Current issue: 58(5)
Articles containing the keyword 'needles'
Category : Article
Seasonal fluctuations in free polyamines, spermidine, spermine, putrescine and potassium concentrations were studied for two years (1992–1993) in three needle years of Scots pine (Pinus sylvestris L.) grown on a drained mire in western Finland. Seven different fertilizer treatments involving five different sources of potassium were used.
Putrescine concentrations were high in winter and in May but low in summer. High peaks in putrescine in March and May could be found in unrefertilized or rock phosphate treatments. Spermidine and spermine concentrations were high in March and May. In December spermine concentrations were low. Biotite increased the needle potassium concentrations less than the other potassium fertilizers but the putrescine concentrations or the putrescine/spermidine ratio to about the same level. This suggests that biotite, although very slowly soluble, can reasonably satisfy potassium nutrition of young pine trees.
The potassium concentrations of needles in all the fertilization treatments were higher in winter than in summer. The response of putrescine to the potassium concentration was strongly negative in all the needle years and sampling times. In March, May and December the response of putrescine to potassium was fairly similar in both years but not in June and August. The results suggest that the potassium concentrations during the growing season cannot be used for estimating the potassium nutrition of trees, because the variation between the years may be substantial, whereas the needle putrescine concentration or putrescine/spermidine ratio indicates the suboptimum potassium status of Scots pine fairly well. Needle putrescine concentrations over 500 nmol g-1FW quite regularly coincided with a unsatisfactory potassium nutrition and concentrations over 1,000 nmol g-1FW were a reliable indication of potassium deficiency. Putrescine/spermidine ratios below 5 indicated a satisfactory potassium nutrition in all needle years throughout the year.
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Sarjala,
E-mail:
ts@mm.unknown
- Kaunisto, E-mail: sk@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.
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Finér,
E-mail:
lf@mm.unknown
Spatial and age-related variation in nutrient concentrations of Scots pine (Pinus sylvestris L.) needles was studied during 1984–86 in three stands of different stages of development. The dry weight of current needles was significantly (p < 0.05) higher in the tree top than in a composite sample representing the whole crown. However, there were no significant differences in the concentrations of nutrients in needles between upper and lower crown levels. The concentrations of mobile nutrients N, P, K and Mg decreased with increasing needle age whereas the concentrations of poorly mobile nutrients Ca, Mn and Fe increased during needle ageing. The coefficient of variation for nutrient concentrations varied irregularly when only a few trees were sampled but stabilized when tree number was ten or more.
The PDF includes an abstract in Finnish.
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Helmisaari,
E-mail:
hh@mm.unknown
The results of an intercalibration of sulphur analysis by 24 laboratories are evaluated. The analysis was made by one or more of six methods. The following three methods were found to be satisfactory as regards relative speed and reliability: Leco S analysis, X-ray fluorescence, and vacuum ICO emission spectroscopy.
The PDF includes an abstract in English.
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Jarva,
E-mail:
mj@mm.unknown
- Tervahauta, E-mail: at@mm.unknown
Quantitative variation in the elemental composition of living Scots pine needles was studied along an atmospheric pollutant gradient in the surroundings of the industrial town Harjavalta, south-western Finland. Two 9-km-long transects, each with nine sample plots, running to the S and SW from factory complex were delimited in a homogenous Scots pine (Pinus sylvestris L.) forest. Needle samples were taken from 10 trees at each site, and from two separate sites in Tuusula near Helsinki. There was considerable spatial variation in the elemental composition of the needles. Heavy metals (Cu, Fe, Zn) showed a clear pattern of exponentially decreasing concentration with increasing distance from the emission source. Sodium and potassium concentrations, as well as the ash weight and air-dry weight, also decreased. Magnesium, manganese and calcium concentrations increased with increasing distance.
The PDF includes an abstract in Finnish.
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Heliövaara,
E-mail:
kh@mm.unknown
- Väisänen, E-mail: rv@mm.unknown
The red spruce (Picea rubens sarg.) population in the Green Mountains in Vermont has showed foliar deterioration that has not been fully explained. The most characteristic needle injuries of the sensitive trees appear in late winter when the first-year needles turn brown. The cytopathological and external observations on the symptoms support the interpretation that winter stress triggers the damage. It is possible that some anthropogenic stress factors (components of acid deposition or ozone) and/or natural factors predispose the trees to the damage.
The PDF includes an abstract in Finnish.
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Kärenlampi,
E-mail:
lk@mm.unknown
- Friedland, E-mail: af@mm.unknown
Seasonal changed in total nitrogen, protein, amino acid, ammonia, nitrate and nitrite concentrations, and nitrate reductase and γ-glutamyltransferase activities in the needles, buds and shoots of young Scots pine (Pinus sylvestris L.) were studied. A relationship between the variation in the nitrogen metabolism and both winter dormancy and its breaking was proposed. Pine tissues stored soluble nitrogen over the winter largely in the form of arginine which, in addition to a high nitrogen content, can neutralize acidic cytoplasmic constituents such as nitrates and nitrites. Specific nitrate reductase and γ-glutamyltransferase activities were highest in late summer or autumn, and is apparently connected to the mobilization of nitrogen reserves for the winter.
The PDF includes an abstract in Finnish.
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Lähdesmäki,
E-mail:
pl@mm.unknown
- Pietiläinen, E-mail: pp@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.
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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.
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Viherä,
E-mail:
av@mm.unknown
- 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.
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Kellomäki,
E-mail:
sk@mm.unknown
- Oker-Blom, E-mail: po@mm.unknown
The monoterpene composition of the needle oil of Pinus oocarpa Schiede ex Schltdl. and Pinus caribaea Morelet growing in Zambia were studied by means of GC-MS. P. oocarpa needle samples were taken from 29 trees representing different clones in a seed orchard and from 43 trees in a commercial plantation in 1980. The P. caribaea needle samples were collected from 17 clones in a seed orchard.
Nine compounds were positively identified in the monoterpene fraction of P. oocarpa and eight in that of P. caribaea. The amounts of these compounds showed marked tree-to-tree variation and the sample trees were screened into distinct groups on the basis of the variation. The results give a basis for selection in favour of pest resistance and turpentine yield.
The PDF includes a summary in Finnish.
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Löyttyniemi,
E-mail:
kl@mm.unknown
- Hiltunen, E-mail: rh@mm.unknown
- Löyttyniemi, E-mail: rl@mm.unknown
- Räisänen, E-mail: sr@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.
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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.
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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.
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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.
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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.
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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.
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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.
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Soikkeli,
E-mail:
ss@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.
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Kellomäki,
E-mail:
sk@mm.unknown
- Oker-Blom, E-mail: po@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.
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Lehtiö,
E-mail:
hl@mm.unknown
The paper deals with variation in the nitrogen, phosphorus, potassium, calcium and magnesium content of vegetation and soil of young Scots pine (Pinus sylvestris L.) stand of Vaccinium site type situated in Central Finland. The material consists of sequential samples representing soil, ground vegetation and trees taken during summer 1974.
The amount of soluble nutrients in the humus layer decreased in June when maximum growth of trees and dwarf shrubs occurred. The nutrient content of this layer subsequently began to increase towards the end of the growing period.
The variation in the nutrient content of the bottom and ground layers followed a similar pattern. Nitrogen content increases at the beginning of the summer. After this phase it started to decrease and reached its lowest values by the end of growing period. Phosphorus and potassium content increased throughout the growing period.
The nutrient content of the needles and wood were positively correlated with tree height and negatively with the age of material. The highest values for the nutrient content were for new cells.
The PDF includes a summary in English.
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Lehtonen,
E-mail:
il@mm.unknown
- Kellomäki, E-mail: sk@mm.unknown
- Westman, E-mail: cw@mm.unknown
In Finland the mite Nalepella is found in Norway spruce (Picea abies (L.) H. Karst.) in forests practically in every tree, and even in the nurseries. The paper reports on the occurrence of Nalepella Haarlovi var. picea-abietis Löyttyniemi in Finland in tree nurseries in Finland. The study is based on a large material, collected in connection with an investigation into spruce spider mites.
Nalepella lives vagrantly on the needles. Due to the sucking of the mites, the needles turn yellow, become dry an die. Single patches from sucking cannot be seen by the naked eye. They occur on all sides of the needles. The worst damage to spruce seedlings in nurseries is caused to the needles located in the top of the seedling. Sometimes the terminal bud dryes and the whole terminal shoot can die. However, the whole seedlings seldom die in consequence of the Nalepella mite alone. Subsequent damage to the injured needles is often caused by fungus Cladosporium herbarum.
The study shows that the mite causes economically significant damages only in the nurseries. In forests no such damages were observed in seedlings or in older trees. In 1965–68, significant damages occurred in 16 nurseries in Finland. About 600,000 four-year-old seedlings were destroyed in 1967. The damages were economically important only in the 4-year-old seedlings.
According to the study, seedlings damaged by Nalepella can be used for planting as they recover rather well after planting in the forest. Moreover, the damages end after planting, and density of the mite population decreases during the first summer.
The mite overwinters as egg on needles. The eggs hatch in Southern Finland in the end of April and in the beginning of May.
The PDF includes a summary in English.
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Löyttyniemi,
E-mail:
kl@mm.unknown
Category : Article
The article deals with outer characters of a pine from Patsjoki-river, in Finnish Lapland (Pinus silvestris L. var. lapponica (Fr.) Hn.). The tables describe the length of the needles, length of the shoots, branching and inflorescence. The statistical calculations of the data are based on W. Johannsen’s (Elemente der exakten Erblichkeitslehre, Jena 1909) (Elements of exact genetics) methods. The results cannot be generalized because of the insufficient amount of data.
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Renvall,
E-mail:
ar@mm.unknown
Category : Research article
The mean temperature during the potential growing season (April–September) may increase by 1 °C by 2030, and by 4 °C, or even more, by 2100, accompanied by an increase in atmospheric CO2 concentrations of 536–807 ppm, compared to the current climate of 1981–2010, in which atmospheric CO2 is at about 350 ppm. This may affect both the growth and frost hardiness of boreal trees. In this work, we studied the responses of height and autumn frost hardiness development in 22 half-sib genotypes of one-year-old Norway spruce (Picea abies (L.) Karst.) seedlings to elevated temperatures and atmospheric CO2 concentration under greenhouse conditions. The three climate treatments used were: T+1 °C above ambient and ambient CO2; T+4 °C above ambient and ambient CO2; and T+4 °C above ambient and elevated CO2 (700 ppm). The height growth rate and final height were both higher under T+4 °C compared to T+1 °C. Temperature increase also delayed the onset, and shortened the duration, of autumn frost hardiness development. Elevated CO2 did not affect the development of height or frost hardiness, when compared to the results without CO2 elevation under the same temperature treatment. Higher temperatures resulted in greater variation in height and frost hardiness development among genotypes. Three genotypes with different genetic backgrounds showed superior height growth, regardless of climate treatment; however, none showed a superior development of autumn frost hardiness. In future studies, clonal or full-sib genetic material should be used to study the details of autumn frost hardiness development among different genotypes.
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Levkoev,
University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland
E-mail:
eino.levkoev@uef.fi
- Mehtätalo, University of Eastern Finland, Faculty of Science and Forestry, School of Computing, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: lauri.mehtatalo@uef.fi
- Luostarinen, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@uef.fi
- Pulkkinen, Natural Resources Institute Finland (Luke), Production systems, Haapastensyrjä Breeding Station, FI-16200 Läyliäinen, Finland E-mail: pertti.pulkkinen@luke.fi
- Zhigunov, Saint-Petersburg State Forest Technical University, Forestry Faculty, RU-194021, Institutskiy per. 5, Saint-Petersburg, Russia E-mail: a.zhigunov@bk.ru
- Peltola, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: heli.peltola@uef.fi
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Pulkkinen,
Metla, Haapastensyrjä, Läyliäinen, Finland
E-mail:
pertti.pulkkinen@metla.fi
- Varis, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: sv@nn.fi
- Jaatinen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: rj@nn.fi
- Leppänen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: al@nn.fi
- Pakkanen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: ap@nn.fi
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Terhonen,
University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland
E-mail:
et@nn.fi
- Marco, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: tm@nn.fi
- Sun, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: hs@nn.fi
- Jalkanen, Finnish Forest Research Institute, Rovaniemi Research Unit, Rovaniemi, Finland E-mail: rj@nn.fi
- Kasanen, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: rk@nn.fi
- Vuorinen, Finnish Forest Research Institute, Suonenjoki Research Unit, Suonenjoki, Finland E-mail: mv@nn.fi
- Asiegbu, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: fa@nn.fi
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Salminen,
Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland
E-mail:
hannu.salminen@metla.fi
- Jalkanen, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: rj@nn.fi
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Saarsalmi,
The Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland
E-mail:
anna.saarsalmi@metla.fi
- Tamminen, The Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pt@nn.fi
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Silfverberg,
The Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland
E-mail:
klaus.silfverberg@metla.fi
- Hartman, The Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: mh@nn.fi
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Savonen,
The Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland
E-mail:
eira-maija.savonen@metla.fi
- Saarsalmi, The Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: as@nn.fi
