Articles containing the keyword 'natural'

A presentation based on the historical development of Russia is given in the form of an overview of the development of Russian forest resources, of the wood, non-wood, and biological aspects of the forest ecosystem. The list of non-wood forest resources includes resin, saps, oils, berries, wild nuts, mushrooms, hay harvesting, game animals, etc. The dynamics of the system are presented in the light of the data of the Forest State Account (FSA) of Russia for the period 1956–1993. The most significant changes in the dynamics of Russia's forest resources are related to concentrated, large-scale wood harvesting operations. The dynamics of non-wood resources follow the process of the economic recession in all parts of the forest sector of Russia, the said recession having begun in the mid-1980s. The forests of Russia are considered to be of immense social and cultural value and a globally significant factor contributing to the sustainable development of forest resources.

• Pisarenko, E-mail: ap@mm.unknown
• Strakhov, E-mail: vs@mm.unknown

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m² ha^-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha^-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

• Brissette, E-mail: jb@mm.unknown

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

The prescribed burning of a 7.3 ha clear-cut and a 1.7 ha partially cut forest (volume 150 m³/ha) was carried out in Evo (61 °12'N, 25°07'E) on 1 June 1992. The forest was a mesic Myrtillus site type forest dominated by Norway spruce (Picea abies (L.) H. Karst.). Practically all the trees and the above-ground parts of the understorey vegetation died in the fire, while the mor layer was thinned by an average of 1.5 cm.

A study was made on the change of germinated seedling population in time and their dependence on environmental factors. Seedlings of Norway spruce, Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), pubescent birch (B. pubescens Ehrh.) and rowan (Sorbus aucuparia L.) were inventoried in 1993 and in 1994 on permanent plots, four times per growing season. Autoregression models were used to compare regeneration of tree species in the burned forest with regeneration in the burnt clear-cut area, and to study the effect of distance from nearest seed source to regeneration.

The average number of seedlings germinating in 1993 was higher than in 1994, probably because of differences between these consecutive years in regard to the amount of seed rain and weather conditions. The number of Norway spruce and rowan seedling was higher inside the forest area than in the clear-cut area. The distance to the bordering forest and to the closest seed tree did not explain the result. It is suggested that the more stable microclimatic conditions under the shade of dead tree promote germination and seedling establishment in the forest area. As rowan is a bird-dispersed species, it is likely that dead trees help the dispersal of rowan seed by providing birds place to sit and defecate. The shade provided by dead trees may influence the further succession of the tree stand and vegetation composition and diversity.

• Vanha-Majamaa, E-mail: iv@mm.unknown
• Suominen, E-mail: rs@mm.unknown
• Tonteri, E-mail: tt@mm.unknown
• Tuittila, E-mail: et@mm.unknown

Comparisons were made between artificially and naturally regenerated stands in the south-eastern part of North Karelia, Finland, and naturally regenerated stands in the western parts of the Republic of Karelia, Russian Federation. The effect of soil fertility and silvicultural operations on the stand structure was also investigated.

The results of the study show clearly that when forests are artificially regenerated the stand structure includes less variation when compared with the stands naturally regenerated. Differences between the regeneration methods are clearer the more fertile the forest site is. Within the regeneration method there is also a clear trend in stand structure, with the variation decreasing the poorer the site. The effect of silvicultural operations, i.e. the cleaning of the sapling stand, has disappeared by the time of first thinning, although it appears to have a permanent effect on the dynamics of the tree species within a stand.

The variation of the stand structure can be regarded as an essential factor for the potential biodiversity of the stand also at its young vegetation succession stage. This capacity for maintaining the forest biodiversity, developed at the young vegetation succession stage, becomes increasingly important in subsequent vegetation succession stages. Natural regeneration provides improved possibilities for the operations preserving forest biodiversity, as it generates more dense stands with a wider variation in stand structure, compared to artificial regeneration.

• Uuttera, E-mail: ju@mm.unknown
• Maltamo, E-mail: mm@mm.unknown

The effects of wood ash and PK fertilization on natural regeneration and sowing of Scots pine (Pinus sylvestris L.) were studied in field experiments on nitrogen-poor (N_tot 0.87–1.26%) peat substrates. The study material was derived from three drained, nutrient-poor pine mires (64°52’ N, 25°08’ E) at Muhos, near Oulu, Finland. The experimental fields were laid out in 1985 as a split-split-plot design including the following treatments; mounding, natural regeneration and sowing and fertilization; PK (400 kg ha^-1) and wood ash (5,000 kg ha^-1). The seedlings were inventoried in circles in July–August 1991.

Changes in the vegetation were small and there were no statistical differences due to the fertilization treatments in the ground vegetation. PK or ash fertilization did not cause vegetation changes harmful to Scots pine regeneration on nitrogen-poor peatlands. Both sowing and fertilization significantly increased the number of pine seedlings, but not their height. Wood ash increased seedling number more than PK fertilizer. The number of seedlings varied from 7,963 (control) to 42,781 ha^-1 (mounding + sowing + ash). The seedling number was adequate for successful regeneration even on non-mounded, non-fertilized naturally regenerated plots.

The number of birch seedlings varied more than that of pine (370–25,927 ha-¹). Mounding especially increased the number of birches. The difference between PK fertiliser and ash was less pronounced than that for pine. In addition, to the field studies the effects of ash and PK fertilizer on the germination of Scots pine seeds was studied in a greenhouse experiment. Soaking in ash solutions strongly reduced seed germination, while the PK solution was less harmful.

• Silfverberg, E-mail: ks@mm.unknown

The results of regenerating 54 and 36–38-year old strip cuttings were surveyed in the Kivalo Research Forest (N 66°20’, E 26°40’). 15 measurement plots were placed on each strip. The most common forest type was Hylocomnium-Myrtillus type. Regeneration of the strips proved to be slow. Most of the spruces growing on the strips probably originated from the time before the cutting. The average number of stems was 1,155 per ha, of which one third consisted of broadleaved trees. The average volume increment of stem wood after cutting had been about 1 m³/ha/yr, but it was increasing at the time of the inventory. Both the reforestation of the strips and the development of the emergent stands were dependent on elevation and site fertility. Site fertility was indicated by the abundance of Vaccinium myrtillus.

The PDF includes an abstract in English.

• Pohtila, E-mail: ep@mm.unknown

Based on literature this paper describes the natural afforestation of Finland that took place after the last ice age and the changes which have taken place during the last 10,000 years. The origin and development of the vegetation and trees are related to the changes in the edaphic and climatic factors. The first tree species to arrive in Finland were the primary colonizing species, birch and Scots pine. The appearance of Norway spruce dates back to about 5000 B.P. There have been great changes in the species composition of Finnish forests during the last several thousands of years but some 2,000–3,000 years ago the various species reached their present balance. The epoch of naural forests, which had lasted some 9,500 years, came to a conclusion, however, when man started to have a marked effect on the forest’s development 300–400 years ago.

The PDF includes an abstract in English.

• Alho, E-mail: pa@mm.unknown

The study uses the methodology of ecological field theory to model the effect of Scots pine (Pinus sylvestris L.) seed trees on the density of tree seedlings and other plants in the field layer. The seed trees had a clear effect on the expected value of the amount and distribution of the ground vegetation. The vicinity of seed trees had an adverse effect on the growth of grasses, herbs and seedlings, while mosses were most abundant near the trees. Models based on the ecological field approach were derived to describe the effect of seed trees on the ground vegetation.

The PDF includes an abstract in Finnish.

• Kuuluvainen, E-mail: tk@mm.unknown
• Pukkala, E-mail: tp@mm.unknown

Forstästhetik is a programme for forest management, resembling an art manifesto. Forest managers are programme executors. Forest aesthetics is forest investigation from the point of view of beauty. In the case of managed forests, it is possible to ask, what is the manager’s programme and his skill to achieve personal solutions. In forests, the functioning and sustainability of the ecosystem are basic principles affecting all other values. On this basis it is possible to evaluate the competence of taste systems and the logic of their application.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in English.

• Sepänmaa, E-mail: ys@mm.unknown

The seed crop of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) is predicted with the help of mean monthly temperatures during May–August one and two years before the flowering year. The prediction models were made separately for Lapland and for the rest of Finland. The models are based on 10-year periods of seed crop measurements and climatic data. The total number of time series was 59.

In Lapland, Norway spruce flowered abundantly and produced an abundant seed crop after warm July–August and two years after cool July–August. In other parts of Finland, warm June and July produced a good flowering year, especially if these months were cool two years before the flowering year.

In Lapland, Scots pine flowered abundantly if the whole previous growing season was warm. Elsewhere in Finland, a cool June preceded prolific flowering in the coming year if the rest of the growing season was considerably warmer than the average.

The prediction models explained 37–49 % of the variation in the size of the seed crop. The occurrence of good and poor seed years was usually predicted correctly. Using the presented models, the prediction of the seed crop is obtainable 1.5 year for Norway spruce and 2.5 year for Scots pine before the year of seed fall.

The PDF includes an abstract in English.

• Pukkala, E-mail: tp@mm.unknown

The effect of the size of seed crop, dispersal of seeds and the early development of seedlings on the density and spatial distribution of young Scots pine (Pinus sylvestris L.) stands are evaluated on the basis of theoretical models. The models include (i) number and spatial distribution of parent trees on the regeneration area, (ii) size of annual seed crop, (iii) seed dispersal from a particular parent tree, (iv) germination of the seeds (germination percentage), (v) death of ageing seedlings after the establishment process, and (vi) height growth of the seedlings.

As expected, stand density and spatial distribution varied within a large range in relation to the density of the parent trees and the distance from them. The simulations also showed that natural seedling stands can be expected to be heterogenous due to the geometry of seed dispersal, emphasizing the frequency of young and small trees. The properties of the seedling stands were, however, greatly dependent on the density of the parent trees and the length of the regeneration period.

The PDF includes an abstract in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Hänninen, E-mail: hh@mm.unknown
• Kolström, E-mail: tk@mm.unknown
• Kotisaari, E-mail: ak@mm.unknown
• Pukkala, E-mail: tp@mm.unknown

A nation that wishes to enhance its social and economic well-being through more intensive utilization of its forest resources must develop a rather comprehensive policy statement to ensure that the expanded exploitation does not lead to the destruction of these resources. The policy must specify the goals to be achieved, provide general direction on how these goals can be achieved, and develop a system of checks-and-balances to ensure achievement of the long-term objectives. The policy must consider resource protection, the economic needs at the various levels of government, the social impacts of utilization on ways of life in all areas of the nation, and the infrastructure needed in the short and long terms.

• Lewis, E-mail: gl@mm.unknown

To conduct an efficient forest policy, both a normative and a positive theory are necessary. In addition, however, the explicit intertemporal considerations in natural resource economics demand that it is made crystal clear which means are permanent and which are non-permanent. The permanent case is far from easy to solve.

That the theoretical problems have practical relevance is shown by Swedish experience. A practical course of action is to weight possible positive effects from a permanent subsidy against possible deleterious outcomes. It is also desirable to avoid jerkiness in forest policy, which is likely to create uncertainty about the permanence of permanent means.

Law may sometimes be more efficient in creating ”credibility” than economic incentives. Regeneration has been mandatory in Sweden since 1903, and nobody refrains from cutting because he believes that regeneration duty will be abolished in some near future.

• Löfgren, E-mail: kl@mm.unknown

The aim of the present study was to survey the occurrence of Otiorrhynchus nodosus Müller weevils and their significance for the natural regeneration of Scots pine (Pinus sylvestris L.). The study was carried out during summer 1982 at Inari in northern Lapland.

There were two sample plots, one situated in a Scots pine seed-tree area and the other, the control sample plot, in an area with a coverage of mountain birch (Betula pubescens subsp. tortuosa, now subsp. czerepanovii). A total of 177 Otiorhynchus weevils were caught. Movement of the weevils reached its climax in July. There were 86% more individuals in the seed-tree area than in the mountain birch area. No damage to the pine germlings or seedlings was not observed, although the situation could be different during the peaks of the veewil populations.

The PDF includes a summary in English.

• Suoheimo, E-mail: js@mm.unknown

The effects of variations in the intensity of drainage and NPK fertilization on the natural regeneration and planting results and the subsequent development of seedling stands under various climatic conditions on drained nutrient poor pine bogs was investigated in a 16-year-old study.

Comparison of height development of Scots pine (Pinus sylvestris L.) stands on drained peatlands to that of pine stands growing in mineral soil sites show that in Southern Finland the most efficient forest improvement measures (10 m ditch spacing and 1,000 kg/ha NPK-fertilization) resulted in growth that corresponds a to a height index of a stand in a Vaccinium type site. Less efficient treatment (30 m ditch spacing and no fertilizer) resulted in growth corresponding the development of young stand in a Calluna type site. In Northern Finland the effect of fertilization on height growth was almost negligible. This is possibly due to a decrease in the nitrogen mobilization from south to north of Finland. Thus, it seems evident that fertilization of young Scots pine stands on nutrient poor drained peatlands can be recommended only in the southern part of the country.

The effect of ditch spacing is same in the whole country. The narrower the spacing the better the height growth. In the south planted stands thrive better than naturally regenerated stands, but the situation is reversed in the north.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown
• Laine, E-mail: jl@mm.unknown
• Lepola, E-mail: jl@mm.unknown

A study on the bilberry (Vaccinium myrtillus L.) was made in the municipality of Pihtipudas (about 63° 30’ N, 23° 30’ W) in 1977. Berry yield was surveyed by picking along 17 lines, each 1,000 m long. The lines were chosen randomly and were situated on different vegetation types throughout the municipality. The picking and use of bilberries were studied by an inquiry addressed to a random sample of families living in the area. Marketing of bilberry was investigated by means of report based on purchasing certificates.

The total yield of bilberry in Pihtipudas was 2.4 million kg (21.9 kg/ha). The yield per hectare were best on Vaccinium and Myrtillus type sites, and on swampy heath sites, where the yield was about 27–65 kg/ha, 50% of the yield on the Vaccinium type and 25% of that of Myrtillus type. Only 1.8% of the total bilberry yield was picked from old forests. Women contributed 54, men 34 and children 12% of the volume.

72% of the berries were used for home consumption by the families, 24% were sold and 4% were used for other purposes. The earnings from bilberries for the families that sold berries was in average FIM 178.

The PDF includes a summary in English.

• Raatikainen, E-mail: mr@mm.unknown
• Raatikainen, E-mail: tr@mm.unknown

The article describes the results of the studies made in 24 Finnish housing areas. They show that the building density is not as important as the way of building and the site planning, in the view of preserving natural vegetation in the site. Building on slopes was difficult with modern building techniques because of the extensive earthwork required. 

This paper was presented in the ‘Man and the Biosphere’ programme Project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki. 

The PDF includes a summary in English. 

• Rosengren, E-mail: cr@mm.unknown

Pyynikki is a unique natural park in the centre of the city of Tampere in Southern Finland. Currently, the forest of Pyynikki is losing its vigour because of aging and environmental factors. In 1977 a policy was designed for the regrowth of Scots pine (Pinus sylvestris L.) forest and improvement of the condition of the trees to avoid the situation that the whole pine forest (34 ha) would be regrown at one time. The period of regrowth of pine forest is 60 years. It is accomplished by cutting small openings, on which 4-year old potted pine saplings are planted. Birch will be planted only on two spots. The aim is that the forest scenery will be maintained as undamaged as possible. The condition of the growing forest will be improved by fertilization and thinning.

This paper was presented in the ‘Man and the Biosphere’ programme project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki.

The PDF includes a summary in English.

• Enivaara, E-mail: ae@mm.unknown

Pair numbers of breeding land birds were estimated from line transects data collected in Finland in 1936–76. The changes observed in the bird populations are in this paper compared with data obtained in the Finnish forest inventories, particularly made in 1951–53 and 1971–76. It is concluded that modern forestry has considerable impact on the breeding bird fauna. In general, more species have increased than decreased due to changes in the forests. Areas affected by forestry are more favourable habitats for many species than natural forests, but, on the other hand, there are certain species which are greatly harmed by the effects of modern forestry.

The PDF includes a summary in English.

• Järvinen, E-mail: oj@mm.unknown
• Kuusela, E-mail: kk@mm.unknown
• Väisänen, E-mail: rv@mm.unknown

In 1933, forest fire caused by locomotive sparkle burned about 600 hectares of forest in a forest district named Vehkatallinmaa, in Central Finland. In 1934–36, the burned area was reforested, using different sowing and planting methods. At the same time, areas with poor runoff were drained. The results from reforestation throughout the area have been good. Also, natural regeneration of coniferous trees, especially Scots pine (Pinus sylvestris L.) has occurred. Even deciduous trees, especially birch (Betula sp.), have regenerated naturally in the area. The forests are an evidence of the adaptability of broadcast sowing on snow crust as a method of reproduction.

The PDF includes a summary in English.

• Kolehmainen, E-mail: vk@mm.unknown

Prescribed burning has reported to avail forest regeneration, for instance, by releasing nutrients for the use of seedlings, changing the pH of the soil and decreasing competition of ground vegetation. The aim of the study was to find out if the effects could be verified. Sample plots were measured in the experimental area of Tuomarniemi, in Central Finland, both in previously burned and untreated seedling stands and young forests. The main species in the sample plots was Scots pine (Pinus sylvestris L.).

According to the results, prescribed burning prepares the soil for regeneration. Germination percentage of the seeds is higher on the burned soil. All the species, Scots pine, Norway spruce (Picea abies (L.) Karst.) and birch species (Betula sp.) grow faster. Prescribed burning increases the amount of birch seedlings by improving its regeneration compared to unburned sites. The seed trees survive burning better if they are tall and have short crown, and have thick bark. In general, prescribed burning improves regeneration in seed tree stands.

The article includes a summary in German.

• Kolehmainen, E-mail: vk@mm.unknown

The Forest Research Institute of Finland has established permanent sample plots to survey the effect of thinnings on the stands. This study compares the development of tended and natural Scots pine (Pinus sylvestris L.) stands growing on three different forest types: Oxalis-Myrtillus, Vaccinium and Calluna site type. The effect of heavy thinning from below (Oxalis-Myrtillus and Vaccinium site types) and increment felling (Calluna site type) was assessed by dividing the trees of the stands in tree classification classes according to their crown storey and defects.

The results show that thinning from below and increment thinning increase the proportion of trees in the 1st crown storey, which is already large in the natural stands. Also the diameter distribution is more even and the mean diameter higher after the thinnings.

In Scots pine stands in natural state, volume increment per stem is highest in the 1st crown storey and diminishes strongly towards the lower crown storeys. Thinnings increased the increment. The study indicates that many of the objectives of the intermediate cuttings, including promoting the growth of the best trees and improving the quality of the stand, have in general been achieved. Consequently, the thinnings give means to achieve the most valuable yield in the stand.

The article includes a summary in English.

• Nyyssönen, E-mail: an@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes forest regeneration on poor forest sites.

• Laitakari, E-mail: el@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes factors that should be taken into account in forest regeneration. 

• Laitakari, E-mail: el@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes inspection of forest regeneration of mineral soil forest types and drained peatlands, and inspection of ditches. 

• Ahola, E-mail: va@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes afforestation of drained peatlands. 

• Lukkala, E-mail: ol@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes the effect of properties of soil on forest regeneration. 

• Aaltonen, E-mail: va@mm.unknown

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes natural regeneration in forests and factors affecting the success of regeneration.

• Tertti, E-mail: mt@mm.unknown

Norway spruce (Picea abies (L.) H. Karst.) is rarely the dominant species on dry mineral soil sites in Northern Finland. These sites are, in general, too poor and dry for spruce, and suit better for Scots pine (Pinus sylvestris L.). According to the study, the natural regeneration of spruce is in Northern Finland poor. In the sample plots, cones could be found in 35% of spruce trees in the stands in natural state and 46% in the harvested stands. Compared to the spruce areas in Northern Finland, or fresh mineral soil sites in Southern Finland, cone and seed production of Norway spruce was in dry mineral soil sites very low due to scarcity of seed trees and their low cone number. There were few spruce seedlings in the sample plots, but according to the observations, spruce is able to regenerate on lichen and heath covered sites. The seedling growth was, however, poor on dry sites. Spruce seedlings were often found near fallen trees and stumps. The growing trees prevent growth of seedlings of all species. Norway spruce seems, however, to be able to spread also to the poor sites. The success depends on the vegetation and dryness of the site. For instance, spruce can spread to dry mineral soil sites from seed trees of nearby peatlands.

The PDF includes a summary in German.

• Tikka, E-mail: pt@mm.unknown

Examination of stands developed under natural conditions can be used to provide basis for comparison for study of the development and yield of stands treated with intermediate fellings. In Finland, the first investigation and the yield and the structure of natural normal stands were published in 1920. This investigation on development and yield of the natural forests of Kainuu in southeastern Northern Finland is based on 92 sample plots on three forest types; Empetrum-Vaccinium type (EVT), Empetrum-Calluna type (ECT) and Vaccinium-Myrtillus type (VMT).

The Scots pine (Pinus sylvestris L.) sample plots represented variation of age classes for construction of mean development series. The Norway spruce (Picea abies (L.) H. Karst.) of the region are so old that development series could be obtained only for dominant trees based on stem analysis.

The average development of Scots pine stand on EMT type within the region is on average more rapid and the yield in cubic volume quantitatively larger and structurally better than that on ECT type. Self-thinning during the early decades of EVT is slower. The pine stands are denser in the age of 70 in Kainuu compared to Central Northern Finland, but the development and yield are similar.

The development, yield and structure of natural Norway spruce stand on VMT proved considerably inferior to the average level of pine stands on EVT, and to a major part on ECT. The mixed pines on spruce sample plots have developed better than spruces of equal age. Spruce stands on VMT in the area developed markedly better than Geranium-Dryopteris-Myrtillus (GDMT) in Central Northern Finland.

It seems that a spruce stand seems to require more fertile site type in north than in the southern part of Finland. These fertile types are relative rare in the north. In the region, the best results are received with pine. As a rule, also the yield of birch (Betula sp.) is poor in the region.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@mm.unknown

The size of the field and the ditching on it as well as the condition of the field at the time of the surrender of Porkkala area (from Finland to Russia) play an important role on how far the natural regeneration of the fields has progressed.

Larger open fields have naturally regenerated only on sides where the surrounding forest can spread the seeds or the thicket of saplings has reached, whereas small parcels of fields have normally been fully forested. Most important species have been e.g. silver birch and pubescent birch, grey and common alders and European aspen as well as pine and spruce. The broad leaved species are dominant.     

The PDF contains a summary in Finnish.

• Kalela, E-mail: ek@mm.unknown

Prescribed burning has been used to treat the mineral soil sites, but the method has been little used in drained peatlands. The course and methods of prescribed burning in drained peatlands, and the effect of burning on sprouting of broadleaved trees, growth of ground vegetation and regeneration of Scots pine (Pinus sylvestris L.) by sowing was studied in drained pine bogs in Southern Finland. The top layer of the peat was mostly Sphagnum peat. The material included a prescribed burned 12 ha drained peatland area in Tuomarniemi district, in addition to which ten previously burned areas were investigated.

The burning had succeeded mostly well, but also unsuccessfully burned sites were observed. Estinguishing of the fire was easy, and no peat fires occurred. The fire burned only the logging residue, ground vegetation and the dry top layer of the peat. The roots of brushwood and grasses survived in the peat that insulated the top layer from the heat. For instance, the abundance of cloudberry (Rubus chamaemorus L.) increased after the fire. Similarly, burning did not affect sprouting of the stumps of downy birch (Betula pubescens Ehrh.). It cannot thus be used as a method to restrict the growth of coppice in regenerated areas. The seeds of Scots pine germinated well on the burned surface. 46% of the seeds developed to seedlings on sphagnum-shrub vegetation and 16% in feathermoss-shrub vegetation.

The PDF includes a summary in German.

• Yli-Vakkuri, E-mail: py@mm.unknown

Natural regeneration of Scots pine (Pinus sylvestris L.) by leaving a seed tree stand on a cutting area has long been the most popular regeneration method in Finland. Results of the method have, however, been unsatisfactory. The aim of the investigation was to study the basic problems of natural regeneration of Scots pine. Regeneration success was studied in 144 sample plots in pine stands at different stages of regeneration in Southern Finland. In addition, the data included information of 42 previously investigated areas.

According to the results, Scots pine can be successfully regenerated naturally on sandy and gravelly soils in Southern Finland. Preparing the ground surface by breaking or burning considerably facilitates the establishment of a seedling stand. The number of seedlings was considerably lower in the ground vegetation than in the mineral soil. Considering growth of the seedlings, root competition of the mother trees was heavy in dense stands, but insignificant in thin stands. The stand density did not affect germination of the seeds. In regeneration areas proper, where the density of mother trees usually is under 50 per hectare, there was in average 4,700 seedlings per hectare in Calluna type forests and 5,200 in Vaccinium type forests.

The PDF includes a summary in English.

• Lehto, E-mail: jl@mm.unknown

Root systems of a Scots pine (Pinus sylvestris L.) stands of seed trees on a Vaccinium sites in Southern Finland were studied by taking soil samples around the seed trees. The results show that root system of an old Scots pine spreads relatively evenly around the tree up to at least 10 meters from the stem. The densest part of the root system is near the stem, which part is often acentric. This is probably due to root competition in the early stages of growth of the tree.

Root systems of the seed trees affect stocking of the site with seedlings and the growth of the seedlings. The root competition can cause, for instance, uneven grouping of the seedlings. It seems that the largest trees of a stand have the most even root system. It is therefore recommended to choose the strongest trees of the stand as seed trees, to ensure even distribution of seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

Pine swamps are easily regenerated by natural regeneration of Scots pine (Pinus sylvestris L.). Usually seeding felling is used, but also strip system or clear cutting and regeneration along stand edge has been suggested. This article discusses the regeneration by clear cutting and sparing the existing undergrowth. The article focuses on pine swamps to be drained and the ones in natural state.

Pine swamps in natural state usually have plenty of trees of smaller diameter classes, that can be trusted to form the future tree generation after the felling. This shortens the rotation by 20-30 years. The undergrowth has been shown to recover quickly. The method suits for regeneration of drained peatlands but could fit also for regeneration of pine swamps in natural state.

The seedlings in the pine swamps are mainly 1-5 years old, and the stock is changing. It seems that larger trees produce a wider selection of age groups, but the seedlings survive longer under smaller mother trees. Part of the younger generations of seedlings seem to be destroyed when the peatland is drained. Further studies are needed to investigate how the draining and felling are to be performed to spare the young seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

• Heikurainen, E-mail: lh@mm.unknown

Norway spruce (Picea abies (L.) Karst.) invading sites is common in Finland. The species tends to establish itself as undergrowth, and takes over when it gets space to grow. To determine whether the undergrowth is suitable as the new generation requires knowledge on the biology of spruce undergrowth. One of the issues is determining the age of the stunted trees. In this investigation, 100 undergrown spruce trees, their crown and their root systems were studied. A method was developed to determine the age of the trees.

The root system of all trees in Vaccinium sites and of stunted trees in Myrtillius sites were superficial. The root systems of older spruces were purely of adventitious origin. The longer the period of stunting growth, the younger is the root system. In addition to acropetal and general adventitious ramification there is often adventitious branching of the roots of pathological causes. Mortality among the long roots is frequent.

A stunted tree has not the same ability as a viable tree to make use of already existing branches for building assimilating surface. When comparing trees with equally large assimilating surface, a stunted tree had greater sum of roots compared to a viable tree. The root system of a stunted undergrown spruce was very superficial compared with the other trees.

The PDF includes a summary in English.

• Sirén, E-mail: gs@mm.unknown

The aim of the study was to determine the effect of grazing of the cutting areas to the ground vegetation and regeneration of spruce. The cutting areas could be divided into two kinds of areas based on the vegetation. Hillocks were drier and poorer than other parts of the cutting areas. Their vegetation did suffer less from grazing than the other parts of the cutting areas. The shade-loving plant species decreased, but as the poorer sites have less edible plants, cattle caused less damage than in the better sites. The even spaces between the hillocks had both positive and negative changes. Cattle transport seeds, tile and fertilize the soil, promote paludification, and decrease competition by the primary species like large grasses. This is beneficial to new species. Grazing is directed to large grass species like Calamagrostis. Those species that cattle reject, become more abundant. Stamping damages especially shallow rooted species and perennial species, like Norway spruce (Picea abies (L.) H. Karst.). Larger tree seedlings may get injuries in the stem.

The PDF includes a summary in German.

• Hertz, E-mail: mh@mm.unknown

The abundance of Norway spruce (Picae abies (L.) H. Karst.) undergrowth is common for the state forests in Karelia near the Russian border, in Finland. In the survey, the occurrence of the undergrowth was studied. The article includes a review on the ownership of the forest, forest soils in the area, and the state of forests in the area. Scots pine (Pinus sylvestris L.) is the dominative species in 67%, Norway spruce in 27% and Betula sp. 6% of the state forests. Only 2% of the forests are 1‒20 years of age. Stands in the age group of 61‒80 years are the most common (25%). Norway spruce undergrowth is most abundant in the municipality of Salmi. The forests are typically moist forest site types or grass-herb site types. If the stands are allowed to develop naturally, even the Vaccinium sites become Norway spruce dominated. Spruce undergrowth is formed seldom under a spruce forest unless the stand is thin or has openings. Because Norway spruce is often rare in the mineral soil sites, the undergrowth is often regenerated from seeds that spread from spruce swamps. Earlier practiced shifting cultivation and its frequent fires prevented regeneration of spruce undergrowth. Similarly, the common felling method used, clear felling in strips, does not promote spruce undergrowth. Consequently, their occurrence is likely to decrease in the future.

The PDF includes a summary in German.

• Pöntynen, E-mail: vp@mm.unknown

Man’s existence on the earth depends on his ability to make use of the space, time, material and energy provided for him by Nature. The more able a nation is to increase the utilization of these resources, the higher is the culture and the standard of life in the nation.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

• Jutila, E-mail: kj@mm.unknown

In a natural state growing closed forest the amount of timber grows yearly. However, in the same time the timber volume also decreases when part of the trees die in the competition for light and other growth factors.

There are many interactive functions and characteristic that influence the growth and drain in a stand. These can be illustrated as mathematical models. The article discusses a set of models.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Lönnroth, E-mail: el@mm.unknown

Natural regeneration has been studied so far mostly on the perspective of regeneration, while the production capacity of the seed crop stand has been of little interest in the earlier studies. This paper studied volume growth of the seed trees and the economic impact of this regeneration method both in a literature review and measuring sample stands consisting of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) dominated stands and mixed forests in Norway.

It is concluded that in the most cases the seed tree stands give better pulpwood and timber yield than the stands in the average. The reason might be that the elite stems can better use their production capacity, and, thus, reach bigger and more valuable dimensions. Even though the growing stock diminishes in the seeding felling, the growth of the stand does not decrease or decreases only little. At the same time, the quality growth improves. In addition, the new tree regeneration is achieved usually without extra costs, and there is no unproductive time period in the stand.

• Barth, E-mail: ab@mm.unknown

The article presents middle-European forests and their characteristics, development and use. The main question is whether the current practice of planted coniferous tree forests should be kept or whether more natural mixed forests should be introduced instead. The article discusses the pros and cons of these and the possible felling and management practices.      

 The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Rubner, E-mail: kr@mm.unknown

­In different altitudes of the Mount Fuji in Japan occur succession of different tree species. For instance, at an altitude of 2,000 meters are pure stands of Tsuga diversifolia (Maxim.), under which is generally found young trees of Abies veitchii (Lindl.), but not of Tsuga. Abies veitchii is in its turn replaced perhaps with Larix sp. The succession of the forests of the volcano have reached maturity, which is not the case in the east–north-east flank of the mountain, where the Hōei eruption destroyed all vegetation in 1707. The vegetation had not revived even by the 1920s. The Hōei eruption site is compared to the much faster return of vegetation in mount Krakatau in the warmer tropical region. The succession of forests in the other parts of the mountain is described in detail. Finally, a succession theory is proposed that is opposed to the natural selection theory. The theory suggests that there is an Innermost Factor that controls the plant succession. According to the theory, every species, every formation, should die its natural death owing to the Innermost Factor.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Hayata, E-mail: bh@mm.unknown

Study is based on the strip-wise survey of forests in southern Finland. From that information the 30 sample plots were chosen, 10 of each of most typical forest site types, MT, VT and CT. The stands are of different ages and development classes, varying from 14 to 159 years.

The article discusses the earlier literature on the factors effecting forest stands and presents the data in detail. The results section is divided into paragraphs on number of stems of the stand, height, crown, breast height diameter, basal area and volume. The statistical numbers are calculated and presented.    

• Lönnroth, E-mail: el@mm.unknown

The northern range of small leaved lime (Tilia cordata Mill.) in Finland has remained the same since the end of 1800s, but according to the studies of subfossiles of lime found in peatlands, the northern limit has once been higher than at the present. The northernmost natural specimens of the species in Reisjärvi do not produce seed, and are therefore probably a relict. The article includes a review on the distribution of the species in Finland and its capacity to regenerate. The natural regeneration of lime in Finland is at present very rare. The species has lost its ability to sexual reproduction, but reproduces readily vegetatively.

The PDF includes a summary in German.

• Hertz, E-mail: mh@mm.unknown

The article begins on the page 27/122 of the PDF file.

The first part of the text deals with a general presentation of the geographical, biological and cultural conditions of the studied areas. The second part presents the characteristics of vegetation classified according the forest types, with lists of species. Forested areas, open lands and swampy areas are dealt with separately. The Saoneshje peninsula is presented separately.

The third part of the text discusses the similarities of the natural conditions between studied area and respective part of Finland. The vegetation and amount of species is clearly more diverse in studied area than in parts of middle-Finland. The study shows that in respect to vegetation Onega-Karelia cannot be seen as a part of the same region than Finland.  

• Norrlin, E-mail: jn@mm.unknown

The frequency of years when Scots pine (Pinus sylvestris L.) produces cones and seeds affects its reproduction in the north. The study area covered most of the pine lands in Northern Finland. Scots pine seems to be able to produce cones relatively often in the north. The amount of seeds produced in one year was, however, not sufficient to produce a dense seedling stand. Thus, the natural pine stands contain usually trees in different ages-classes, which have germinated in different years. The cone production is highest in 150-170 years old trees. Pine also needs warm summers to produce viable seeds. Brush fires avail the growth of seedlings, because they clear of ground vegetation that hinders germination of seeds. The seedlings need also moisture to survive; good regeneration years have often had rainy summers.

The PDF includes a summary in German.

• Lassila, E-mail: il@mm.unknown

This fourth part of the six-article series about protection forest in the Northern Finland is a proposal for organizing reindeer grazing to enable scots pine (Pinus sylvestris L.) regeneration near the timber line. Protection forests in the Northern Finland cover third of the natural pastures of reindeer in the area. In these areas reindeer grazing can harm the young pine seedlings. The proposal suggests temporary restrictions in grazing in the coniferous forests. Also, in the northernmost parts of Lapland the pine timberline area would be used only as winter pastures. Regional limits should be set for the number of reindeer. Also the ownership of reindeer herds and herding coopearatives included problematic issues that should be solved.

The article is divided in six parts. A German summary is in a separate PDF.

• Renvall, E-mail: ar@mm.unknown

The second part of the six-article series about protection forest in Northern Finland outlines the principles of protecting Scots pine (Pinus sylvestris L.) timber line. The protected areas should include at least all of the viable pine stands and those birch (Betula sp.) lands that are necessary to safeguard fuel wood supply in the pine forest zone. Outside the actual pine forest zone also those birch stands that are near populated regions should be protected to secure sustainable fuel wood supply. Third, south and down of the pine forest zone should be protected pine forest stands and adjacent open fell areas where forests are especially vulnerable. A new protection forest commission should be established to execute the protection forest legislation.

The article is divided in six parts. The parts II and III of the article series are included in the same PDF. A German summary is in a separate PDF.

• Renvall, E-mail: ar@mm.unknown

The success of natural regeneration of Scots pine (Pinus sylvestris L.) is dependent on the amount and quality of seeds produced in each year. While seed production of Scots pine in Northern Finland is well known, there is little information about frequency of good seed years in Southern and Central Finland. The success of regeneration of Scots pine was studied by defining from the growth rings of felled sample trees in which year they started to grow. The aim was to choose sample trees so that they would form a continual series from seedlings to 100 years old trees. In the material there was too little sample trees from certain years. However, within the period of 1827-1910 it could be identified 13 good regeneration years of pine in Southern Finland. According to the study, pine has regenerated very well every 6th year and at least moderately well every 4th year. When compared to the previous studies made in Northern Finland, part of the good regeneration years seems to be same both in Northern and Southern Finland. Regeneration of Scots pine is affected also by the type and condition of the site.

The PDF includes a summary in German.

• Ilvessalo, E-mail: li@mm.unknown

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m³/ha (ranging from 80 to 428 m³/ha) and after the cutting 120 m³/ha (39–220 m³/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

• Leinonen, E-mail: kl@mm.unknown
• Leikola, E-mail: ml@mm.unknown
• Peltonen, E-mail: ap@mm.unknown
• Räsä­nen, E-mail: pr@mm.unknown

The aim of the present work was to clarify the structure of selected natural Pinus kesiya Royale ex Gord. And P. merkusii Jungh. et de Vriese stands, with particular attention on the amount and quality of naturally-occurring seedlings and young trees. Furthermore, basic information required in the management of pine stands in watershed areas of northern Thailand was obtained.

Large number of pine seedlings were found in P. kesiyana stands only. Two of the examined four localities where this species occurred also included various intermediary height classes under the mature trees. In dense stands the number of seedlings was generally smaller as compared with lower seed tree densities. Neither one of the two localities where P. Merkusii was investigated indicated sufficient natural regeneration. Young pines (over 5 m height) seemed to survive the frequent ground fires quite well, whereas younger seedlings were destroyed and the ground layer vigour was lowered in these cases.

In situ sowing experiments at the beginning of the dry season indicated a faster development and better survival of emerging P. Kesiya seedlings as compared to P. Merkusii. Soil preparation and exposure to sun decreased the survival of seedlings in both species. Utilization of natural regeneration and direct sowing of pines as a silvicultural method as well as the general significance of the two pine species in the succession of plant communities under the influence of forest fires is also discussed.

The PDF includes a summary in Finnish.

• Turakka, E-mail: at@mm.unknown
• Luukkanen, E-mail: ol@mm.unknown
• Bhumibhamon, E-mail: sb@mm.unknown

The article is fifth part of a series of papers on fully stocked natural normal stands on mineral soils in Finland. This part studies the stands in Northern Lapland, dominated by Scots pine (Pinus sylvestris L.). This investigation was concerned mainly with Scotch pine stands, using Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula sp.) stands for comparison only. 107 sample plots were measured.

The most common forest types in the area are Empetrum-Myrtillus-(Cladina) type, EM(C1), Ericacea-Cladinae type, ErCIT, P-L, and Cladina type, C1T. Stand development is more rapid and wood production greater in EM(C1) type than ErCIT, while the C1T stands are further behind in all respects. The average differences in stand characteristics between forest types are roughly similar, but for cubic volume and total production less, than between the more southerly forest types. Measurements made from increment cores taken at breast height have confirmed that variation of the pine annual ring width has on average been very considerable, in accordance with the climatic, mainly temperature, variations, in the investigation area close to the north pine forest limit.

The few plots from birch and spruce stands measured as samples in the northern Lapland investigation area indicate the generally poor development and wood production of these stands by comparison with pine stands.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@mm.unknown

The article is third part of a series of papers on fully stocked natural normal stands on mineral soils in Finland. This part studies area between the ca. 62nd and 66nd parallels of the strip of land on the Gulf of Bothnia stretching from the coast to an altitude of 150 m above the sea level. The material consists of 121 sample plots in Scots pine (Pinus sylvestris L.) stands, 36 sample plots in Norway spruce (Picea abies (L.) H. Karst.) and 22 sample plots in birch (Betula sp.) stands.

Since the vegetation gradually changes from south to north, it was considered necessary to separate sub-types (marked s.) for certain southern-central forest types; these are poorer in vegetation but obviously more generally found than the main types. The Myrtillus s. sub-type shows slower development of pine stands than the Myrtillus type. The number of stems on the former is greater, owing to the slow initial development, but the mean diameter and height are smaller than on the latter. The difference in volume and growth increases with age. The slower the rate of self-thinning on the sub-type has the effect that the differences in total production are small.

The Vaccinium sub-type s. (VTs.) is poorer in vegetation than the southern-central type, differs from VT less than was the difference in the MT sub-types. The Empetrum-Vaccinium type (EVT) in general differs considerably from the VT but less from the VTs., in relation to which the difference shows mainly in the volume and total production. The EVT differs from the Calluna type as regards in all stand characteristics.

The results of this study suggest that the s.c. sub-type MT could be placed between the types MT and VT. This has significance especially in forest mensuration. However, in practical forest inventories it would seem possible to combine MT and MTs. to avoid having too many site classes. The types VT and VTs. can generally be considered nearly as one type. Similarly, CT and ECT (Empetrum-Calluna type) may be regarded as one site group. The differences may also partly be due to differences in early treatment of the forests.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@mm.unknown

Timber production and profitability were evaluated for spontaneously-regenerated mixtures on two formerly clearcut areas. The abandoned areas developed into birch-dominated (Betula pendula Roth and Betula pubescens Ehrh.) stands with successional ingrowth of Norway spruce (Picea abies (L.) H. Karst.). An experiment with randomized treatments within blocks was established, using three management strategies and one unthinned control, resulting in variation in optimal rotation age, merchantable volume and species composition. The management strategies were evaluated based on total production (volume) by using measured growth data 42 years after clearcutting and the modelled future stand development. The long-term effects of spontaneous regeneration and management strategies were evaluated based on land expectation value (LEV) and compared with a fifth management strategy using artificial regeneration and intense thinnings. 12 years after treatment, at a stand age of 42 years, the unthinned control had produced the highest total stem volume. At interest rates of 2% or higher, the unmanaged forest was an economically viable strategy, even compared to an intensive management strategy with a preferred merchantable timber species. Interest rates clearly impacted the profitability of the different management strategies. This study shows that when spontaneous regeneration is successful and dense, the first competition release can have a high impact on the development of future crop trees and on the species mixture.

• Dahlgren Lidman, Department of Forest Ecology and Management, Swedish University of Agricultural Science, Umeå, Sweden https://orcid.org/0000-0002-2474-1810 E-mail: felicia.lidman@slu.se
• Holmström, Southern Swedish Forest Research Centre, Swedish University of Agricultural Science, Alnarp, Sweden https://orcid.org/0000-0003-2025-1942 E-mail: emma.holmstrom@slu.se
• Lundmark, Department of Forest Ecology and Management, Swedish University of Agricultural Science, Umeå, Sweden https://orcid.org/0000-0003-2271-3469 E-mail: tomas.lundmark@slu.se
• Fahlvik, The Forestry Research Institute of Sweden, Ekebo, Sweden https://orcid.org/0000-0002-2179-7800 E-mail: nils.fahlvik@skogforsk.se

Fire is a common disturbance in boreal forests causing changes in biological diversity at various spatial scales. In the past 100 years, forest management has limited fire outbreaks, but in the future, the fire-affected forest area is expected to increase in many regions due to climate change. Burned forests are typically salvage-logged, but the effect of this type of management versus natural regeneration on biological diversity is not well understood, particularly the mid-term effect to tree establishment and understory vegetation composition and diversity. Various management methods were used after a large fire in 1992 in a peatland-forest complex and neighbouring managed forests, which created an experimental setup for study of the effect of management after fire in the Sliteres National park, northwestern Latvia. Understory vegetation was described in plots using a design of four forest and three management types: natural regeneration (unmanaged) and managed sites with salvage logging followed by no further human intervention and salvage logging with planting. Post-fire management had different effect in each forest type. Species richness was higher in forest types with salvage logging than in natural regenerated sites on rich wet and rich dry forest types, but not for the poor forest types. Tree regeneration was generally greater in salvage-logged stands, but differed between forest types. Species composition was related to tree regeneration and canopy openness. In contrast to other studies, salvage logging had a positive mid-term effect to ground vegetation diversity and tree establishment in the studied stands, implying potential for concomitant management and conservation of ground cover vegetation in semi-natural stands.

• Kārkliņa, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: annija.karklina@silava.lv
• Brūmelis, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: guntis.brumelis@lu.lv
• Dauškane, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: iluta.dauskane@lu.lv
• Elferts, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia; University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: didzis.elferts@lu.lv
• Freimane, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: lasma.freimane@silava.lv
• Kitenberga, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: mara.kitenberga@silava.lv
• Lībiete, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: zane.libiete@silava.lv
• Matisons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: robism@inbox.lv
• Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: aris.jansons@silava.lv

Geographic variations in growth, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density were investigated for Larix sibirica (Münchh.) Ledeb. naturally grown in Mongolia. A total of 250 trees with 20 to 30 cm in stem diameter at a height of 1.3 m above ground level were selected from each natural stand in five different provenances in Mongolia. In addition, five trees in each stand were cut for measuring dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density. Mean values of stress-wave velocity of stems in each stand ranged from 2.92 to 3.41 km s^–1, and the mean value of five stands was 3.23 km s^–1. Mean values of dynamic Young’s modulus of logs in each stand ranged from 5.17 to 9.72 GPa. A significant correlation (r = 0.798, p < 0.01) was found between stress-wave velocity of stems and dynamic Young’s modulus of logs. Among the five stands, the highest and the lowest values of average annual ring number were 193 and 44, respectively. Mean values of basic density in five trees within each stand were examined and ranged from 0.52 to 0.56 g cm^–3. Significant differences among five stands were found in tree height, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width and latewood percentage, suggesting that L. sibirica trees naturally grown in Mongolia have geographic variations in mechanical properties of wood.

• Tumenjargal, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: t_bayasaa88@yahoo.com
• Ishiguri, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: ishiguri@cc.utsunomiya-u.ac.jp
• Aiso-Sanada, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan E-mail: haiso@ffpri.affrc.go.jp
• Takahashi, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: zo.r.by0814@gmail.com
• Baasan, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: bayartsetseg@must.edu.mn
• Chultem, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: ganbaatar_ch@must.edu.mn
• Ohshima, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: joshima@cc.utsunomiya-u.ac.jp
• Yokota, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: yokotas@cc.utsunomiya-u.ac.jp

An understanding of the genetic variation of the beech, especially at the edge of its natural distribution, is essential because of the change in natural distribution of the species resulting from changing climatic conditions. The main aim of the study was to determine the level of genetic diversity of European beech at the north-eastern edge of its natural range. The other aim was to check the genetic variation of beech from the two centres, the north and the south of Poland, which were identified in previous findings based on pollen analyses and phenotypic traits. The research material was the progeny of twelve beech provenances. The genetic structure of the populations was determined by ten highly variable microsatellite DNA loci. The results confirmed the high genetic diversity of beech at the north-eastern edge of its natural distribution, which infers the probability of their good adaptation to the changing climate and an extension of the range. Genetic analyses confirmed the existence of two genetic centres for beech in Poland. The populations from south-eastern Poland had a slightly higher diversity than the populations from the north-western area, which may indicate that the colonisation of Poland occurred by two routes. The results are important for creating the borders of the provenance regions and for limiting the transfer of seeds and seedlings. The choice of forest reproductive material, based on the knowledge of genetic diversity, is very important for the stability of future forests.

• Kempf, Department of Genetics and Forest Tree Breeding, Faculty of Forestry, University of Agriculture in Krakow, Al. 29-listopada 46, 31–425 Krakow E-mail: m.kempf@ur.krakow.pl
• Konnert, Bavarian Office for Forest Seeding and Planting, Forstamtsplatz 1, 83317 Teisendorf, Germany E-mail: monika.konnert@asp.bayern.de

Changes in the structure and development of managed Scots pine (Pinus sylvestris L.) stands with respect to changing environmental conditions were set for the period 1979–2015. The study was conducted in conditions of natural pinewoods and pine-oak sites on five permanent research plots (0.25 ha) in Eastern Bohemia, Czech Republic (CR). Studied forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics. The standing volume of regularly distributed tree layer in 2015 was in the range of 320–434 m³ ha^–1, which indicates an increase by 5.9–20.0% over 10 years. Correlation between pine radial increment and the amount of precipitation was generally the strongest one. Positive statistically significant correlation between diameter increment and temperature was demonstrated only for the average March temperature of the current year. Within the CR, study site can be characterised as a medium polluted area both for sulphur and nitrogen, despite this SO₂ concentrations and N deposition in combination with extreme climate events caused severe defoliation in pine stands. Conversely, radial growth was positively significantly correlated with mean NO_x concentrations. Drought mainly in combination with even medium environmental pollution can further worsen the health status of pine stands in lowland areas of Central Europe. Thus, formulation of silvicultural techniques able to mitigate the impact of these stress factors is needed.

• Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: vacekstanislav@fld.czu.cz
• Vacek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: vacekz@fld.czu.cz
• Bílek, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: bilek@fld.czu.cz
• Simon, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, 613 00 Brno, Czech Republic E-mail: jaroslav.simon@mendelu.cz
• Remeš, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: remesj@email.cz
• Hůnová, Czech Hydrometeorological Institute, Na Šabatce 17 143 06 Prague, Czech Republic E-mail: hunova@chmi.cz
• Král, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: kraljan@fld.czu.cz
• Putalová, Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic E-mail: putalova@fld.czu.cz
• Mikeska, University of Hradec Králové, Faculty of Science, Rokitanského 62, 500 03 Hradec Králové, Czech Republic E-mail: Mikeska.Miroslav@uhul.cz

• Kreutz, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: andreas.kreutz@wald-rpl.de
• Aakala, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland http://orcid.org/0000-0003-0160-6410 E-mail: tuomas.aakala@helsinki.fi
• Grenfell, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: russell.grenfell@gmail.com
• Kuuluvainen, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi

• Hökkä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: hannu.hokka@metla.fi
• Repola, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jaakko.repola@metla.fi
• Moilanen, Finnish Forest Research Institute, Oulu Unit, P.O. Box 413, FI-90014 University of Oulu, Finland E-mail: mikko.moilanen@metla.fi
• Saarinen, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland E-mail: markku.saarinen@metla.fi

• Erber, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: gernot.erber@boku.ac.at
• Kanzian, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: christian.kanzian@boku.ac.at
• Stampfer, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: karl.stampfer@boku.ac.at

• Grenfell, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland E-mail: russell.grenfell@helsinki.fi
• Aakala, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland E-mail: ta@nn.fi
• Kuuluvainen, University of Helsinki, Dept of Forest Sciences, Helsinki, Finland E-mail: tk@nn.fi

• Bace, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: bace@fld.czu.cz
• Svoboda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: ms@nn.cz
• Janda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: pv@nn.cz

• Hökkä, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland E-mail: hannu.hokka@metla.fi
• Repola, Finnish Forest Research Institute, Rovaniemi Research Unit, FI-96301 Rovaniemi, Finland E-mail: jr@nn.fi
• Moilanen, Finnish Forest Research Institute, Muhos Research Unit, Muhos, Finland E-mail: mm@nn.fi
• Saarinen, Finnish Forest Research Institute, Parkano Research Unit, Parkano, Finland E-mail: ms@nn.fi

• Abella, Department of Environmental and Occupational Health, University of Nevada Las Vegas, Las Vegas, Nevada 89154-3064 USA E-mail: scott.abella@unlv.edu

• Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: guntis.brumelis@lu.lv
• Strazds, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: ms@nn.lv
• Eglava, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga LV1586, Latvia E-mail: ze@nn.lv

• Kaitaniemi, Hyytiälä Forestry Field Station, University of Helsinki, Hyytiäläntie 124, FI-35500 Korkeakoski, Finland E-mail: pk@nn.fi
• Riihimäki, Section of Ecology, Department of Biology, University of Turku, FI-20014 Turku, Finland E-mail: jr@nn.fi
• Koricheva, School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK E-mail: jk@nn.uk
• Vehviläinen, Section of Ecology, Department of Biology, University of Turku, FI-20014 Turku, Finland E-mail: hv@nn.fi

• Hallikainen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@metla.fi
• Hyppönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@metla.fi
• Hyvönen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: juha.hyvonen@metla.fi
• Niemelä, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jn@nn.fi

• Wang, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, China E-mail: yw@nn.cn
• Korpelainen, Department of Applied Biology, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: hk@nn.fi
• Li, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, China E-mail: licy@cib.ac.cn

• Storaunet, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway E-mail: ken.storaunet@skogforsk.no
• Rolstad, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway E-mail: jr@nn.no
• Gjerde, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway E-mail: ig@nn.no
• Gundersen, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway E-mail: vsg@nn.no

• Siipilehto, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jouni.siipilehto@metla.fi
• Siitonen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: juha.siitonen@metla.fi

• Drobyshev, SUFOR Project, Department of Plant Ecology and Systematics, Ecology Building, Sölvegatan 37, Lund University, SE-223 62 Lund, Sweden E-mail: igor.drobyshev@ekol.lu.se
• Niklasson, SUFOR Project, Southern Swedish Forest Research Centre, SLU, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: mn@nn.se
• Angelstam, Grimsö Wildlife Research Station, Department of Conservation Biology, Forest Faculty, SLU, SE-730 91 Riddarhyttan, Sweden E-mail: pa@nn.se

• Hannerz, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: mats.hannerz@skogforsk.se
• Almqvist, The Forestry Research Institute of Sweden (SkogForsk) Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ca@nn.se
• Hörnfeldt, Swedish University of Agricultural Sciences, Dept. of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: rh@nn.se

• Purdy, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 E-mail: bgp@nn.ca
• Macdonald, Dept. of Renewable Resources, University of Alberta, Edmonton, AB, Canada T6G 2E3 E-mail: ellen.macdonald@ualberta.ca
• Dale, Dale, Dept. of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 E-mail: mrtd@nn.ca

• Lexer, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria E-mail: lexer@edv1.boku.ac.at
• Hönninger, Institute of Silviculture, University of Agricultural Sciences, Peter-Jordanstrasse 70, A-1190 Vienna, Austria E-mail: kh@nn.at
• Scheifinger, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: hs@nn.at
• Matulla, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: cm@nn.at
• Groll, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: ng@nn.at
• Kromp-Kolb, Institute of Meteorology and Physics, University of Agricultural Sciences, Türkenschanzstrasse 18, A-1180 Vienna, Austria E-mail: hkk@nn.at

In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.

• Sikström, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ulf.sikstrom@skogforsk.se
• Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: karin.hjelm@skogforsk.se
• Holt Hanssen, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway E-mail: kjersti.hanssen@nibio.no
• Saksa, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi
• Wallertz, Swedish University of Agricultural Sciences (SLU), Asa Forest Research Station, SE-360 30 Lammhult, Sweden E-mail: kristina.wallertz@slu.se

• Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga, LV-1586, Latvia; E-mail: guntis.brumelis@lu.lv
• Jonsson, Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden E-mail: bgj@nn.se
• Kouki, School of Forest Sciences, University of Eastern Finland, Joensuu, Joensuu E-mail: jk@nn.fi
• Kuuluvainen, Department of Forest Sciences, University of Helsinki, Finland E-mail: tk@nn.fi
• Shorohova, Saint-Petersburg State Forest Academy, Saint-Petersburg, Russia & Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland E-mail: es@nn.ru

• Kuuluvainen, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi
• Aakala, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ta@nn.fi

• Bergeron, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 E-mail: bergeron.yves@uqam.ca
• Leduc, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 E-mail: al@nn.ca
• Harvey, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 E-mail: bdh@nn.ca
• Gauthier, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8 E-mail: sg@nn.ca

In managed European hemiboreal forests, windstorms have a notable ecological and socio-economic impact. In this study, stand properties affecting windstorm damage occurrence at the stand-level were assessed using a Generalized Linear Mixed model. After 2005 windstorm, 5959 stands dominated by birch (Betula spp.), Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.), with mean height > 10 m were inventoried. Windstorm damage was positively associated with spruce and pine-dominated stands, increasing mean height, fresh forest edges, decreasing time since the last thinning and stronger wind gusts. Tree species composition – mixed or monodominant – was not statistically significant in the model; while, the admixture of spruce in the canopy layer was positively associated with higher windstorm damage. Stands on peat soils were more damaged than stands on mineral soils. Birch stands were more damaged than pine stands. This information could be used in forest management planning, selection of silvicultural treatments to increase forest resilience to natural disturbances.

• Donis, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 E-mail: janis.donis@silava.lv
• Kitenberga, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 E-mail: mara.kitenberga@gmail.com
• Šņepsts, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 E-mail: guntars.snepsts@silava.lv
• Dubrovskis, Latvia University of Life Sciences and Technologies, Liela iela 2, Jelgava, Latvia, LV-3001 E-mail: edgars.dubrovskis@llu.lv
• Jansons, Latvian State Forest Research Institute “Silava”, Rigas 111, Salaspils, Latvia, LV-2169 E-mail: aris.jansons@silava.lv

• Ersson, Swedish University of Agricultural Sciences (SLU), School of Forest Management, SE-739 21 Skinnskatteberg, Sweden https://orcid.org/0000-0003-2442-7482 E-mail: back.tomas.ersson@slu.se
• Hansson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-9788-1734 E-mail: linnea.hansson@skogforsk.se
• Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se
• Sandström, Swedish University of Agricultural Sciences (SLU), Department of Forest Resource Management, SE-901 83 Umeå, Sweden https://orcid.org/0000-0003-0977-0071 E-mail: per.sandstrom@slu.se
• Sonesson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-2018-7496 E-mail: johan.sonesson@skogforsk.se

• Rouvinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: sr@nn.fi
• Kouki, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jari.kouki@joensuu.fi

• DeLong, Ministry of Forests, 1011 4th Ave, Prince George, BC, Canada V2L 3H9 E-mail: craig.delong@gems1.gov.bc.ca