A simple, manually-operated and easily portable device for sampling volumetric soil cores to a depth of 100 cm with a minimum soil disturbance is described. The device consists of a sample tube, a sampler and an extension tube. A dead blow nylon mallet is used to force the sampler into the soil and a small winch attached to an aluminium tube pulls the sampler from the soil. The total weight of the equipment (sampler, mallet and winch) is 18.5 kg and may be carried in the trunk of a small car. Sampling is easily done by one person in good physical condition but four-handed operation is recommended as more efficient. The sampling device has been in heavy use during the summers of 1993–95 when several hundred soil cores have been extracted on various sites all over Finland.
Coniferous and non-coniferous fine root and rhizome production was measured after one growing season using the ingrowth bag method in Scots pine (Pinus sylvestris L.) stands differing in ages from 7 to 105 years in Southern Finland. Total fine-root production decreased from the 7-year to 20-year-old stands, and then increased slightly in the 85- to 105-year-old stands. Most of the total fine-root biomass in the youngest age groups came from non-conifer species, whereas most of the total fine-root biomass in the three older age groups came from conifer species. The maximum coniferous fine-root production was found to occur at crown closure in the 11- to 13-year-old stands. Rhizome production was the lowest and highest in the 20- and 85- to 105-year-old stands, respectively. The increase in rhizome production in the 85- to 105-year-old stands was associated with an abundant understory cover of Vaccinium myrtillus and V. vitis-idaea and an increase in light penetration. The ingrowth bag method was found to be useful in assessing the relative fine-root production among species-group and successional stages of Scots pine stands.
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The structure of 20 Scots pine (Pinus sylvestris L.) trees was analysed as a water transport system. There is a tight linear regression between the cross-sectional area of the stem at the height of its lowest living branch and the cross-sectional area of its coarse roots, between the cross-sectional area of the stem at the height of its lowest living branch and the total cross-sectional area of its branches, and between the cross-sectional area of the base of a branch and the total cross-sectional area of subsidiary branches of that branch. The capacity of successive organs, measured as cross-sectional areas, to transport water was thus found to be regular within a tree.
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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.
The anatomical variation of a lateral root was compared with that of the stem of the same tree at breast height by concentrating on the intrelationships of certain anatomical features in Betula pendula and B. pubescens. The results showed that root wood has several essential features of stem wood, such as gelatinous fibres, growth eccentricity, scalariform perforation plates in the vessels and pith flecks. However, some of the anatomical differences are significant. The differences between the species were more pronounced in the root than in the stem anatomy.
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Length variation of fibres and vessels was studied in the branches, stems and roots of Betula pendula Roth and B. pubescense Ehrh. The cells were significantly shorter in the branches and roots than in the stems. There was no significant difference in the cell length between the upper and lower radii of the branches and roots. The length increased from the pith to the surface and decreased in the branches and stems from the base onwards. In the roots the length increased in that direction. The differences between the tree species were small although the cells of B. pubescens were a little longer.
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The amounts of harvestable logging residues and stump and root wood were examined in the area where 100,000 solid m3 of stemwood was cut in 1975. The cutting amounts of stemwood from work sites suitable for harvesting of logging residues was 35,000 m3, and suitable for harvesting of stump and root wood 38,000 m3. The increase in the yield of wood (without bark) from logging residues compared with the unbarked stemwood was 2.4%. The same percentage of wood from stump and root wood was 5.0–5.8% depending on the harvesting loss.
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In this study an attempt was made to use manometric Warburg technique in studying the growing season variations in the respiration rates of the roots of 1–3-year-old seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.). The respiration rates in both short-roots and long-roots have also been investigated.
According to the results, respiration intensity was the greatest in Scots pine and Norway spruce short-roots but also considerable in the long-root tips at the points of elongation. When the oxygen uptake rate per weight unit in the pine short-roots is given value of 100, the rate in the long-root tips is 61 and in the basal area 36. The corresponding values for spruce are 100, 69 and 43. The relative carbon dioxide release rates are different for the basal parts of the long-roots: pine 53 and spruce 57, when the CO2 release from the short-roots is 100. The CO2 release rate in the basal parts of the long-roots is relatively greater than the oxygen uptake. The respiration rate of the root systems of pine was larger than that of spruce due to the larger size of the root system.
The respiration rate per unit weight of pine roots of the 1- to 3-year-old seedlings decreases significantly with the increasing age. In spruce, the decrease was smaller. The result could have been different if only the short-roots of the same growing season were studied from all seedlings.
During the first growing season the root respiration rate decreased from the middle of the summer towards autumn. An experiment with pine seedlings grown in the mineral soil showed a very rapid increase in respiration rate in the spring. The rate, especially oxygen uptake, is at its greatest in the roots at the time of fastest growth.
Draining transforms root systems of trees growing in peatlands towards the ones growing on mineral soil. However, even after efficient draining the root systems differ from the root systems of trees growing on mineral soil. This investigation concentrates on root systems of forests of similar mire types growing in similar draining conditions but having different tree species compositions. The peatland, situated in Pieksämäki in Southern Finland, was drained in 1937. Sample plots, measured in 1956, consisted of mixed forest of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and birch (Betula sp.) in different compositions, and were in natural condition.
The sedge pine bog studied in this investigation was shown to have larger total amount of roots and mycorrhiza than in previously studied dwarf shrub pine bogs. This reflects better growth conditions of the better site. The depth of root system was, however, similar. Root systems of birch were deeper than those of the coniferous tree species. Differences between Scots pine and Norway spruce were small. Corresponding differences between the species were found in the density and total number of mycorrhizas. The abundance of mycorrhizas in the roots of birch increased in deeper layers of peat, but decreased especially in spruce roots. In earlier studies the abundance of mycorrhizas decreased in the roots growing in deeper layers in pure Scots pine stands, but no such variation was seen in this study. The result suggest that the deep root system of birch may affect also the root systems of the coniferous trees. On the other hand, birch roots can have advantage over the coniferous trees.
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The purpose of the investigation was to study the amount, quality and distribution by layers of depth of horizontal roots in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) stands in Southern Finland. The sample plots included stands on soil varying from sandy to stony, and stands of varying ages from seedling stands to an old stand, in Myrtillus and Vaccinium type forests.
In a Norway spruce stand, the amount of roots increases rapidly and reaches its maximum, about 450 meters/m3, at an age of 100-110 years. In a Scots pine stand the maximum, about 370 m/m3, is reached earlier, at an age of 60-70 years. The root system of pine expands more rapidly than that of spruce. The total length of the horizontal root system of pine amounts to 1,000 m soon after 40 years of growth, of spruce at the age of 60. Later the situation changes, and at the age of 110 the root systems of both species are about the same size, but older trees of spruce have more extensive root system.
Majority of horizontal roots are under 1 mm in diameter. Of the horizontal roots of spruce stands the majority lie in the humus layer and in the topmost mineral soil stratum. Over half of horizontal spruce roots are, thus, at a maximum depth of 5 cm, while majority of the roots of Scots pine lie at maximum in depth of 10 cm. At the same layer grow also the roots of the ground vegetation, which may affect the competition between the species.
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The article contains a literature review about the spatial order of plants and a description of the small-scale experiments with corn. The literature is primarily of German origin. The question of the spatial conditions of trees in forest is important for practice of silviculture. The first part of the article illustrates based on the literature the importance of roots and root concurrence for the development of plants or forest stands. The second and third part deepens the methodological knowledge on root research. Fourth part is the field experiments with corn. There are no clear relation to be found between yield and the number of plants.