Articles containing the keyword 'tase'

A process-oriented tree and stand growth model is extended to be applicable to the analysis of timber quality, and how it is influenced by silvicultural treatments. The tree-level model is based on the carbon balance and it incorporates the dynamics of five biomass variables as well as tree height, crown base, and breast height diameter. Allocation of carbon is based on the conservation of structural relationships, in particular, the pipe model. The pipe-model relationships are extended to the whorl level, but in order to avoid a 3-dimensional model of entire crown structure, the branch module is largely stochastic and aggregated. In model construction, a top-down hierarchy is used where at each step down, the upper level sets constraints for the lower level. Some advantages of this approach are model consistency and efficiency of calculations, but probably at the cost of reduced flexibility. The detailed structure related with the branching module is preliminary and will be improved when more data becomes available. Model parameters are identified for Scots pine (Pinus sylvestris L.) in Southern Finland, and example simulations are carried out to compare the development of quality characteristics in different stocking densities.

• Mäkelä, E-mail: am@mm.unknown
• Ikonen, E-mail: vi@mm.unknown
• Vanninen, E-mail: pv@mm.unknown

Seasonal changed in total nitrogen, protein, amino acid, ammonia, nitrate and nitrite concentrations, and nitrate reductase and γ-glutamyltransferase activities in the needles, buds and shoots of young Scots pine (Pinus sylvestris L.) were studied. A relationship between the variation in the nitrogen metabolism and both winter dormancy and its breaking was proposed. Pine tissues stored soluble nitrogen over the winter largely in the form of arginine which, in addition to a high nitrogen content, can neutralize acidic cytoplasmic constituents such as nitrates and nitrites. Specific nitrate reductase and γ-glutamyltransferase activities were highest in late summer or autumn, and is apparently connected to the mobilization of nitrogen reserves for the winter.

The PDF includes an abstract in Finnish.

• Lähdesmäki, E-mail: pl@mm.unknown
• Pietiläinen, E-mail: pp@mm.unknown

A monitoring program is planned for the terrestrial environment around industries in Sweden, which emit acid compounds and heavy metals. Directions for the County Government Boards are being prepared. The paper deals with the present pollution situation in Sweden, based on recent scientific results, the justifications for local monitoring, and the organizing of the monitoring including the parameters suggested.

Four examples from a case study at an oil power station illustrate reporting of the data and the difficulties in interpreting the results. The examples are the distribution of a lichen indicator, heavy metal content and phosphatase activity in the moor layer, soil respiration and tree growth.

• Westman, E-mail: lw@mm.unknown

The investigation is concerned with testing chemical totalizer of radiation (Frankfurt radiometer) for use in measuring the components of a simple energy balance (latent heat = net radiation – sensible heat) so as to gain an estimate for evaporation. The meter is based on the temperature dependence of the inversion rate of sugar solution. The relationship is exponential. It was found that radiation sums for 2–6-day periods can be reliably determined with this meter when global radiation is below 20 MJ·m^-2d^-1. Determining sensible heat is noticeably inaccurate, and hence the calculation of evaporation values, too. In comparing evaporation from different types of ground and plant cover one thus has to be content with drawing conclusions on the basis of net radiation values. The totalizer is therefore only suited to describing radiation conditions.

The PDF includes a summary in Finnish.

• Mannerkoski, E-mail: hm@mm.unknown

This study was carried out on behalf of the Central Association of Finnish Forest Industries (now Finnish Forest Industries Federation) in order to obtain information about the wood raw material situation, to serve, in turn, as a basis for the forest industries’ long-term planning. The study deals with the potential supply of roundwood, industrial residue and forest residue by the year 200 by five wood-supply areas. Examination of the situation during the period of 1972–80 is based on available balances and that concerning the period 1985–2000 in the estimated quantities available for industrial use.

The PDF includes a summary in English.

• Suomen Metsäteollisuuden Keskusliitto, E-mail: –

The significance of water budget in June and July for forest and peatland vegetation, and consequent effects on fauna, climate and agriculture has been studied.

In June, the difference between evaporation and precipitation is greater than it is later in the summer. North of the line zero difference of evaporation and precipitation, coinciding with a line of sharp change in forest vegetation, the uppermost part of podsol remains wet throughout the summer. During July, the line of zero difference moves from north to south over the greater part of Finland, run-off being minute and podsol at the driest in this month. This line, indicating the length of the period with evaporation greater than precipitation and causing a sharp change in forest vegetation, in frequency of peatlands, amount of growing stock productive capacity of forests etc. This line is significant also for cultivation: because of the lower evaporation north of this line, night temperature below the freezing point often appear in summer.

The PDF includes a summary in English.

• Solantie, E-mail: rs@mm.unknown

The Finnish forest industries have doubled their use of wood raw material during the past two decades. The average annual overcut of 4.0 million m³ in 1960–64 has been turned into an average annual surplus of 2.7 million m³ in 1965–69. By 1974 industry’s requirements for domestic roundwood would increase by about 6.3 million m³, if all new capacity can be taken into full production. The MERA allowable cut, if realized, would leave a 1.5 million m³ annual surplus in the forest balance in 1974. Less intensive forestry programs would mean a 1.5 to 4.4 million m³ overcut in 1974.

The PDF includes a summary in English.

• Linnamies, E-mail: ol@mm.unknown

• Dzerdzeevskii, E-mail: bd@mm.unknown

The financial accounting of the forestry needs redefining in Finland due to the effect of forest improvement, especially peatland drainage, on timber balance and valuation of forest land. The aim of the study was to develop methods to determine the timber balance using a separate forest land account. The problems of timber balance are related to the technical methods to assess timber balance and the cost of the work, quantitative determination of the profit, and qualitative determination of the profit. One main problem is to whether to define the quantitative profit as a sustainability of timber resources or difference in the allowable cut and outturn. The article discusses the strengths and weaknesses of the methods, and concludes that regardless of the method that is used to calculate the timber balance, profit or loss accounts have less exact nature in forestry than in other sectors. Replacing reliably calculated revenue surplus with operating result based on timber account would lead to tentative results.

The PDF includes a summary in German.

• Keltikangas, E-mail: vk@mm.unknown

The field of work of the 7th National Forest Inventory was carried out during 1977–84. This report consists of the analysis of the forest resources, long-term development of forests and the results by ownership categories in Finland.

The area of forestry land, 26.4 million ha, has decreased slightly because of the increase of build-up areas and communication routes. Forest land, which is suitable to growing wood profitably, amounted 20.1 million ha. It has increased, although not as fast as earlier, due to drainage and fertilization of scrub and waste land swamps and the afforestation of agricultural land.

The growing stock volume was 1,660 million m³ and the estimated gross annual increment 68.4 million m³. A large quantity of young, rapidly growing stands, and fellings markedly below the increment, are the principal factors increasing the growing stock. The volume of Scots pine (Pinus sylvestris L.) has increased most but the greatest proportional increase has been in the volume of broadleaved trees.

The silvicultural quality of stands has improved and the increase in saw log tree volume has resulted in an increase in the total growing stock volume. The proportional volume of saw logs, however, has decreased. Both aging mature stands and postponed thinnings increase the risk of losses due to mortality and decay. Too dense stands retard the diameter growth of trees. The proportion of unsuccessful artificial regeneration has increased.

The area of private forests has slightly decreased, while companies and collective bodies have increased their ownership. Non-farmer private ownership already accounts for one half of the area of private forests. The silvicultural quality of company forests is best and the increase of the growing stock and its increment is proportionally greatest in these forests.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown
• Salminen, E-mail: ss@mm.unknown

The paper aimed at testing the potential of refining tree rot diagnostics carried out by means of electrical impedance tomography (EIT). Examined was the use of EIT datasets with electrical resistance values and sapwood proportion determined on the basis of tomograms. Making use of datasets with resistance values in EIT rot diagnostics is not a default method, although datasets stay unaffected by a fixed colour scale and subsequent subjective evaluation unlike tomograms. Tomography measurement was carried out for 27 individuals of Norway spruce (Picea abies [L.] Karst.) in two stands north-east of Brno, Czech Republic. Once felled down, radial cut-outs were sampled at the measurement site and used for localising rot and determining the extent of the area of decay. The results were subsequently compared with tomograms. EIT datasets containing values of electrical resistance found by measuring were statistically processed and compared with the extent of rot area identified within the cuts. Sapwood proportion values were also detected using the tomograms. The baseline assumption that sapwood proportion decreases as the rot area in the radial cut expands was confirmed. In trees with rot percentage to 35% approximately, sapwood proportion was exceeding 30% except one tree. In trees with rot percentage exceeding 35%, sapwood proportion was below 30%. On the basis of interpreted datasets, the trees can be split into three characteristic groups that correspond to the occurrence, extent and nature of the rot.

• Humplík, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: premysl.humplik@mendelu.cz
• Čermák, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: petr.cermak@mendelu.cz
• Žid, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: tomas.zid@mendelu.cz