Current issue: 56(2)

Under compilation: 56(3)

Scopus CiteScore 2021: 2.8
Scopus ranking of open access forestry journals: 8th
PlanS compliant
Silva Fennica 1926-1997
Acta Forestalia Fennica

Articles containing the keyword 'ALS'

Category: Article

article id 5595, category Article
R.A. Fleming. (1996). A mechanistic perspective of possible influences of climate change on defoliating insects in North America's boreal forests. Silva Fennica vol. 30 no. 2–3 article id 5595.
Keywords: climate change; disturbance regimes; boreal forest dynamics; Abies balsamea; natural selection; North America; Choristoneura fumiferana; insect outbreaks; phenological relationships; plant quality; extreme weather; thresholds
Abstract | View details | Full text in PDF | Author Info

There is no doubt that tree survival, growth, and reproduction in North America's boreal forests would be directly influenced by the projected changes in climate if they occur. The indirect effects of climate change may be of even greater importance, however, because of their potential for altering the intensity, frequency, and perhaps even the very nature of the disturbance regimes which drive boreal forest dynamics. Insect defoliator populations are one of the dominating disturbance factors in North America's boreal forests and during outbreaks trees are often killed over vast forest areas. If the predicted shifts in climate occur, the damage patterns caused by insects may be considerably changed, particularly those of insects whose temporal and spatial distributions are singularly dependent on climatic factors. The ensuing uncertainties directly affect depletion forecasts, pest hazard rating procedures, and long-term planning for pest control requirements. Because the potential for wildfire often increases in stands after insect attack, uncertainties in future insect damage patterns also lead to uncertainties in fire regimes. In addition, because the rates of processes key to biogeochemical and nutrient recycling are influenced by insect damage, potential changes in damage patterns can indirectly affect ecosystem resilience and the sustainability of the multiple uses of the forest resource.

In this paper, a mechanistic perspective is developed based on available information describing how defoliating forest insects might respond to climate warming. Because of its prevalence and long history of study, the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used for illustrative purposes in developing this perspective. The scenarios that follow outline the potential importance of threshold behaviour, historical conditions, phenological relationships, infrequent but extreme weather, complex feedbacks, and natural selection. The urgency of such considerations is emphasized by reference to research suggesting that climate warming may already be influencing some insect lifecycles.

  • Fleming, E-mail: rf@mm.unknown (email)
article id 5591, category Article
Egbert Beuker, Seppo Kellomäki, Marja Kolström. (1996). Changes in wood production of Picea abies and Pinus sylvestris under a warmer climate: comparison of field measurements and results of a mathematical model. Silva Fennica vol. 30 no. 2–3 article id 5591.
Keywords: Pinus sylvestris; climate change; Picea abies; simulation model; global warming; provenance trials
Abstract | View details | Full text in PDF | Author Info

To project the changes in wood production of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) in Finland as a result of climate change, two separate studies were made. The first study, at the Faculty of Forestry, University of Joensuu, based its projections on mathematical models; the second one, at the Finnish Forest Research Institute, based projections on measurements of wood production in two series of aged provenance experiments. The results of the two studies were similar for both species: after a 4°C increase of the annual mean temperature a drastic increase in wood production in northern Finland, but little effect, or even some decrease in the southern part of the country. However, the assumptions used in the two studies differed. One important difference was that in the models the temperature is assumed to be increasing gradually over the years, whereas in the provenance experiments, climate changed immediately when the seedlings were transferred to the planting sites. Another problem with the provenance experiments is that when material is moved in a north-south direction in Finland, not only temperature but also photoperiod changes markedly. To compare these two studies, site factors (e.g. soil type, temperature, precipitation) and silvicultural factors (e.g. plant spacing, survival, time of thinning, thinning intensity) from the provenance experiments were included a variable in the mathematical models.

  • Beuker, E-mail: eb@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Kolström, E-mail: mk@mm.unknown
article id 5471, category Article
Hannu Fritze. (1992). Effects of environmental pollution on forest soil microflora - a review. Silva Fennica vol. 26 no. 1 article id 5471.
Keywords: soil respiration; forest soil; litter decomposition; acidification; lime; heavy metals; pollution; microflora; fungal hyphae
Abstract | View details | Full text in PDF | Author Info

The article is a literature review focusing on the reaction of soil respiration, litter decomposition and microflora of forest soils to various pollutants like acidic deposition, heavy metals and unusual high amounts of basic cations. There is a great deal of evidence indicating that environmental pollution affects soil microbial activity and community structure. Much of the data originates from experimental designs where high levels of pollutants were applied to the soil under field or laboratory conditions. Furthermore, many were short-term experiments designed to look for large effects. These experiments have an indicative value, but it has to be kept in mind that environmental pollution is a combination of many pollutants, mostly at low concentrations, acting over long periods of time. There is therefore consequently a demand for research performed in natural forest environments polluted with anthropogenic compounds. 

  • Fritze, E-mail: hf@mm.unknown (email)
article id 5395, category Article
Mirja Kortesharju, Jouko Kortesharju. (1989). Studies on epiphytic lichens and pine bark in the vicinity of a cement works in northern Finland. Silva Fennica vol. 23 no. 4 article id 5395.
Keywords: Pinus sylvestris; bark; lichens; air pollution; heavy metals; calcium; Bryoria; Parmeliopsis; cement; elements
Abstract | View details | Full text in PDF | Author Info

The element content (Ca, Mg, K, Na, Fe, Mn, Zn, Cu, Pb, S) of Scots pine (Pinus sylvestris L.) bark and Bryoria lichens, as well as the occurrence and coverage of epiphytic lichens and the length of Bryoria species, were studied in the vicinity of Kolari cement works, NW Finland. Fruticose Bryoria species had the highest coverage on pine trunks at a distance of 2 km or more from the cement works. At a distance of 1 km the foliose – or even crustose – Parmeliopsis species were most abundant, while nearer to the works lichens were almost completely absent. The length of Bryoria was reduced at distances of less than 2 km from the cement works. The calcium content in Bryoria species increased very steeply close to the works; by a factor of 60 at a distance of 1 km compared to 16 km. No corresponding increase in other elements was observed near the cement works. All the elements studied in pine bark showed a significant negative correlation with distance, and a significant positive correlation with the calculated dust deposition levels. There were only minor differences between the north and south of the pine trunks, or the side facing or away from the works. Pine bark analysis is recommended for element accumulation studies.

The PDF includes an abstract in English.

  • Kortesharju, E-mail: mk@mm.unknown (email)
  • Kortesharju, E-mail: jk@mm.unknown
article id 5367, category Article
Kari Heliövaara, Rauno Väisänen. (1989). Quantitative variation in the elemental composition of Scots pine needles along a pollutant gradient. Silva Fennica vol. 23 no. 1 article id 5367.
Keywords: Pinus sylvestris; needles; Finland; nutrients; Harjavalta; air pollution; heavy metals; herbivores
Abstract | View details | Full text in PDF | Author Info

Quantitative variation in the elemental composition of living Scots pine needles was studied along an atmospheric pollutant gradient in the surroundings of the industrial town Harjavalta, south-western Finland. Two 9-km-long transects, each with nine sample plots, running to the S and SW from factory complex were delimited in a homogenous Scots pine (Pinus sylvestris L.) forest. Needle samples were taken from 10 trees at each site, and from two separate sites in Tuusula near Helsinki. There was considerable spatial variation in the elemental composition of the needles. Heavy metals (Cu, Fe, Zn) showed a clear pattern of exponentially decreasing concentration with increasing distance from the emission source. Sodium and potassium concentrations, as well as the ash weight and air-dry weight, also decreased. Magnesium, manganese and calcium concentrations increased with increasing distance.

The PDF includes an abstract in Finnish.

  • Heliövaara, E-mail: kh@mm.unknown (email)
  • Väisänen, E-mail: rv@mm.unknown
article id 5343, category Article
R. J. K. Rinne, A. I. Mäkinen. (1988). Regional and species variations in metal content of two woodland mosses Pleurozium schreberi and Hylocomium splendens in Finland and northern Norway. Silva Fennica vol. 22 no. 1 article id 5343.
Keywords: Hylocomnium splendens; mosses; air pollution; heavy metals; bioindicators; Pleurozia shcreberi; air pollution monitoring
Abstract | View details | Full text in PDF | Author Info

The woodland mosses Pleurozia shcreberi (Willd. ex Brid.) Mitt. and Hylocomnium splendens (Hedw.) Schimp. were used in air pollution monitoring. During late summer and autumn 1977, 44 samples of Pleurozia shcreberi were collected in semi-open coniferous forests from Southern Finland (60°N) to Northern Finland and Northern Norway (70°N). Additional 26 samples of Hylocomnium splendens were collected in similar places south of 61°30’N. Analysis of both moss species revealed decreasing concentration gradients from south to north for Cu, Fe, Pb and Zn. Conversely, Mn and Mg levels increased with latitude, while Ca did not change significantly. Some decreasing west to east concentration gradients for Cu, Zn and Pb were measured in P. schreberi and in H. splendends collected from Southern Finland.

A comparison between these two mosses showed significant differences in Cu content (ave. 22% higher in H. splendends) and Zn content (ave. 8% higher in P. schreberi). However, the differences were considered minor in relation to regional differences in Finland.

In local study of emissions from the Koverhar steel works in Southern Finland, Fe and Zn concentrations in P. schreberi and H. splendens were found to decrease significantly with increasing distance up to 6 kilometres north and south of the source.

The PDF includes a summary in Finnish.

  • Rinne, E-mail: rr@mm.unknown (email)
  • Mäkinen, E-mail: am@mm.unknown
article id 5211, category Article
Risto Jalkanen, Esko Jalkanen, Jyrki Jalkanen, Marja Jalkanen. (1984). Maanpinnan rikkomisen 10-vuotisvaikutus korvasienisatoon. Silva Fennica vol. 18 no. 2 article id 5211.
English title: Ten-year effects of breaking the soil surface on the yield of Gyromitra esculenta.
Original keywords: korvasieni; sienisato; maankäsittely; kivennäismaa
English keywords: yield; soil preparation; mushrooms; Gyromitra esculenta; false morel; fruit bodies
Abstract | View details | Full text in PDF | Author Info

The yield of Gyromitra esculenta (Pers.) Fr. was surveyed during 1973–82 in a Norway spruce (Picea abies (L.) H. Karst.) dominated stand in Central Finland. The soil surface was treated with different light methods, mainly removing the vegetation and humus layer.

It was shown that is possible to improve the natural yield of G. esculenta by breaking the soil surface. In the 286 m2 of treated the yield could be improved over 50 fold compared to the control area. In the untreated control area, the yield per hectare was 0.98 kg/yr. In treated plots the yield was 52.4 kg/yr (in the best year 191 kg/ha/yr). Fruit bodies of G. esculenta were found in treated plots every year after the soil treatment. The yield was at its best in the two first years declining later to the level of 10–20% of the first year’s yield.

The best natural yield was reached in the last year. The previous year’s precipitation was an important factor influencing the yield of the mushroom.

The PDF includes a summary in English.

  • Jalkanen, E-mail: rj@mm.unknown (email)
  • Jalkanen, E-mail: ej@mm.unknown
  • Jalkanen, E-mail: jj@mm.unknown
  • Jalkanen, E-mail: mj@mm.unknown
article id 5145, category Article
Torleif Bramryd. (1981). Environmental effects of heavy metals distributed from power plants. Silva Fennica vol. 15 no. 4 article id 5145.
Keywords: Finland; coal; mosses; air pollution; environmental impact; heavy metals; indicator plants; energy production; power plant; Scots pine needles; bioindicator
Abstract | View details | Full text in PDF | Author Info

Increased prices on oil have resulted in the search for alternative energy sources, e.g. coal, peat, biomass, different types of waste. Combustion especially of waste, coal and peat emits large quantities of air pollutants such as heavy metals but also harmful organic substances. Heavy metals are not easily separated from the smoke, and the concentrations are often high in the emissions even with advanced fly-ash separators.

Ecological investigations carried out around a coal burning power plant in Finland using mosses and pine needles as parameters are presented in the paper. Increased concentrations of Pb, Cd, Cr, Ni, Cu and V have been found near the plant. Often a clear gradient was found with increased concentrations at decreased distance from the power plant.

  • Bramryd, E-mail: tb@mm.unknown (email)
article id 5143, category Article
Ib Johnsen. (1981). Heavy metal deposition on plants in relation to immission and bulk precipitation. Silva Fennica vol. 15 no. 4 article id 5143.
Keywords: vegetation; air pollution; environmental impact; heavy metals; accumulation; immission; deposition; heavy metal intake
Abstract | View details | Full text in PDF | Author Info

Monitoring of heavy metal accumulation in plants has been used to reflect the deposition of heavy metals in terrestrial ecosystems. In some cases, the accumulation rates in plants are linearly correlated to deposition measured as bulk precipitation collected in funnel samplers. It is uncertain, however, how large the contribution due to adsorption/impaction of small particles is to this relationship. The need for design of enlightening experiments on deposition rates in different vegetation types and their relation to immission and bulk precipitation data is discussed.

  • Johnsen, E-mail: ij@mm.unknown (email)
article id 5140, category Article
Lars Westman. (1981). Monitoring of coniferous forest ecosystems in Sweden. Silva Fennica vol. 15 no. 4 article id 5140.
Keywords: soil respiration; conifers; tree growth; acidification; Sweden; air pollution; monitoring programme; acid compounds; heavy metals; bioindicators; phosphatase activity
Abstract | View details | Full text in PDF | Author Info

A monitoring program is planned for the terrestrial environment around industries in Sweden, which emit acid compounds and heavy metals. Directions for the County Government Boards are being prepared. The paper deals with the present pollution situation in Sweden, based on recent scientific results, the justifications for local monitoring, and the organizing of the monitoring including the parameters suggested.

Four examples from a case study at an oil power station illustrate reporting of the data and the difficulties in interpreting the results. The examples are the distribution of a lichen indicator, heavy metal content and phosphatase activity in the moor layer, soil respiration and tree growth.

  • Westman, E-mail: lw@mm.unknown (email)
article id 5016, category Article
H. Vasander, A. Mäkinen, P. Pakarinen. (1979). Kangaskorpimaannosten hivenainejakautumista ja -määristä. Silva Fennica vol. 13 no. 1 article id 5016.
English title: Trace elements in soil profiles of paludified spruce forests.
Original keywords: maaperä; turvemaat; korvet; maannos; mikroravinteet; hivenaineet; kangaskorpi; raskasmetallit
English keywords: peatlands; soil; gleysol; trace elements; metals
Abstract | View details | Full text in PDF | Author Info

Gleysol profiles of five southern Finnish sites dominated by Norway spruce (Picea abies (L.) H. Karst.) were described according to the Canadian system of soil classification, and the total contents of five metals (Pb, Zn, Cu, Mn, Fe) were analysed in each soil profile. Lead, zinc and manganese showed highest concentrations in the organic surface horizons with a decrease towards mineral soil horizons. Vopper distribution was somewhat irregular. Iron had maximum values in the mineral soil: in A-horizon of Rego Gleysols and in B-horizon of Fera Gleysols. A preliminary comparison of metal pools in soil (root layer) with annual atmospheric input shows that the role of atmospheric deposition is relatively greater in the case of Cu, Zn and Pb than for Fe or Mn.

The PDF includes a summary in English.

  • Vasander, E-mail: hv@mm.unknown (email)
  • Mäkinen, E-mail: am@mm.unknown
  • Pakarinen, E-mail: pp@mm.unknown
article id 4773, category Article
Veli-Pekka Järveläinen, Totte Vadén. (1968). Ammattitietous ja sen leviäminen maatilametsätaloudessa. Silva Fennica vol. 2 no. 4 article id 4773.
English title: Professional insight and its diffusion within farm forestry.
Original keywords: metsänhoito; maatilametsätalous; metsänomistajat; ammatillinen tieto; metsäosaaminen; tiedonlähteet; metsäkoulutus
English keywords: forest professionals; forest owners; forest education; forestry skills; forestry knowledge; farm forestry; information source
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to describe the diffusion of the professional insight in forestry taking place among forest owners and as factors attached thereto. The material is based on interviews of 289 forest owners in municipalities of Jämsä and Karstula in Central Finland in 1966. The forest owners were a random sample of all males in the municipalities, who were in the possession of at least 2 ha of cultivated land and 10 ha of forest.

Mass media (papers, radio and television) was an important source of information for the forest owners. Forest educational events are specially planned to spread information on forestry to forest owners, but 40% told that they had never participated any such event. Only 8% had got professional forest education. Knowledge concerning forests and forest management may also be inherited from the forest owner’s parents, or in discussions with professional forest officers or neighbours. About 73% of the forest owners had been in touch with professional foresters at least once during the last three years.

A third of the forest owners regarded professional insight their most important source of information on forestry, a little smaller group considered instruction in forestry questions the most important source. The third largest group had achieved their knowledge on forestry on own experience and inherited knowledge. Forest owners favouring mass media, own experience and inherited knowledge were often owners of a small forest holding.

The PDF includes a summary in English.

  • Järveläinen, E-mail: vj@mm.unknown (email)
  • Vadén, E-mail: tv@mm.unknown
article id 4694, category Article
Seppo Ervasti. (1960). Metsäntuotteet Ison-Britannian rakennusaineiden mainonnassa. Silva Fennica vol. 0 no. 104 article id 4694.
English title: The position of forest products in advertising of building materials in Great Britain.
Original keywords: Suomi; Iso-Britannia; rakennustuotteet; markkinointi; mainonta
English keywords: Finland; building materials; Great Britain; marketing; advertising; sawn goods; wood-based panels
Abstract | View details | Full text in PDF | Author Info

This paper concentrates on analysing advertising of building materials used in residential, agricultural and factory building, power station construction, warehouse building and the joinery industry in Great Britain, concentrating on advertising to consumers, including architects, engineers, building entrepreneurs, farmers and do-it-yourself practitioners. The material is based on questionnaires answered by 8 professionals of the field, and assessment of two leading English paper in the field of construction in January 1 – June 30, 1959.

It was concluded that forest products were clearly less advertised than other building materials. The unweight average degree of advertising of all forest products was. 1.7, while the score was 2.6 for other materials. Of the different forest products stand out advertising of plywood and sawn good. The most extensively advertised materials were metals, concrete and cement, and some covering materials. Forest products accounted only ¼ of the advertising space in the publications.

The most important media used in advertising building materials were trade journals, calendars and yearbooks, courses and lectures, exhibitions and fares and direct advertising. The most important audience of advertising were architects, followed by the entrepreneurs. It is suggested that the advertising of Finnish products in Great Britain might be best organized by placing it in the hands of two organizations: the sales organisation and a separate body for advertising. The producers would manage the advertising of individual brands to sales level, while the other levels (agents, importers, merchants) would manage the joint advertising of the forest products to the lower sales levels and consumers. A Finnish market research and information offices might be established in Great Britain.

The PDF includes a summary in Finnish.

  • Ervasti, E-mail: se@mm.unknown (email)

Category: Article

article id 7386, category Article
V. Lihtonen. (1946). Valtakunnan metsätalouden järjestely metsiemme poistuman ja tuottohakkausmäärän valossa. Silva Fennica vol. 53 no. 3 article id 7386.
English title: Regulation of Finnish forestry in the light of removal and rental cut.
Original keywords: hakkuut; metsänhoito; metsätalous; metsävarat; hakkuukertymä; poistuma; tuottohakkuut
English keywords: forestry; Finland; forest resources; fellings; removals
Abstract | View details | Full text in PDF | Author Info

This investigation concerns the felling volumes in Finland in 1935-1945 as regards future fellings. The statistics are divided in two time periods: 1935-1939, when there was an upward trend in the trade cycle, and 1940-1945, when the trade was disturbed by the Second World War. Fellings of household timber and for sales are presented separately.

Removal was annually in average 38.1 million cubic meters (cbm) without bark in 1935-1939, and 29.8 million cbm in 1940-1945. According to the statistics, felling volumes decreased by about one quarter after the period of 1935-1945. Reduction was largest in private and company forests, but smaller in the state forests. The increment balance for the 1935-1945 shows an excess of growth that gives an accumulated yield of 24.4 million cbm.

In private forests the cut is about half as large as the growth of the standing stock due to the poor silvicultural condition of the forests. Private forests account for about ¾ of the total forest area in Finland. In the state lands the cut is 130% of the growth. The report introduces also rental cut, a method developed by the writer, which defines the volume to be cut aiming at the same time to optimise the future increase of the yield. The principle is to preserve the young and vigorous stands, while cutting stands that have low growth.

According to the statistics, the felling volume of private forests has followed the variations in demand. It seems likely that in the coming years the fellings will not be kept within the limits calculated by the rental cut. Consequently, the reserve formed during the war will be utilized. To meet the demand of wood, forest management must be improved and preference should be given to regeneration fellings. Improving transportation systems, such as roads, would give access to forest resources that are now difficult to harvest.

The PDF includes a summary in English.

  • Lihtonen, E-mail: vl@mm.unknown (email)
article id 7305, category Article
P. Kokkonen. (1934). Maanjakotoimituksessa syntyvien palstojen muodosta metsätalouden kannalta. Silva Fennica vol. 40 no. 28 article id 7305.
English title: Conditions of forestry in land plots formed in the parceling of land.
Original keywords: metsänhoito; maanjako; tilajako; metsäpalsta
English keywords: forest management; forest ownership
Abstract | View details | Full text in PDF | Author Info

The shape of land lots formed in parceling of land has been affected by many variables. It is an important economic factor when the land is used in forestry or agriculture. The report concentrates on the larger farms with relatively large forest holdings. In the general parceling of the land that started in the middle of 1700s, the allotted plots were often long and narrow, and the width of the plot could be 20‒50 meters. Later these farms may have been further parceled.

Narrow plots are difficult to manage from the forestry point of view. For example, it is not possible to build a forest road in the plot, and wood harvesting is difficult. To use natural regeneration for a specific tree species is impossible, because the seed trees in the adjacent plot are so near. When the boundaries are long and the properties narrow, there is bigger risk for felling trees on the land of the neighbour. The optimal form for a plot is rectangle which is 3‒6 times longer than its width. Local examples of parceling and the effects of the shape of the plots are given in the article.

The PDF includes a summary in German.

  • Kokkonen, E-mail: pk@mm.unknown (email)
article id 7264, category Article
P. Kokkonen. (1931). Studies on the root systems of cereals I: the Root form, their structure, function and position in root system. Silva Fennica vol. 37 no. 2 article id 7264.
Keywords: root systems; cereals; rye; function; oat; wheat; barley
Abstract | View details | Full text in PDF | Author Info

Knowledge on the roots systems and their properties is needed when for example assessing the wintering properties of a plant. The article presents the studies on the roots and their functions made with rye, wheat, oat and barley.

The data has been collected during the whole growing season. The experiments took place in the green houses of the University of Helsinki and on the experiment field in Tikkurila, some kilometres north from Helsinki.

The roots of cultivable crop can be divided according their function, state of development, structure and position in the root system into four classes. The classes are sprouting roots, nutriment roots, nutriment-support roots and support roots.

The PDF contains a summary in Finnish. 

  • Kokkonen, E-mail: pk@mm.unknown (email)
article id 7212, category Article
P. Kokkonen. (1927). On the relation between the hibernation of rye and the extensibility and the tensile strength of its roots. Silva Fennica vol. 33 no. 3 article id 7212.
Keywords: root system; cereals; hibernating; rye; extent; extensibility
Abstract | View details | Full text in PDF | Author Info

In attempts to improve the autumn cereals, wheat and rye, hibernation plays an essential role. Those varieties that hibernate well should be marketed and others rejected. Concerning roots, it seems that varieties that hibernate well have more extent root system than those hibernating poorly.

Four varieties of rye were chosen for experiments, two that knowingly hibernate well and two that don’t. The experiments were grown in the Botanical gardens of the university and at the same time in experiment field in Tikkurila.

The results proof that plant hibernating well have more extensible roots than others and hence they survive better in frosting soil that extents.

The PDF contains a summary in English and in Finnish.

  • Kokkonen, E-mail: pk@mm.unknown (email)
article id 7529, category Article
Lauri Ilvessalo. (1913). Experiments with foreign tree species in state forest Vesijako, Finland. Silva Fennica vol. 2 no. 2 article id 7529.
Keywords: larch; Abies balsamea; Picea glauca; Pinus mugo; white spruce; balsam fir; Abies alba; Abies pectinata; Picea alba; Pinus strobus; Pinus montana; Pinus mugho; Siberian stone pine; Siberian fir; Abies sibirica o. pichta; white fir; Weymouth pine; European
Abstract | View details | Full text in PDF | Author Info

The study area is state owned forest of Vesijako in southern middle Finland that has earlier been intensively managed with slash-and-burn agriculture and then partly reforested with foreign coniferous tree species after controlled burnings. The total area planted with foreign species consists of 66 sample areas, altogether 28 hectares. The data has been collected in summer 1909. 

The most of studied sample areas have been unsuccessful, but there are still many areas that are too young to be assessed. The originally with foreign species reforested areas are now pine stands. The tree species in experiments have been e.g. larch (Larix sibirica and L. europaea), Siberian stone pine (Pinus cembra sibirica), Siberian fir (Abies sibirica o. pichta), balsam fir (Abies balsamea), white fir (Abies pectinate also Abies alba), white spruce (Picea alba also Picea glauca), Weymouth pinen (Pinus strobus) and European / Swiss mountain pine (Pinus montana  also P. mugo, P. mugho).

The most important result of the experiments with controlled burning is that stand of grey alder (Alnus incana) with only low economic value can be effectively altered into coniferous forests (Pinus silvestris).
  • Ilvessalo, E-mail: li@mm.unknown (email)
article id 7657, category Article
Matti Rousi. (1990). Breeding forest trees for resistance to mammalian herbivores - a study based on European white birch. Silva Fennica vol. 0 no. 210 article id 7657.
Keywords: Betula pendula; vole; breeding; resistance; clonal forestry; phenotypic plasticity; pests; mammals; Betula platyphylla; interspecific hybrids; climatic adaptibility; hare
Abstract | View details | Full text in PDF | Author Info

Resistance to browsing by mammals differs among birch species, and among origins and families of European white birch (Betula pendula Roth). The variation in resistance is large even among individual seedlings of the same family.

On the surface of the bark of European white birch seedlings there are resin droplets, and the number of droplets is strongly and positively correlated with resistance to browsing by hares. The resistance of European white birch apparently is not expensive metabolically because the rapid growth rate of seedlings was positively correlated with hare resistance, and no correlation was found between seedling size and vole resistance. In cafeteria experiments voles and hares were very discriminating in their feeding on birch seedlings. In field experiments, however, environmental heterogeneity partly masked differences in vole resistance among birch families. Fertilization of seedlings seems not to have a clear effect on resistance to hares. On the other hand, there were indications that greenhouse temperature had an effect on resistance to voles. Practical forestry applications of differences in resistance, e.g. use of species hybrids and clonal forestry, are discussed. The prospects for resistance breeding are good.

The PDF includes a summary in Finnish.

  • Rousi, E-mail: mr@mm.unknown (email)

Category: Research article

article id 10608, category Research article
Lennart Noordermeer, Erik Næsset, Terje Gobakken. (2022). Effects of harvester positioning errors on merchantable timber volume predicted and estimated from airborne laser scanner data in mature Norway spruce forests. Silva Fennica vol. 56 no. 1 article id 10608.
Keywords: forest inventory; ALS; forest harvester; GNSS; precision forestry
Highlights: Timber volume was estimated using harvester and airborne laser scanner (ALS) data acquired with different scanners over eight years; The year of ALS acquisition did not have a significant effect on errors in timber volume estimates; Accuracies of timber volume estimates decreased significantly with increasing levels of positioning error; When using inaccurately positioned harvester data, larger grid cells are beneficial.
Abstract | Full text in HTML | Full text in PDF | Author Info

Newly developed positioning systems in cut-to-length harvesters enable georeferencing of individual trees with submeter accuracy. Together with detailed tree measurements recorded during processing of the tree, georeferenced harvester data are emerging as a valuable tool for forest inventory. Previous studies have shown that harvester data can be linked to airborne laser scanner (ALS) data to estimate a range of forest attributes. However, there is little empirical evidence of the benefits of improved positioning accuracy of harvester data. The two objectives of this study were to (1) assess the accuracy of timber volume estimation using harvester data and ALS data acquired with different scanners over multiple years and (2) assess how harvester positioning errors affect merchantable timber volume predicted and estimated from ALS data. We used harvester data from 33 commercial logging operations, comprising 93 731 harvested stems georeferenced with sub-meter accuracy, as plot-level training data in an enhanced area-based inventory approach. By randomly altering the tree positions in Monte Carlo simulations, we assessed how prediction and estimation errors were influenced by different combinations of simulated positioning errors and grid cell sizes. We simulated positioning errors of 1, 2, …, 15 m and used grid cells of 100, 200, 300 and 400 m2. Values of root mean square errors obtained for cell-level predictions of timber volume differed significantly for the different grid cell sizes. The use of larger grid cells resulted in a greater accuracy of timber volume predictions, which were also less affected by positioning errors. Accuracies of timber volume estimates at logging operation level decreased significantly with increasing levels of positioning error. The results highlight the benefit of accurate positioning of harvester data in forest inventory applications. Further, the results indicate that when estimating timber volume from ALS data and inaccurately positioned harvester data, larger grid cells are beneficial.

  • Noordermeer, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: (email)
  • Næsset, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail:
  • Gobakken, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail:
article id 10534, category Research article
Matti Haapanen, Seppo Ruotsalainen. (2021). Adaptive performance of genetically improved and unimproved seedlings of Scots pine. Silva Fennica vol. 55 no. 5 article id 10534.
Keywords: Pinus sylvestris; cold hardiness; growth rhythm; seed orchards; bud set; freezing test; reproductive materials
Highlights: We studied the variation in adaptive traits in one-year-old seedlings of Scots pine representing different levels of genetic gain and geographical origins; All the adaptive traits analyzed showed clinal co-variation with the latitude of origin; Differences in adaptive performance between genetically improved and unimproved reproductive materials were mostly small and insignificant when the effect of the latitudinal origin was considered; First-generation seed orchard materials implied slightly poorer autumn frost hardiness compared to other materials, but the results were ambiguous.
Abstract | Full text in HTML | Full text in PDF | Author Info

Our main objective was to determine whether various genetically improved reproductive materials of Scots pine (Pinus sylvestris L.) differ in growth rhythm, autumn cold acclimation and resilience from unimproved materials. The study consisted of two successive indoor experiments with Scots pine seedlings representing four levels of genetic gain (unimproved natural stands, first-generation seed orchards, 1.5-generation seed orchards and seed orchards established with freezing-tested parents) and a wide range of geographical origins within Finland. The seedlings were assessed for terminal shoot elongation, growth cessation, bud set, freezing injuries and bud flushing over the first growth period. All the adaptive traits showed a latitudinal trend regardless of the genetic level. Seed orchard progenies and natural stand progenies did not differ significantly in the timing of growth cessation, bud set, and the flushing rate of the frost-injured seedlings, after the trait variation was adjusted to the latitude of origin. The differences in autumn frost hardiness were insignificant, too, except for the somewhat higher injury rate displayed by the first-generation seed orchard materials. The finding was not conclusive due to ambiguous results from the two experiments. Overall, we did not find evidence of alarming compromises in the adaptive performance of genetically improved materials.

  • Haapanen, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland ORCID E-mail: (email)
  • Ruotsalainen, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 5, FI-57200 Savonlinna, Finland ORCID E-mail:
article id 10371, category Research article
Katalin Waga, Jukka Malinen, Timo Tokola. (2021). Locally invariant analysis of forest road quality using two different pulse density airborne laser scanning datasets. Silva Fennica vol. 55 no. 1 article id 10371.
Keywords: ALS; DEM; forest road quality; reference DEM; unpaved forest road
Highlights: Airborne laser scanning is used to assess forest road quality; High-pulse data analysis classified roads with good performance; Two-step classification further improved the accuracy; A reference surface improved the classification results of the low pulse data; 66–75% of the roads were correctly classified using the reference surface.
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Two different pulse density airborne laser scanning datasets were used to develop a quality assessment methodology to determine how airborne laser scanning derived variables with the use of reference surface can determine forest road quality. The concept of a reference DEM (Digital Elevation Model) was used to guarantee locally invariant topographic analysis of road roughness. Structural condition, surface wear and flatness were assessed at two test sites in Eastern Finland, calculating surface indices with and without the reference DEM. The high pulse density dataset (12 pulses m–2) gave better classification results (77% accuracy of the correctly classified road sections) than the low pulse density dataset (1 pulse m–2). The use of a reference DEM increased the precision of the road quality classification with the low pulse density dataset when the classification was performed in two-steps. Four interpolation techniques (Inverse Weighted Distance, Kriging, Natural Neighbour and Spline) were compared, and spline interpolation provided the best classification. The work shows that applying a spline reference DEM it is possible to identify 66% of the poor quality road sections and 78% of the good ones. Locating these roads is essential for road maintenance.

  • Waga, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland ORCID E-mail: (email)
  • Malinen, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland; Metsäteho Ltd., Vernissakatu 1, FI-01300 Vantaa, Finland ORCID E-mail:
  • Tokola, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland E-mail:
article id 10276, category Research article
Adas Marčiulynas, Vaida Sirgedaitė-Šėžienė, Povilas Žemaitis, Āris Jansons, Virgilijus Baliuckas. (2020). Resistance of Scots pine half-sib families to Heterobasidion annosum in progeny field trials. Silva Fennica vol. 54 no. 4 article id 10276.
Keywords: Pinus sylvestris; field trials; half-sib families; root rot pathogen; total phenolic compounds; tree susceptibility
Highlights: Large genetic variation was estimated in the resistance of Scots pine half-sib families to root rot in field trials; A strong relationship was observed between family resistance to root rot and phenolic compound concentration in the wood.
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Five Scots pine (Pinus sylvestris L.) progeny field trials, each established in different Lithuanian regions of provenance in 1983, were studied. Each progeny field trial consists of 140 half-sib families from seven populations (20 families from each population). The evaluation was carried out in 2012 and 2018 to assess the families resistance to Heterobasidion annosum (Fr.) Bref. An index of resistance in the infected plots was calculated. To verify the accuracy of the method, total phenolic compounds (TPC) was chosen as key parameter to compare with the plant resistance index. During the six years between the two assessments, the percentage of living Scots pine trees in the progeny field trials decreased up to 20 percentage points (range: 4 p.p. to 20 p.p.). In 2018 the area of H. annosum damaged plots (in percentage from total field trial area) varied from 17 to 27%. Tree mortality in the trial correlates with site soil fertility – more fertile soils were distinguished by higher tree percentage loss and vice versa. Using analysis from combined data of all progeny trials, the family variance component reached 13.3 ± 2.2% and family heritability was 0.81. Family heritability estimates for root rot resistance show possibilities of high breeding effectiveness. The correlations between the trials in family resistance estimates were negligible (ranging from 0 to 0.28). The significant high correlation coefficient was determined between the resistance index and TPC concentration (r = 0.77, p = 0.0003). This allows us to assume that plant resistance is directly linked on TPC synthesis. The results indicate that the chosen methods of chemical resistance for identification of root rot-resistant genotypes are applicable for the selection of Scots pine half-sib families in the field trials with higher resistance to pathogens.

  • Marčiulynas, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail: (email)
  • Sirgedaitė-Šėžienė, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail:
  • Žemaitis, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail:
  • Jansons, Latvian State Forest Research Institute “Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail:
  • Baliuckas, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail:
article id 10209, category Research article
Claudie-Maude Canuel, Nelson Thiffault, Michael K. Hoepting, James C.G. Farrell. (2019). Legacy effects of precommercial thinning on the natural regeneration of next rotation balsam fir stands in eastern Canada. Silva Fennica vol. 53 no. 4 article id 10209.
Keywords: silviculture; Abies balsamea; PCT; conifer; density management
Highlights: We investigated the potential legacy effects of precommercial thinning in next rotation, dense natural balsam fir stands; Precommercial thinning had few legacy effects on next rotation stands and should not impair their regeneration; Balsam fir dominated the regeneration layer. Other tree species were almost absent.
Abstract | Full text in HTML | Full text in PDF | Author Info

The Green River precommercial thinning (PCT) trial was established between 1959–1961 in New Brunswick (Canada) within natural balsam fir (Abies balsamea (L.) Mill.)-dominated stands. Three silviculture scenarios differing only by the increasing nominal spacings of PCT treatments (1.2 m, 1.8 m, 2.4 m) were compared to an unthinned control within randomized replicates that were clearcut harvested in 2008 and treated with herbicide in 2011. During the fourth post-harvest growing season, we assessed regeneration, competing vegetation and coarse woody debris (CWD; differentiated between large woody debris and slash) to assess the legacy effects of PCT on regeneration of next rotation stands. Our results confirmed that silviculture scenarios including PCT significantly increased conifer stocking in treated plots compared to control conditions, but only in the 1.8 m nominal spacing. Considering that treated and untreated stands were fully stocked, we conclude that PCT using the spacing gradient tested has no legacy effect on the regeneration of next rotation natural balsam fir stands. Given the known sensitivity of balsam fir to future climate conditions in this region, we suggest that future treatments should promote tree species diversity to support ecosystem resilience to climate change by favouring more warm-adapted species, such as some hardwoods.

  • Canuel, Faculté de foresterie, géographie et géomatique, Université Laval, Québec, QC G1V 0A6, Canada;  Canadian Wood Fibre Centre, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 10380, Sainte-Foy Stn., Québec, QC G1V 4C7, Canada E-mail:
  • Thiffault, Canadian Wood Fibre Centre, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 10380, Sainte-Foy Stn., Québec, QC G1V 4C7, Canada ORCID E-mail: (email)
  • Hoepting, Canadian Wood Fibre Centre, Natural Resources Canada, 1219 Queen St. E., Sault Ste. Marie, ON P6A 2E5, Canada E-mail:
  • Farrell, Canadian Wood Fibre Centre, Natural Resources Canada, 1350 Regent Street, P.O. Box 4000, Fredericton, NB E3B 5P7, Canada E-mail:
article id 10019, category Research article
Junyan Liu, Junfeng Tang, Si-Chong Chen, Wenbao Ma, Zheng Zheng, Tingfa Dong. (2019). Do tree cavity density and characteristics vary across topographical habitats in the tropics? A case study from Xishuangbanna, southwest China. Silva Fennica vol. 53 no. 1 article id 10019.
Keywords: heterogeneity; cavity-dependant animals; tropical rainforest; biodiversity conservation
Highlights: Cavities were significantly more abundant in high- and low-slope than high-plateau habitats; There are more “butt hollow” cavities in high-slope habitat and they occurred at a lower height; More “crack” cavities in low-slope habitat and they had a narrower entrance diameter; Certain types of cavities are concentrated in specific habitats, which provide opportunities for forest management and biodiversity conservation.
Abstract | Full text in HTML | Full text in PDF | Author Info

Despite the influence of cavities on the survival and distribution of cavity-dependent fauna, the variation in the density and characteristics of tree cavities across different habitat types in tropical forests is unknown. In this study, we surveyed 26 312 living trees from 376 species and compared cavity density and characteristics (height, size, type, and orientation) across five habitat types (valley, low-slope, high-slope, high-gully, and high-plateau) in a 20-hectare tropical rainforest in southwest China. From a total of 2047 cavities, we found that cavity density was mainly driven by habitat rather than tree species richness or diameter at breast height (DBH), and the characteristics of cavities were not uniformly distributed across habitats. Cavities were significantly more abundant in high- and low-slope than high-plateau habitats. Compared with other habitats, more “butt hollow” cavity types were found in high-slope habitat and they occurred at a lower tree height, whereas more “crack” cavities were found in low-slope habitat and they had a narrower entrance diameter. Although the mean orientation of cavities faced towards the northeast, cavity orientation varied significantly across habitat types. Our results indicate that certain types of cavities are concentrated in specific habitat types, which can provide avenues for forest management and biodiversity conservation. We highlight the importance of habitat heterogeneity in providing resources for cavity nesters.

  • Liu, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China; Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail:
  • Tang, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail:
  • Chen, Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex RH17 6TN, UK; Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Beer-Sheva 8499000, Israel E-mail:
  • Ma, Ecological Restoration and Conservation of Forests and Wetlands Key Laboratory of Sichuan Province, Sichuan Academy of Forestry, Chengdu 610081, China E-mail:
  • Zheng, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail:
  • Dong, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail: (email)
article id 1611, category Research article
Ilpo Ervasti. (2016). Wood fiber contents of different materials in the paper industry material chain expressed in roundwood equivalents (RWEs). Silva Fennica vol. 50 no. 4 article id 1611.
Keywords: pulpwood; paper production; raw materials; roundwood equivalent (RWE); wood pulp; recycled fiber; recovered paper; material recycling
Highlights: The paper industry material recycling chain consists of different material streams; Consumed paper products form a huge fiber source for industry. However, a reliable measuring system should be developed to quantify these fiber volumes; Converting factors are introduced to quantify the wood fiber contents of different paper industry-related materials of the chain, namely, wood pulp, paper and recovered paper; By using these conversion factors it is possible to convert for example global recovered paper utilization volumes into wood fiber volumes expressed in roundwood equivalents (RWEs).
Abstract | Full text in HTML | Full text in PDF | Author Info

At present, there are no means for reliably comparing the wood fiber contents of different material streams within the paper industry material chain with each other. The aim of this article is to introduce conversion factors that make it possible to quantify the volume of wood expressed in roundwood equivalent (RWE) values for different paper industry-related materials in the material chain. These conversion factors apply to wood pulp, paper, and recovered paper. European data are used in quantifying the paper industry material streams and calculating the RWE conversion factors. The introduced conversion factors can be used to estimate RWE volumes at a global scale. With assumption that paper recycling did not occur and that paper production volume remained unchanged, an additional volume of 666 million m3 RWEs would be required globally per annum to produce 167 million tons of virgin wood pulp to replace 222 million tons of recovered paper utilized by the paper industry in 2010. This volume is approximately the same as 1.6 times the total removal of wood in Europe (EU27), or the total annual removal of wood in the USA, Canada, and Brazil combined.

  • Ervasti, Aalto University, Industrial Engineering and Management, Maarintie 8, 02150 Espoo, Finland E-mail: (email)
article id 1267, category Research article
Caroline Mary Adrianne Franklin, Karen A Harper, Liam Kyte Murphy. (2015). Structural dynamics at boreal forest edges created by a spruce budworm outbreak. Silva Fennica vol. 49 no. 3 article id 1267.
Keywords: edge influence; balsam fir; insect disturbance; structure; forest influence
Highlights: Insect outbreak edges were 10 m wide with different canopy cover, stem density and tree structural diversity than adjacent ecosystems; Although edge influence on forest structure was weak, forest influence was stronger and extended further, creating an edge zone skewed towards the disturbed area; After thirty years, high-contrast and structurally-diverse transition zones persist on the landscape.
Abstract | Full text in HTML | Full text in PDF | Author Info
Natural disturbances such as insect outbreaks create boundaries that influence vegetation patterns and ecological processes.  To better understand the effects of natural edge creation on relatively intact forests and adjacent disturbed areas, we investigated forest structure on both sides of 30 year-old forest edges created by a spruce budworm (Choristoneura fumiferana Clemens) outbreak in the boreal forest of Cape Breton Highlands National Park, Canada.  Our objectives were: 1) to determine edge influence (compared to interior forest) and forest influence (compared to disturbed areas) on vegetation structure, and 2) to gain insight into the structural development of the edges.  Canopy cover, tree density, radial growth and deadwood were sampled in 5 m x 20 m plots along 120 m transects across six edges.  Randomization tests were used to estimate the magnitude and distance of edge and forest influence.  Narrow transition zones approximately 10 m wide characterized the spruce budworm-induced edges.  Edge influence did not extend into the forest; however, forest influence on structure was detected up to 40 m from the edge into the disturbed area.  We found evidence of the insect outbreak in the form of reduced radial growth during the disturbance across the entire disturbed area-forest gradient, which indicates that spruce budworm activity may not have ceased directly at the edge.  Tree mortality caused by the insect outbreak resulted in snags, many of which have transformed into logs since the outbreak collapsed.  Spruce budworm outbreak-induced forest edges are narrow but dynamic boundaries separating two distinct vegetation communities in the boreal landscape.
  • Franklin, Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, Alberta, T6G 2H1, Canada E-mail: (email)
  • Harper, School for Resource and Environmental Studies, Dalhousie University, Suite 5010, 6100 University Ave., Halifax, Nova Scotia, B3H 3J5, Canada E-mail:
  • Murphy, Department of Environmental Science, Saint Mary’s University, 923 Robie St., Halifax, Nova Scotia, B3H 3C3, Canada E-mail:
article id 1219, category Research article
Thomas P. Sullivan, Druscilla S. Sullivan. (2014). Diversifying clearcuts with green-tree retention and woody debris structures: conservation of mammals across forest ecological zones. Silva Fennica vol. 48 no. 5 article id 1219.
Keywords: clearcutting; green-tree retention; small mammals; coniferous forests; ecological zones; Myodes gapperi; population dynamics; red-backed voles; woody debris structures
Highlights: Species diversity of small mammals increased with structural complexity left on clearcut sites; Productivity of red-backed vole populations was higher in sites with green-tree retention (GTR) and windrows of woody debris; GTR and windrows may provide additive effect for providing habitat to conserve mammals on clearcuts.
Abstract | Full text in HTML | Full text in PDF | Author Info
We tested the hypotheses (H) that on newly clearcut-harvested sites, (H1) abundance and species diversity of the forest-floor small mammal community, and (H2) abundance, reproduction, and recruitment of red-backed voles (Myodes gapperi Vigors), would increase with higher levels of structural retention via green-tree retention (GTR) and woody debris (dispersed and constructed into windrows). Study areas were located in three forest ecological zones in southern British Columbia, Canada. For H1, mean total abundance did generally increase with the gradient of retained habitat structure. Mean species richness and diversity were similar among treatment sites but did show an increasing gradient with structural compexity. For H2, mean abundance, reproduction, and recruitment of M. gapperi were higher in GTR and windrow sites than those without retained structures. There was a positive relationship between mean abundance of M. gapperi and total volume of woody debris across treatments. This study is the first investigation of the responses of forest-floor small mammals to an increasing gradient of retained habitat structure via GTR and woody debris on clearcuts. Our assessment of a combination of these two interventions suggested a potentially strong additive effect that could be cautiously extrapolated across three forest ecological zones. With the advent of low levels of GTR on clearcuts, woody debris structures should help provide some habitat to conserve forest mammals on harvest openings.
  • Sullivan, Department of Forest and Conservation Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: (email)
  • Sullivan, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail:
article id 56, category Research article
Johan Holmgren, Andreas Barth, Henrik Larsson, Håkan Olsson. (2012). Prediction of stem attributes by combining airborne laser scanning and measurements from harvesters. Silva Fennica vol. 46 no. 2 article id 56.
Keywords: ALS data; pre-harvest inventory; tree detection
Abstract | View details | Full text in PDF | Author Info
In this study, a new method was validated for the first time that predicts stem attributes for a forest area without any manual measurements of tree stems by combining harvester measurements and Airborne Laser Scanning (ALS) data. A new algorithm for automatic segmentation of tree crowns from ALS data based on tree crown models was developed. The test site was located in boreal forest (64°06’N, 19°10’E) dominated by Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris).The trees were harvested on field plots, and each harvested tree was linked to the nearest tree crown segment derived from ALS data. In this way, a reference database was created with both stem data from the harvester and ALS derived features for linked tree crowns. To estimate stem attributes for a tree crown segment in parts of the forest where trees not yet have been harvested, tree stems are imputed from the most similar crown segment in the reference database according to features extracted from ALS data. The imputation of harvester data was validated on a sub-stand-level, i.e. 2–4 aggregated 10 m radius plots, and the obtained RMSE of stem volume, mean tree height, mean stem diameter, and stem density (stems per ha) estimates were 11%, 8%, 12%, and 19%, respectively. The imputation of stem data collected by harvesters could in the future be used for bucking simulations of not yet harvested forest stands in order to predict wood assortments.
  • Holmgren, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: (email)
  • Barth, The Forestry Research Institute of Sweden, Uppsala, Sweden E-mail:
  • Larsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail:
  • Olsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail:
article id 93, category Research article
Pertti Pulkkinen, Saila Varis, Raimo Jaatinen, Aulis Leppänen, Anne Pakkanen. (2011). Increasing survival and growth of Scots pine seedlings with selection based on autumn coloration. Silva Fennica vol. 45 no. 4 article id 93.
Keywords: Pinus sylvestris; adaptation; field trials; harsh conditions; needles; nursery; selection
Abstract | View details | Full text in PDF | Author Info
This study evaluates the possibility of using autumn coloration of young Scots pine (Pinus sylvestris L.) seedlings as an indicator of adaptation to harsh climate conditions. One-year old seedlings from natural stands with different origins and seed orchards were classified as “red/reddish” and “green” based on the needle color after artificially increased night length in nursery and then measured after 14 years in field trials. In almost all the studied groups seedlings classified as “red/reddish” had significantly higher survival rate than seedlings classified as “green”. The survival of “red/reddish” was 14.2% higher than “green” among natural stand seed material and 56.2% among seed orchard material. During the study period the survival difference between “red/reddish” and “green” seedlings tended to increase. The seedling color had limited connection with the height growth, even though the trees classified as “red/reddish” were slightly taller than those classified as “green”. However, the total productivity over all field trials, described here as a heightsum, of “red/reddish” trees was 15% higher than productivity of “green” trees from natural stand material, and 61% higher than those from seed orchard material. It seems that controlled selection based on autumn color can be utilized within seed crops of different types with the aim to increase the adaptability of seed material to different environmental conditions.
  • Pulkkinen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: (email)
  • Varis, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail:
  • Jaatinen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail:
  • Leppänen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail:
  • Pakkanen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail:
article id 451, category Research article
Thomas P. Sullivan, Druscilla S. Sullivan, Pontus M. F. Lindgren, Douglas B. Ransome. (2010). Green-tree retention and life after the beetle: stand structure and small mammals 30 years after salvage harvesting. Silva Fennica vol. 44 no. 5 article id 451.
Keywords: biodiversity; stand structure; Pseudotsuga menziesii; ecological indicators; green-tree retention; small mammals; mountain pine beetle; Pinus contorta; salvage harvest
Abstract | View details | Full text in PDF | Author Info
We report on a retrospective investigation of the impacts of salvage harvesting of lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.), killed by an outbreak of mountain pine beetle (Dendroctonus ponderosae Hopk.) in the 1970s, with variable retention of Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco). Our inference to biodiversity was coniferous stand structure and four mammal species: the southern red-backed vole (Myodes gapperi Vigors), common shrew (Sorex cinereus Kerr), red squirrel (Tamiasciurus hudsonicus Erxleben) and northern flying squirrel (Glaucomys sabrinus Shaw). We tested hypotheses that, at 30 years after salvage harvest of beetle-killed lodgepole pine trees, (1) abundance and diversity of stand structure, and (2) abundance of mammal species, will increase with higher levels of green-tree retention (GTR). Stand structure attributes and small mammals were sampled during 2005–2008 in young pine stands, with a range of GTR seed-trees (none, dispersed, and aggregated Douglas-fir), and uncut forest in south-central British Columbia, Canada. Diameters and heights of Douglas-fir and lodgepole pine and basal area of total conifers supported hypothesis (1). Mean abundance of the red-backed vole was consistently higher (2.3 to 6.4 times) in the uncut forest than other stands. Overall mean patterns of abundance for common shrews, red squirrels, and northern flying squirrels were similar among treatment stands. Mean abundance of the red-backed vole supported hypothesis (2), but numbers of the other three species did not. There is “life after the beetle” at 30 years after salvage harvesting, and this was enhanced by GTR.
  • Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: (email)
  • Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail:
  • Lindgren, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail:
  • Ransome, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail:
article id 127, category Research article
Mika Rekola, Annukka Valkeapää, Tapio Rantala. (2010). Nordic forest professionals’ values. Silva Fennica vol. 44 no. 5 article id 127.
Keywords: forest professionals; values; cognitive mapping; Nordic countries
Abstract | View details | Full text in PDF | Author Info
The present study analyses the values held by forest professionals in three Nordic countries: Finland, Norway, and Sweden. The data is from a large (n = 1113) internet survey that used cognitive mapping as a research tool, which is a novelty in value measurement. The questionnaire is based on the organisational value theory of Schein (1992), supplemented with relevant forest-related and environmental values. The forest-related main value factors were in the following order of importance: Expertise, Private forestry, Forest production, Nature conservation, and Tradition. The measurement included two kinds of cases: action values, referring to present decision-making, and ideal values, referring to decisions concerning future ideals. Most of the values’ scores were similar. Almost all values received higher scores of importance in the ideal cases compared to action cases, a fact that can probably be explained by constraints related to the professionals’ current working environment. Some international differences were also found: Sweden and Norway were closer to each other and both differed from Finland, where private forestry, forest production, and traditions are highly valued. Moreover, respondents working in industry were found to be slightly more production-oriented than other forest professionals. The study also revealed several weaknesses of the cognitive mapping method in measuring values.
  • Rekola, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail: (email)
  • Valkeapää, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail:
  • Rantala, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail:
article id 156, category Research article
Ilkka Korpela, Hans Ole Ørka, Matti Maltamo, Timo Tokola, Juha Hyyppä. (2010). Tree species classification using airborne LiDAR – effects of stand and tree parameters, downsizing of training set, intensity normalization, and sensor type. Silva Fennica vol. 44 no. 2 article id 156.
Keywords: airborne laser scanning; ALS; laser; Optech ALTM3100; Leica ALS50-II; canopy; crown modeling; monoplotting; backscatter amplitude; intensity; discriminant analysis
Abstract | View details | Full text in PDF | Author Info
Tree species identification constitutes a bottleneck in remote sensing-based forest inventory. In passive images the differentiating features overlap and bidirectional reflectance hampers analysis. Airborne LiDAR provides radiometric and geometric information. We examined the single-trees-level response of two LiDAR sensors in over 13 000 forest trees in southern Finland. We focused on the commercially important species. Our aims were to 1) explore the relevant LiDAR features and study their dependencies on stand and tree variables, 2) examine two sensors and their fusion, 3) quantify the gain from intensity normalizations, 4) examine the importance of the size of the training set, and 5) determine the effects of stand age and site fertility. A set of 570 semiurban broad-leaved trees and exotic conifers was analyzed to 6) examine the LiDAR signal in the economically less important species. An accuracy of 88 90% was achieved in the classification of Scots pine, Norway spruce, and birch, using intensity variables. Spruce and birch showed the highest levels of confusion. Downsizing the training set from 30% to 2.5% of all trees had only a marginal effect on the performance of classifiers. The intensity features were dependent on the absolute and relative sizes of trees, especially for birch. The results suggest that leaf size, orientation, and foliage density affect the intensity, which is thus not affected by reflectance only. Some of the ecologically important species in Finland may be separable, since they gave rise to high intensity values. Comparison of the sensors implies that performance of the intensity data for species classification varies between sensors for reasons that remained uncertain. Both range and gain receiver normalization improved species classification. Weighting of the intensity values improved the fusion of two LiDAR datasets.
  • Korpela, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: (email)
  • Ørka, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway E-mail:
  • Maltamo, University of Eastern Finland, School of Forest Science, P.O. Box 111, FI-80101 Joensuu, Finland E-mail:
  • Tokola, University of Eastern Finland, School of Forest Science, P.O. Box 111, FI-80101 Joensuu, Finland E-mail:
  • Hyyppä, Finnish Geodetic Institute, Department of Photogrammetry and Remote Sensing, P.O.Box 15, FI-02431 Masala, Finland E-mail:
article id 149, category Research article
Juha Kaitera, Heikki Nuorteva. (2010). Effects of Melampyrum extracts on the growth of axenic cultures of Cronartium flaccidum and Peridermium pini. Silva Fennica vol. 44 no. 2 article id 149.
Keywords: Scots pine; alternate host; anti-fungal phytochemicals; fungal growth regulation; pine stem rust
Abstract | View details | Full text in PDF | Author Info
For 3–6 months, mycelial colonies cultured from 5 isolates of each of two pine stem rusts (Cronartium flaccidum and Peridermium pini) were grown on nutrient-rich agar supplemented with Melampyrum extracts. Non-autoclaved extracts of M. pratense significantly reduced the growth of P. pini. The growth of C. flaccidum isolates was slightly stimulated after the second month of incubation but after that was inhibited during incubation months 4–6. We observed considerable variation in colony growth, a significant component of which was explained by incubation time, isolate, growth medium and their interaction. Rust species (C. flaccidum or P. pini) was not an important factor in growth variation. While sterilized extracts of M. pratense, M. sylvaticum and M. nemorosum did not significantly affect growth, colonies of C. flaccidum were slightly stimulated, whereas colonies of P. pini were slightly inhibited. Generally, isolates of P. pini grew better and showed a slower rate of degeneration than C. flaccidum on all media.
  • Kaitera, Finnish Forest Research Institute, Northern Finland Regional Unit, FI-91500 Muhos, Finland E-mail: (email)
  • Nuorteva, Finnish Forest Research Institute, Southern Finland Regional Unit, FI-01301 Vantaa, Finland E-mail:
article id 196, category Research article
Aaron R. Weiskittel, Laura S. Kenefic, Robert S. Seymour, Leah M. Phillips. (2009). Long-term effects of precommercial thinning on the stem dimensions, form and branch characteristics of red spruce and balsam fir crop trees in Maine, USA. Silva Fennica vol. 43 no. 3 article id 196.
Keywords: Acadian Forest; growth and yield; Abies balsamea; Picea rubens; precommercial thinning
Abstract | View details | Full text in PDF | Author Info
The effects of precommercial thinning (PCT) on stem dimensions, form, volume, and branch attributes of red spruce [Picea rubens Sarg.] and balsam fir [Abies balsamea (L.) Mill.] crop trees were assessed 25 years after treatment in an even-aged northern conifer stand. Treatments were a uniform 2.4 x 2.4-m spacing and a control (no PCT). The PCT treatment significantly increased individual tree diameter at breast height (DBH), height growth, crown ratio, and crown width, while it reduced the tree height to DBH ratio. PCT also significantly increased stem taper and consequently, regional volume equations overpredicted observed stem volume by 2 to 15%, particularly for the spaced trees. PCT also increased the number and maximum size of branches on the lower bole. The sizes of knots on half of the sampled spruce crop trees in the spaced plots precluded them from being used as select structural lumber; there were no other effects on log grade. Our findings indicate that PCT can have a long-term influence on the structural attributes of individual trees, and that improved stem-volume prediction equations are needed in the Acadian region of North America.
  • Weiskittel, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: (email)
  • Kenefic, U.S. Forest Service, Northern Research Station, Bradley, ME 04411, USA E-mail:
  • Seymour, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail:
  • Phillips, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail:
article id 267, category Research article
Manfred Gronalt, Peter Rauch. (2008). Vendor managed inventory in wood processing industries – a case study. Silva Fennica vol. 42 no. 1 article id 267.
Keywords: building materials; service level; solid structure timber; SST; wood construction
Abstract | View details | Full text in PDF | Author Info
Solid structure timber (SST) is an important building material in the wood construction business, in which its production volume is largely related to that respective business. Due to the large variability in the demand and seasonal factors, SST producers’ inventories are likely to be simultaneously overstocked for one type of timber and out of stock of another. An inventory policy that ensures a high service level and relatively low stocks is required. In the present paper, we propose the vendor managed inventory (VMI) approach for controlling the stock of deals that are produced at a sawmill and delivered as raw material for SST-production. We evaluate two VMI implementations against the actual inventory management for three different market scenarios. Furthermore, we layout the necessities for reconfiguring the business processes, and subsequently set up an organisational framework within VMI, which is indeed applicable in this segment of the woodworking industry. In our application background, VMI as an inventory control system is able to reduce the overall raw material stock by more than 37% by simultaneously increasing the SST service level.
  • Gronalt, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail: (email)
  • Rauch, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail:
article id 578, category Research article
Kevin Boston, Pete Bettinger. (2001). Development of spatially feasible forest plans: a comparison of two modeling approaches. Silva Fennica vol. 35 no. 4 article id 578.
Keywords: forest planning; heuristics; linear programming; wildlife goals
Abstract | View details | Full text in PDF | Author Info
Spatial goals are becoming more frequent aspects of forest management plans as regulatory and organizational policies change in response to fisheries and wildlife concerns. The combination of green-up constraints (harvesting restrictions that prevent the cutting of adjacent units for a specified period of time) and habitat requirements for red-cockaded woodpeckers (RCW) in the southeastern U.S. suggests that spatially feasible forest plans be developed to guide management activities. We examined two modeling approaches aimed at developing management plans that had both harvest volume goals, RCW habitat, and green-up constraints. The first was a two-stage method that in one stage used linear programming to assign volume goals, and in a second stage used a tabu search – genetic algorithm heuristic technique to minimize the deviations from the volume goals while maximizing the present net revenue and addressing the RCW and green-up constraints. The second approach was a one-stage procedure where the entire management plan was developed with the tabu search – genetic algorithm heuristic technique, thus it did not use the guidance for timber volume levels provided by the LP solution. The goal was to test two modeling approaches to solving a realistic spatial harvest scheduling problem. One is where to volume goals are calculated prior to developing the spatially feasible forest plan, while the other approach simultaneously addresses the volume goals while developing the spatially feasible forest plan. The resulting forest plan from the two-stage approach was superior to that produced from the one-stage approach in terms of net present value. The main point from this analysis is that heuristic techniques may benefit from guidance provided by relaxed LP solutions in their effort to develop efficient forest management plans, particularly when both commodity production and complex spatial wildlife habitat goals are considered. Differences in the production of forest products were apparent between the two modeling approaches, which could have a significant effect on the selection of wood processing equipment and facilities.
  • Boston, Forest Fibre Solutions, Carter Holt Harvey, Tokoroa, New Zealand E-mail: (email)
  • Bettinger, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail:
article id 594, category Research article
Walter Zucchini, Matthias Schmidt, Klaus von Gadow. (2001). A model for the diameter-height distribution in an uneven-aged beech forest and a method to assess the fit of such models. Silva Fennica vol. 35 no. 2 article id 594.
Keywords: diameter-height distribution; mixture models; bivariate normal distribution; SBB distribution; goodness-of-fit; pseudo-residuals; beech forest
Abstract | View details | Full text in PDF | Author Info
This paper illustrates the application of a mixture model to describe the bivariate diameter-height distribution of trees growing in a pure, uneven-aged beech forest. A mixture of two bivariate normal distributions is considered but the methodology is applicable to mixtures of other distributions. The model was fitted to diameter-height observations for 1242 beech trees in the protected forest Dreyberg (Solling, Germany). A considerable advantage of the model, apart from the fact that it happens to fit this large data set unusually well, is that the individual parameters all have familiar interpretations. The bivariate Johnson SBB distribution was also fitted to the data for the purpose of comparing the fits. A second issue discussed in this paper is concerned with the general question of assessing the fit of models for bivariate data. We show how a device called ‘pseudo-residual’ enables one to investigate the fit of a bivariate model in new ways and in considerable detail. Attractive features of pseudo-residuals include the fact that they are not difficult to interpret; they can be computed using generally available statistical software and, most important of all, they enable one to examine the fit of a model by means of simple graphs.
  • Zucchini, Georg-August-Universität Göttingen, Institute for Statistics and Econometrics E-mail: (email)
  • Schmidt, Forest Research Station of Lower Saxony E-mail:
  • Gadow, Georg-August-Universität Göttingen, Institute for Forest Management and Yield Sciences E-mail:

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