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  • Kalela, Erkki K. (Suomen metsätieteellinen seura, 1949)
  • Riihinen, Päiviö (Suomen metsätieteellinen seura, 1963)
  • Shirley, Hardy L. (Suomen metsätieteellinen seura, 1954)
  • Kubin, Eero; Kemppainen, Lauri (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1991)
    Air and soil temperatures were measured in 1974-85 in 3 clear felled areas and 3 neighbouring forest stands dominated by Norway spruce (Picea abies) in N. Finland. Daily temperatures were measured with thermograph plotters and maximum and minimum thermometers in meteorological screens (2 m above the ground), and a Grant device at 10 cm above the ground and at 5, 50 and 100 cm below ground level. Clear felling had no significant influence on air temperature at 2 m above the ground. The daily air temperature maxima at 10 cm were greater in the clear fell area than in the forest; the daily temperature minima at 10 cm were less in the clear fell area. Night frosts were more common in the clear fell area. Daily soil temperatures at 5 cm depth were 2-3 degrees C greater in the clear fell area than in the forest; temperatures at 50 cm and 100 cm depth were 3-5 degrees C greater. A sparse sapling stand developed from plantings and natural regeneration. Consequently, the differences between the clear fell area and the forest did not diminish during the 12 years following clear felling.
  • Silvola, Jouko; Välijoki, Jukka; Aaltonen, Heikki (Suomen metsätieteellinen seura, 1985)
    At sites in SE Finland, hourly respiration varied mainly in the range 100-500 mg CO2/msuperscript 2 with changes following those in soil surface temp. with a time lag of 3 h. After groundwater table was reduced by about 0.5 m, respiration increased 2.5-fold (resulting in a rate of peat decomposition considerably in excess of the rate of production of new organic matter in the peat). Application of fast-dissolving PK or urea rapidly increased soil respiration at the site poorest in nutrients. Ash gave the greatest steady increase. At sites rich in nutrients, fertilizer treatment reduced soil respiration for 1-2 yr. Treatment with micronutrients caused an intial reduction in respiration followed by a pronounced increase.
  • Finér, Leena (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1991)
    The effects of PK (plus Ca, Mg, S, Cl and B) and NPK (plus Ca, Mg, S, Cl and B) were studied (1984-87) in an 85-yr-old Scots pine (Pinus sylvestris) stand growing on a drained low-shrub pine bog in E. Finland. Fertilizer was applied in spring 1985. The amounts of elements applied (kg/ha) were: N 150, P 53, K 100, Ca 135, Mg 25, S 28, Cl 95 and B 2.4. The total dry mass of the stand before fertilizer application was 78 t/ha, of which above-ground compartments accounted for 69%. The annual above-ground dry mass production was 6.3 t/ha. The study period was too short to detect any fertilizer response in stems. Foliar and cone dry mass increased after NP or NPK fertilizer application, the dry mass of living branches increased after NPK fertilizer and the dry mass of dead branches decreased after PK or NPK fertilizer. The total dry mass accumulation was not affected. Trees in a control plot (no fertilizer) took up the following nutrient amounts annually from the soil (kg/ha): N 15.6, Ca 12.8, K 4.1, P 1.3, Mg 1.7, S 1.5 and Mn 1.5. The annual uptake of Fe, Zn, Cu and B was 510, 130, 70 and 50 g/ha, respectively. More than 50% of the nutrient uptake (except K and Fe) was released in litterfall. Fertilized stands accumulated more N, P, K and B. Fertilizer application inhibited the uptake of Mn and Ca.
  • Wilde, S. A.; Iyer, J. G. (Suomen metsätieteellinen seura, 1963)
  • Hallman, Erkki; Hari, Pertti; Räsänen, Pentti K.; Smolander, Heikki (Suomen metsätieteellinen seura, 1978)
  • Kubin, Eero; Kemppainen, Lauri (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1994)
    The effect of scarification, ploughing and cross-directional plouhing on temperature conditions in the soil and adjacent air layer have been studied during 11 consecutive growth periods by using an unprepared clear-cut area as a control site. The maximum and minimum temperatures were measured daily in the summer months, and other temperature observations were made at four-hour intervals by means of a Grant measuring instrument. The development of the seedling stand was also followed in order to determine its shading effect on the soil surface. Soil preparation decreased the daily temperature amplitude of the air at the height of 10 cm. The maximum temperatures on sunny days were lower in the tilts of the ploughed and in the humps of the cross-directional ploughed sites compared with the unprepared area. Correspondingly, the night temperatures were higher and so the soil preparation considerably reduced the risk of night frost. In the soil at the depth of 5 cm, soil preparation increased daytime temperatures and reduced night temperatures compared with unprepared area. The maximum increase in monthly mean temperatures was almost 5 °C, and the daily variation in the surface parts of the tilts and humps increased so that excessively high temperatures for the optimal growth of the root system were measured from time to time. The temperature also rose at the depths of 50 and 100 cm. Soil preparation also increased the cumulative temperature sum. The highest sums accumulated during the summer months were recorded at the depth of 5 cm in the humps of cross-directional ploughed area (1127 dd.) and in the tilts of the ploughed area (1106 dd.), while the corresponding figure in the unprepared soil was 718 dd. At the height of 10 cm the highest temperature sum was 1020 dd. in the hump, the corresponding figure in the unprepared area being 925 dd. The incidence of high temperature amplitudes and percentage of high temperatures at the depth of 5 cm decreased most rapidly in the humps of cross-directional ploughed area and in the ploughing tilts towards the end of the measurement period. The decrease was attributed principally to the compressing of tilts, the ground vegetation succession and the growth of seedlings. The mean summer temperature in the unprepared area was lower than in the prepared area and the difference did not diminish during the period studied. The increase in temperature brought about by soil preparation thus lasts at least more than 10 years.
  • Heikkilä, Risto; Mikkonen, Timo (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1992)
  • Heliövaara, Kari; Väisänen, Rauno (Suomen metsätieteellinen seura, 1984)
  • Lakari, O. J. (Suomen metsätieteellinen seura, 1919)
  • Renvall, August (Suomen metsätieteellinen seura, 1914)
  • Lönnroth, Erik (Suomen metsätieteellinen seura, 1926)
  • Heikinheimo, Olli (Suomen metsätieteellinen seura, 1915)
  • Cajander, A. K. (Suomen metsätieteellinen seura, 1923)
  • Yli-Vakkuri, Paavo (Suomen metsätieteellinen seura, 1961)