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Articles containing the keyword 'otos'

Category : Article

article id 5582, category Article
Jonathan J. Ruel, Matthew P. Ayres. (1996). Variation in temperature responses among populations of Betula papyrifera. Silva Fennica vol. 30 no. 2–3 article id 5582. https://doi.org/10.14214/sf.a9227
Keywords: Betula papyrifera; adaptation; photosynthesis; growth; temperature; climate warming; elevation
Abstract | View details | Full text in PDF | Author Info

How will global warming affect southern populations of boreal trees? In paper birch, Betula papyrifera (Betulaceae), alpine trees with an evolutionary history of relatively cool summers may be more sensitive to climate warming than valley populations. We evaluated this scenario by growing seedlings from different populations in four temperature treatments (mountain field site, valley field site, and two greenhouse rooms).

Populations from low elevations germinated earlier and had higher germination success than population from high elevations (16.8 vs. 22.0 d; 72% vs. 11%). At the valley site, seedlings from native populations grew faster than seedlings from higher elevations (mean ± SE = 0.25 ± 0.02 vs. 0.09 ± 0.04 mm · cm-1 · d-1) while at the mountain site, all seedlings grew at similar rates. Seedling grown in cooler environments had higher root : shoot ratios, perhaps to compensate for temperature limitations in nutrient uptake by roots. Leaf area varied among populations but was not affected by environmental differences across the field sites. Net photosynthetic rates at valley temperatures were higher for seedlings grown in the valley than for seedling grown in the mountains or the warm greenhouse (12.0 vs. 10.3 and 5.8 μmoles · m-2 · s-1), perhaps due to adaptive phenotypic adjustments. Climatic warming could rapidly produce important phenotypic changes in birch trees (e.g. decreased root : shoot ratio, reduced growth in alpine populations). On a longer time-scale, warming could also result in genetic changes as natural selection favours valley genotypes in alpine sites where they are presently rare.

  • Ruel, E-mail: jr@mm.unknown (email)
  • Ayres, E-mail: ma@mm.unknown
article id 5581, category Article
Oddvar Skre, Knut Nes. (1996). Combined effects of elevated winter temperatures and CO2 on Norway spruce seedlings. Silva Fennica vol. 30 no. 2–3 article id 5581. https://doi.org/10.14214/sf.a9226
Keywords: Norway spruce; Picea abies; photosynthesis; provenance; growth; Norway; N fertilization; carbon dioxide; winter temperatures
Abstract | View details | Full text in PDF | Author Info

A total of 1,800 3-year old seedlings of Norway spruce (Picea abies (L.) H. Karst.) from two Norwegian and one German provenance were treated with two different nitrogen levels during the 1992 growth season. The plants were kept during the following winter at two different temperature levels. In the spring of 1993, the nutrient application was resumed, and the plants were divided between three different treatments, 350 and 650 p.p.m. in open top chamber and a control plot outside the chambers. This treatment was repeated also during the following 1994 growth season.

The growth and primary production were studied by photosynthesis experiments and by non-destructive growth measurements. The result indicate that raised winter temperature may lead to increased needle loss and reduced growth the following season, particularly in northern provenances. Carbon dioxide significantly influenced growth in addition to nutrient level and winter temperature. High CO2 also seemed to cause increased photosynthesis at early season, and earlier budbreak and growth cessation than in control plants.

  • Skre, E-mail: os@mm.unknown (email)
  • Nes, E-mail: kn@mm.unknown
article id 5576, category Article
Matti Nuorteva, Lennart Saari. (1996). Winter ecology of a female White-backed Woodpecker Dendrocopos leucotos (Bechstein). Silva Fennica vol. 30 no. 1 article id 5576. https://doi.org/10.14214/sf.a9221
Keywords: winter food; Dendrocopos leucotos; white-backed woodpecker; prey insects; sawflies
Abstract | View details | Full text in PDF | Author Info

In the winter of 1977/78, a White-backed Woodpecker (Dendrocopos leucotos Bechstein) was observed in the archipelago of southwestern Finland 200 km from its breeding areas. It foraged on insects living in mall dead alder and birches. The potential prey species were identified by rearing the insects from the trunks used by the White-backed Woodpecker. Altogether 628 adult insects emerged. In addition to the big larvae the potential food also included larvae of Sciaridae and Cecidomyidae (Diptera) living in dense clumps.

  • Nuorteva, E-mail: mn@mm.unknown (email)
  • Saari, E-mail: ls@mm.unknown
article id 5529, category Article
Jukka Lippu. (1994). Patterns of dry matter partitioning and 14C-photosynthate allocation in 1.5-year-old Scots pine seedlings. Silva Fennica vol. 28 no. 3 article id 5529. https://doi.org/10.14214/sf.a9169
Keywords: Pinus sylvestris; carbon; photosynthesis; root growth; allocation; shoot growth; 14C-incorporation; dry matter partitioning
Abstract | View details | Full text in PDF | Author Info

Change in dry matter partitioning, 14C-incorporation, and sink 14C-activity of 1.5-year-old Scots pine (Pinus sylvestris L.) seedlings grown in growth chamber conditions were studied during a 91-day experiment. On five sampling dates, seedlings were labelled with 14CO2 and whole-plant allocation patterns were determined. Intensively growing shoots modified the dry matter partitioning: during shoot growth the proportion of roots decreased but after that it increased. Based on their large proportion of dry matter, the needles (excluding current needles) were the strongest sink of carbon containing 40% of the incorporated 14C. Despite their small initial sink size, the elongating shoots (current main shoot + current branch) and their needles were the second strongest sink (30–40% of the total 14C) which reflects their high physiological activity. The proportion of 14C in the current year’s main shoot increased during shoot growth but decreased as the growth began to decline after 70 days. 10–20% of the total assimilated 14C was translocated to the roots. Laterals above 2nd order were the strongest sink in the root system, containing twice as much 14C as the other roots together. Alternation between shoot and root growth can be seen clearly: carbon allocation to roots was relatively high before and after the period of intensive shoot growth. Changes in root sink strength resulted primarily from changes in root sink activity rather than sink size.

  • Lippu, E-mail: jl@mm.unknown (email)
article id 5526, category Article
Pertti. Hari, Pasi Aalto, Kaarle Hämeri, Markku. Kulmala, Tapani. Lahti, Sari. Luoma, Lauri Palva, Toivo Pohja, Erkki. Pulliainen, Erkki. Siivola, Timo Vesala. (1994). Air pollution in eastern Lapland : challenge for an environmental measurement station. Silva Fennica vol. 28 no. 1 article id 5526. https://doi.org/10.14214/sf.a9160
Keywords: photosynthesis; automation; carbon dioxide; ozone; measurement systems; aerosols; sulphur dioxid; weather
Abstract | View details | Full text in PDF | Author Info

The Värriö environmental measurement station has been designed and constructed during 1991 and 1992. The measurement system consists of measurement units for gases (sulphur dioxide, ozone, carbon dioxide), particles, photosynthesis and irradiation. A meteorological station is also included. The preliminary measurement period was started on August, 1991. During the first year (1991–1992) some parts of the system were redeveloped and rebuilt. Full, continuous measurement started in August 1992. The system has been working quite reliably, with good accuracy. The preliminary results show that pollution episodes are observed when the wind direction is from Monchegorsk or Nikel, the main emission sources in Kola Peninsula.

  • Hari, E-mail: ph@mm.unknown (email)
  • Aalto, E-mail: pa@mm.unknown
  • Hämeri, E-mail: kh@mm.unknown
  • Kulmala, E-mail: mk@mm.unknown
  • Lahti, E-mail: tl@mm.unknown
  • Luoma, E-mail: sl@mm.unknown
  • Palva, E-mail: lp@mm.unknown
  • Pohja, E-mail: tp@mm.unknown
  • Pulliainen, E-mail: ep@mm.unknown
  • Siivola, E-mail: es@mm.unknown
  • Vesala, E-mail: tv@mm.unknown
article id 5481, category Article
Pekka Nygren, Pertti Hari. (1992). Effect of foliar application with acid mist on the photosynthesis of potassium-deficient Scots pine seedlings. Silva Fennica vol. 26 no. 3 article id 5481. https://doi.org/10.14214/sf.a15642
Keywords: Pinus sylvestris; photosynthesis; nutrient deficiency; seedlings; acid deposition; potassium concentration
Abstract | View details | Full text in PDF | Author Info

The interactive effects of potassium deficit and foliar application with acid water (pH 5.5, 4.5, 4.0 and 3.0 given consecutively) on CO2 exchange rate of Pinus sylvestris L. seedlings was investigated in field conditions. No reduction of the CO2 exchange rate was observed in the seedlings supplied with sufficient potassium. Only the seedlings having the lowest needle K concentration (2.4 mgg-1) had an apparently low CO2 exchange rate before the applications with acid water. The CO2 exchange rate of most of the seedlings with low needle K concentration (3.9–6.0 mgg-1) decreased after the acid water application. The threshold acidity for the reduction varied between pH 4,0 and 3.0 depending on the needle K concentration. The reduction was more apparent at high irradiance. It was concluded that acid precipitation disturbs the CO2 exchange only in conditions of mineral nutrient deficit.

The PDF includes an abstract in Finnish.

  • Nygren, E-mail: pn@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
article id 5414, category Article
Heikki Smolander, Seppo Kellomäki, Pauline Oker-Blom. (1990). Typpipitoisuuden vaikutus männyn neulasten fotosynteesiin ja verson itsevarjostukseen. Silva Fennica vol. 24 no. 1 article id 5414. https://doi.org/10.14214/sf.a15566
English title: The effect of nitrogen concentration on needle photosynthesis and within shoot shading in Scots pine.
Original keywords: mänty; ravinteisuus; fotosynteesi; kasvupaikkatekijät; verson rakenne; säteilyn sitomistehokkuus
English keywords: Pinus sylvestris; photosynthesis; shading; fertility; site factors; shoot structure; light interception efficiency
Abstract | View details | Full text in PDF | Author Info

A close relationship between photosynthetic capacity and nitrogen concentration of leaves is known to exist. In conifers, nitrogen also affects the pattern of mutual shading within a shoot, which is a basic unit used in studying photosynthesis of coniferous trees. These effects of needle nitrogen concentration on photosynthetic capacity and mutual shading of needles were analysed for Scots pine (Pinus sylvestris L.) shoots taken from five young stands growing on sites of different fertility. The effect of nitrogen concentration on needle photosynthesis was studied based on measurements of the photosynthetic radiation response of shoots from which two thirds of the needles were removed in order to eliminate the effect of within shading.

An increase of one percentage unit in nitrogen concentration of needles increased the photosynthetic capacity of needles by 25 mg CO2 dm-2h-1. The effect of nitrogen on within-shoot shading was quantified in terms of the silhouette area to total needle area ratio of a shoot (STAR), which determines the relative interception rate per unit of needle area on the shoot. Although nitrogen promoted needle growth, an increase in nitrogen concentration decreased the within-shoot shading. This effect resulted from a decrease in needle density on the shoot and an increased needle angle with increasing nitrogen content.

The PDF includes an abstract in Finnish.

  • Smolander, E-mail: hs@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Oker-Blom, E-mail: po@mm.unknown
article id 5409, category Article
Jukka Lippu, Pasi Puttonen. (1990). Istutustaimen juuriston alkukehitys kasvupaikalla. Silva Fennica vol. 24 no. 1 article id 5409. https://doi.org/10.14214/sf.a15561
English title: The early development of seedling roots at the planting site: A literature review.
Original keywords: menetelmät; maan kosteus; maan lämpötila; juuriston kehitys; fotosynteesituote; fysiologinen sopeutuminen; istutustaimet
English keywords: planting; soil temperature; root growth; soil moisture; photosynthates; acclimatization; methodology
Abstract | View details | Full text in PDF | Author Info

The structure and functional responses of roots in planted seedlings when acclimatizing at the planting site are reviewed. A wide range of methods for classifying roots has been employed, and the terminology used is not uniform. Roots can be classified by their morphology, origin, and function. The temporal and spatial variation of soil temperature, moisture, structure, and concentration of nutrients are among the most important properties to which root systems acclimatize. In order to reliably describe the function of the root system, several parameters usually have to be measured. Studies on the root-soil interface have indicated that roots are not necessarily in continuous contact with soil. The control mechanism of root growth is inadequately known and theoretically formulated. Generally, only the mass needed for water and nutrient uptake has been allocated to the roots. However, the amount of photosynthates allocated to the roots is high. Acclimatization of seedlings out at the planting site is a complicated process which is influenced by the growing conditions at both the nursery and at the site. The function, distribution and structure of roots are controlled by the environment in a way similar to the shoot, but the control mechanism is imperfectly known.

The PDF includes an abstract in English.

  • Lippu, E-mail: jl@mm.unknown (email)
  • Puttonen, E-mail: pp@mm.unknown
article id 5405, category Article
Pertti Hari, Eeva Korpilahti, Toivo Pohja, Pentti K. Räsänen. (1990). A field system for measuring the gas exchange of forest trees. Silva Fennica vol. 24 no. 1 article id 5405. https://doi.org/10.14214/sf.a15557
Keywords: photosynthesis; CO2; monitoring; measuring methods; transpiration; environment; gas exchange; respiration
Abstract | View details | Full text in PDF | Author Info

A third generation of forest tree gas exchange measuring system design for the use in the field is described. The system is designed to produce data for determining the dependence of the rate of tree photosynthesis, respiration and transpiration on environmental factors. The system consists of eight cuvettes, a tubing system, two infrared gas analysers, an air flow controller, a data logger, and a computer. The measuring cuvette is a clap type, i.e. it is mostly open, only closing during measurement. CO2 exchange is measured as the change in the cuvette concentration of CO2, and, transpiration is measured as the increase in water vapour concentration while the cuvette is closed. The environmental factors measured are temperature, irradiance and air pressure. The system was planned in 1987 and constructed in 1988. It worked reliably in late summer 1988 and the quality of data seems to be satisfactory. 

The PDF includes an abstract in Finnish.

  • Hari, E-mail: ph@mm.unknown (email)
  • Korpilahti, E-mail: eeva.korpilahti@luke.fi
  • Pohja, E-mail: tp@mm.unknown
  • Räsänen, E-mail: pr@mm.unknown
article id 5210, category Article
Heikki Smolander, Juha Lappi. (1984). The interactive effect of water stress and temperature on the CO2 response of photosynthesis in Salix. Silva Fennica vol. 18 no. 2 article id 5210. https://doi.org/10.14214/sf.a15389
Keywords: drought stress; willow; temperature; photosynthetic capacity; Salix sp.; Salix sp. cv. Aquatica; CO2 conductance
Abstract | View details | Full text in PDF | Author Info

The interactive effects of water stress and temperature on the CO2 response of photosynthesis was studied in Salix sp. cv. Aquatica using the closed IRGA system. A semi-empirical model was used to describe the CO2 response of photosynthesis. The interactive effect of water stress and temperature was divided into two components: the change in CO2 conductance and the change in the photosynthetic capacity. The CO2 conductance was not dependent on the temperature when the willow plant was well watered, but during water stress it decreased as the temperature increased. The photosynthetic capacity of the willow plant increased along with an increase in temperature when well-watered, but during water stress temperature had quite opposite effect.

The PDF includes a summary in Finnish.

  • Smolander, E-mail: hs@mm.unknown (email)
  • Lappi, E-mail: jl@mm.unknown
article id 5169, category Article
Seppo Kellomäki, Pasi Puttonen, Heikki Tamminen, Carl Johan Westman. (1982). Effect of nitrogen fertilization on photosynthesis and growth in young Scots pines. Preliminary results. Silva Fennica vol. 16 no. 4 article id 5169. https://doi.org/10.14214/sf.a15084
Keywords: Pinus sylvestris; fertilization; Scots pine; stem growth; nitrogen fertilization; needle area; photosynthetic rate
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Puttonen, E-mail: pp@mm.unknown
  • Tamminen, E-mail: ht@mm.unknown
  • Westman, E-mail: cw@mm.unknown
article id 5153, category Article
T. Raunemaa, R. Erkinjuntti, M. Gerlander, A. Hautojärvi, K. Kaisla, H.-S. Katainen. (1981). Multielement analysis of treated pine seedlings. Silva Fennica vol. 15 no. 4 article id 5153. https://doi.org/10.14214/sf.a15380
Keywords: Pinus sylvestris; needles; photosynthesis; Scots pine; roots; air pollution; acid rain; environmental impact; acid deposition; elemental concentrations
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • 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
article id 5151, category Article
A. Mäkelä, P. Hari, Seppo Kellomäki. (1981). A model for the effect of air pollutants on forest growth. Silva Fennica vol. 15 no. 4 article id 5151. https://doi.org/10.14214/sf.a15378
Keywords: photosynthesis; growth; modelling; air pollution; environmental impact; allocation of photosynthates
Abstract | View details | Full text in PDF | Author Info

A model was constructed, the aim of which was to predict growth under conditions where air pollutants are present. The model is based on photosynthesis and on the allocation of photosynthetic products for growth. It is assumed that air pollutants released during energy production mainly affect photosynthesis in two ways: 1) directly by injuring the photosynthetic mechanism, and 2) indirectly by leaching nutrients. The two ways were studied empirically in order to identify a sub-model for the photosynthesis of a plant exposed to air pollutants. 

The stand model will be applied to two purposes. The present stage of forests in Finland is compared with the simulated state based on the assumption that no pollutants are present. In addition, the decrease in forest yield under different conditions derived from predictions about long-range pollutant transport in Europe is analysed.

  • Mäkelä, E-mail: am@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
article id 5125, category Article
Ilppo Greis, Seppo Kellomäki. (1981). Crown structure and stem growth of Norway spruce undergrowth under varying shading. Silva Fennica vol. 15 no. 3 article id 5125. https://doi.org/10.14214/sf.a15066
Keywords: Norway spruce; Picea abies; photosynthesis; height growth; shading; crown; undergrowth; crown structure
Abstract | View details | Full text in PDF | Author Info

The crown structure and stem growth of Norway spruce (Picea abies (L.) H. Karst.) undergrowth was studied in relation to the prevailing light conditions and potential photosynthesis. Shading decreased the stem height growth more than the length increment of laterals, producing a plate-shaped crown in deep shade. Needles responded to shading by adopting a horizontal inclination in deep shade. The needles were wide and thin respectively in shade. In the open the needle cross-section was almost square. Stem radial growth and height growth were both affected by shading exhibiting a linear response to the prevailing light conditions and the potential photosynthesis. Light conditions under dominating trees were closely correlated with the basal area of the dominating trees.

The PDF includes a summary in Finnish.

  • Greis, E-mail: ig@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
article id 5123, category Article
Heljä-Sisko Katainen, Seppo Kellomäki. (1981). Happaman veden vaikutus männyn taimiin. Silva Fennica vol. 15 no. 3 article id 5123. https://doi.org/10.14214/sf.a15064
English title: Effect of foliar application of dilute sulphuric acid on Scots pine seedlings.
Original keywords: mänty; taimet; pituuskasvu; neulasvauriot; fotosynteesi; happamuus; hapan sade
English keywords: Pinus sylvestris; photosynthesis; Scots pine; height growth; acidity; seedlings; needle damages; acid rain
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Kellomäki, E-mail: sk@mm.unknown
article id 5118, category Article
Matti Nuorteva, Jyrki Patomäki, Lennart Saari. (1981). Large poplar longhorn, Saperda carcharias (L.), as food for white-backed woodpecker, Dendrocopos leucotos (Bechst.). Silva Fennica vol. 15 no. 2 article id 5118. https://doi.org/10.14214/sf.a15059
Keywords: Populus tremula; nature conservation; aspen; Saperda carcharias; Dendrocopos leucotos; white-backed woodpecker; larvae; pupal chambers
Abstract | View details | Full text in PDF | Author Info

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

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

The PDF includes a summary in Finnish.

  • Nuorteva, E-mail: mn@mm.unknown (email)
  • Patomäki, E-mail: jp@mm.unknown
  • Saari, E-mail: ls@mm.unknown
article id 5092, category Article
Seppo Kellomäki, Markku Kanninen. (1980). Eco-physiological studies on young Scots pine stands. IV. Silva Fennica vol. 14 no. 4 article id 5092. https://doi.org/10.14214/sf.a15033
Keywords: Pinus sylvestris; Scots pine; height growth; radial growth; basic density; crown; photosynthate supply; light conditions
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Kanninen, E-mail: mk@mm.unknown
article id 5080, category Article
Annikki Mäkelä, Pertti Hari, Seppo Kellomäki. (1980). Eco-physiological studies on young Scots pine stands. III. Silva Fennica vol. 14 no. 3 article id 5080. https://doi.org/10.14214/sf.a15021
Keywords: Pinus sylvestris; biomass; Scots pine; canopy layer; wood formation; needle biomass; photosynthate allocation
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Hari, E-mail: ph@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
article id 5079, category Article
Seppo Kellomäki, Pertti Hari, Pirkko Ilonen, Markku Kanninen. (1980). Eco-physiological studies on young Scots pine stands. II. Silva Fennica vol. 14 no. 3 article id 5079. https://doi.org/10.14214/sf.a15020
Keywords: Pinus sylvestris; photosynthesis; Scots pine; stand density; needle biomass; crown class; needle distribution
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Hari, E-mail: ph@mm.unknown
  • Ilonen, E-mail: pi@mm.unknown
  • Kanninen, E-mail: mk@mm.unknown
article id 5078, category Article
Seppo Kellomäki, Pertti Hari. (1980). Eco-physiological studies on young Scots pine stands. I. Tree class as indicator of needle biomass, illumination and photosynthetic capacity of crown system. Silva Fennica vol. 14 no. 3 article id 5078. https://doi.org/10.14214/sf.a15019
Keywords: Pinus sylvestris; Scots pine; canopy; photosynthetic capacity; needle biomass; tree class
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • Hari, E-mail: ph@mm.unknown
article id 5048, category Article
Seppo Kellomäki. (1979). The effect of solar radiation and air temperature on basic density of Scots pine wood. Silva Fennica vol. 13 no. 4 article id 5048. https://doi.org/10.14214/sf.a14905
Keywords: Pinus sylvestris; photosynthesis; Scots pine; temperature; basic density; solar radiation
Abstract | View details | Full text in PDF | Author Info

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 (email)
article id 5019, category Article
Pertti Hari, Markku Kanninen, Seppo Kellomäki, Olavi Luukkanen, Paavo Pelkonen, Raimo Salminen, Heikki Smolander. (1979). An automatic system for measurements of gas exchange and environmental factors in a forest stand, with special reference to measuring principles. Silva Fennica vol. 13 no. 1 article id 5019. https://doi.org/10.14214/sf.a14873
Keywords: Pinus sylvestris; photosynthesis; Scots pine; environmental factors; ecology; transpiration; measurement tecniques; forest stand
Abstract | View details | Full text in PDF | Author Info

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 (email)
  • 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
article id 5008, category Article
Jyrki Raulo, Gustaf Sirén. (1978). Neljän visakoivikon päätehakkuun tuotos ja tuotto. Silva Fennica vol. 12 no. 4 article id 5008. https://doi.org/10.14214/sf.a14862
English title: Yield in volume and money of final cutting in four curly birch stands.
Original keywords: tuotos; visakoivu; laatu
English keywords: Betula pendula var. carelica; curly birch; timber yield
Abstract | View details | Full text in PDF | Author Info

Curly birch (Betula pendula f. carelica Sok.) is characterized by large variations in stem form and the internal structure of the wood, and is generally divided in to four types on the basis of visible external stem characteristics. First plantation experiments in Finland in the 1920’s in experimental areas of the Finnish Forest Institute, had become ripe for cutting and were felled. The study material of this study consists of one 52-year old and three 42–43 -year old stands of curly birch.

The yield suitable for plywood manufacture from the oldest stand was 34,777 kg/ha and that of curly grained branch wood 39,452 kg/ha. The corresponding figures of the other stands were, on average 24,219 and 57,271 kg/ha. The yield from the stands were sold at the present-day price. The result was economically better than from any other forest tree species grown in Finland. The younger stands were obviously cut too early. It was concluded that the genetic quality of the seedlings used in the plantations in the 1920’s and 1930’s was not very high.

The PDF includes a summary in English.

  • Raulo, E-mail: jr@mm.unknown (email)
  • Sirén, E-mail: gs@mm.unknown
article id 5006, category Article
Seppo Kellomäki. (1978). Typpilannoituksen vaikutus havupuiden fotosynteesikapasiteettiin. Silva Fennica vol. 12 no. 3 article id 5006. https://doi.org/10.14214/sf.a14860
English title: Effects of nitrogen fertilization on photosynthetic capacity of coniferous trees.
Original keywords: havupuut; lannoitus; typpilannoitus; fotosynteesikapasiteetti; neulasmassa
English keywords: biomass; photosynthetic capacity; nitrogen fertilization; coniferous trees; needle mass
Abstract | View details | Full text in PDF | Author Info

The effect of nitrogen fertilizers on the photosynthetic capacity of conifers is assessed on the basis of literature. The review emphasizes the role of changes of needle mass as a factor affecting the result of nutrient application. In particular, the increase in needle mass results in a considerable increase in photosynthetic capacity. The effect of fertilization on the photosynthetic rate seems to be of minor importance. The effect on the photosynthetic rate is, however, poorly documented as is the case for the effect of fertilization on the respiration rate. There is evidence that proper application of nitrogen fertilizers may double the photosynthetic capacity of conifers, mainly as a result of increase in needle mass.

The PDF includes a summary in English.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 4980, category Article
Eero Väisänen, Pertti Hari, Seppo Kellomäki. (1977). Annual growth level of some plant species as a function of light available for photosynthesis. Silva Fennica vol. 11 no. 4 article id 4980. https://doi.org/10.14214/sf.a14834
Keywords: light; temperature; methods; annual growth; forest vegetation; net photosynthesis
Abstract | View details | Full text in PDF | Author Info

A quantitative method for determining the annual growth level of plant species has been presented. In particular, attention was paid to the dependence of the growth level on the amount of light available for photosynthesis. A mathematical model for the dependence of structural matter production on photosynthetic production has been presented for some plant species.

The study is based on the assumption that the total amount of annual net photosynthesis plays a role of primary importance in determining the relationship between photosynthetic production and structural matter production. The basic environmental factors determining the photosynthetic rate are light and temperature, if the water and nutrient supply is adequate. The dependence of photosynthetic rate on light and temperature was determined by monitoring the CO2 uptake rate of natural plant populations between the photosynthetic levels of different plant populations with an infrared gas analyser.

The PDF includes a summary in Finnish.

  • Väisänen, E-mail: ev@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
article id 4964, category Article
Seppo Kellomäki, Pertti Hari, Eero Väisänen. (1977). Annual production of some forest mosses as a function of light available for photosynthesis. Silva Fennica vol. 11 no. 1 article id 4964. https://doi.org/10.14214/sf.a14815
Keywords: photosynthesis; stand density; light intensity; Hylocomnium splendens; mosses; Dicranum polysetum; Pleurozium schreberi
Abstract | View details | Full text in PDF | Author Info

The aim of the present paper was to study the annual production of Pleurozium schreberi (Brid.) Mitt., Hylocomnium splendens (Hedw.) B.S.G and Dicranum polysetum Sw. as a function of light available for photosynthesis. The productivity of the above moss species is studied using the harvested quadrats method in Norway spruce (Picea abies) stands of the Myrtillus site type representing different stand density classes (basal area from 0 to 34 m2/ha) in Southern Finland.

The annual production of each species in different stands was correlated with the amount of light available for photosynthesis i.e. with the photosynthetic production. Functions for the dependence of productivity on light conditions were produced for each species. The individual functions and their ecological significance is discussed. The adaptation of each species to low light intensity is evident since no meaningful addition to production takes place when the photosynthetic light ratio reaches values greater than 0.3–0.4. In other words, the level of photosynthesis which is 30–40% of that possible in the open, provides sufficient supply of carbohydrates or the basic functions of the moss species studied. Pleurozium schreberi and Dicranum polysetum seem to have greater light requirements than Hylocomnium splendens.

The PDF includes a summary in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Väisänen, E-mail: ev@mm.unknown
article id 4953, category Article
Seppo Kellomäki, Pertti Hari. (1976). Rate of photosynthesis of some forest mosses as a function of temperature and light intensity and effect of water content of moss cushion on photosynthetic rate. Silva Fennica vol. 10 no. 4 article id 4953. https://doi.org/10.14214/sf.a14799
Keywords: photosynthesis; temperature; light intensity; Pleurosium schreberi; Hylocomnium splendens; Dicranum undulatum; mosses; water deficiency
Abstract | View details | Full text in PDF | Author Info

The photosynthetic rate of Pleurosium schreberi (Willd.), Hylocomnium splendens (Hedw.) and Dicranum undulatum (Sw.) grown in plastic containers was monitored with infrared gas analyser in open air under natural weather conditions. It proved that the photosynthetic rate of wet moss cushions was satisfactorily predicted by temperature and light intensity. In dry moss cushions this kind of model gave too high an estimate for photosynthetic rate. Water requirements of each moss species were found to be moderate, and water content of moss cushions limited photosynthetic rate only under serious water deficiency.

The PDF includes a summary in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
article id 4940, category Article
Paavo Pelkonen, Heikki Smolander. (1976). Männyn kaasunvaihdon elpyminen talvilevon keskeytyessä. Silva Fennica vol. 10 no. 2 article id 4940. https://doi.org/10.14214/sf.a14786
English title: Increase in gas exchange rate in Scots pine by terminating the winter rest period.
Original keywords: mänty; fotosynteesi; aineenvaihdunta; haihdunta; talvilepo
English keywords: Pinus sylvestris; Scots pine; net photosynthesis; winter dormancy; transpiration
Abstract | View details | Full text in PDF | Author Info

The activation of CO2 exchange was monitored in two Scots pine (Pinus sylvestris L.) seedlings transferred from the field to the laboratory in December. Gas exchange was monitored by an URAS I infrared gas analyser in a so-called open IRGA-system with trap type chambers. Transpiration was also measured at the same time by weighing the potted seedlings twice a day. The measuring period lasted eleven days. During the period, the level of both transpiration and net photosynthesis increased about ten times. Furthermore, it was found that the level of photosynthesis at high temperatures was relatively lower at the beginning than at the end of the measuring period.

The PDF includes a summary in English.

  • Pelkonen, E-mail: pp@mm.unknown (email)
  • Smolander, E-mail: hs@mm.unknown
article id 4937, category Article
Pertti Hari, Mikko Huhtamaa, Paavo Pelkonen, Veli Pohjonen, Raimo Salminen. (1976). A new approach for measuring light inside the canopy in photosynthesis studies. Silva Fennica vol. 10 no. 2 article id 4937. https://doi.org/10.14214/sf.a14782
Keywords: photosynthesis; canopy; light intensity; measuring methods
Abstract | View details | Full text in PDF | Author Info

Light intensity inside the canopy varies considerably both in space and time. A new apparatus was developed which is disturbed as little as possible by the above-mentioned variation. The construction is based on the linear relationships between light intensity (measured using silicon diodes) and photosynthesis. This procedure permits linear operations (summing and integration) to be carried out on the output of the diodes without any loss of accuracy. There are five diodes in each assimilation chamber. A model, in which the independent variables include ligth, measured with the present equipment, and temperature, fits the photosynthetic rates well even inside the canopy.

The PDF includes a summary in Finnish.

  • Hari, E-mail: ph@mm.unknown (email)
  • Huhtamaa, E-mail: mh@mm.unknown
  • Pelkonen, E-mail: pp@mm.unknown
  • Pohjonen, E-mail: vp@mm.unknown
  • Salminen, E-mail: rs@mm.unknown
article id 4888, category Article
Olavi Luukkanen. (1973). Havaintoja kuusen vapaapölytysjälkeläistöjen ja männyn metsikköalkuperien CO2-aineenvaihdunnasta. Silva Fennica vol. 7 no. 4 article id 4888. https://doi.org/10.14214/sf.a14726
English title: Observations on CO2 exchange in open pollinated progenies of Norway spruce and provenances of Scots pine.
Original keywords: kuusi; mänty; metsänjalostus; pluspuu; fotosynteesi; geneettinen muuntelu; pimeähengitys; yhteyttämisteho
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; tree breeding; photosynthesis capacity; genetic variance; dark respiration
Abstract | View details | Full text in PDF | Author Info

Photosynthesis and dark respiration in five families of autochtonous Norway spruce (Picea abies (L.) H. Karst.) and in seedlings from twenty Finnish stands of Scots pine (Pinus sylvestris L.) were investigated in constant environmental conditions. Values of CO2 exchange were compared with the height growth and weight of seedlings in Norway spruce and with the weight alone in Scots pine. No statistically significant differences were found in CO2 exchange among progenies or stands. Photosynthetic efficiency and photosynthetic capacity showed a positive correlation both in spruce and in pine. Growth and net photosynthetic capacity were linearly and positively correlated in pine. Spruce and a higher light compensation point than pine. The use of an open IRGA system with several simultaneous measurements and the trap-type cuvette construction in genetic work are discussed.

The PDF includes a summary in English.

  • Luukkanen, E-mail: ol@mm.unknown (email)
article id 4867, category Article
Matti Kärkkäinen. (1972). Näkökohta keskimääräisestä tuotoksesta metsätyötieteessä. Silva Fennica vol. 6 no. 2 article id 4867. https://doi.org/10.14214/sf.a14670
English title: A point of view on the average output in forest work science.
Original keywords: metsäntutkimus; metsätyö; työntutkimus; tuotos; ajanmenekki
English keywords: time consumption; time studies; forest research; forest work; work studies; output
Abstract | View details | Full text in PDF | Author Info

The paper deals with the concepts of time consumption and output in forest work science. When output is defined as the inverse of time consumption and vice versa, it is possible to show the important consequences in probability functions. For instance, it is not the same if the dependent variable in a regression analysis is output or time consumption. Also, the average differ depending on if they are based on the time consumption figures or on the average output.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4863, category Article
Olavi Luukkanen. (1972). Metsäpuiden fotosynteesin geneettinen vaihtelu. Silva Fennica vol. 6 no. 2 article id 4863. https://doi.org/10.14214/sf.a14666
English title: Genetic variation of photosynthesis in forest trees.
Original keywords: fotosynteesi; geneettinen muuntelu; hengitys; fotorespiraatio; poppeli; hiilidioksidi; kaasuaineenvaihdunta
English keywords: photosynthesis; carbon dioxide; photorespiration; CO2 exhange
Abstract | View details | Full text in PDF | Author Info

In the literature review the current status of information on the genetic variation of CO2 exchange and some reviews and investigations on this subject are listed. Photorespiration is separately discussed and unpublished data of an electron microscope study of poplar leaf microbodies are presented.

Considerable genetic inter- and intraspecific variation is found in several characteristics that affect CO2 exchange in trees. Photosynthesis in young trees does not correlate well with growth through the whole rotation cycle. A special interest has been shown to marginal environmental conditions (e.g. water deficit, low temperature, and low light intensity), as opposed to optimal conditions often employed in laboratory studies of CO2 exchange in trees.

In an unpublished poplar studies by the author et.al. a preliminary experiment with poplar clones showed variation in the CO2 competition point. This variation was negatively correlated with the photosynthesis efficiency of these clones.

The PDF includes a summary in English.

  • Luukkanen, E-mail: ol@mm.unknown (email)
article id 4806, category Article
Esko Leinonen, Pentti Rikkonen. (1969). Puutavaran kuorma- ja kuormaotantamittaus. Silva Fennica vol. 3 no. 4 article id 4806. https://doi.org/10.14214/sf.a14594
English title: Load and load sampling measurement of timber.
Original keywords: puutavara; puunkuljetus; puutavaranmittaus; kuormamittaus; otos
English keywords: timber scaling; load sampling; timber transportation; wood measurement; load measurement; measurement of roundwood
Abstract | View details | Full text in PDF | Author Info

Measurement of timber in a vehicle load or in a bundle is best performed at the mill where the measuring of large quantities can be mechanized and sampling is possible. Load measurement methods include calculation of the number of units, measurement of pile volume, weight scaling and determination of solid content in accordance with Archimedes principle by immersion in water. For some timber assortments, load measurement is sufficiently accurate and suitable unit of measure. The accuracy of load measurement can be increased or the result can be converted by sampling to a more appropriate unit of measure.

In load sampling measurement, a sample is taken from the population, and the desired more accurate measurement is made from the sample. The basic measurement for the whole population can be converted into the more accurate measuring unit by means of the ratio between it and the basic measure. Unit, pile and weight sampling can be used. The aim for pulpwood is to calculate the dry matter content without bark, which means that the amount of bark and the dry weight of wood must be determined by sampling.

The size of the sample depends on size of the population, variation of the ratio between the loads, and the accuracy required. As the quantity of wood to be measured decreases, sampling measurement will reduce the measuring costs by up to 80%. In addition, there is saving in costs by rationalization.

The PDF includes a summary in English.

  • Leinonen, E-mail: el@mm.unknown (email)
  • Rikkonen, E-mail: pr@mm.unknown
article id 4771, category Article
J. G. Gordon, G. E. Gatherum. (1968). Photosynthesis and growth of selected Scots pine populations. Silva Fennica vol. 2 no. 3 article id 4771. https://doi.org/10.14214/sf.a14556
Keywords: Pinus sylvestris; photosynthesis; Scots pine; height growth; provenance; growth; photoperiod
Abstract | View details | Full text in PDF | Author Info

Eight Scots pine (Pinus sylvestris L.) seed sources, ranging from 42° to 66° north latitude, were grown under a constant, 16-hour photoperiod in a greenhouse for approximately 6 months. Rates of photosynthesis, as measured by an IRGA, and growth, as measured by increase in height and fresh and dry weight, differed among seed sources at the end of the six-month growing period. Photosynthetic capacity and growth were strongly related to latitude of seed source, and were greatest in the seed sources coming from a parent environment in which maximum photoperiods are about 16 hours.

Photosynthetic efficiency (rate of photosynthesis per gram needle weight) was also strongly related to latitude of seed source, but was lowest in the seedlings which exhibited the greatest growth and photosynthetic capacity. This may have been due to (1) more mutual shading of needles on the larger seedlings and (2) a lesser proportion of juvenile needles on the larger seedlings or (3) biochemical differences in the use of photosynthate in the needles. Seed source and light intensity had an interacting effect on rates of photosynthesis only in seedlings of the two northernmost seed sources.

The PDF includes a summary in Finnish.

  • Gordon, E-mail: jg@mm.unknown (email)
  • Gatherum, E-mail: gg@mm.unknown
article id 4676, category Article
Gustaf Sirén. (1958). Eräitä havaintoja keskisuomalaisen ja paikallisen mäntyrodun biologisista ja teknillisistä ominaisuuksista Perä-Pohjolassa. Silva Fennica no. 96 article id 4676. https://doi.org/10.14214/sf.a9122
English title: Biological and technical properties of the local Scots pine and proveniences of Central Finland in Northern Finland.
Original keywords: Pohjois-Suomi; mänty; Pinus sylvestris; kasvu; alkuperä; tuotos; taudinkestävyys; provenienssi; Keski-Suomi
English keywords: Scots pine; northern Finland; growth; resistance; provenience; pathogen resistance; disease resistance; Central Finland
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to find out if it is possible to use Scots pine (Pinus sylvestris L.) seed from Central-Finnish origin in Northern Finland to supplement supply of local seeds. The principle has been to limit transfer of seeds to 200 km. According to this study, it seems possible to permit 300-400 km transfer of seeds at the same height above the sea level, not including the timber line area.

The author’s observations indicate that the trees originating from seeds of Central Finland at 20-35 years age withstand damage caused by snow and pine blister rust as well as the local provenience. However, the seedlings seem to be more susceptible to snow blight. Spraying of 2-3% sulphurated lime in the autumn before the arrival of snow proved to be most effective way to prevent the damage.

Southern proveniences have been found to grow faster than the local proveniences in Northern Finland. The stands of Tuomarniemi (Central Finland) and Rovaniemi (Northern Finland) provenances had no distinct difference in the summerwood percentage, and the volume weight of the Tuomarniemi provenience was higher than the weight of the provenience of Rovaniemi. The Tuomarniemi stand also gave largest yield, but the difference was probably due to partly at age difference of the sample trees. The naturally regenerated local provenance showed the greatest volume weight.

The article includes a summary in English.

  • Sirén, E-mail: gs@mm.unknown (email)

Category : Article

article id 7170, category Article
Yrjö Ilvessalo. (1967). Luonnonnormaalien metsiköiden kehityksestä Kainuussa ja sen lähiympäristössä. Acta Forestalia Fennica vol. 81 no. 5 article id 7170. https://doi.org/10.14214/aff.7170
English title: The development of natural normal forest stands in southeastern Northern Finland.
Original keywords: kuusi; metsätyypit; mänty; kasvu; tuotos; luonnonnormaalit metsät; Kainuu
English keywords: Pinus sylvestris; Norway spruce; Picea abies; yield; Scots pine; northern Finland; growth; forest types; natural stands; natural normal stands
Abstract | View details | Full text in PDF | Author Info

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

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

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

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

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

The PDF includes a summary in English.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 7042, category Article
Yrjö Ilvessalo. (1920). Kasvu- ja tuottotaulut Suomen eteläpuoliskon mänty-, kuusi- ja koivumetsille. Acta Forestalia Fennica vol. 15 no. 4 article id 7042. https://doi.org/10.14214/aff.7042
English title: Growth and yield tables for the Scots pine, Norway spruce and birch in the southern part of Finland.
Original keywords: Etelä-Suomi; kuusi; Picea abies; mänty; Pinus sylvestris; metsätyyppi; koivu; Betula sp.; Keski-Suomi; kasvu- ja tuotostaulukko; runkolukusarja
English keywords: Southern Finland; forest site type; stem frequency distribution series; Central Finland
Abstract | View details | Full text in PDF | Author Info

The first proper growth and yield tables were prepared in Finland already in 1872, but they have been used little as the needs of forestry and forest sciences increased. One of the problems of the old yield tables was how the site quality classes are determined. The new growth and yield tables use the forest site type classification, which enables the use of same site types for all tree species. This makes it possible to compare the growth of different tree species in same kind of sites. The tables also use stem frequency distribution series. In the first stage, the tables were prepared for Southern and Central Finland.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 7041, category Article
Yrjö Ilvessalo. (1920). Tutkimuksia metsätyyppien taksatoorisesta merkityksestä nojautuen etupäässä kotimaiseen kasvutaulujen laatimistyöhön. Acta Forestalia Fennica vol. 15 no. 3 article id 7041. https://doi.org/10.14214/aff.7041
English title: Studies on mensurational significance of forest site types as part of preparation of Finnish growth and yield tables.
Original keywords: metsätyypit; kasvupaikkatyypit; kasvu- ja tuotostaulukot
English keywords: tree growth; growth and yield tables; forest site types
Abstract | View details | Full text in PDF | Author Info

New growth and yield tables were prepared for Southern Finland. To finalize the tables, it had to be determined whether the forest site types developed by Cajanus could be used in mensurational research.

Comparative study was performed in 1916-1919 to study the growth of the trees in different forest site types. Total of 467 sample sites were measured in Southern and Central Finland. All the forest site types were found to have a distinctive vegetation typical to the site. It can be concluded that the ground vegetation can be used to determine the forest site type. The growth of trees was different in different forest site types, yet similar within each site type. The forest site types are uniform, natural and easy to determine, and can thus be used to classify the forest stands and used in mensurational research and a basis to growth and yield tables.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 7525, category Article
Pertti Hari, Johan Ross, Marja Mecke. (1996). Production process of Scots pine. Acta Forestalia Fennica no. 254 article id 7525. https://doi.org/10.14214/aff.7525
Keywords: Pinus sylvestris; photosynthesis; Scots pine; allocation; structure; annual cycle; irradiance; stand models; geographical features
Abstract | View details | Full text in PDF | Author Info

The accompanying collective research report is the result of the research project in 1986–90 between the Finnish Academy and the former Soviet Academy of Sciences. The project was organized around common field work in Finland and in the former Soviet Union, and theoretical analyses of tree growth determining processes. Based on theoretical analyses, dynamic stand growth models were made and their parameters were determined utilizing the field results.

Annual cycle effects the tree growth. Our theoretical approach was based on adaptation to local climate conditions from Lapland to South Russia. The initiation of growth was described as a simple low and high temperature accumulation driven model. The model was linked with long-term temperature data.

Analysis of field measurements of CO2 exchange showed that irradiance is the dominating factor causing variation in photosynthetic rate in natural conditions during summer. The penetration of irradiance into Scots pine (Pinus sylvestris L.) canopy is a complicated phenomenon. A moderately simple but balanced forest radiation regime sub-model was constructed.

The common field excursions in different geographical regions resulted in a lot of experimental data of regularities of woody structure. The water transport seems to be a good common factor to analyse these properties of tree structure. The produced theoretical and experimental material was utilized in the development of stand growth model that describes the growth and development of Scots pine stands in Finland and the former Soviet Union. The core of the model is carbon and nutrient balances. This means that carbon obtained in photosynthesis is consumed or growth and maintenance and nutrients are taken according to the metabolic need. Since the fundamental metabolic processes are the same in all locations, the same growth model structure can be applied in the large range of Scots pine. The model enables the analysis of geographical differences in the growth of Scots pine. The present approach enables utilization of structural and functional knowledge gained in places of intensive research, in the analysis of growth and development of any stand.

  • Hari, E-mail: ph@mm.unknown (email)
  • Ross, E-mail: jr@mm.unknown
  • Mecke, E-mail: ph@mm.unknown
article id 7661, category Article
Jesada Luangjame. (1990). Salinity effects in Eucalyptus camaldulensis and Combretum quadrangulare: ecophysiological and morphological studies. Acta Forestalia Fennica no. 214 article id 7661. https://doi.org/10.14214/aff.7661
Keywords: biomass; photosynthesis; allocation; photorespiration; transpiration; respiration; water deficit; salinity; carbon dioxide compensation point; leaf resistance; water-use efficiency; stomatal resistance; stomatal movement; Eucalyptus camaldulensis; Combretum quadrangulare
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to investigate the ecophysiological and morphological characteristics of two salt-tolerant tree species, Eucalyptus camaldulensis Dehn. and Combretum quadrangulare Kurz. A greenhouse experiment with different levels of NaCl salinity (0, 0.5, 1.0, 1.5, and 2.0%) was set up and the results were compared with those of a field study on non-saline and saline soils. The determination of optimum gas exchange and the development and evaluation of photosynthetic models with and without water deficit were also included in this study.

Morphological characteristics under saline conditions showed that shoot height and diameter growth, shoot internode length, root length/biomass, leaf width and length, leaf area, number and biomass, and shoot/root and leaf/root ratios decreased with salinity, while leaf thickness increased with salinity. More growth was allocated to the roots than to the leaf canopy. Ecophysiological studies in laboratory showed that photosynthesis, stomatal conductance and water potential decreased with salinity, while the CO2 compensation point increased with salinity. Transpiration, dark respiration and photorespiration increased at low salinity but decreased at high salinity levels. In the field study, however, there were no significant differences in stomatal conductance and opening between saline and non-saline soils. Model predictions supported the results of the field measurements. Adaptation to salinity was reflected in an acclimatization of tree structure in the field study. There were both functioning and structural changes of seedlings in the greenhouse experiment

In terms of ecophysiological and morphological characteristics, E. Camaldulensis showed better salt tolerance than C. Quadragulare both in the greenhouse experiment and field study

The PDF includes a summary in Finnish.

  • Luangjame, E-mail: jl@mm.unknown (email)
article id 7653, category Article
Ladawan Atipanumpai. (1989). Acacia mangium : Studies on the genetic variation in ecological and physiological characteristics of a fastgrowing plantation tree species. Acta Forestalia Fennica no. 206 article id 7653. https://doi.org/10.14214/aff.7653
Keywords: photosynthesis; provenance; water stress; foliar analysis; stomata; heritability; half-sib families; photorespiration; dark respiration; transpiration; Acacia mangium; carbon dioxide compensation; dendrometry; leaf conductance
Abstract | View details | Full text in PDF | Author Info

Genetic variation in the physiological characteristics and biomass accumulation of Acacia mangium Willd. was studied in both field and laboratory conditions. Variation in the growth characteristics, foliar nutrient concentration, phyllode anatomy and stomatal frequency was analysed in 16 different origins under field conditions in Central Thailand. Family variation and heritability of growth and flowering frequency were calculated using 20 open-pollinated families at the age of 28 months. The effect of environmental factors on diameter growth in different provenances is also discussed.

Under laboratory conditions, such physiological characteristics as transpiration rate, leaf conductance and leaf water potential were measured at varying soil moisture conditions. The responses of photosynthesis, photorespiration and dark respiration as well as the CO2 compensation point to temperature and irradiance were also investigated. All physiological characteristics indicated differences among provenances. An attempt was made to relate the results obtained in the laboratory to the growth performance in the field. Recommendations on provenance selection for the planting of A. mangium in Thailand are also given.

The PDF includes a summary in Finnish.

  • Atipanumpai, E-mail: la@mm.unknown (email)
article id 7649, category Article
Eeva Korpilahti. (1988). Photosynthetic production of Scots pine in the natural environment. Acta Forestalia Fennica no. 202 article id 7649. https://doi.org/10.14214/aff.7649
Keywords: annual cycle; rate of photosynthesis; transpiration rate; stomatal regulation; irradiance response
Abstract | View details | Full text in PDF | Author Info

The dependence of the rates of photosynthesis and transpiration are studied on the environmental factors and on the control of the plant metabolism with Scots pine (Pinus sylvestris L.) in the natural environment. The importance of the different environmental factors to the photosynthetic production are evaluated. In modelling the dependence of the rates of photosynthesis and transpiration on the environmental factors and on the control processes, a dynamic system analysis approach is applied. Irradiance, temperature and water are explored during the annual cycle. Field measurements of the CO2 exchange and environmental factors over three years are used in the analysis of the rate of the photosynthesis. The effect of different environmental factors on photosynthetic production is evaluated by model estimations using weather data in a 20-year period.

The PDF includes a summary in Finnish.

  • Korpilahti, E-mail: ek@mm.unknown (email)
article id 7643, category Article
Pauline Oker-Blom. (1986). Photosynthetic radiation regime and canopy structure in modeled forest stands. Acta Forestalia Fennica no. 197 article id 7643. https://doi.org/10.14214/aff.7643
Keywords: spatial variation; radiation models; penumbra; grouping effect; photosynthetic radiation
Abstract | View details | Full text in PDF | Author Info

The relationship between canopy structure and photosynthetic radiation regime are studied in a theoretical basis. In modelling the canopy structure, a statistical approach is applied and the radiation field inside a stand is described in terms of random variables and their distribution. A comparison is made between horizontally homogenous stands and grouped forest stands in order to assess the influence of grouping of foliage on the irradiance distribution in a forest stand. Results show that grouping considerably reduces the interception of radiation and causes a large spatial variation. In coniferous stands the grouping of needles into shoots and the effect of penumbra are shown to have an important influence on the distribution of radiation on the needle area.

The PDF includes a summary in Finnish.

  • Oker-Blom, E-mail: po@mm.unknown (email)
article id 7634, category Article
Heikki Smolander. (1984). Measurement of fluctuating irradiance in field studies of photosynthesis. Acta Forestalia Fennica no. 187 article id 7634. https://doi.org/10.14214/aff.7634
Keywords: Pinus sylvestris; photosynthesis; Scots pine; shoot geometry; microvariation in irradiance
Abstract | View details | Full text in PDF | Author Info

The problems caused by the temporal and spatial microvariation in irradiance during field measurements of photosynthesis are studied. It is concluded on the basis of variation analyses based on irradiance data measured in a Scots pine (Pinus sylvestris L.) stand that the microvariation should be measured by integrating it over the measurement time and space.

However, the curvlinearity of the light response of photosynthesis results in biased estimates when linear integration (mean irradiance) is used. The significance of the bias is examined using a simulation technique on irradiance material. Whether the actual integral of photosynthesis can be approximated with mathematical method is next studied. The method gave satisfactory results only for a low curvature response, but the latter method was applicable also to the high curvature response. However, both methods presuppose that the mean and variance are known. Measurement of the variance is based on integration of the second power.

A new method, where the nonlinearity problem is avoided, is presented to measure fluctuation of the irradiance. The method enables the shoot geometry to be taken into account and it is also applicable to transpiration studies.

The PDF includes a summary in Finnish.

  • Smolander, E-mail: hs@mm.unknown (email)
article id 7624, category Article
Pertti Hari, Seppo Kellomäki, Annikki Mäkelä, Pirkko Ilonen, Markku Kanninen, Eeva Korpilahti, Markku Nygren. (1982). Metsikön varhaiskehityksen dynamiikka. Acta Forestalia Fennica no. 177 article id 7624. https://doi.org/10.14214/aff.7624
English title: Dynamics of early development of tree stand.
Original keywords: tiheys; mänty; metsikön rakenne; metsikön kehitys; valo-olosuhteet; yhteyttäminen
English keywords: Pinus sylvestris; stand structure; photosynthesis; Scots pine; density; stand development; light conditions
Abstract | View details | Full text in PDF | Author Info

The report concludes a series of studies on the early development of young Scots pine (Pinus sylvestris L.) stands. The basis assumption made in the study series was that the within-stand light regime is the main driving force for total tree growth and its allocation of photosynthates for crown, stem and root growth. An individual tree growing in a stand under a varying light regime which is controlled by the stand structure, is the basic unit used in the study. The photosynthesis of an individual tree is determined by the light regime. The stand is formed from individual trees.

The model is applied in simulation of the growth and development of tree stands. Several computer runs representing various densities, height distributions and tree species mixtures were carried out. Potential application areas, properties of the model and future needs of investigations are discussed.

The PDF includes a summary in English.

  • Hari, E-mail: ph@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Mäkelä, E-mail: am@mm.unknown
  • Ilonen, E-mail: pi@mm.unknown
  • Kanninen, E-mail: mk@mm.unknown
  • Korpilahti, E-mail: ek@mm.unknown
  • Nygren, E-mail: mn@mm.unknown
article id 7596, category Article
Olavi Luukkanen. (1978). Investigations on factors affecting net photosynthesis in trees : gas exchanges in clones of Picea abies (L.) Karst. Acta Forestalia Fennica no. 162 article id 7596. https://doi.org/10.14214/aff.7596
Keywords: Norway spruce; Picea abies; photosynthesis; water stress; temperature; clones; heredity; mesophyll resistance
Abstract | View details | Full text in PDF | Author Info

The net photosynthetic rate per unit of foliage was studied in two-year old cuttings of Norway spruce (Picea abies (L.) H. Karst.), representing four clones, at varying temperature and soil moisture. The CO2 compensation point (Γ), photorespiration, dark respiration, and water balance were also investigated. All these characteristics indicated differences among the clones. A correlation between CO2 exchange and transpiration suggested that stomatal control determined at least a part of this variation during a favourable water balance. An inverse relationship existed between Γ and net photosynthetic rate, and the same curvilinear model explained this variation in unstressed as well as stressed plants at a given temperature. An increase in Γ seems to be a normal result of water stress, particularly at high temperature, indicating an increase in mesophyll resistance to CO2 diffusion. This result was in agreement with calculated values of mesophyll resistance. It also supported our earlier conclusions about the significance of mesophyll resistance during water stress.

  • Luukkanen, E-mail: ol@mm.unknown (email)
article id 7595, category Article
Erkki Hallman, Pertti Hari, Pentti K. Räsänen, Heikki Smolander. (1978). Effect of planting shock on the transpiration, photosynthesis, and height increment of Scots pine seedlings. Acta Forestalia Fennica no. 161 article id 7595. https://doi.org/10.14214/aff.7595
Keywords: Pinus sylvestris; photosynthesis; Scots pine; planting; stress; seedlings; drought; transpiration; water deficit
Abstract | View details | Full text in PDF | Author Info

In the experiment Scots pine (Pinus sylvestris L.) seedlings were transplanted out in the field. The effect of the treatments on gas metabolism and daily height increment were examined. The seedlings were 5-year old Scots pine plants growing in clay pots, covered with plastic bags. Transpiration and photosynthetic rates were monitored with open IRGA measuring system for a few days before being subjected to the treatments and for one month after. In addition, the daily amounts of transpired water and daily height increments were measured. A model for the potential rate of each metabolic process was constructed.

Planting and additional exposure had a strong and rather permanent effect on the self-regulation of the processes. This effect is very similar to that caused by water deficit. Exposure makes the disturbance more pronounced. Transpiration of the transplanted seedlings decreased in a few days after planting to less than half of the potential value and that of the exposed ones decreased to a quarter of the potential value. The daily amounts of photosynthesis decreased to half of the potential value. There was no recovery in photosynthesis during the whole monitoring period of four weeks. There was a slight recovery in transpiration about five weeks after transplanting.

Thus, the treatment probably generated stress conditions throughout the whole growing period, which is characterized by strong self-regulation of photosynthesis and transpiration, thus causing an essential decrease in the total amount of CO2 fixed. The photosynthesis was depressed especially at elevated temperatures after planting, as during water deficit. Planting and additional exposure did not produce any detectable changes in the dependence of the growth rate on temperature or in the effect of self-regulation on height growth. On the other hand, the level of growth was decreased as a result of planting out.

The PDF includes a summary in Finnish.

  • Hallman, E-mail: eh@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Räsänen, E-mail: pr@mm.unknown
  • Smolander, E-mail: hs@mm.unknown

Category : Research article

article id 10375, category Research article
Amy Wotherspoon, Nelson Thiffault, Robert L. Bradley. (2020). Resource availability and physiological response of black spruce to scarification in two climatic regions of Québec (Canada). Silva Fennica vol. 54 no. 4 article id 10375. https://doi.org/10.14214/sf.10375
Keywords: Picea mariana; foliar δ18O; foliar δ13C; needle gas exchange; photosynthetic nitrogen use efficiency; water use efficiency
Highlights: Mechanical scarification of clearcut sites in two climatic regions maintained high growth rates of regenerating black spruce 18 years after treatment; In both regions, scarification reduced soil moisture and increased water use efficiency; In the cooler-humid region, scarification improved soil nitrogen mineralization.
Abstract | Full text in HTML | Full text in PDF | Author Info

Scarification is a mechanical site preparation technique designed to create microsites that will favor the growth of planted tree seedlings after clearcutting. However, the positive growth response of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) to scarification varies across different sites. We hypothesized that this was due to different forms of physiological stress induced by different climates or by the severity of competition from ericaceous shrubs. We thus compared the effects of scarification on black spruce needle gas exchange and other foliar properties, as well as on indices of soil water and nitrogen availability, in relatively warm-dry (Abitibi) vs. cool-humid (Côte-Nord) climates in the province of Québec (Canada). We found a similar positive effect of scarification on tree height in Abitibi and Côte-Nord. Scarification reduced soil moisture in both climatic regions, but increased soil N mineralization in Côte-Nord only. Accordingly, scarification increased the instantaneous water use efficiency in both climate regions, but decreased photosynthetic N use efficiency in Côte-Nord only. In both regions, we found a positive relationship between foliar δ18O and δ13C on scarified plots, providing further evidence that increased growth due to scarification depends on a decrease in stomatal conductance. We conclude that scarification increases total evapotranspiration of trees evenly across the east-to-west moisture gradient in the province of Québec, but also improves long-term soil nutritional quality in a cooler-humid climate.

  • Wotherspoon, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada E-mail: amy.wotherspoon@usherbrooke.ca (email)
  • Thiffault, Canadian Wood Fibre Centre, Canadian Forest Service, Natural Resources Canada, 1055 du. P.E.P.S., P.O. Box 10380, Québec, G1V 4C7, Canada E-mail: nelson.thiffault@canada.ca
  • Bradley, Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada E-mail: robert.bradley@usherbrooke.ca
article id 95, category Research article
Venceslas Goudiaby, Suzanne Brais, Yvon Grenier, Frank Berninger. (2011). Thinning effects on jack pine and black spruce photosynthesis in eastern boreal forests of Canada. Silva Fennica vol. 45 no. 4 article id 95. https://doi.org/10.14214/sf.95
Keywords: nitrogen; light; Picea mariana; Pinus banksiana; photosynthesis; thinning
Abstract | View details | Full text in PDF | Author Info
A decrease in the average diameter of commercially harvested tree species in the Eastern boreal forest of Canada has led to a decrease in availability of quality wood for the forest industry. Commercial thinning has been proposed as a means to increase stem diameter growth. However, little is known about physiological responses underlying species responses to thinning. We assessed the effect of canopy opening on the photosynthetic response of mature jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP) trees. Two years after thinning and for each species, light response curves and the diurnal course of photosynthesis were characterized from measurements taken in a completely randomized block experiment on current-year and one-year-old needles of 12 trees from stands subjected to different levels of canopy opening. Soil water content, air and soil temperatures, and needle N concentration were not affected by thinning for either species. However, light availability increased with basal area removed and could explain the significantly positive relationship between thinning intensity and diurnal course of photosynthesis for one-year-old needles of jack pine. Black spruce photosynthesis did not respond to increases in light. Light-saturated rate of net photosynthesis (Amax), photosynthetic efficiency (α), light compensation point (LCP), and diurnal respiration (Rd) did not vary with thinning for either of the species. Jack pine and black spruce responses to thinning should be interpreted in light of species autecology.
  • Goudiaby, NSERC/UQAT/UQÀM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, Québec, Canada E-mail: venceslas.goudiaby@uqat.ca (email)
  • Brais, NSERC/UQAT/UQÀM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, Québec, Canada E-mail: sb@nn.ca
  • Grenier, NSERC/UQAT/UQÀM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, Québec, Canada E-mail: yg@nn.ca
  • Berninger, University of Helsinki, Faculty of Agriculture and Forestry, Department of Forest Sciences, Finland E-mail: fb@nn.fi
article id 450, category Research article
Miaoer Lu, Pekka Nygren, Jari Perttunen, Stephen G. Pallardy, David R. Larsen. (2011). Application of the functional-structural tree model LIGNUM to growth simulation of short-rotation eastern cottonwood. Silva Fennica vol. 45 no. 3 article id 450. https://doi.org/10.14214/sf.450
Keywords: Populus deltoides; carbon allocation; L-system; photon flux interception; photosynthetic production; voxel model
Abstract | View details | Full text in PDF | Author Info
The functional-structural tree growth model LIGNUM was developed as a general research tool that can be applied to several tree species. The growth simulation of short-rotation eastern cottonwood (Populus deltoides Bartr. ex Marsh.) inherits the basic LIGNUM modeling concepts including modular tree structure, L-system-based description of structural development, and carbon budget. New developments of LIGNUM model in this study were the incorporation of a biochemically-derived photosynthesis submodel; nested time steps for simulating physiological processes, structural development, and annual biomass production; incorporation of field-measured weather data for modeling the response of physiological processes to environmental variation; and application of a Monte-Carlo voxel space submodel for simulating the stochasticity of tree growth and improving computational efficiency. A specific parameter system was applied for modeling P. deltoides growth in the central Missouri, USA, environment. This adaptation of LIGNUM was applied on modeling growth of P. deltoides in a short-rotation agroforestry practice. The simulated height and biomass growth were close to field observations. Visualization of simulation results closely resembled the trees growing in an open site. The simulated response of tree growth to variations in photon flux input was reasonable. The LIGNUM model may be used as a complement to field studies on P. deltoides in short-rotation forestry and agroforestry.
  • Lu, Deparment of Forestry, University of Missouri, Columbia, MO, USA E-mail: ml@nn.us
  • Nygren, The Finnish Society of Forest Science, P.O. 18, FI-01301 Vantaa, Finland E-mail: pekka.nygren@metla.fi (email)
  • Perttunen, Finnish Forest Research Institute, Vantaa, Finland E-mail: jp@nn.fi
  • Pallardy, Deparment of Forestry, University of Missouri, Columbia, MO, USA E-mail: sgp@nn.us
  • Larsen, Deparment of Forestry, University of Missouri, Columbia, MO, USA E-mail: drl@nn.us
article id 292, category Research article
Sanna Susiluoto, Frank Berninger. (2007). Interactions between morphological and physiological drought responses in Eucalyptus microtheca. Silva Fennica vol. 41 no. 2 article id 292. https://doi.org/10.14214/sf.292
Keywords: photosynthesis; chlorophyll fluorescence; root/shoot ratio; RuBP; xylem permeability
Abstract | View details | Full text in PDF | Author Info
We studied the response of Eucalyptus microtheca to drought in a greenhouse experiment. As a result of the drought the growth of the seedlings decreased and allocation patterns changed so that allocation to the roots increased. However, changes in photosynthesis and stomatal conductance under drought were rather modest. We showed, using chlorophyll fluorescence and measurements of photosynthesis under high CO2 that the biochemical capacity of photosynthesis increased under drought. The results suggest that changes in root/shoot ratio are the primary reactions that initiate a series of compensatory reactions that mitigate the effects of drought in Eucalyptus microtheca.
  • Susiluoto, University of Helsinki, Department of Forest Ecology, PL 27, 00014 University of Helsinki, Finland E-mail: sannamaija.susiluoto@helsinki.fi (email)
  • Berninger, Departement des Sciences biologiques, Université du Québec à Montréal, CP 8888 Succ Centre Ville, Montreal, Canada E-mail: fb@nn.ca
article id 328, category Research article
Pedro J. Aphalo, Markku Lahti, Tarja Lehto, Tapani Repo, Aino Rummukainen, Hannu Mannerkoski, Leena Finér. (2006). Responses of silver birch saplings to low soil temperature. Silva Fennica vol. 40 no. 3 article id 328. https://doi.org/10.14214/sf.328
Keywords: biomass; Betula pendula; photosynthesis; electrical impedance; mineral nutrients; soil temperature; stomatal conductance; water relations
Abstract | View details | Full text in PDF | Author Info
Two-year-old silver birch (Betula pendula) saplings were grown for a third growing season in controlled-environment rooms (dasotrons) at three soil temperatures (5, 10, and 20 °C). All trees grew the first flush of leaves, but the growth of the second flush was almost completely inhibited at the two lower temperatures. The dry weight of the second-flush leaves was 50 times larger at 20 °C than at 5 and 10 °C, with about 100 times more nitrogen. Root growth was less affected than shoot growth. Chlorophyll content, net assimilation rate and stomatal conductance were lower at low soil temperatures. The value of the cytoplasm resistance estimated from the electric impedance spectra was lower at 5 °C than at 10 or 20 °C. Leaf water potential was highest at the lowest soil temperature, and intercellular carbon dioxide concentration was only slightly lower in saplings growing in cooler soil. We conclude that the effect of long-term exposure to cold soil on net assimilation and growth was not caused by stomatal closure alone. It is likely to be additionally mediated by the limited nitrogen acquisition at the low soil temperatures, and perhaps additionally by some other factor. As the growth depression of aboveground parts in response to low soil temperature was more significant in silver birch than what has earlier been found in conifers, the relative changes in air and soil temperature may eventually determine whether birch will become more dominant in boreal forests with climate change.
  • Aphalo, University of Helsinki, Department of Biological and Environmental Sciences E-mail: pja@nn.fi
  • Lahti, The Finnish Forest Research Institute E-mail: ml@nn.fi
  • Lehto, University of Joensuu, Faculty of Forestry, Box 111, FI-80101 Joensuu, Finland E-mail: tarja.lehto@joensuu.fi (email)
  • Repo, The Finnish Forest Research Institute E-mail: tr@nn.fi
  • Rummukainen, University of Joensuu, Faculty of Forestry, Box 111, FI-80101 Joensuu, Finland E-mail: ar@nn.fi
  • Mannerkoski, University of Joensuu, Faculty of Forestry, Box 111, FI-80101 Joensuu, Finland E-mail: hm@nn.fi
  • Finér, The Finnish Forest Research Institute E-mail: lf@nn.fi
article id 533, category Research article
Anna Liisa Ruotsalainen, Juha Tuomi, Henry Väre. (2002). A model for optimal mycorrhizal colonization along altitudinal gradients. Silva Fennica vol. 36 no. 3 article id 533. https://doi.org/10.14214/sf.533
Keywords: alpine gradient; mycorrhiza; nutrient uptake kinetics; photosynthetic nutrient use efficiency
Abstract | View details | Full text in PDF | Author Info
Mycorrhizal associations are generally favourable for vascular plants in nutrient-poor conditions. Still, non-mycorrhizal plants are common in high arctic and alpine areas, which are often poor in nitrogen and phosphorus. The relative proportion of mycorrhizal plants has been found to decrease along with increasing altitude, suggesting that the advantage of the mycorrhizal symbiosis may change along an altitudinal gradient. This may be related to the environmental factors that possibly constrain the amount of photosynthesized carbon to be shared with mycorrhizal fungi. We propose a simple optimization model for root colonization by fungal symbionts and analyze the advantages of mycorrhizas in relation to the nutrient use efficiency of photosynthesis (PNUE), the kinetics of nutrient uptake and the soil nutrient levels. Our model suggests that mycorrhizas are not usually favoured at low PNUE values. At low nutrient levels, mycorrhizas may be advantageous if they have a lower threshold concentration of nutrient uptake (xmin) compared to non-mycorrhizal roots. If mycorrhizal roots have a higher maximum capacity of nutrient uptake (Vmax), mycorrhizas can be favourable for the host plant even at relatively low nutrient concentrations and at relatively low PNUE. Consequently, the possible patterns along altitudinal gradients essentially depend on PNUE. If the soil nutrient concentration is constant and PNUE decreases, the advantage of mycorrhizal symbiosis declines independently of the nutrient uptake kinetics. If PNUE remains constant and the soil nutrient concentration decreases along with increasing altitude, the emerging colonization pattern (either increasing, decreasing or intermediate) depends on the nutrient uptake kinetics. Additionally, if both PNUE and the soil nutrient concentration decrease, several patterns may emerge, depending on the nutrient uptake kinetics.
  • Ruotsalainen, Department of Biology, Botanical Museum, Box 3000, FIN-90014 University of Oulu, Finland E-mail: annu.ruotsalainen@oulu.fi (email)
  • Tuomi, Department of Biology, Box 3000, FIN-90014 University of Oulu, Finland E-mail: jt@nn.fi
  • Väre, Botanical Museum, Finnish Museum of Natural History, Box 7, FIN-00014 University of Helsinki, Finland E-mail: hv@nn.fi
article id 529, category Research article
Tuula Aalto, Pertti Hari, Timo Vesala. (2002). Comparison of an optimal stomatal regulation model and a biochemical model in explaining CO2 exchange in field conditions. Silva Fennica vol. 36 no. 3 article id 529. https://doi.org/10.14214/sf.529
Keywords: photosynthesis; Scots pine; optimization; Pinus sylvestris L.; CO2 exchange; biochemical model
Abstract | View details | Full text in PDF | Author Info
Gas exchange of Pinus sylvestris L. was studied in subarctic field conditions. Aspects on optimal control of the gas exchange were examined using approach by Hari et al. (Tree Phys. 2: 169–175, 1986). Biochemical model by Farquhar et al. (Planta 149: 78–90, 1980) was utilized to describe the photosynthetic production rate of needles. The model parameters were determined from field measurements. The results from the optimization approach and biochemical model were compared and their performance was found quite similar in terms of R2 calculated using measured exchange rates (0.89 for optimization model and 0.85 for biochemical model). Minor differences were found in relation to responses to intercellular carbon dioxide concentration and temperature.
  • Aalto, Finnish Meteorological Institute, Air Quality Research, Sahaajankatu 20 E, FIN-00810 Helsinki, Finland E-mail: tuula.aalto@fmi.fi (email)
  • Hari, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: ph@nn.fi
  • Vesala, University of Helsinki, Dept. of Physics, P.O. Box 64, FIN-00014 University of Helsinki, Finland E-mail: tv@nn.fi
article id 591, category Research article
Qibin Yu. (2001). Can physiological and anatomical characters be used for selecting high yielding hybrid aspen clones? Silva Fennica vol. 35 no. 2 article id 591. https://doi.org/10.14214/sf.591
Keywords: photosynthesis; growth; leaf; stomatal characters
Abstract | View details | Full text in PDF | Author Info
Stomatal, CO2 exchange parameters and several leaf and growth traits were recorded in a five-year-old hybrid aspen clone trial. The field trial consisted of four aspen hybrid clones (Populus tremula L. x P. tremuloides Michx.) and one local Populus tremula seedling source. The mean estimated height of hybrid aspen clones was 1.6 times higher than for P. tremula. Similarly, basal diameter was 1.5 times and breast diameter 1.8 times higher in the hybrids. Differences were observed for physiological and growth traits among hybrid clones and P. tremula, but, only stomatal characters of hybrid clones differed significantly from those in P. tremula. Hybrid clones had larger guard cells (22.9 mm) than P. tremula (19.2 mm), whereas P. tremula had a higher stomatal density (211.3/mm2) than the hybrid clones (164.4/mm2). Among four hybrid clones, net photosynthesis was strongly correlated with foliar nitrogen. Height correlated significantly with foliar nitrogen, but negatively with leaf fresh weight, leaf dry weight and stomatal density. The results suggested that yield components could be controlled by many genes, specific to each clone. No single gas exchange or morphological variable can provide a reliable indicator of yield potential.
  • Yu, Department of Plant Biology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: qibin.yu@helsinki.fi (email)
article id 674, category Research article
Tuula Aalto. (1998). Carbon dioxide exchange of Scots pine shoots as estimated by a biochemical model and cuvette field measurements. Silva Fennica vol. 32 no. 4 article id 674. https://doi.org/10.14214/sf.674
Keywords: Pinus sylvestris; photosynthesis; Scots pine; CO2 exchange; cuvette measurements
Abstract | View details | Full text in PDF | Author Info
A biochemical model was used to calculate CO2 fluxes to Scots pine shoots in two boreal measurement stations, Hyytiälä in southern Finland (61°51’N, 24°17’E) and Värriö in northern Finland (67°46’N, 29°35’E). The results of the model were compared with cuvette measurements performed in field conditions. A differential equation for change in gas concentration inside a closed cuvette was constructed and solved in order to obtain conductances and fluxes. The results were generally in a good agreement, the correlation coefficients varied from 0.74 to 0.95. Some discrepancies were also found. The model followed more intensively changes in temperature. This could be seen in northern Finland measurements at low temperatures (< 18 °C). The modelled temperature response indicated low fluxes at low temperatures, but measurements did not show any decrease. The irradiation response was relatively similar in both measuring sites and according to the model. Cuvette measurements showed slightly smaller quantum yields as a result from shading of the needles. The temperature dependences of the biochemical model parameters Jmax and Vc(max) were re-evaluated from the field measurements. The results for Vc(max) agreed well with earlier estimations, while the results for Jmax indicated relatively high values at low temperatures especially in northern Finland. Exponential fitting produced also substomatal concentrations of CO2, which agreed quite well with the model. The daily minimum of substomatal/ambient concentration ratio varied from 0.4 to 0.8.
  • Aalto, Department of Physics, P.O. Box 9, FIN-00014 University of Helsinki, Finland E-mail: tuula.aalto@helsinki.fi (email)
article id 673, category Research article
Lauri Palva, Eero Garam, Sari Palmroth, Raimo Sepponen, Pertti Hari. (1998). Utilizing a multipoint measuring system of photosynthetically active radiation in photosynthetic studies within canopies. Silva Fennica vol. 32 no. 4 article id 673. https://doi.org/10.14214/sf.673
Keywords: carbon dioxide; instrumentation; measurement; photosynthetically active radiation
Abstract | View details | Full text in PDF | Author Info
A novel multipoint measuring system of photosynthetically active radiation (PAR) has been constructed and operated within a Scots pine canopy. A regular grid of 800 measuring points has been incorporated into a cuvette to observe the spatial and temporal distribution of PAR incident on the needles of a twig along with simultaneous measurements of the CO2 exchange in order to determine the dependence of photosynthesis on PAR. It was shown that large errors can result if the photosynthetic rate is estimated using the mean value of PAR instead of the instantaneous values of PAR detected at given points in the region of the needles. The results demonstrate that the obtained regression between the CO2 exchange rate estimated using the multipoint PAR measuring system and the measured CO2 exchange rate is as good within a canopy as in unshaded conditions.
  • Palva, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: lauri.palva@hut.fi (email)
  • Garam, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: eg@nn.fi
  • Palmroth, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: sp@nn.fi
  • Sepponen, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: rs@nn.fi
  • Hari, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: ph@nn.fi
article id 696, category Research article
Jukka Lippu. (1998). Redistribution of 14C-labelled reserve carbon in Pinus sylvestris seedlings during shoot elongation. Silva Fennica vol. 32 no. 1 article id 696. https://doi.org/10.14214/sf.696
Keywords: Scots pine; root growth; carbon storage; 14C labelling; photosynthates; shoot growth
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This study examined the later use of 14C reserves formed in previous autumn in Scots pine (Pinus sylvestris L.) seedlings. The seedlings were allowed to photosynthesise 14CO2 in early September when shoot and needle growth was over. The following spring the seedlings were harvested in five samplings during the shoot growth period. The distribution and concentration of 14C were determined and the results were compared with the growth data. It was observed that reserves were not used markedly for the new growth. Most of the 14C was found in one-year-old needles (30–40%) and in the root system (40–50%) which was due to both their high activity as a storage sink and their large sink size. The high initial 14C-activity in the finest roots decreased indicating respiration of reserves. Only a small percent of the reserve carbon was found in the new shoots which indicated that reserves are of minor importance in building a new shoot. An allocation of about 15% of the autumn storage to the stem suggested that in seedlings the stem is of minor importance as a storage organ.
  • Lippu, Department of Forest Ecology, P.O. Box 24 (Unioninkatu 40 B), FIN-00014 University of Helsinki, Finland E-mail: jukka.lippu@helsinki.fi (email)

Category : Review article

article id 313, category Review article
Heikki Hänninen, Koen Kramer. (2007). A framework for modelling the annual cycle of trees in boreal and temperate regions. Silva Fennica vol. 41 no. 1 article id 313. https://doi.org/10.14214/sf.313
Keywords: frost hardiness; climatic adaptation; bud burst; climatic change; dormancy; phenology; photosynthetic capacity
Abstract | View details | Full text in PDF | Author Info
Models of the annual development cycle of trees in boreal and temperate regions were reviewed and classified on the basis of their ecophysiological assumptions. In our classification we discern two main categories of tree development: 1) fixed sequence development, which refers to irreversible ontogenetic development leading to visible phenological events such as bud burst or flowering, and 2) fluctuating development, which refers to reversible physiological phenomena such as the dynamics of frost hardiness during winter. As many of the physiological phenomena are partially reversible, we also describe integrated models, which include aspects of both fixed-sequence and fluctuating development. In our classification we further discern simple E-models, where the environmental response stays constant, and more comprehensive ES-models, where the environmental response changes according to the state of development. On the basis of this model classification, we have developed an operational modelling framework, in which we define an explicit state variable and a corresponding rate variable for each attribute of the annual cycle considered. We introduce a unifying notation, which we also use when presenting a selection of previously published models. To illustrate the various developmental phenomena and their modelling, we have carried out model simulations. Finally, we discuss the ecophysiological interpretation of the model variables, methodological aspects of the empirical development and testing of the models, the introduction of new aspects to the modelling, other closely related models, and applications of the models.
  • Hänninen, Plant Ecophysiology and Climate Change Group (PECC), Department of Biological and Environmental Sciences, Box 65, FI-00014 University of Helsinki, Finland E-mail: heikki.hanninen@helsinki.fi (email)
  • Kramer, Alterra, P.O. Box 47, 6700 AA Wageningen, The Netherlands E-mail: kk@nn.nl

Category : Research note

article id 10561, category Research note
Urszula Zajączkowska, Piotr Dąbrowski, Waldemar Kowalczuk, Grzegorz Tarwacki. (2022). Leaf photosynthetic capacity, trunk wood structure and stem xylem sap flow in 700-years old Quercus robur L.: a pilot study upon oak ‘Bartek’, a natural monument in Poland. Silva Fennica vol. 56 no. 3 article id 10561. https://doi.org/10.14214/sf.10561
Keywords: photosynthetic capacity; ‘Bartek’ oak; tree stem tomography; xylem sap flow
Highlights: Photosynthetic and hydraulic capacity of a 700-year-old Quercus robur is comparable to reference values from the literature measured in younger oak trees.
Abstract | Full text in HTML | Full text in PDF | Author Info

Physiological studies of long-lived trees are particularly important at this time, especially in light of the need for trees to adapt to global climate change. The results of the present studies were obtained on an approximately 700-year-old Quercus robur L. – the ‘Bartek’ oak. The tree has to adapt to changing climatic conditions, starting from the transition between the Medieval Warm Period and the Little Ice Age, up to the present time of rapid global climate change. Tomograph imaging showed decay of the tree trunk interior and revealed that undamaged wood forms a thin layer around the trunk perimeter. Two series of experiments were carried out to assess the physiological state of the tree. The first concerned measurements related to photosynthetic capacity: chlorophyll a fluorescence, gas exchange (CO2 assimilation, transpiration), stomatal conductance and leaf water potential. The second series concerned xylem sap flow velocity and anatomical studies of stem wood. Photosynthetic capacity was within the limits reported for young healthy trees. The diurnal pattern of velocity of xylem sap flow was also typical for young vigorous trees and flow velocity correlated positively with solar radiation and negatively with air relative humidity. Anatomical observations of the outermost wood showed relatively narrow annuals rings with large diameter earlywood vessels. The results indicate that the veteran tree does not show signs of water stress probably due to a good balance of water flow and that leaf area of the canopy needs only the current ring of wood to feed transpiration of the canopy.

  • Zajączkowska, Department of Forest Botany, Warsaw University of Life Sciences - SGGW, 159 Nowoursynowska Street, 02-776 Warsaw, Poland ORCID https://orcid.org/0000-0002-7119-7547 E-mail: urszula_zajaczkowska@sggw.edu.pl (email)
  • Dąbrowski, Department of Environmental Development Warsaw University of Life Sciences - SGGW, Warsaw, Poland ORCID https://orcid.org/0000-0002-2867-8839 E-mail: piotr_dabrowski@sggw.edu.pl
  • Kowalczuk, Ekosystem Waldemar Kowalczuk Tomasz Kowalczuk, Otwock, Poland E-mail: ekosystem@ekosystem.waw.pl
  • Tarwacki, Forest Protection Department, Forest Research Institute, Sękocin Las, Poland ORCID https://orcid.org/0000-0001-5979-7788 E-mail: G.Tarwacki@ibles.waw.pl

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