented with growth curves. There were no statistically significant differences in site index between the three soil type groups. Some recommendations for management of aspen stand are given. Damages caused by moose, fungi and other injuries are discussed as a problem for height yield production and a good timber quality.

  • Johansson, ORCID ID:E-mail:
article id 5174, category Article
Tiina Heinonen. (1983). Haavikon lannoituskoe. Silva Fennica vol. 17 no. 1 article id 5174. https://doi.org/10.14214/sf.a15089
English title: A fertilization experiment in a Populus tremula stand.
Original keywords: haapa; lannoitus; typpi; pohjapinta-ala

The growth response of aspen (Populus tremula L.) to fertilization was studied in an experiment laid out in a naturally regenerated 35-year old stand on a previously burned-over land. The site was rather fertile. One-tree plot method was used. Applications of nitrogen (150 kg/ha as ammonium nitrate with lime), phosphorus (35 kg/ha as superphosphate), and potassium (66 kg/ha as potassium chloride) separately and in all possible combinations were used; the test included 11 replications. The growth reaction was measured as basal area growth excluding bark during 5 years. The factorial effects were computed using Yates method.

Potassium did not have any effect on basal growth of the trees. The response to phosphorus was also rather small. On the other hand, nitrogen appeared to have increased the basal area growth. The growth increase obtained with nitrogen alone was greater than when it was applied together with phosphorus and/or potassium.

The PDF includes a summary in English.

  • Heinonen, ORCID ID:E-mail:
article id 5118, category Article
Matti Nuorteva, Jyrki Patomäki, Lennart Saari. (1981). Large poplar longhorn, Saperda carcharias (L.), as food for white-backed woodpecker, Dendrocopos leucotos (Bechst.). Silva Fennica vol. 15 no. 2 article id 5118. https://doi.org/10.14214/sf.a15059

In a locality in Southern Finland where the white-backed woodpecker, Dendrocopos leucotos (Bechst.), was previously breeding was found many conical borings excavated during the winter in young aspens (Populus tremula L.) on average 8.1 cm in diameter. Full-grown larvae of Saperda carcharias (L.) (Coleoptera, Cerambycidae) hibernated in pupal chambers constructed about 0.5 m above ground level. Below this chamber the larva has usually prepared an exit hole. After the larva has blocked itself in the pupating chamber it is easy to prey for the woodpecker during the whole winter.

There were usually 1–5 conical borings in the same trunk. The number of these borings did not correspond with the amounts of larvae eaten, since the woodpecker often made these borings in places from which it could not obtain a prey. The woodpeckers stopped excavating in those cases when the larvae in the galleries were dead. The exit holes and the conical borings occluded within a few years. The galleries within the tree will not heal and several years later a new larva may utilize them. In the wintering habitats of the white-backed woodpecker the availability of food could be improved by increasing the amount of S. sarcharias larvae. This is easily done by encouraging young aspens.

The PDF includes a summary in Finnish.

  • Nuorteva, ORCID ID:E-mail:
  • Patomäki, ORCID ID:E-mail:
  • Saari, ORCID ID:E-mail:
article id 5114, category Article
Matti Kärkkäinen. (1981). Haapa- ja poppelilajien (Populus) käyttö. Silva Fennica vol. 15 no. 2 article id 5114. https://doi.org/10.14214/sf.a15055
English title: Utilization of aspen and poplars (genus Populus).
Original keywords: haapa; poppelit; viljely; puulajit; käyttö

The aim of this study was to establish from the literature the purposes and for which aspen (Populus tremula L.) and related poplar species are used and can be used.  According to the literature, numerous Populus species can be utilized in the industry with success instead of light softwood species in addition to them. The main emphasis is in the growing of large-sized timber, and there is no clear trend to changing to the short-rotation forestry of poplar. However, the utilization of the good sprouting properties of Populus species will probably increase as this regeneration method is cheap.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
article id 5090, category Article
Matti Kärkkäinen, Raili Voipio. (1980). Suomalainen haapa- ja poppelilajeja (Populus) koskeva kirjallisuus 1759...1979. Silva Fennica vol. 14 no. 4 article id 5090. https://doi.org/10.14214/sf.a15031
English title: Finnish literature on aspen and poplar species (genus Populus), 1759–1979.

The first Finnish paper on aspen (Populus tremula L.) was published in 1759 in Åbo (Turku). After this dissertation, numerous scientific and other articles and reports have been published. In this bibliography about 340 papers are listed. Most of the papers deal only with aspen or other species of the genus Populus. Besides these even those articles have been included which deal with other problems but contain some information on the features of poplars.

The titles are listed without any translation or classification. If an article has a summary, it is shown in the title.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
  • Voipio, ORCID ID:E-mail:
article id 5086, category Article
Jussi Meriluoto. (1980). MCPA- ja 2,4,5-T-herbisidien käyttökelpoisuus taimiston hoidossa. Silva Fennica vol. 14 no. 4 article id 5086. https://doi.org/10.14214/sf.a15027
English title: Applicability of MCPA- and 2,4,5-T-herbicides in sapling stand management.

The applicability of MCPA- and 2,4,5-T-herbicides for use in the management of sapling stands and the possibilities of carrying out foliar spraying at an earlier date than at precent with smaller doses of the active ingredient were examined in this study. The results were obtained from foliage spraying experiments carried out in Central Finland in summer 1976. MCPA and 2,4,5-T were as effective as each other against deciduous tree species. However, MCPA was slightly more effective against aspen (Populus tremula L.) than 2,4,5-T. The spraying date had no effect on the mortality rate of aspen or birch (Betula pendula Roth and B. pubescens Ehrh.) There were only very slight differences between the results for different dosage levels. The damage caused to Scots pine (Pinus sylvestris L.) was very slight. The temperature conditions prevailing during spraying affected spraying effectiveness in such way that the mortality rate decreased during cold period.

The PDF includes a summary in English.

  • Meriluoto, ORCID ID:E-mail:
article id 5004, category Article
Matti Kärkkäinen. (1978). Haapatukkien lahoisuus. Silva Fennica vol. 12 no. 3 article id 5004. https://doi.org/10.14214/sf.a14858
English title: Occurrence of decay in aspen logs.
Original keywords: haapa; tukki; laho; tyvitukit
English keywords: aspen; Populus tremula; logs; decay; butt logs

At three Finnish match factories 1,629 aspen logs were measured (see Kärkkäinen and Salmi 1978). When the estimation was based on the condition of the butt cross section of a log, less than half of the logs were sound without any discoloration or decay. Based on the condition of the top cross-section, the corresponding figure was a little higher than 50%. The logs with decay were bigger than those without it. There were relatively more butt logs among the logs with decay than among the totally sound logs.

The PDF includes a summary in Finnish.

  • Kärkkäinen, ORCID ID:E-mail:
article id 4950, category Article
Matti Kärkkäinen. (1976). Lisähavaintoja haapatukkien poikkipinta-alan mittaamisesta. Silva Fennica vol. 10 no. 4 article id 4950. https://doi.org/10.14214/sf.a14796
English title: Auxiliary observations on the measurement of the cross-sectional area of aspen logs.

In this study the area, 8 diameters, and 16 radii were measured of 174 discs representing aspen logs in a mill. The average difference between the largest and smallest diameter was 18 mm, or 7% of the longest diameter. The difference between the largest and smallest radius was 29 mm, or 22% of the longest radius. The diameter was on the average 2.4 mm longer than the two corresponding radii.

The exact area of each disc was measured using a planimeter. In comparison, the area based on the circle formula the diameter being the arithmetic mean of largest and smallest diameters overestimated the area by 1.7%. The results also indicated that the use of random direction in the measurement of diameter overestimated the cross-sectional area on the average by 1.8%.

The study is continuation of the earlier study where the bibliography is presented. As far as the results are comparable, they support each other.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
article id 4922, category Article
Matti Kärkkäinen. (1975). Koivu- ja haapatukkien poikkipinta-alan mittaaminen. Silva Fennica vol. 9 no. 3 article id 4922. https://doi.org/10.14214/sf.a14764
English title: Measurement of the cross-sectional area of birch and aspen logs.

The aim of the study was to determine the extent to which the cross section of birch (Betula sp.) and aspen (Populus tremula L.) logs differ from a circle and to test some simple methods for measuring the cross-sectional area which can be used, for instance, for determining the volume of the logs. The material consisted of 420 debarked birch disks and 240 aspen disks which were representative of the logs arriving at two factories.

The convex deficit values for the material were very small, the cross-sectional area error being in general less than 1%. On the other hand, the other parameters deviated from the circular form to quite a large degree. It was also evident that the radii measured from the piths to the surface of the wood varied considerably more in the same disk, as regards length, than the diameters measured in different directions.

It was evident that the shape of the average cross-sectional area was not in general elliptical. It thus appears that any method for measuring the cross-sectional area which is based on elliptical formula is not suitable. The method which gave the best result was that in which the cross-sectional area was taken as the average of the area of the circle calculated from the smallest diameter and that calculated from the diameter passing at right angles to it. This method also appeared to be the best for disks which deviated to quite a large degree from the circular form. The suitability of this method is increased by the fact that the relative error is only slightly dependent on the size of the disk.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
article id 4871, category Article
Kari Löyttyniemi. (1972). Hybridihaavikoiden hyönteistuhoista. Silva Fennica vol. 6 no. 3 article id 4871. https://doi.org/10.14214/sf.a14678
English title: Insect damages in hybrid aspen stands.
Original keywords: hybridihaapa; hyönteistuhot

Hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) has been grown in Finland for about 20 years, and the area of the stands is currently about 400 ha. Growing is planned to be greatly expanded to grow raw material for match industry. The aim of this investigation was to study susceptibility of hybrid aspen to insect damages. Insect damages in hybrid aspen, growing in Southern Finland, were examined in 15 stands in 1972. Saperda species were observed to be the most numerous and harmful insect species. Saperda carcharias L. occurred in 26% and Saperda populnea L. in 36% off trees inspected. Mass occurrence of Chionaspis salicis L. was observed in some sample areas.

  • Löyttyniemi, ORCID ID:E-mail:
article id 4858, category Article
Tauno Kallio. (1972). Erään 10-vuotiaan hybridihaapametsikön lahovikaisuus. Silva Fennica vol. 6 no. 1 article id 4858. https://doi.org/10.14214/sf.a14661
English title: Decay in a ten-year old stand of hybrid aspen.
Original keywords: hybridihaapa; sienitaudit; laho; bakteerit

A ten-year old stand of hybrid aspen (Populus tremula x Populus tremuloides), growing in Southern Finland on about 1.5 ha of Oxalis-Myrtillus type (OMT) soil and affected by crown blight, was examined in 1971. The study revealed that almost all trees, both those removed by thinning and the remaining growing stock, were decayed. A number of bacteria, Fungi imperfecti species and ascomycetous fungi were isolated from the discoloured heartwood of the affected trees. No fungus of the Bacidiomycetes was found in the discoloured wood material.

The PDF includes a summary in English.

  • Kallio, ORCID ID:E-mail:
article id 4576, category Article
Bo-Eric Blumenthal. (1942). Studier angående aspens förekomst och egenskaper i Finland. Silva Fennica no. 56 article id 4576. https://doi.org/10.14214/sf.a9080
English title: Distribution and properties of aspen in Finland.

Aspen (Populus tremula L.) is a common tree in Finland, and has been used, for instance, in matchstick industry. However, there has been little studies on its distribution and properties. In this study, 142 sample trees in different forest site types in Valtimo and Onkamo in Eastern Finland were measured in detail in 1935.

According to the results, during the first 10 years aspens height growth is fastest of the Finnish tree species surpassing, for instance, Scots pine (Pinus sylvestris L.) and birch (Betula sp.) . The diameter growth is similar to Scots pine up to the age of 50 years, after which the growth of aspen exceeds Scots pine. Branchless portion of the stem compared to the height of the tree increases until it reaches about 50% of the height of the tree. In poorer sites aspen is prone to decay.

Aspen regenerates easily both by root shoots and seeds. If root shoots are left to grow, the mother tree should be free of decay. In general, seedlings are of better quality. Good quality aspen stands require thinning and a rich forest type. If an old aspen stand has decay, the trees should be ring-barked and the site regenerated with a new tree species.

The article includes an abstract in German.

  • Blumenthal, ORCID ID:E-mail:

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