Articles containing the keyword 'Scots pine'

The purpose of this study was to compare the Weibull distributions estimated for the entire growing stock of a stand and separately for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) in describing the basal area diameter distributions in mixed stands. The material for this study was obtained by measuring 553 stands located in eastern Finland. The parameters of the Weibull distribution were estimated using the method of maximum likelihood. The models for these parameters were derived using regression analysis. Also, some parameter models from previous studies were compared with the measured distribution. The obtained distributions were compared using the diameter sums of the entire growing stock, diameter sums by tree species and of the sawtimber part of the growing stock. The results showed that far more accurate results were obtained when the distributions were formed using parameter models separately for the different tree species than when using parameter models for the entire growing stock. This was already true when considering the entire growing stock of the stand and especially when the results were examined by tree species. When the models for the entire growing stock were applied by tree species in relation to basal areas, the results obtained were overestimates for Norway spruce and underestimates for Scots pine. The models from earlier studies, where parameter models were estimated separately for tree species from the National Forest Inventory data, showed good fits also in regard to the data of this study.

• Maltamo, E-mail: mm@mm.unknown

Possibilities of distance-independent and -dependent competition indices to describe the competition stress of an individual tree was studied in Southern Finland. Five half-sib open-pollinated families and one check lot of Scots pine (Pinus sylvestris L.) was used as study material in order to analyse competitive interactions of crown form and stand density variation. Almost all competition indices correlated strongly with radial increment. Thus distance-independent indices were adequate to describe competition in young row plantations, where distance effects between trees were implicitly eliminated. Correlations between indices and height increment were not significant. Along with the increase in competition, the width and length of the crown and the diameter increment of the stem of some narrow-crowned families decreased slowly compared to wide-crowned families.

• Mäkinen, E-mail: hm@mm.unknown

Estimates of individual heritability and genetic correlation are presented for a set of 10 growth and quality traits based on data from 16 Scots pine (Pinus sylvestris L.) progeny trials in Finland. Seven of the traits (tree height, stem diameter, crown width, Pilodyn value, branch diameter, branch angle and branch number) were objectively measured, whereas three traits (stem straightness, branching score and overall score) were assessed visually. The genetic correlations were mostly moderate or low, and favourable from the tree breeder's point of view. All variables related to tree size correlated relatively strongly and positively. Tree height exhibited a more favourable genetic relationship with the crown form traits than diameter, the latter showing positive correlation with branch diameter. Except for the slight negative correlation between branch angle and branch diameter, the branching traits were not notably correlated. The pilodyn value was positively correlated with stem diameter, reflecting negative correlation between diameter growth and wood density. The highest genetic correlations occurred among the two visually evaluated quality scores and branch diameter. All of the heritabilities were less than 0.4. Overall score, Pilodyn, branch angle, branching score and tree height showed the highest heritability.

• Haapanen, E-mail: mh@mm.unknown
• Annala, E-mail: ma@mm.unknown
• Velling, E-mail: pv@mm.unknown

Postfire recovery of species diversity (including a number of species, entropy of species relative coverage (Shannon index of species diversity) was studied in lichen and green moss site types of Scots pine (Pinus sylvestris L.) forests in the central part of the Kola Peninsula. The results obtained indicate the difference in the dynamics of characteristics of biodiversity of forest components during postfire recovery. The stabilization of separate components of forest community varies in time from 5–15 to 120–140 years after the fire. Characteristics of the dwarf shrub and herb stratum recovered and stabilized 5–15 years after fire, while the complete stabilization of characteristics of moss-lichen cover is observed in community with fire ages of 90–140 years. Species richness of tree stratum recovered 120–140 years after fire. Time of complete stabilization of species richness of the community was estimated 120–140 years after fire. The size of the area over which characteristics of the biodiversity were estimated effected the mean values and, in most cases, the character of variation of studied characteristics. Over an area of 1 x 1 m dynamics of characteristics of species diversity coincide in forests of the studied types. Regardless of forest type within the area of 100 m² species richness recovered 30 years after the fire (i.e. 3–5 times earlier than the establishment of the complete stabilization of the forest structure). That means that floristic composition of the forest remained unchanged from 30 to 210 years after the fire.

• Gorshkov, E-mail: vg@mm.unknown
• Bakkal, E-mail: ib@mm.unknown

Investigations carried out in the Kola peninsula (northern taiga) and in the South-western part of Western Siberia (southern taiga and forest-steppe) revealed identical course of the postfire restoration process of forest litter thickness in Scots pine (Pinus sylvestris L.) forests. Despite the differences in mean annual temperature (2°C) and other climatic characteristics the recovery time for thickness of forest litter in both regions amounts to 90–100 years after fire in pine forests of lichen site type and 120–140 years – in green moss type; the thickness of forest litter therewith corresponds 3–4 cm and 7–8 cm respectively. That mean that within the natural borders of pine forests, communities of a specific type possess uniform characteristics of restoration. On the basis of empirical data, it appears that the predicted increase of mean annual temperature of earth surface by (2°C) will not bring changes into the character of postfire recovery of forest litter thickness. It was shown that during the period of the recovery, which spans about 90 years after fire in pine forests of lichen and green moss-lichen site types and 140 years in ones of green moss site types, the rate of increasing of carbon store in the forest litter averaged 0.6 t ha^-1 year^-1, 0.1 t ha^-1 year^-1 and 0.2 t ha^-1 year^-1, respectively.

• Gorshkov, E-mail: vg@mm.unknown
• Bakkal, E-mail: ib@mm.unknown
• Stavrova, E-mail: ns@mm.unknown

Two dynamic models predicting the development of frost hardiness of Finnish Scots pine (Pinus sylvestris L.) were tested with frost hardiness data obtained from trees growing in the natural conditions of Finland and from an experiment simulating the predicted climatic warming. The input variables were temperature in the first model, and temperature and night length in the second. The model parameters were fixed on the basis of previous independent studies. The results suggested that the model which included temperature and photoperiod as input variables was more accurate than the model using temperature as the only input variable to predict the development of frost hardiness in different environmental conditions. Further requirements for developing the frost hardiness models are discussed.

• Leinonen, E-mail: il@mm.unknown
• Hänninen, E-mail: hh@mm.unknown
• Repo, E-mail: tr@mm.unknown

The effects of realistically elevated O₃ and CO₂ concentrations on the needle ultrastructure and photosynthesis of ca. 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied during one growth period in open-top field chambers situated on a natural pine heath at Mekrijärvi, in eastern Finland. The experiment included six different treatments: chamberless control, filtered air, ambient air and elevated O₃, CO₂ and O₃ + CO₂. Significant increases in the size of chloroplast and starch grains were recorded in the current-year needles of the saplings exposed to elevated CO₂ These responses were especially clear in the saplings exposed to elevated O₃ + CO₂ concentrations. These treatments also delayed the winter hardening process in cells. In the shoots treated with O₃, CO₂ and combined O₃ + CO₂ the P_max was decreased on average by 50% (ambient CO₂) and 40% (700 ppm CO₂). Photosynthetic efficiency was decreased by 60% in all the treated shoots measured under ambient condition and by 30% in the CO₂ and O₃ + CO₂ treated shoots under 700 ppm. The effect of all the treatments on photosynthesis was depressive which was probably related to evident accumulation of starch in the chloroplasts of the pines treated with CO₂ and combined O₃ + CO₂. But in O₃ treated pines, which did not accumulate starch in comparison to pines subjected to ambient air conditions, some injuries may be already present in the photosynthetic machinery.

• Palomäki, E-mail: vp@mm.unknown
• Holopainen, E-mail: th@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Laitinen, E-mail: kl@mm.unknown

The eddy covariance technique is a novel micrometeorological method that enables the determination of the atmosphere-biosphere exchange rate of gases such as ozone and carbon dioxide on an ecosystem scale. This paper describes the technique and presents results from the first direct measurements of turbulent fluxes of O₃, CO₂ and H₂O above a forest in Finland. The measurements were performed during 15 July-5 August 1994 above a Scots pine (Pinus sylvestris L.) stand near the Mekrijärvi research station in Eastern Finland.

The expected diurnal cycles were observed in the atmospheric fluxes of O₃, CO₂ and H₂O. The data analysis includes interpretation of the O₃ flux in terms of the dry deposition velocity and evaluation the dependency of the net CO₂ flux on radiation. The eddy covariance method and the established measurement system has proved suitable for providing high-resolution data for studying ozone deposition to a forest as well as the net carbon balance and related physiological processes of an ecosystem.

• Aurela, E-mail: ma@mm.unknown
• Laurila, E-mail: tl@mm.unknown
• Tuovinen, E-mail: jt@mm.unknown

Variation in needle nutrient concentrations with age and vertical location in the crown was studied in three Scots pine (Pinus sylvestris L.) stands growing on peat soils in Eastern Finland. The concentrations of N, P, Fe and Zn decreased down the crown and those of Ca and Mn increased. Potassium and magnesium concentration patterns differed between sites.

Potassium and Mg concentrations were highest in the current needles at all heights in the crown, iron and manganese concentrations were highest in the oldest needles. The concentrations of N, P and Zn did not vary with needle age.

• Finér, E-mail: lf@mm.unknown

Moose (Alces alces L.) browsing was studied in young Scots pine (Pinus sylvestris L.) stands mixed with deciduous trees in high-density winter ranges. The proportional use of twig biomass decreased as the availability increased. The total as well as proportional biomass consumption were higher on the moist than on the dry type of forest. The per tree consumption of pine was higher on the moist type, where the availability of pine was lower. Deciduous trees were more consumed on the moist type, where their availability was relatively high. The consumption of pine saplings increased as the availability of birch increased. Pine stem breakages were most numerous when birch occurred as overgrowth above pine and at high birch densities. The availability of other deciduous tree species did not correlate with browsing intensity of Scots pine. Moose browsing had seriously inhibited the development of Scots pines in 6% of the stands, over 60% of available biomass having been removed. Rowan and aspen were commonly over-browsed and their height growth was inhibited, which occurred rarely by birch. There was no difference in the proportion of young stands in forest areas with high and low moose density. A high proportion of peatland forests was found to indicate relatively good feeding habitats in the high-density areas.

The PDF includes an abstract in Finnish.

• Heikkilä, E-mail: rh@mm.unknown
• Härkönen, E-mail: sh@mm.unknown

Three Scots pine (Pinus sylvestris L.) plantations carrying 35 plots with initial spacings from 800 to 5,000 plants/ha were studied. Planting designs varied from a square to a rectangle with 5-metre row distance, the plant-to-plant distance being 0.8 metres. At current dominant height of 6 m, rectangularity had no effect on height, diameter, or volume growth of trees. Slight ovality of stems was observed in rectangular plots but the differences in the cross-wise mean diameters were very small, not over 1.1 mm in terms of plot-wise means. The diameter of the thickest living branch of a tree was linearly dependent of the dbh. The branches were clearly thicker between the planting rows at under 1,600 stems/ha stand density. A non-square planting pattern is a conceivable alternative when the line corridors suitable for mechanized silvicultural operations are preferred.
The PDF includes an abstract in Finnish.

• Salminen, E-mail: hs@mm.unknown
• Varmola, E-mail: mv@mm.unknown

It was examined whether the present site classification method, and especially its applicability to site productivity estimation, could be improved in upland Scots pine (Pinus sylvestris L.) forests in Southern Finland by developing a classification key based on Two-way Indicator Species Analysis (TWINSPAN), and/or by inclusion of soil texture, stoniness and the humus layer depth more closely in the classification method. TWINSPAN clusters (TW) explained 71%, and forest site types (FST) 64% of the variation in site index (SI) (H₁₀₀). When soil texture (TEXT) was added to the regression model, the explanatory power increased to 82% (SI = TW + TW * TEXT) and to 80% (SI = FST + FST * TEXT), respectively. Soil texture alone explained 69% of the variation in site index. The influence of stoniness on site index was significant (P <0.05) on sorted medium sand soils and on medium and fine sand moraine soils. The thickness of the humus layer (2–6 cm) was not significantly (P=0.1) related to site index.

It is suggested that the proposed TWINSPAN classification cannot replace the present forest site type system in Scots pine stands in Southern Finland. However, the TWINSPAN key may be used to aid the identification of forest types. The observation of dominant soil texture within each forest type is recommended.

The PDF includes an abstract in Finnish.

• Nieppola, E-mail: jn@mm.unknown

The efficacy of pine tar as a moose (Alces alces L.) contact repellent was tested in young Scots pine (Pinus sylvestris L.) stands suffering from moose damage in Southern Finland during the winter 1981–82. Application of tar to shoots by spraying protected the trees satisfactorily throughout the winter.

The PDF includes an abstract in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown
• Heikkilä, E-mail: rh@mm.unknown
• Repo, E-mail: sr@mm.unknown

Model computations on the management of Scots pine (Pinus sylvestris L.) at the seedling stage showed that a rising temperature due to the suggested climate change could increase the competition capacity of birch species (Betula pendula) more than Scots pine, whose growth could even decline during the course of a rise in temperature. A temperature rise could, thus, bring the time of removal of birches forward when aiming at Scots pine timber stands composed of these tree species. The increasing proportion of birches makes the removal of birches even more urgent and emphasizes the need for careful management of Scots pine stands under rising temperatures. The first thinning of Scots pine is generally brought forward; this is particularly the case when wide spacing is applied in planting. A furthrer rise in temperature magnifies the above patterns by reducing further the competitive capacity of Scots pine in relation to birches.
The PDF includes an abstract in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Kolström, E-mail: mk@mm.unknown

The light reflected from the crowns of Scots pine (Pinus sylvestris L.) clones was measured spectroradiometrically during and after growing season. Standard deviations of the spectra of pine clones showing differences in moose browsing intensity were compared. A new algorithm was developed for predicting the browsing intensity of moose (Alces alces).

The PDF includes an abstract in Finnish.

• Silvennoinen, E-mail: rs@mm.unknown
• Hämäläinen, E-mail: rh@mm.unknown
• Nygrén, E-mail: kn@mm.unknown
• Weissenberg, E-mail: kw@mm.unknown

The shape of Scots pine (Pinus sylvestris L.) knots close to the pith of butt logs was investigated. 1,100 knots were split in a vertical direction, and their shape was measured. Knot diameter and branch angle were calculated at a distance of 40 mm from the pith of the stem. The mean diameter of all the knots in the material was 14 mm, and the branch angle 70°. Regression analysis was used to devise a formula for predicting branch angle on the basis of knot diameter. Knot size and branch angle were negatively correlated. Especially the shape of larger knots was curved. Knots achieved their maximum diameter at distance of 4–5 cm from the stem pith. The branch wood was almost completely situated above the formation point of the branch.

The PDF includes an abstract in Finnish.

• Pietilä, E-mail: jp@mm.unknown

A survey was conducted in Finland in 1988 to determine whether the pine wood nematode Bursaphelenchus mucronatus Mamiya & Enda 1979 (Nematoda: Aphelenchoididae) or the closely related species B. mucronatus would occur in Finnish forests. Dead or dying standing trees and timber of two conicer species, Pinus sylvestris L. (Scots pine) and Picea abies (L.) H. Karst. (Norway spruce) were analysed for the presence of these nematodes. Monochamus spp. pine sawyers (Coleoptera: Cerambycidae) were also collected and inspected for the presence of dispersal fourth juvenile stages (dauerlarva) of the nematodes. The species B. xylophilus was not found, but B. mucronatus appeared to be widespread in the country. Individuals of this nematode were found both from Scots pine and Norway spruce. Adults of two Monochamus species were found, M. galloprovincialis and M. sutor. Only two of the examined beetles of the former species had dauerlarvae in their body.

The PDF includes an abstract in Finnish.

• Tomminen, E-mail: jt@mm.unknown
• Nuorteva, E-mail: mn@mm.unknown
• Pulkkinen, E-mail: mp@mm.unknown
• Väkevä, E-mail: jv@mm.unknown

The material of the study consisted of 21 Scots pine (Pinus sylvestris L.) trees that had been pruned in the 1930’s and 1940’s. The butt log of the pruned stems was peeled into veneer from which the length and shape of the resin taps were determined. The length of the resin tap was affected in the first place by the knot diameter and the height of the knot along the stem. The length of the resin tap was about 1.5-fold that of the knot diameter. With an increase in the height above the ground of a knot, its length decreases. The resin taps were particularly long on poor sites and in the butt end of the stems, however, the variation in tap length was large both within and between the individual tree stands. The shape of the resin taps is presented in this study by diameter classes. The resin taps studied in the work were longer than those measured in other works. This may be due to the fact that the knots were uncovered by peeling instead of sawing.

The PDF includes an abstract in Finnish.

• Pietilä, E-mail: jp@mm.unknown

In Northern Finland as well as in Northern Sweden there is a shortage of high-quality Scots pine (Pinus sylvestris L.) seeds, mostly due to unsuitable temperatures during the development and maturation of cones and seeds. Methods have been developed for elimination of non-productive seeds and for invigoration of seeds. In the present work, these methods were tested on poorly developed seed lot from Rovaniemi, Northern Finland (66°15’–66°30’; 180 m a.s.l.). The seeds were conditioned using the following treatments:

1. PREVAC method (5 min, 97 kPa below atmospheric pressures) for removal of mechanically damaged seeds (7%)

2. Invigoration using incubation at controlled moisture content (30% f.w) and continuous air supply, for 14 days at 5°C.

3. Additional water supply for 16 hours at 5°C.

4. Drying in dehumidified air until a near maximum difference in density between viable and dead seeds was obtained

5. Separation in a sedimentation flume to achieve a gradient of fractions of different germination rate and capacity.

The treatments resulted in an improvement of germination percentage from 33 to about 95% and a reduction in mean germination time from 8.8 days to 6 days if the control and the best fractions (32% seeds) were compared.

• Bergsten, E-mail: ub@mm.unknown

Succession of insect attacks on young Scots pine (Pinus sylvestris L.) was studied in heavily, moderately and slightly polluted pine stands within a three-kilometre distance from a prominent emission source in Western Finland. The total number of pest species was highest in the moderately polluted stand, but unlike other herbivores, aphids were also abundant in the heavily polluted stands. A few positive but no negative interactions were detected between herbivores, which suggests that insect species may benefit from a previous occurrence of other species in the same tree.

The PDF includes an abstract in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Väisänen, E-mail: rv@mm.unknown

The effect of root exposure on the shoot and root development of Pinus sylvestris (L.) seedlings was studied at two soil temperatures. Roots of bare-rooted three-year-old seedlings were exposed to the temperature of 32°C at relative humidity of 50–40% for 85, 155 and 270 minutes which corresponds to accumulated water pressure deficit of 24, 47 and 91 mbar·h, respectively. Thereafter, seedlings were grown for 65 days at the soil temperatures of 12 and 23°C. Drought exposures inhibited new root initiation, delayed shoot elongation, and reduced shoot and needle growth. The stronger the exposure the larger the proportion of needles from the lower part of current shoot that remained undeveloped. Low soil temperature increased the effect of exposures so that needle elongation and initiation of new root tips of seedlings in cold soil with the longest exposure were inhibited totally. Root growth assessments made in warm soil may overestimate the acclimation potential of planted seedlings.

The PDF includes an abstract in English.

• Rikala, E-mail: rr@mm.unknown
• Puttonen, E-mail: pp@mm.unknown

Models concerning the effects of temperature on dormancy release in woody plants were tested using two-year old seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.). Chilling experiments suggest that the rest period has a distinct end point. Before the attainment of this end point high temperatures do not promote bud development towards dormancy release, and after it further chilling does not affect the subsequent bud development. A new hypothesis of dormancy release is suggested on the basis of a comparison between present and earlier findings. No difference in the proportion of growth commencing seedlings were detected between the forcing temperatures of 17°C and 22°C. The rest break of 50% of Norway spruce and Scots pine seedlings required six and eight weeks of chilling, respectively. Great variation in the chilling requirement was found, especially for Scots pine.

The PDF includes an abstract in Finnish.

• Hänninen, E-mail: hh@mm.unknown
• Pelkonen, E-mail: pp@mm.unknown

The study material consisted of 13 rather old Norway spruce (Picea abies (L.) H. Karst.) and 17 Scots pine (Pinus sylvestris L.) stands located in different parts of Finland. In each stand the seed crops, radial growth and amount of latewood were measured during a period of about ten years. Seed production reduces the radial growth of spruce and pine in the year of seed maturing. In Southern and Central Finland also the proportion of latewood is reduced. Seed production accounts for about 14% of the variation in radial growth of a spruce stand growing in Lapland, and 27% in other parts of Finland. In pine stands the seed crop explains 19% of the variation in radial growth in Lapland, and only 7% in the rest of Finland. In spruce stands an average seed crop reduces radial growth by 14% in Lapland and 5% in the rest of the country. An abundant seed production causes a reduction of about 20%. In southern parts of Finland, the proportion of latewood is reduced by 5% in an average seed year and by 24% in a good seed year. In pine stands an average seed crop decreases the width of annual ring by 5%, and a good seed crop by 15%. Outside Lapland, also the proportion of latewood is reduced: in an average seed year by 5%, and in a good seed year by 16%. The reduction in volume growth of spruce stands due to an average seed crop was estimated to be about 10% in Lapland, and 6% in other parts of Finland. A prolific seed production causes a reduction of 20%. In old pine stands the reduction is 5% in an average seed year, and 15% in a good seed year.

The PDF includes an abstract in English.

• Pukkala, E-mail: tp@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

This study deals with significance of the number of needle year classes in estimating the nitrogen, phosphorus, potassium and magnesium status of Scots pine (Pinus sylvestris L.) plants on the basis of needle analysis. Due to the nutrient retranslocation deficiencies in these nutrients are best determined by analysing separately the needles of the topmost branch whorls possessing one, two or three needle year classes. The concentrations of those nutrients which are not scarce will then increase as needle year classes decrease. In cases of deficiency, on the other hand, the content of the nutrient concerned will remain the same or decrease. Only severe deficiencies are revealed by the examination of the nutrient concentrations of only the youngest or the oldest needles.

The PDF includes an abstract in English.

• Raitio, E-mail: hr@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

Paratization of Petrova resinella L. in the gall stage was studied in the surrounding of Harjavalta, south-western Finland, in relation to industrial air pollution. Of the studied 283 galls, 28% produced a moth, 52% of the larvae/pupae were paratisized, and 20% were empty or contained a dead larva. The proportion of paratisized galls did not depend on the distance from emission sources of industrial air pollutants.

The PDF includes an abstract in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Väisänen, E-mail: rv@mm.unknown

The purpose of the study was to determine the effects of the origin of seeds and the location of cultivation of Scots pine (Pinus sylvestris L.) on certain properties particularly important to the pulp industry. The research material consisted of six parallel trials of the same 12 provenances. Increment cores were taken of a total of 1,267 sample trees, 19 years old. The location of the trial site generally affected the properties to a larger extent than the origin of the seed. The effect of the variation of wood density and fibre yield on the cultivation values of the provenances was only a few percentages on average, however, at most the effect was nearly 10%. Eastern Finnish provenances adapted well to western Finnish conditions.

The PDF includes an abstract in Finnish and French.

• Velling, E-mail: pv@mm.unknown
• Nepveu, E-mail: gn@mm.unknown

A mathematical model was developed for determining the value of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) stems on the basis of sawing and pulping. The model was based on selling prices of sawn goods, pulp and other products as well as processing costs. Sawing was applied to large-dimension parts of stems and pulping to other parts and small stems. Bark and other residues were burned. The quality of pine stems was described by the distance of the lowest dead branch. In spruce only stem size affected the quality-

According to the results, the size of stem affects considerably the value of pine stems and clearly that of spruce stems. The main reason is an increase in the productivity of frame sawing as the stem size increases. In pine another factor is the higher price of sawn goods. The effect of pulp price increases as the stem size decreases. Even in large sized stems the effect of pulp was notable as the value of chips and saw dust was determined on the basis of product values in export. The competition ability of mechanical pulp was greatly affected by the price of electricity.

The PDF includes an abstract in English.

• Kärkkäinen, E-mail: mk@mm.unknown

A computer model was developed for predicting knottiness of wood material of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula sp). The prediction included location of knots, their size and quality, i.e. if they are dead or living knots. The model suits best for tree species where branches are born at the base of shoots, in Finland such tree species is Scots pine.

The usefulness of the model was tested in the prediction of knots in wooden elements of joinery industry. According to the results, the shape of cross section affects the surface quality of elements. Especially useful is a quadratic cross section as it increases the probability to get a knotless surface.

The PDF includes an abstract in English.

• Kärkkäinen, E-mail: mk@mm.unknown

Dimensions (length, width and thickness) of needles in crowns of young Scots pine (Pinus sylvestris L.) were found to be related linearly to each other. Similarly, the needle area was linearly correlated with the needle biomass. In the lower crown, needle length was linearly correlated with the length of the shoot, but in the upper crown needle length did not vary according to any regular pattern. Needle density was negatively correlated with shoot length. In the lower crown the needle density varied 20–40 cm^-1 and in the upper crown 15– 20 cm^-1. The increasing angle of aging needles seemed to be characteristic for Scots pine shoots.

The PDF includes an abstract in Finnish.

• Ross, E-mail: jr@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Oker-Blom, E-mail: po@mm.unknown
• Ross, E-mail: vr@mm.unknown
• Vilikainen, E-mail: lv@mm.unknown

Six seed collections were made in September–December 1984 in a natural Scots pine (Pinus sylvestris L.) stand in Southern Finland. The seeds were germinated immediately after the cone collection and three photoperiods (0.8 and 24 hours) were used in germination tests.

The seeds collected in September and October possessed relative dormancy, i.e. they did not germinate in darkness and at 10°C. Later in November and December the seeds were capable to germinate in darkness and at low temperature also. The gradual change in germination capacity is attributed to chilling temperatures in natural environments or in cone storage.

The PDF includes a summary in English.

• Nygren, E-mail: mn@mm.unknown

Variation of monoterpene composition of Pinus sylvestris L. was studied in Southern, Central and Northern Finland using data from both natural stands and plus trees. The natural stands were analysed using different techniques and for fewer terpenes than the plus trees.

There were large differences between areas in the proportion of 3-carene in trees from natural stands, as has been discussed by previous authors. The proportion of 3-carene is bimodally distributed and believed to be controlled by a single gene with large effect. For this reason, we stratified our samples into high carene (>10%) and low carene (<10%) groups. Univariate analysis did not reveal any additional differences between natural populations in different zones for components other than 3-carene. In plus trees, several components showed significant differences, but the proportion of 3-carene did not differ between areas. Multivariate discrimination analysis did not distinguish between areas for natural stands. However, for the plus trees discriminant analysis allowed us to discriminate between the zones relatively efficiently. The proportion of correct classification was greater than 64% using the best methods. The central zone was most distinct, and 80% of its trees were correctly classified. Broad generalizations are not possible due to the limitations imposed by our data. Our analysis of phenotypic variation does not support the suggestion that plus trees selected from the north represent a southern type.

The PDF includes an abstract in Finnish.

• Muona, E-mail: om@mm.unknown
• Hiltunen, E-mail: rh@mm.unknown
• Morén, E-mail: em@mm.unknown
• Shaw, E-mail: ds@mm.unknown

The size, nutrient contents and terpene composition of needles of Scots pine (Pinus sylvestris L.) saplings untouched and repeatedly browsed by the moose (Alces alces L.) were compared. Material was collected from a 14-years old and 2.5 m high pine stand in Bromarv, Southern Finland. The average length and fresh and dry weight of the needles were measured, and nutrient content (N, P, K, Ca, Mg, B, Cu) was determined.

The needles of repeatedly browsed pines became long and robust. There was, however, no difference between the dry matter percentage between the needles. The average nitrogen content was higher in the rebrowsed trees. Nitrogen content is, however, not directly correlated with the palatability of pine needles. Even phosphorus and boron content were higher in the damaged trees. No difference was found in Ca, K, Mg and Cu contents of the browsed and control pine saplings.

The PDF includes a summary in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown

Totally 653 battens and planks sawn from butt logsof Scots pine (Pinus sylvestris L.) were chosen from 3 saw mills. The sawn goods were sorted according to normal sorting principles. In order to determine growth rate in the youth, the mean value of the average ring width was measured at the butt end at various distances from the pith.

The average ring width increased as the quality of the sawn goods decreased. The difference between the quality classes in ring width was measured between 2 and 4 cm from the pith. As the size of sawn goods, and, simultaneously, the log size increased, the average ring width increased in a given quality class. Research reinforced previous results, in which slow diameter growth of young Scots pines has been shown to reflect the good quality of sawn goods.

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• Halinen, E-mail: mh@mm.unknown

A test sawing was made of 807 Scots pine (Pinus sylvestris L.) saw logs of varying size and quality. The most important knot characteristic affecting the value of sawn goods was the diameter of the thickest dry knot. The new minimum requirements for pine logs were proposed on the basis of top diameter of the log and the diameter of the thickest dry and living knot.

The PDF includes a summary in English

• Kärkkäinen, E-mail: mk@mm.unknown
• Halinen, E-mail: mh@mm.unknown

The study deals with the interaction of various soil preparation and reforestation methods. The most favourable time of the year for broadcast sowing and the effect of stabilization after soil preparation on restocking were studied as special problems.

Prescribed burning, scalping and disc ploughing made a better combination with sowing than planting, and ploughing better combination with planting than sowing. The longer the period was between sowing and germination the fewer seedlings emerged. The best stocking was clearly resulted with sowing in June. Stabilization of soil after preparation had a negative effect on reforestation results.

The PDF includes a summary in English.

• Pohtila, E-mail: ep@mm.unknown
• Pohjola, E-mail: tp@mm.unknown

This is the latest report in a series of publications from an on-going investigation which is concerned with the influence of different fertilization treatments and ditch spacings on the growth of Scots pine (Pinus sylvestris L.) seedlings and transplants growing on nutrient drained poor bogs in different parts of Finland. This paper concentrates on duration of the growth response to NPK-fertilization on the experimental plots. The experiment was established and the treatments performed in 1965–66.

The results show that climate, expressed as effective temperature sum (dd°C, threshold +5°C) has a clear influence on the duration of the fertilization effect. In Southern Finland (>1,200 dd°C), the duration was at least 15 years. In Central Finland (1,200–1,000 dd°C), it appears to be almost 10 years, and in Northern Finland (<1,000 dd°C), slightly shorter. The amount of fertilizer applied clearly influenced the duration of the fertilization effect. The dosage of 500 kg/ha (N 14, P 7.8, K 8.3 per cent) had, on average, a shorter duration than the greater dosages of 1,000 and 1,500 kg/ha. However, there was no clear difference between the latter two dosages.

The PDF includes a summary in Finnish.

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

Ascocalyx abietina (now Gremmeniella abietina Lagerb.) infects Scots pine (Pinus sylvestris L.) by means of ascospores or conidia. Ascospores are dispersed by the wind, while the conidia are splash dispersed. The infection rate is positively correlated with the number of inocula. The aim of this study was to determine the extent to which G. abietina spreads to the trees surrounding the diseased trees and to find the correct time to perform sanitation cutting.

The results were obtained from Ascocalyx-inventory carried out in a Scots pine progeny test at Loppi, Southern Finland. Three Siberian provenances were totally destroyed, while the Finnish progenies remained relatively healthy. The two rows adjacent to the destroyed plots were inventoried separately.

There were 29.7% more diseased or dead trees in the two adjacent rows than in the rest of the same plots. The difference was statistically significant. The trees had probably been infected by conidia, because the effect of the destroyed plot only extended to the adjacent two rows. Furthermore, pycnidia had mainly developed on the dead shoots.

On the basis of the life cycle of the fungus and the results, the correct time to carry out sanitation cutting is the first winter after the disease symptoms have appeared. If it is done later, the disease could be spread and bark beetles (Tomicus spp.) could propagate in dying trees. Susceptible provenances may spread the disease to surrounding resistant trees owing to the increasing number of spores.

The PDF includes a summary in English.

• Uotila, E-mail: au@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

In the 1980 and 1981, windthrown and felled Scots pine (Pinus sylvestris L.) were examined at 8 localities in Sweden. The number and length of egg galleries as well as the number of exit holes of Tomicus piniperda (L.) and T. minor (Hart.) were recorded on sample sections (30 m in length) distributed at 3 m intervals on the 37 fallen pine stems, which were successfully colonized by the beetles. In addition, 78 uprooted pines were surveyed in 6 localities. Most trees were attacked by T. piniperda, but only a few by T. minor. Successful colonization often resulted in the production of several thousand beetles per tree, the maximum being approximately 1,800. The attack density of T. piniperda seldom exceeded 200 egg galleries/m³ bark area, and the brood production usually remained below 1,000 beetles/m³. Much higher figures were obtained or T. minor. In T. piniperda, the rate of reproduction (i.e. the number of exit holes /egg gallery) decreased rapidly with increasing attack density, whereas T. minor seemed to be less sensitive to intraspecific competition.

The PDF includes a summary in Finnish.

• Långström, E-mail: bl@mm.unknown

The study based on young Scots pine (Pinus sylvestris L.) of varying density showed that number of living branches per whorl and total number of living branches per tree were negatively correlated with stand density. On the contrary, the number of dead branches increased with increasing stand density. The diameter of living and dead branches decreased with increasing stand density. Consequently, the branchiness, i.e. the share of the branch cross-sectional area from the surface area of the stem, decreased in dense stands compared with the thin stands. At the densest stands the branchiness, however, levelled of indicating a greater decrease of the radial growth at stems than at branches. The 2/3 power law described relatively well the relationship between stand density and mean squared branch diameter of living branches.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

Harvest index and number of associated traits were measured in a 16-year-old Scots pine (Pinus sylvestris L.) progeny test based on full-sib families. It was found that harvest index is a highly heritable trait and that a number of yield components are positively correlated with it. It is suggested that harvest index and tree ideotypes should be the basis of selection in cultivated trees. It is emphasized that an integrated approach to tree improvement including silviculture, soil science, industrial and economic constraints and tree breeding is a prerequisite for maximal response.

The PDF includes a summary in Finnish.

• Velling, E-mail: pv@mm.unknown
• Tigerstedt, E-mail: pt@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

The effect of nitrogen fertilization and two insecticides on the occurrence of the plant pine bark bug, Aradus cinnamomeus Panzer, was investigated in a young Scots pine (Pinus sylvestris L.) stand in Southern Finland. Three years after the treatment the bug density was lowest in the trees treated with lindane or dimethoate. However, in spite of the increasing height growth of the trees, they did not grow significantly faster than the control trees. Nitrogen fertilization increased both bug density and the height growth of the trees. Thus, the value of nitrogen fertilization against Aradus cinnamomeus remains obscure.

The PDF includes a summary in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Annila, E-mail: ea@mm.unknown
• Terho, E-mail: et@mm.unknown

An inventory of Scots pine (Pinus sylvestris L.) graft collection in Kolari (67°15’ N, 23°45’ S) showed that severe damage by arctic hare (Lepus timidus L.), root and bank vole (Microtus oeconomus Pallas and M. agrestis L.) and moose (Alces alces L.) was done to grafts in size and in rather poor condition. Furthermore, the damage by arctic hare was dependent on the dry matter content of the needles. Another inventory in a fertilization experiment in a pine pole-stage forest showed that nitrogen fertilization increased the damage by arctic hare. On the basis of the present results, an assumption was made that the formation of repellent substances against herbivorous mammals is connected with wintering process of northern pines.

The PDF includes a summary in Finnish.

• Rousi, E-mail: mr@mm.unknown

The effect of meteorological factors, the total sulphur content of the needles, and SO₂ concentration in the ambient air on total peroxidase activity of Scots pine (Pinus sylvestris L.) needles was investigated in material obtained from Southern Finland. The correlation between temperature and total peroxidase activity was highest during the most active growing period. Linear correlation between relative humidity and total peroxidase activity appears to be low. The correlation between atmospheric SO₂ concentration and total peroxidase activity was also low and varied inconsistently. The detected low association between the sulphur dioxide pollutant and the total peroxidase activity was assumed to be related to the sensitivity of peroxidase activity, many eco-physiological factors and to the genetic variation in conifers. It is difficult to separate a response due to this pollutant from environmental and genetic factors in a complex coniferous forest. Using total peroxidase activity as a routine indicator of air pollution seems to be unsuitable because of the large sample size required in order to obtain a reliable measurement of the pollutant’s effect under low pollution levels.

The PDF includes a summary in Finnish.

• Jokinen, E-mail: jj@mm.unknown
• Häkkinen, E-mail: ah@mm.unknown
• Karjalainen, E-mail: rk@mm.unknown
• Markkanen, E-mail: km@mm.unknown
• Säynätkari, E-mail: ts@mm.unknown

A study based on four young Scots pines (Pinus sylvestris L.) showed that the number of needle-covered shoots per crown volume unit was independent on tree position representing a constant value of 600–700 shoots/m³. This was true, even though the total shoot number decreased with deteriorating tree position. In tree crown there were fourth-order shoots in good light conditions but only first- and second-order-shoots, when light conditions were poor. The length of shoots decreased in accordance with increasing order of the shoot.

The share of the needle biomass and growth increased, when the shoot order increased. Similarly, the share of needles increased with deteriorating tree position. This was especially true in the upper crown. On the other hand, the share of the crown from the total biomass and growth increased with improving tree position. The percentage of crown system of a dominant tree in a sparse stand was 64% of that of biomass and 83% of that of growth. The corresponding values for a suppressed tree in a dense stand were 36% and 35%. The growth of wood, bark and needles in crown systems was linearly correlated with prevailing light conditions around the branch. It is evident that the tree position and light condition within the stand control the wood, bark and needle growth in the crown system and their interrelationships.

The PDF includes a summary in English.

• Viherä, E-mail: av@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The objective of the study was to compare different reforestation methods on ploughed areas in Finnish Lapland. Four species were compared: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), silver birch (Betula pendula Roth) and Siberian larch (Larix sibirica Ledeb.). The experiments were established in different parts of Lapland on different types of sites in 1970–72.

In Scots pine there was a difference of 15 percentage points in survival of seedlings between the best and worst methods of regeneration. Containerized seedlings and paper pot seedlings had the best survival rates. In Norway spruce the respective difference between sowing and planting was about 20 percentage points. In favour of planting. The survival rate can be increased by about 20 percentage points by selecting the right tree species. The average height varied from 25 cm (the sowed Norway spruce) to 179 cm (the planted silver birch) after 10 growing seasons. The birch was planted at the most fertile sites only. The longer time passed from the afforestation the clearer was the effect of the local growing conditions on the development of the seedlings. The elevation of the site was one factor seemed to influence the success of the seedlings.

The PDF includes a summary in English.

• Pohtila, E-mail: ep@mm.unknown
• Pohjola, E-mail: tp@mm.unknown

A dynamic programming approach toward stem value estimation for standing Scots pine (Pinus sylvestris L.) trees was developed. The determination of the saw log value was based on the sawing pattern and on the final products composition. The combination of taper curve models and bark models providing taper curves both over bark and under bark, which constituted the basis of the optimum stem scaling. A computer program was developed to determine the optimum log sequence of the stem aiming at maximizing the value of the final products. To examine the reliability of the computation system, 445 Scots pine sample trees from 29 stands were used as a test material. The stem values of sample trees were calculated in two ways: 1) with 12 measured diameters, and 2) with 12 estimated diameters derived from measured tree characteristics. In both cases the values of the intermediate diameters were calculated via cubic spline interpolation.

The PDF includes a summary in Finnish.

• Luo, E-mail: fl@mm.unknown

Empirical measurements showed that the strength of a dead branch of Scots pine (Pinus sylvestris L.) was related to the second power of the branch diameter and the third power of the basic density of branch wood. The same factors affected also the strength of living branches. Especially, the contribution of wood density was important. The significance of the results is discussed considering the natural process of self-pruning and its effect on the branchiness of the stem.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

The needle area distribution and crown structure of a young planted Scots pine (Pinus sylvestris L.) stand are described. The crown structure and crown shape showed apparent regularity in crown structure regardless of stand dynamics. Similarly, the shoot structure and individual needle area showed regularity in the number of needles per branch and shoot length unit, and consequent phytoarea density inside the needle cylinder. Also, the shoot area and needle area distributions were found to show a regular distribution of needle biomass throughout the crown, also inside the crown, in the dominant trees. In the suppressed trees the needle biomass was located in the upper crown and on the surface area of the crown. Estimates of the canopy needle area and distributions are given. The results were applied in calculations of the within-stand light regime. The results correlated well with the empirical results.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Oker-Blom, E-mail: po@mm.unknown

Application of nitrogen at levels of 200, 400 and 600 kg ha^-1 resulted in increases of 35, 18 and 12% in the photosynthetic rate in young Scots pine (Pinus sylvestris L.). The number of buds, degree of branching, and needle size were positively related to the amount of nitrogen applied. A 10–40% increase in the average needle area was found. A positive correlation was found between total photosynthesis and stem growth.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Puttonen, E-mail: pp@mm.unknown
• Tamminen, E-mail: ht@mm.unknown
• Westman, E-mail: cw@mm.unknown

Relationships between densities of pine bark bug, Aradus cinnamomeus Panzer and the height growth of young Scots pine (Pinus sylvestris L.) were studied in several habitats, including a highly infested area in Southern Finland. The slower the growth of the pines was, the greater was the height up to which bugs were found. On the average, maximum bug density was noted at a height corresponding to a fifth of the height of the tree. In stands restocked by natural generation, the greatest bug densities were noted in pines about three metres high and over twenty years old. Bug densities in trees whose height growth had been decelerating for five years were twice those in trees whose growth was accelerating. A significant negative correlation was found between the bug density and the last-year height increment.

The PDF includes a summary in Finnish.

• Heliövaara, E-mail: kh@mm.unknown

A mature Scots pine (Pinus sylvestris L.) stand growing on a site of the Vaccinium type in Southern Finland was fertilized with nitrogen-rich NPK fertilizer at a level of 150 kg pure nitrogen per hectare. The sample plots were also irrigated during four growing seasons. The total amount of irrigation during this period was 1,200 mm. Fertilization alone increased the coverage of grasses and dwarf shrubs. The culmination of the increase occurred during the second growing season after the start of the treatment. The rapid effect of irrigation on the coverage of ground vegetation was not so strong as that of fertilization. It was concluded on the basis of the developed growth model that the coverage of dwarf shrubs, especially Calluna vulgaris, was, however, increased with the fertilization treatment for a prolonged period. Fertilization and irrigation had no visible effect on the coverage of lichens and mosses.

The PDF includes a summary in Finnish.

• Mälkönen, E-mail: em@mm.unknown
• Aro-Heinilä, E-mail: va@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

A comparison study concerning the effects of acid rain on Scots pine (Pinus sylvestris L.) seedlings has been performed. Two different X-ray fluorescence methods, PIXE and IXRF, were employed to produce multielement analyses of the samples. Seedlings were treated for 3 months with watering of pH=7 or pH=3 liquids on the needles and on the roots. One year and two years old needles of the seedlings were inspected for changes in photosynthetic rate as well as for changes in elemental concentrations.

Twelve elements from Si to Zn were compared in the samples. The PIXE results show that the amounts of most of these elements in the needles of the seedlings grown in sand increase, when treated with acid water. This growth is clearer when the roots are treated with acid water. The elemental concentrations of the needles in the seedlings grown in soil on the other hand decrease slightly.

• Raunemaa, E-mail: tr@mm.unknown
• Erkinjuntti, E-mail: re@mm.unknown
• Gerlander, E-mail: mg@mm.unknown
• Hautojärvi, E-mail: ah@mm.unknown
• Kaisla, E-mail: kk@mm.unknown
• Katainen, E-mail: hk@mm.unknown

A method to determine sulphur as sulphate has been applied to search for surface concentration of sulphate sulphur on needle samples. The method is based on reducing sulphates as volatile hydrogen sulphide gas by using hydriodic acid. The hydrogen sulphide gas is swept with nitrogen into an absorbent solution. Sulphide ion concentration in solution is then measured using ion selective electrodes.

The method was applied on one to four years old needle samples collected from Scots pine (Pinus sylvestris L.) at 0.9 to 15.9 km distances from a 1,064 MW coal-fired power plant in Southern Finland. Surface sulphate values found in the samples closer than 4 km to the power plant were 50 to 100% higher than a nearly constant background level. No significant variation of values with needle age was found. The advantages of the method compares to other methods for sulphur determination are speed, reasonable sensitivity and low detection limit.

• Hautojärvi, E-mail: ah@mm.unknown
• Ahonen, E-mail: sa@mm.unknown
• Erkinjuntti, E-mail: re@mm.unknown
• Katainen, E-mail: hk@mm.unknown
• Lappalainen, E-mail: tl@mm.unknown
• Raunemaa, E-mail: tr@mm.unknown

Scanning Electron Microscopy was used to study structural changes in epicuticular vax of Pinus sylvestris L. with time. Changes in the contact angle of water droplets and in cuticular transpiration were also measured. By using material from a polluted and an unpolluted site it was shown that the ageing process occurs faster on polluted air, leading to greater cuticular transpiration and smaller contact angles at polluted sites.

• Cape, E-mail: jc@mm.unknown
• Fowler, E-mail: df@mm.unknown

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

Our preliminary findings indicate that the content of total sulphur and soluble fluorides in needles of the Scots pine (Pinus sylvestris L.) reflects the degree of air pollution with sulphur and fluorine compounds. A project for a map of air pollution in Poland, based on chemical analysis of Scots pine needles, is presented. Results of the total sulphur and soluble fluoride content in 2-year old needles from 15- to 25-year-old trees should yield a picture of air pollution with sulphur and fluorine compounds. The first stage will involve the preparation of a map of the area between the Warsaw and Plock agglomerations. This area will be divided into 10 squares with side dimension of 25 km each. Samples will be taken at 5 different sites in each square and also approximately every 5 km along a straight line between these towns.

• Molski, E-mail: bm@mm.unknown
• Bytnerowicz, E-mail: ab@mm.unknown
• Dmuchowski, E-mail: wd@mm.unknown

Air pollution injury to vegetation often occurs near a fertilizer factory in Central Sweden. The causing incidence often occurs in the winter and the symptoms appear when metabolism starts in the spring. Deciduous and coniferous trees and bushes were injured in the spring of 1979. Samples of Scots pine (Pinus sylvestris L.) needles were analysed for sulphur, total fluorine and nitrogen content, some of them for nitrate and ammonium. All the compounds showed elevated levels, clearly connected with the degree of exposure of the sampling site. The levels were higher in the spring than later in the growing season, indicating involvement in metabolism or leaching. None of the compounds was significantly in excess, although, elevated to an extent to indicate the cause of injury. Most probably the nitrogen compounds were involved. The problems encountered in tracing the causing pollutant, when injury appeared long after the incidence, might be easier solved with regularly used technical monitoring and bioindicator technique.

• Kvist, E-mail: kk@mm.unknown
• Jakobsson, E-mail: cj@mm.unknown

Ultrastructure of mesophyll of second-year green needles of Picea abies (L.) H. Karst. and Pinus sylvestris (L.) has been studied in several polluted areas in Finland since 1976 (Soikkeli and Tuovinen 1979, Soikkeli 1981a). Four different types of injuries have been found. The types differ with the origin of the material:

1) In needles collected from areas pollute by S-communds the types with reduced grana and/or the with lightening of plastogobuli with simultaneous accumulation of lipid-like material are observed.

2) In needles expose to fluorides (alone or in addition to other pollutants) the type with swollen and/or that with curled thylakoids are found. Both of the latter have also stretched envelopes. In each type of the injury three stages of cell disruption have been described: slight-medium, severe and very severe. On the slight-medium stage the injuries are usually found only in chloroplasts. On severe stage other organelles show injuries, too. In very severe injury all cell organelles are badly disorganized or they disappear completely. The most abundant injuries are usually in needles collected after their second winter. The severity of cell injury depends on the closeness of emission source or on the measured concentration of SO₂.

• Soikkeli, E-mail: ss@mm.unknown

Information on input of acidifying compounds like SO₂ and NO_x is necessary to understand effects of acidification. The uptake on NO and NO2 respectively was studied on seedlings and shoots of Scots pine (Pinus sylvestris L.). Experiments were conducted both in laboratory (NO and NO₂ respectively) and in the field (NO₂) under light and dark conditions. In all three cases there was a linear relationship between the uptake rate and the NO_x-concentration. The uptake follows a diurnal pattern i.e. the uptake rate was strongly correlated with the stomatal movements. Uptake rates were converted to deposition rate and the results showed that field exposure with NO₂ gave the higher deposition rate.

• Skärby, E-mail: ls@mm.unknown
• Bengtson, E-mail: cb@mm.unknown
• Boström, E-mail: cb@mm.unknown
• Grennfelt, E-mail: pg@mm.unknown
• Troeng, E-mail: et@mm.unknown

The development of the stomatal area wax structure of Scots pine (Pinus sylvestris L.) needles was studied in flushing needles with a scanning electron microscope. The needles were obtained from eleven Finnish plus tree progenies. The needles were taken from trees that were either nearly uninfected or heavily infected by Lophodermella sulcigena (Rostr.) Höhn.

No difference in the early developmental stages of stomatal vax structure were observed between the southern Finnish, central Finnish and northern Finnish progenies. The general structure differed in the stomatal cavity chamber size. The stomatal openings were larger in heavily infected trees than in healthy trees. This might have an influence on the mechanical penetration of the fungal hyphae.

The PDF includes a summary in Finnish.

• Jalkanen, E-mail: rj@mm.unknown
• Huttunen, E-mail: sh@mm.unknown
• Väisänen, E-mail: tv@mm.unknown

Ethanolic sprays of GA₄ or GA₇ on 9-year old Scots pine (Pinus sylvestris L.) grafts, repeated four times during the shoot elongation period, resulted in a statistically significant increase in female flowering one year after the treatment. Of the two compounds, GA₄ seemed to be somewhat more efficient, yielding 47 female strobili/100 shoots vs. 36 and 6 strobili/100 shoots in GA₇ and control treatments respectively. The mixture of GA₄ and GA₇ compounds was also applied and seemed to have an effect intermediary to those of the pure compounds. However, due to the limited amounts of material, none of the differences between the gibberellins could be statistically confirmed. Male flowering frequencies were also too low to allow any firm conclusions, but the numerical results suggested that the purified gibberellins may promote male and female flowering in different ways.

The PDF includes a summary in Finnish.

• Luukkanen, E-mail: ol@mm.unknown

The objective of the investigation was to determine the differences between timber grown on a peatland before and after draining, in respect of compressive strength parallel to the grain, static bending strength and density. In addition, the characteristics of boundary zone between the wood formed before, and after the draining with wider growth rings was studied. 41 Scots pine (Pinus sylvestris L.) and 22 Norway spruce (Picea abies (L.) H. Karst.) trees were studied.

The compressive strength of pine usually decreased from the butt end upwards, but no trend was observed in spruce wood. In coniferous trees, wide-ringed wood formed subsequent to draining was slightly lighter than the close-ringed wood produced prior the draining. The density of pine as well as spruce increases as the width of the growth rings decrease up to a certain limit. The strength of the different kinds of wood seems to decrease from the butt end upwards.

In both species, the compressive strength parallel to the grain and the bending strength are lowest in such wood that contains exclusively wide-ringed wood formed subsequent to draining. Also, compressive and bending strength increase with decreasing width of the growth rings. The longitudinal shrinkage of compression wood in spruce was several times that of normal wood, and the bending strength was lower than that of normal wood particularly in spruce. The compressive strength parallel to the grain in dry condition was, however, higher than in normal wood both in pine and spruce.

The PDF includes a summary in English.

• Ollinmaa, E-mail: po@mm.unknown

Needle damages, transpiration, photosynthesis and needle and stem height growth of Scots pine (Pinus sylvestris L.) seedlings treated with dilute sulphuric acid were studied. The acidity of the solution was pH 3. Application of a dilute solution of sulphuric acid equivalent to the normal amount of precipitation occurring during the growing season damaged the surface of two-year-old needles but not that of the current-year needles. A reduction in the photosynthetic rate of 10–30% was observed compared with the untreated seedlings. Transpiration of the seedlings was not affected by the treatment. Needle growth and stem height growth of the seedlings growing on a substrate representing poor sandy soil were reduced. Increased needle growth and stem height growth were characteristic for the seedlings growing on substrate representing fertile moraine.

The PDF includes a summary in English.

• Katainen, E-mail: hk@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The effect of soil compaction on transpiration and height increment of Scots pine (Pinus sylvestris L.) seedlings following planting out were investigated in a small-scale pot experiment. Compacted and loosely-packed fine sand and fine-sand moraine were used as the planting substrates. The compacted soils used corresponded to the normal type of soil to be found in tilled forest soils in Finland. The effect of soil compaction on seedling transpiration during water stress was also studied in a separate experiment.

Seedlings planted in compact soil had a higher rate of transpiration than those in loosely-packed soil. The recovery in transpiration, which started halfway through the growing season, was faster, however, in the seedlings planted in loosely-packed soil. Under conditions of water stress, the seedlings planted in compact fine-sand moraine started to reduce the transpiration rate at higher soil moisture values than those planted in loosely-packed soil. No corresponding difference was observed for fine sand. Compaction was not found to affect the overall height growth, but it did at certain time during the growing season.

The PDF includes a summary in English.

• Smolander, E-mail: hs@mm.unknown
• Kostamo, E-mail: jk@mm.unknown
• Räsänen, E-mail: pr@mm.unknown

The specific needle area of young Scots pine (Pinus sylvestris L.) showed a substantial within-tree and between-tree variation which was associated with the position of the tree and the position of the whorl as indicated by the prevailing crown and branch illumination. In suppressed trees the values of the specific needle area were three to four times those in dominating trees. A similar morphogenesis was discernible in comparison of the lower and the upper part of the crown. The mean specific needle area value for the whole stand was 184 cm²/g.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Oker-Blom, E-mail: po@mm.unknown

The share of stem, branch and needle growth was dependent on the within-stand light regime in a young Scots pine (Pinus sylvestris L.) stand. The share of needle growth increased at the expense of stem and branch growth in poor light conditions. In good light condition the share of branch wood increased substantially. The share of stem wood growth was greatest in moderate shading, emphasizing the role of an adequate stand density for growing high-quality timber. The basic density of the stem wood was considerably greater in suppressed trees than in dominating trees. The differences were related to the illumination of the crown system.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown

The amount of volatile oil and monoterpene composition in Scots pine (Pinus sylvestris L.) needles were studied in trees growing near two factories and in the city of Kuopio, Central Finland. Trees in these locations are exposed principally to sulphur dioxide and fluoride emissions.

The amount of volatile oil increased with increasing injury class in the trees growing near the fertilizer factory. The amounts of volatile oil in trees near the pulp mill differed in the various injury classes. More oil was found in younger needles. The greatest differences in monoterpene composition were in the amounts of camphene, α-pinene, myrcene and tricyclene.

The PDF includes a summary in Finnish.

• Lehtiö, E-mail: hl@mm.unknown

Crown and stem growth of young Scots pines (Pinus sylvestris L.) were studied in relation to photosynthate supply and light condition in a stand. The magnitude of needle and bud formation, and radial and height growth were to a great extent dependent on the photosynthate supply. However, in shaded conditions the growth of each characteristics was greater than expected on the basis of photosynthate supply. In the stem system this was especially apparent for height growth. Consequently, height growth was favoured at the expense of radial growth in shaded conditions. It also appeared that the basic density of wood was negatively related to both tree position and photosynthate supply.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Kanninen, E-mail: mk@mm.unknown

On the basis of a limited material, the drying of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) timber at room temperature decreased the thickness of the bark proportionally to the decrease in the moisture content. The decrease was the greatest in the middle portion of the trunk. In the spruce material, the decrease in bark thickness was exceeded by the shrinkage of the wood. During soaking, the bark thickness of both tree species decreased, too, contrary to the presupposed hypothesis. In both cases, the shrinkage was the greatest in the middle portion of the trunk. In the spruce material, the decrease in bark thickness was exceeded by the shrinkage of the wood. Possible explanation for the phenomenon is discussed.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

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

The PDF includes a summary in English.

• Meriluoto, E-mail: jm@mm.unknown

Dependence of the growth increase given by fertilization on different stand characteristics is examined in this article. The aim was to determine whether the volume growth increase can be accurately determined beforehand when fertilization is carried out on mineral soil sites at a dosage of 120 kg N/ha. The material consisted mostly on of mature stands ready for cutting, a total of 22 Scots pine (Pinus sylvestris L.) and 20 Norway spruce (Picea abies (L.) H. Karst.) stands. Increase in basal area, height quality class and basal area of the stand were found to best explain the increment and its increase in the regression equations calculated for different types of fertilizer and the control level.

The PDF includes a summary in English.

• Jokinen, E-mail: rj@mm.unknown

The proportions of needle and wood in current-year shoots in crown systems of young Scots pine (Pinus sylvestris L.) trees was studied. The proportion of needles out of the total shoot biomass increased according to the increasing number of the whorl counted from the apex. In the lower part of the crown system the needle biomass of newly-formed shoots was 50–60 fold compared to that of wood and bark biomass. In the upper part of the crown system the same ratio was 1–2. The variation in ratio between needle and wood biomass was whorl-specific and independent of tree class. The magnitude of the ratio was not related to the position of the tree in the stand nor to the prevailing light conditions within the state.

The PDF includes a summary in Finnish.

• Mäkelä, E-mail: am@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The technique of double normalizing, i.e. normalizing the relative needle biomass and the length of the living crown system, is applied to the modelling of the distribution of needle biomass in the canopy of young Scots pine (Pinus sylvestris L.) stands. The study based on the parameters of β-function shows that at the individual-tree level, the variance in needle distribution was not closely associated with any tree characteristics. A shift in the point of maximum needle biomass upwards unsuppressed trees was, however, evident. This was associated with an increase in the height of the trees. At the stand level, the stand mean height and stand density had an equal and a rather high potential for explaining the variance in the needle distribution. The normalized crowns are utilized in models for determining light extinction in the crown. A special technique for determining the amount of photosynthates available for growth in a particular tree is presented.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Ilonen, E-mail: pi@mm.unknown
• Kanninen, E-mail: mk@mm.unknown

The concept of tree class as indicated by dominant, codominant, intermediate and suppressed trees is analysed using empirical material representing 13 younger Scots pine (Pinus sylvestris L.) stands. The relative needle biomass, i.e. the needle biomass related to the maximum needle biomass in the stand, was closely related to the relative height of the tree and independent of the stand characteristics. Furthermore, the relative illumination of the crown system was related to the relative height of the trees as well as the relative photosynthetic capacity and tree-to-tree variation in growth. When calculated per needle biomass unit it appeared that height growth, radial growth, needle growth and other growth parameters were the highest in the suppressed trees. The suppressed trees thus appear to be more efficient in utilizing available resources than other tree classes. The ecologic significance of the results is discussed.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Hari, E-mail: ph@mm.unknown

In order to be recorded in the national list of untested seed orchards, set by law, a seed orchard must attain certain objectives. It is impossible to define universal requirements for all categories of seed orchards of all species. The present paper suggests minimum requirements for a clonal region seed orchards of Pinus sylvestris L in Finland. The clonal composition as well as factors influencing on the mating pattern have been given precise numerical threshold values. To be approved the seed orchard must fulfil all the requirements at the same time. The goal is to control the genetic superiority of the forest reproductive material obtained from registered untested seed orchards.

The PDF includes a summary in English.

• Koski, E-mail: vk@mm.unknown

Soft X-ray radiation (Grenz rays) has been used in the X-ray radiography of seeds. It is based on the principle that the different parts of the seed absorb X-rays to a slightly varying extent. Empty seeds and empty regions in the seeds appears as dark areas on the film. X-ray radiography without staining and X-ray contrast radiography were compared to study the stored seeds of Scots pine (Pinus sylvestris L.). The results were compared with the results of germination in a Jacobsen germinator according to ISTA norms.

Normal X-ray radiography gave too good estimates of germinative capacity of the seeds, and was shown to suit only when it is used to study fully ripe seeds which have recently been collected in an undamaged condition. The results of X-ray contrast radiography when barium chloride was used as the stain, however, followed closely the germination results.

The PDF includes a summary in Finnish.

• Ryynänen, E-mail: mr@mm.unknown

The aim of the present study was to establish whether hormone treatments would promote flowering in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) grafts under Finnish conditions. Also, an attempt was made to test the efficiency of hormones as well as the variation in response among different clones. Six Scots pine and six Norway spruce clones were selected in each seed orchard based on their flowering intensity, and treated with growth hormones (GA, NAA) of different dosages by spraying. Flowering was observed one year after the treatments.

None of the treated or untreated spruce grafts flowered. However, poor flowering in the natural stands indicated that the environmental conditions during the previous years did not favour flowering. On the other hand, a distinct increase in flowering in Scots pine was observed as a result of spraying with hormone solutions. Treatments with gibberellin had a distinct promoting effect both on male and female flowering in the Scots pine grafts, although the responses varied between the different hormones or clones. The relative effect was generally stronger in male flowering.

The PDF includes a summary in Finnish.

• Luukkanen, E-mail: ol@mm.unknown
• Johansson, E-mail: sj@mm.unknown

In this paper the connection between seed weight and amount and duration of growth are studied at the progeny level within stands or climatically uniform areas, and at the provenance level within larger geographic areas. The material consists of materials of several experiments in the nursery of Maisala in Southern Finland in 1971–76. The origins of the plant material used in the different experiments ranged from progenies of individual Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) H. Karst.) trees to provenance selections covering almost the whole natural range of these species.

The effect of seed weight on plant height is strongest immediately after germination and subsequently decreases steadily, when the genetic growth properties of the plants themselves become effective. The effect is usually visible at least until the end of the 1st growing season. This relationship varies considerably depending on the material studied. The connections between the duration and the amount of height growth also proved to differ according to the nature of genetic variation. In wide selection of provenances, which show clear genetic differentiation in annual growth rhythm. The variation in the duration of growth accounts for most of the differences in total height growth. At the individual and family level or between provenances of a limited area, there seems to be no clear connection between the duration and the amount of growth. It seems that the duration of the annual growing period is a genetic property, which is not affected by seed weight.

The total height alone in 1-year old test material grown in a greenhouse had hardly any value in the forecasting of growth capacity. The growth differences were caused mainly by the variation in seed size and growth rate differences during the growing period.

The PDF includes a summary in Finnish.

• Mikola, E-mail: jm@mm.unknown

The paper discusses the variation of flowering and seed crop of Scots pine (Pinus sylvestris L.) stands based on literature published in Finland. According to the studies, the list of good seed years given by different authors do not completely match, and no essentially new about the periodicity of the seed crop or the causes of variation has been found. The difficulty in classification of the seed crops in different years in different stands and locations can be handled through the concept of capacity. It is suggested in the paper that to be able to compare the occurrence of good flowering and seed years of different stands and localities, a case exceeding 50% of the capacity is described as abundant, and a case exceeding 75% as very heavy.

The PDF includes a summary in Finnish.

• Koski, E-mail: vk@mm.unknown

Establishment of seed orchards to produce genetically improved seed started in the USSR in the 1960’s. The aim is that within 10–15 years the total seed production will reach 50% of the seed used. The paper describes seed production in seed orchards of Scots pine (Pinus sylvestris L.) in the forest-steppe of the European part of the USSR. The orchards have been established either by grafting or by planting of seedlings originating from plus trees. The grafts begin flowering relatively early, however, only at the age of 8–10 years seed crops become relatively regular and abundant. The cone yield in young seed orchards have great variability, and the yield of cones varies between clones. Cone yield does not always correlate with a good seed yield. One of the reasons for high amount of empty seeds is the difference in the periods of flowering between the clones.

The seed crops can be improved by establishing optimal conditions for the growth of the trees. Also, when a seed orchard is founded, the peculiarities of the generative activities of the clones and their reactions to changes in the environmental conditions must be taken account by taking an individual and selective measure approach to improvement measures. The orchards can be established with clones for their genetic combining ability and their requirements for the stimulation of seed-bearing.

The PDF includes a summary in Finnish.

• Efimov, E-mail: je@mm.unknown

Planting of forest trees takes place in USSR on millions of hectares but without permanent forest seed bases having yet been established in every region of the country. Consequently, local seed does not suffice the need, and it is necessary to secure it from other geographical regions. To avoid negative consequences of seed transfer it is necessary to study geographic variation of the genetic characteristics of forest trees and construct scientifically based division into seed zones. Geographic transfer of seed can also be regarded as a breeding measure. A large research program is being carried out in the USSR on the subject. Most of the existing trials are provenience tests of Scots pine (Pinus sylvestris L.). Over 2,000 hectares of new provenience experiments is to be established in near future.

The PDF includes a summary in Finnish.

• Prokazin, E-mail: ep@mm.unknown

The study concerned with variations in the density of the wood of different provenances in provenance test series of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) RH. Karst.), established in 1931. Increment cores were collected from 10 sample trees from each sample block. The density of the pine wood was noticeably higher than that of spruce. The basic density was in average 450 kg/m³ for Scots pine, and the variation between different origins was 3–9%, while the average basic density of spruce was under 400 kg/m³ and the variation 3–10%. Statistically significant differences were found between the mean basic densities of different provenances in all sub-experiments for spruce, but only in one pine sub-experiment. However, these differences were not due to the altitude or latitude of the place of the origin. Volume growth seems to be the dominant component in the formation of dry matter yield.

The PDF includes a summary in Finnish.

• Velling, E-mail: pv@mm.unknown

Radial growth of Scots pine (Pinus sylvestris L.) was investigated in seven camping areas located in Southern Finland. Radial growth reduction of 20–40% were found. The magnitude of this reduction was related to the amount of damage in the trees, and the age of the trees. A loss of humus, exposure of the roots and soil compaction were associated with the use of area but not related to the reduction in growth.

The PDF includes a summary in Finnish.

• Nylund, E-mail: ln@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Nylund, E-mail: mn@mm.unknown

Branching and terminal growth of lateral shoots and needle growth of Scots pine (Pinus sylvestris L.) is investigated as a function of the whorl’s position and age and prevailing light climate. Number of buds per whorl was linearly and positively related to the whorl’s position and prevailing light climate. The growing whorl’s number counting from the apex was associated with declining bud number. The terminal growth of lateral shoots increased exponentially within the values 0.6–1.0 of the whorls position. Under these values the terminal growth was negligible. The growing whorl’s number indicated curvlinear decrease in shoot growth respectively, and only negligible growth occurred when the whorl’s age exceeded 10 years. The shoot growth was linearly related to the prevailing light climate but differences between dominating and dominated trees were apparent. The distribution of needle growth in the crown system was similar to that of shoot growth.

The PDF includes a summary in Finnish.

• Ilonen, E-mail: pi@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kanninen, E-mail: mk@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The effect of solar radiation and air temperature on the basic density of Scots pine (Pinus sylvestris L.) wood has been investigated on the basis of material obtained from the literature. Solar radiation seemed to affect basic density during earlywood formation. Temperature had the greatest effect on basic density  in late summer. The varying effects of radiation and temperature seemed to be associated with the dynamics of the crown system of trees. Especially the capacity of the crown system to produce the amount of photosynthesis needed in tracheid growth is assumed to be of importance in controlling the variation in the basic density of Scots pine wood. Growth of thracheids from the point of view of photosynthate supply is discussed.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown

In this study the loose volume of 58 piles of pulpwood were measured before and after barking by rotary ring barker. The volume was 2,121 m³. A recommendation is made, based on the results of the study, concerning the barking loss from piled wood: for green Scots pine (Pinus sylvestris L.) pulpwood, 8.8% of the stacked volume; for seasoned pine pulpwood, 6.1% of the stacked volume; and 8.0% for birch (Betula sp.) pulpwood, green and seasoned. The amount of bark left on bolts was small for pine bolts, namely 0.33%, but quite large for birch bolts, 2.84% of the green weight.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The radial growth of Scots pine (Pinus sylvestris L.) stands at the age 30–40 years was measured retrospectively five years after the fertilizing and thinning of the stands. The abrupt effect of fertilizing was culminated 3–4 years after the treatment. The effect of thinning increased throughout the monitoring period. In stands that had been both thinned and fertilized, the effect of thinning was covered almost entirely by the effect of fertilizing, but fertilizing and thinning gave greater response than applying fertilizer or thinning only. 

The PDF includes a summary in Finnish.

• Haapanen, E-mail: th@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@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

The development of Scots pine (Pinus sylvestris L.) seedlings and damage caused by Hylobius abietis L. (Coleoptera, Curculionidae) were studied during a three-year period. Olfactory responses of H. abietis was studied in laboratory with several volatile oils isolated from different kinds of P. sylvestris seedlings. Resistance of seedlings against H. Abietis was evaluated in terms of their monoterpene composition. Three aspects of resistance (preference, antibiosis and tolerance) were evaluated separately. Seedling chemotype was found to be associated with these aspects of host resistance on only minor scale. Discussion was attached to a further search for host resistance arising from other properties and constituents of oleoresin. Height growth of the seedlings recovering from weevil damage was 86–91% compared to healthy seedlings.

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• Selander, E-mail: js@mm.unknown
• Kalo, E-mail: pk@mm.unknown

A system for measuring the net photosynthesis, transpiration and environmental factors within the canopy and ground cover vegetation is described. The system operates continuously throughout the growing season in a young Scots pine (Pinus sylvestris L.) stand. A data-logging unit controls the system and carries out the measurements on the readings of the sensors of photosynthesis, transpiration, light intensity outside the canopy, light climate inside the assimilation chambers, and dry and wet temperatures from selected points. These measurements are shown digitally and automatically punched onto paper tape.

The PDF includes a summary in Finnish.

• Hari, E-mail: ph@mm.unknown
• Kanninen, E-mail: mk@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Luukkanen, E-mail: ol@mm.unknown
• Pelkonen, E-mail: pp@mm.unknown
• Salminen, E-mail: rs@mm.unknown
• Smolander, E-mail: hs@mm.unknown

The material was obtained from Scots pine (Pinus sylvestris L.) stems which were pruned 27 years earlier up to the height of 5–6 m. Rotary cutting was made from 16 pruned stems and 3 unpruned ones. The length of bolts was 70 cm and the thickness of veneer 1.5 mm. The proportion of good quality veneer was 46% in pruned stems and 14% in the others. Veneer with exellent quality was obtained from pruned stems up to the height of tree meters, that is to say a little under the pruning line.
The PDF includes a summary in English.

• Laakso, E-mail: pl@mm.unknown
• Saikku, E-mail: os@mm.unknown

The effect of temperature and water supply in the basic density of Scots pine (Pinus sylvestris L.) wood was studied on the basis of material obtained from the literature. On a monthly basis, the basic density increased with increasing mean temperature for June, July and August. The rainfall in these months had no detectable effect on the basic density except through the difference between rainfall and evaporation in July. On a yearly basis, the basic density increased with increasing mean temperature, temperature sum and length of growth period. The effect of water supply on the basic density was evident, and a linear relationship between basic density and annual rainfall was detected. The variation in basic density was, however, explained only partly by the chosen factors. Possible reasons for the poor explanatory power have been discussed.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown

The study is the first report of a larger project concerning fire ecology in the Finnish boreal forests. Modern forestry has never been practiced in the Ulvinsalo strict nature reserve (2,500 ha) in Northern Finland in the county of Kuhmo. Forest fires have been uncommon because of mosaic of mineral and peat soils. The forests are mostly Norway spruce (Picea abies (L.) H. Karst.) dominated with Scots pine (Pinus sylvestris L.) often as the oldest trees of a stand. Forest fires were dated by counting annual rings from cambium to the fire scar in pines. 73 stands covering 1,207 ha were surveyed, over 80% of which was on mineral soil.

50% of the area had burned at least once during the life time of the present pine trees. 48 different forest fires were found, the first being from the year 1712 and the latest from 1969. The average time elapsed between the fires was about 82±43 years, and range 18–219 years. It was assumed that the stands where no fire scars were found, had, however, regenerated after fires but no fires have occurred since after that. In latter part of the 19th century 21 forest fires were dated, in the other half centuries only 4–9. This may have been caused by the increased human activity in the late 1800’s. The fire rotation of the area is 280 years, and spruce is almost the only tree species, which can regenerate in the present situation.

The PDF includes a summary in English.

• Haapanen, E-mail: ah@mm.unknown
• Siitonen, E-mail: ps@mm.unknown

A simultaneous equation model to determine taper curve for Scots pine is presented. The diameters at relative heights are endogenous variables and height an exogenous variable. Any equations may be substituted by the measured value of diameter. Solution of the system of equations yields 11 diameters at relative heights. Intermediate values are obtained by interpolation. Interpolation allows the use of diameters measured at absolute heights, too.

The PDF includes a summary in Finnish.

• Kilkki, E-mail: pk@mm.unknown
• Saramäki, E-mail: ms@mm.unknown
• Varmola, E-mail: mv@mm.unknown

Monoterpene hydrocarbon contents of needles in Scots pine (Pinus sylvestris L.) plants both damaged and untouched by the moose (Alces alces L.) were compared in the study. The material was collected in an 8-year-old plantation in Central Finland. Needle samples were taken from the topmost shoot whorl of the plants in the middle of April, 1976. Only minor differences were found between the plant groups. Thus, terpenes in pine presumably play no important role in the browsing preference by moose.

The PDF includes a summary in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown
• Hiltunen, E-mail: rh@mm.unknown

The distribution of the dry matter and nutrients in Scots pine (Pinus sylvestris L.) tree stock growing on a Vaccinium type site, ground vegetation, and humus were determined in the study. The greatest part of the dry matter in the tree was found in the stemwood. The living branches, roots, bark, needles and dead branches decreasing order of magnitude made up the rest of the biomass. The trees contained over 90%, the field layer vegetation 3% and the bottom layer vegetation 2% of the dry matter in the tree stand. The tree stock contained 86–95% of the total amount nutrients in the stand. The field layer vegetation contained less nutrients than the bottom layer vegetation. Nitrogen, however, was an exception, the amount being approximately the same in both vegetation layers. 

The PDF includes a summary in English.

• Lehtonen, E-mail: il@mm.unknown

The success of certain Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) provenances from Northern Finland was studied in a tree damage area occasioned by air pollution in the town of Oulu over the period of 1972-76. The pine strains from more northerly and easterly areas and the spruce strains from the immediate vicinity of the site itself were being observed to thrive best. The results point in a similar direction to those of other comparable experiments, except that the mortality rate amongst the saplings was exceptionally high and the proportion of healthy saplings in good condition was found to be unusually low. Structural properties suggestive of resistance to pollution were observable selectively in certain provenances, these including the xeromorphy of needles or thickness of the epidermis. The chief cause of mortality amongst the saplings was found to be the damage inflicted by pollution during the winter, while that arising in the summer months was relatively slight.

The PDF includes a summary in Finnish.

• Huttunen, E-mail: sh@mm.unknown

The study is part of a project designed to elucidate the nutrient budget of a Scots pine (Pinus sylvestris L.) stand. Results of variation in the nutrient contents were compared with those obtained for the previous growing season.

The potassium and calcium contents varied the greatest in the humus layer. However, in the bottom and field layer vegetation and needles the variation in the nitrogen content was the greatest. The nutrient contents of the needles were affected by the physiological stage of development, needle age and the position in the crown of the tree. The nutrient content of the rainfall increased in the order: free rainfall, throughfall, and stem flow.

The PDF includes a summary in Finnish.

• Lehtonen, E-mail: il@mm.unknown

A method is presented in this study for calculating the basic density of whole tree- and logging residue chips and the results of trial measurements on some commonly used chip sorts. The basic density of Scots pine whole tree chips was found to be 1–18 kg/m³ smaller than that of pine pulpwood of the same age. The basic density of Norway spruce whole tree chips was 4–22 kg/m³ greater than that of similar aged pulpwood. The basic density of birch whole tree chips was 4–16 kg/m³ and grey alder whole tree chips 7–24 kg/m³ greater than pulpwood of the same age. The basic density of conifer logging residue chips was considerably greater than that of pine and spruce whole tree ships.

The PDF includes a summary in English.

• Mäkelä, E-mail: mm@mm.unknown

This study, comprising three experiments, aims to determine the effect of the geographical origin of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seeds, and the duration of the time lag between the moisture treatment and subsequent irradiation on the gamma-irradiation sensitivity of seeds.

The studies showed that the greater the irradiation dose seeds were subjected to the slower the rate of germination. In general, small radiation doses (250–1,000 rad) had a stimulating effect and the final germination percentage (36–40 days) increased. However, when the level was further increased, the germination percentage decreased. Air-dry and moistened seeds withstood irradiation better than others. In a study with moistened seeds from different geographical sources, pine and spruce seeds from Northern Finland were less able to withstand irradiation than those originating from the south.

The PDF includes a summary in English.

• Lehtiniemi, E-mail: tl@mm.unknown