Articles by Juhani Päivänen

The development, structure, production and fertilisation of planted black spruce (Picea mariana (Mill.) B.S.P) and Scots pine (Pinus sylvestris L.) stands growing on a drained, originally treeless Sphagnum papillosum fen (LkKaN) in Central Finland up to the age of 30 years were studied. For black spruce the stem number was 2250 stems ha–1, dominant height was ca 7.1 m, the mean stand volume 26 m3 ha–1, the annual mean volume increment 1.5 m3 ha–1 and the total mortality based on stem number was 21%. For Scots pine the comparable characteristics were 1015 stems ha–1, 10.4 m, 45 m3 ha-1 , 3.3 m3 ha-1 and 59% respectively. Fertilisation had no apparent impact on the stand characteristics. About 63% of the planted black spruce individuals had at least one vegetatively generated layer. High number of layers seemed to have a negative effect on dominant parent tree growth. It is concluded that growth and yield of black spruce are generally not competitive in operational forestry in Finland. However, black spruce could be used as an alternative tree species in treeless areas that resist afforestation, and it might also be cultivated for decorative purposes.

• Sarkkola, Department of Forest Ecology, P. O. Box 27, Fin-00014 University of Helsinki E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

The effect of tree stand thinning and ditch network maintenance on the water table level was studied in an uneven-aged Scots pine (Pinus sylvestris L.) stand growing on a drained dwarf shrub pine bog in southern Finland. The water table level was monitored once a week during the growing seasons (May–September) of 1991–1999. This time span is divided into the following treatment periods: calibration (1991–1992), thinning (1993–1994), ditch cleaning (1995), and proper ditch network maintenance (1996–1999). The growing season of 1995 was not included in the calculations because the ditch cleaning treatment failed. The layout included three thinning intensities (9.5, 15.0, and 28.1% removal of the initial stand volume) and an unthinned control. For the ditch maintenance treatment there was an additional control sample plot. The effect of the treatments on the water table level was evaluated both by a graphical approach and linear regression analysis. Only a slight, ecologically insignificant rise in the water table level was caused by the thinning cuttings. Ditch maintenance seemed to eliminate this change. It was concluded that in the planning stage, a careful evaluation of the real need of maintaining the ditch network (ditch cleaning or complementary ditching) should be done in connection with the first commercial thinning in order to avoid unnecessary costs.

• Päivänen, Department of Forest Ecology, Box 24, FIN-00014 Helsinki University, Finland E-mail: ei.tietoa@nn.oo
• Sarkkola, E-mail: ei.tietoa@nn.oo

Scots pine (Pinus sylvestris) transplants (2+1+1 or 1+2 years old), the seeds of which had been collected from mire pines in different localities of South Finland, were planted in the early 1930s in a sandy Vaccinium site type at Tuusula (60°22´ N; 25°00´ E), north of Helsinki. The sample plots have been measured several times. At the time of the latest inventory the stands were about 50 years old. The stand development (standing volume, volume increment, dominant height, stem form) has been compared with the local mineral soil stands. The results show that seeds originated from mire pines produce offspring with form and growth (phenotypes) similar to those of pines originating from mineral soil. Keywords: Hereditary, mire, Scots pine, stand development, stem form, peatland

• Päivänen, Department of Peatland Forestry, University of Helsinki, Unioninkatu 40B, SF-00170 Helsinki, Finland E-mail: ei.tietoa@nn.oo

Peatlands complexes, site type classification and utilization of peatlands in northeast China are reviewed. The number of mire plant species common to both Finland and northeast China is about 120. Peatlands have been reclaimed for agriculture for a long time, but amelioration for forestry is only in the beginning. However, the potential of peatlands for forestry after drainage is considered high. Keywords: China, peatland complexes, peatland site types, peatland utilization.

• Zhao, Changchun Institute of Geography, Chinese Academy of Sciences, People's Republic of China E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

The paper discusses the nature of peatlands, peatland utilization and the research activity in this field in the German Democratic Republic. The discussion is based partly on literature and partly on a study tour the author took to the GDR in August 1984. A report in English delivered over to the Academy of Finland and the Academy of Science in the GDR who financed the trip is available at request from the author.

• Päivänen, E-mail: ei.tietoa@nn.oo

Estimations of the peatland area in Canada vary from 110 to 170 mill, hectares depending on the definition. Most of the peatlands are situated in the cool and humic boreal zone. The potential of peatlands for wood production especially in Newfoundland, Alberta and Ontario after amelioration (drainage, fertilization, afforestation) are discussed based on literature and several visits to these provinces.

• Päivänen, E-mail: ei.tietoa@nn.oo

The paper deals with the initial development of black spruce (Picea mariana) (Mill.) B.S.P., provenance St. John River Valley, New Brunswick, Canada), compared with that of native Scots pine (Pinus sylvestris) in a planting experiment on a drained smallsedge bog in southern Finland during the first thirteen years since planting. The results of the experiment showed that the every growth paramenter of black spruce was somewhat lower than that of Scots pine. Partly, the slow growth may have been connected with the stagnation period common to Picea species in general after planting. Also the provenance of black spruce is probably not the most suitable one to the conditions in southern Finland. It is considered to be worth-wile to continue follow-up studies. Especially the different nutrient requirements of the two tree species may turn out only later.

• Päivänen, E-mail: ei.tietoa@nn.oo

The paper discusses the research activity in the field of forest amelioration (including forest drainage, forest fertilization, afforestation etc.) on peatlands and forest hydrology in the Chechgslovak Socialist Republik. The discussion is based partly on literature and partly on a study tour the author took to CSS in June 1981. A report in English delivered over to the Academy of Finland and the Czechoslovak Academy of Sciences who financed the trip is available at request from the author.

• Päivänen, E-mail: ei.tietoa@nn.oo

• Starr, E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

The layout of a drainage system for a milled peat harvesting site is seen in Fig. 1. The ditch spacing used is 20 m and the ditches are about 1.5 m deep. However, sometimes it is necessary to use subsurface drains to increase the drainage effect of open ditches. In the rick areas at the end of the strips, where the harvested peat is stored, subsurface drains are the only method to drain the peatlayers. Eight different kinds of subsurface drains were tested in summer 1978 at Kaikonsuo (63°40'N, 26°40'E) peat harvesting field managed by The State Fuel Centre (VAPO). Two experimental fields were laid down: one in the strip area (Fig. 2) and the other in the rick area (Fig. 3). Five of the subsurface drain types used in the experiment were so called material drains: a board pipe drain with an inner cross-section of 64x102 mm (Fig. 8), and two sizes of plastic pipe drains (PVC) with an inner diameter of 40 and 65 mm. Two types of both drainsizes were used, one of which was bare (Fig. 9) the other covered with a filter material (Fibertix; Fig. 10). Three types of "nonmaterial" subsurface drains were tested in the experiment: a mole drain made with the Pajulahti Oy mole drain trencher (Fig. 4 and 5), a mole drain made with the VAPO mole drain plow (Fig. 6), and a narrow water furrow made with the Suokone Oy disc trencher. The ground water level in each drainage treatment was measured once a week. In the strip area, in each treatment, there were measuring wells in two rows; five in a row. In the rick area there were five wells in each treatment. In the strip area (Fig. 11) the distance to the ground water level in the control strips was about 50 cm. The mole drains or the narrow water furrows did not have any effect on the ground water level. The board pipe drains had the greatest lowering effect on the ground water level. In the strips with the plastic pipe drains the distance to the ground water level was about 80 cm. In the rick area the results obtained with the board pipe drain, with the mole drains and those of the control were similar to the results of the strip area. In the treatments drained with the plastic pipe drains the distance to the ground water level varied from 55 to 95 cm. The filter material did not increase the drainage effect of the pipe drains as expected, the case was rather the reverse. It would be necessary to continue the experiment to find out the duration of the drainage effect reached with the different kinds of subsurface drains and, after that, to make economical calculations on the profitability of the types of subsurface drainage studied.

• Menonen, E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

The paper deals with the extent of peat-land utilization for different purposes such as forestry, agriculture, peat mining, berry picking, water reservoirs, peatland conservation, etc. It appears that in some cases it is possible to use the same peatland area for several purposes at the same time (multiple use). However, sometimes the use of a particular peatland area is so intensive that no other uses are possible. For this reason a special council for peatland research and utilization was appointed by Suoseura (Finnish Peatland Society) in the spring 1976. The task of this council is to coordinate all activities in this field.

• Päivänen, E-mail: ei.tietoa@nn.oo

This study is a sequel to papers previously published on the possibilities of extending the period of planting Scots pine (Pinus silvestris L.) on drained open peatlands over the entire growing season (Päivänen 1968, 1971), The study was carried out using the same plots as in the experiments described in the above-mentioned papers. This final investigation was carried out in order to find ou t whether the differences recorded in the previous studies had been leveled out or accentuated when 9—11 growing seasons in the field had elapsed since planting. As the smallest unit which the study was based on was a single row of young trees, the study must be considered as being completed by now. This is because the interactions between adjacent tree rows will become significant as soon as the crowns and root systems get closed. Mortality still increased by a few per cent units during the last 5—6 growing seasons. This increase, however, was of similar magnitude irrespective of the planting date. In the mean height of the trees, on the other hand, the differences caused by differences in the planting date were clearly visible in the final inventory (Figs. 1—3). The differences in height development had even become accentuated by the time of the final inventory, 9—11 growing seasons after planting. A clear correlation was observed, in the case of all experimental members, between the mean heights recorded in the final inventory and that carried out after the trees had spent four growing seasons in the field (Fig. 5). According to the results obtained the season-alness of planting work can be decreased on drained peatlands by extending the planting season of pine till the turn of the month between July and August. Plantings performed in the fall usually proved slightly less successful than those carried out in June and July. The nursery ought to be situated close to the areas to be planted since the handling and transportation of unrooted plants during the growing season must take place with extreme care.

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Mannerkoski, E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

• Mannerkoski, E-mail: ei.tietoa@nn.oo
• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo
• Seppälä, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo
• Seppälä, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Päivänen, E-mail: ei.tietoa@nn.oo

• Paavilainen, E-mail: ep@nn.fi
• Päivänen, E-mail: juhani.paivanen@helsinki.fi
• Saarinen, E-mail: ms@nn.fi

• Päivänen, E-mail: juhani.paivanen@helsinki.fi

• Päivänen, E-mail: juhani.paivanen@helsinki.fi

• Päivänen, E-mail: juhani.paivanen@helsinki.fi

• Päivänen, E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto, Metsätieteiden osasto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto, Metsätieteiden osasto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto, Metsätieteiden osasto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, Helsingin yliopisto, Metsätieteiden osasto E-mail: juhani.paivanen@helsinki.fi
• Päivänen, E-mail: tp@nn.fi

• Päivänen, Helsingin yliopisto, Metsätieteiden osasto E-mail: juhani.paivanen@helsinki.fi

• Päivänen, E-mail: ei.tietoa@nn.oo

• Ojanen, Helsingin yliopisto E-mail: paavo.ojanen@helsinki.fi
• Aapala, Suomen ympäristökeskus E-mail: kaisu.aapala@syke.fi
• Hotanen, Luonnonvarakeskus E-mail: juha-pekka.hotanen@luke.fi
• Hökkä, Luonnonvarakeskus E-mail: hannu.hokka@luke.fi
• Kokko, Suomen ympäristökeskus E-mail: aira.kokko@syke.fi
• Minkkinen, Helsingin yliopisto E-mail: kari.minkkinen@helsinki.fi
• Myllys, Luonnonvarakeskus E-mail: merja.myllys@luke.fi
• Punttila, Suomen ympäristökeskus E-mail: pekka.punttila@syke.fi
• Päivänen, Helsingin yliopisto E-mail: juhani.paivanen@helsinki.fi
• Rehell, Metsähallitus Luontopalvelut E-mail: sakari.rehell@metsa.fi
• Turunen, Geologian tutkimuskeskus E-mail: jukka.turunen@gtk.fi
• Valpola, Geologian tutkimuskeskus E-mail: samu.valpola@gtk.fi
• Vähäkuopus, Geologian tutkimuskeskus E-mail: tuija.vahakuopus@gtk.fi

• Sarkkola, Luonnonvarakeskus E-mail: sakari.sarkkola@luke.fi
• Päivänen, Helsingin yliopisto E-mail: juhani.paivanen@helsinki.fi