Suo - Mires and peat 32 (1981)

A survey about the recent state of the importance of mire-ecosystem models in Finnish circumstances was made. The developmental level of the models in question was in early 1970ies not very high. They were working models based mainly on the general sketches on an ecosystem. The task of the study project presented in this paper (Suo 4—5/1981) was to collect empirical raw material to relevant models of certain basic structures and functions of southern boreal mire-ecosystems. The project succeeded in giving dimensions and levels of the parameters concerning primary production of the mires in question. A dynamic model of the primary production of the whole community in a raised bog is being constructed. With regard to the decomposition pool some basic data on soil animal populations was collected, and the total decomposition was tried to determine. The vertical environmental gradients in the peat were found to be important. Although the results of the project could not much improve the models of ecosystem functions (Fig. 2) empirical material was produced available for mathematical modelling.

• Reinikainen, Sähköposti: ei.tietoa@nn.oo

The study was carried out in three ombrotrophic bog sites, a virgin pine bog (Kaurastensuo), a site with NPK-fertilization in 1970 and a site with NPK-fertilization in 1978 (plot no. 8 in Reinikainen & Lindholm 1980; Fig. 1). Samples for nutrient analysis were taken in October 1979, and the following total nutrients were determined: N, P, K, Ca, Mg, Cu, B. The amount of plant biomass and production was calculated according to Vasander (1981). The surface peat (0—20 cm) was very poor in nutrients compared to earlier observations in pine bog sites. In the site NPK -1978 there were probably still hails of slow-soluble fertilizers as the amounts of P and Ca were high in the ground layer (Fig. 1). The amounts of nutrients were usually proportionally higher in the field layer vegetation and the needles than were their proportions of biomass and production (Fig. 1, Table 2). However, there was little B and Cu in the needles except for in the site NPK-1978 (Fig. 1). According to the estimated nutrient budget (Table 3), 23.7 kg/ha K corresponding to 43 % of the added potassium was found neither in the surface peat nor in the vegetation. If it all had leached, the annual loss would evenly distributed be 2,63 kg/ha. This loss is of the same magnitude as leaching found in earlier studies of fertilized bogs, but appr. twice the value of virgin bogs. The budget was positive for phosphorus and nitrogen mainly because of the compression and increasing bulk density of the peat in NPK-1970. In the last years the supply of N and P has not been sufficient to maintain post-fertilization pine growth level.

• Vasander, Sähköposti: ei.tietoa@nn.oo

The seasonal fluctuation of runoff and nutrient contents and loads of bog waters were studied from April to October in 1980 in the drained and fertilized ombrotrophic bog in Lammi, southern Finland. The nutrient loads were calculated on basis of the observations in three small drainage basins (Table 1). The data included continuous runoff observations and weekly made water quality observations. The concentrations of N, P, K, Ca, Mg, Na and Fe were analysed; pH and conductivity were measured (Table 2). Nutrient contents varied more in one weir during the study period than between the weirs at certain sampling time. Concentrations and loads were clearly dependent on the runoff. The monthly loads of N, P and K varied significantly during the observation period. More than half of the observed leaching occurred during April and May. The losses of K and N were higher from the ditched and fertilized drainage basin than from the virgin area, but P loads were about the same in all the basins. Annual nutrient yields calculated for three ombrotrophic bog watersheds were generally low and quite similar to results in earlier studies.

• Lehmusvuori, Sähköposti: ei.tietoa@nn.oo

Cellulose decomposition rates and the vertical distribution of the activity of decomposers were studied during one year in the mires Heinisuo and Kaurasten-suo in the following mire site types: LuSN, TuSN, LkN, KR, RaR, TR, NR and RhNR. The most important factor controlling the decomposition was oxygen availability due to the ground water table and its stability. Another important factor was the temperature, as was seen when comparing the results of the summer and the winter observations. In some cases the decomposition activity depended on the trophic level of the mire site type, for example in the hollows of RaR, TR, NR, and RhNR.

• Tuominen, Sähköposti: ei.tietoa@nn.oo

Vertical distribution of soil mites, springtails and enchytraeid worms was studied in virgin and forest-improved parts of a raised bog Laaviosuo in Lammi in 1975 and -76. The forest-improving practices were drainage in 1966 and NPK-fertilization in 1970. The drainage had lowered the ground water table by 10—15 cm (Table 1.). In both the virgin and the drained study sites, the water table was deeper in the Sphagnum /uscu/n-dwarf shrub-dominated hummocks than in the S.angustifolium-Eriophorum-dominated hollows. Those micro-relief structures were considered as separate microhabitats. The ground water table was closely correlated with the topsoil moisture and it also stated the lower limit of aerobic conditions in the peat. In the hollows the animals were relatively more restricted to the uppermost soil layers than in the hummocks (Fig. 1). This was most probably due to the high water table and thin aerobic layer in the hollows. The distribution of enchytraeids and prostigmatid mites had changed after drainage so that a greater portion of animals lived in the deeper soil layers in relation to the virgin site. In the other animal groups no such difference was observed. The vertical distribution of enchytraeids and ori-batids is plotted against the ground water table in Figs. 2 and 3. The very significant correlations result from great differences between the microhabitats. Inside the microhabitats there were no close correlations (Table 2). In the samples taken from frozen soil most enchytraeids and oribatids were usually found in the deeper soil layers (Tables 3 and 4). This most probably resulted from active migration to avoid coldness. However, in the virgin site hollows the oribatids stayed in the topsoil, possibly because the waterlogged and anaerobic conditions in deeper layers are unsuitable for their overwintering.

• Markkula, Sähköposti: ei.tietoa@nn.oo

Three natural pine bog sites TR, NR and RhNR (see Ruuhijärvi & Reinikainen 1981, Lindholm 1981) in the mire Heinisuo were studied in 1980 with regard to certain parts of the soil fauna. Samples were taken monthly. The micro-habitats of the hummocks and hollows were treated separately. The results on animal numbers are presented preliminary. Nematods (Fig. 1) amounted to on an average 64 000—91 000 specimens/m2 in the uppermost 3 cm of the peat. There were no regular differences between the sites. Small amount of nematods was obviously due to too great sample pieces. Enchytraeids (Fig. 2) reached numbers of the same magnitude observed in other pine bog sites, 6 800—12 800/m2. There were less enchytraeids in the poorest habitat TR. The vertical and horizontal distribution as well as the seasonal fluctuation of enchytraeids were similar to those of the nematods. The occurrence of lumbricids and macro-arthropods (Table 1) showed greater differences between the micro-habitats than between the site types. The numbers were in general higher than those in the drier pine bog habitats IR and RaR (see Vilkamaa 1981, Markkula 1981).

• Raevaara, Sähköposti: ei.tietoa@nn.oo

The densities and biomasses of different soil invertebrate groups were investigated 1) in a dwarf shrub pine bog in its virgin state, 2) in a young (20 years) drainage area fertilized with NPK and 3) in an old (60 years) unfertilized drainage area of the same bog type. Monthly samples for nematodes, enchytraeids, micro-arthropods and macroarthropods were taken during the summers 1973 and 1974. The densities and biomasses of most animal groups were significantly higher in the drained sites in comparison to the virgin site. The average total biomasses were 2,38 g/m2, 5,84 g/m2 and 4,92 g/m2 for the virgin bog, young drainage area and old drainage area, respectively. Oribatid mites and enchytraeid worms consisted of 70—80 % of the total biomass in all the sites, the former dominating in the virgin bog, the latter in the drainage areas.

• Vilkamaa, Sähköposti: ei.tietoa@nn.oo

Cloudberry (Rubus chamaemorus) production was studied in 1979 in four mire site types. The number of sample plots (4 m2) was 272. RaR and IR site types were studied both in the virgin and drained state. The crop values obtained (VNR 40.6 kg/ha, others 26.5—31.6 kg/ha) were rather high compared to those of earlier studies. This was probably due to the absence of night frost during the flowering period. In drained site types the mean crops were appr. 74 °/o of those in virgin bogs. In drained IR the cloudberry crop was appr. twofold compared to that of the drained RaR.

• Jääskeläinen, Sähköposti: ei.tietoa@nn.oo

The growth rate of Sphagnum fuscum growing in the hummocks of an ombrotrophic raised bog was measured. The method used was a nylon textile strip, which was anchored in the peat so that the free end of the strip was above the hummock. The distance of a certain mark in the strip and the capitula of Sphagnum was measured weekly or biweekly. The data presented here are from the years 1976 and 1977. Moreover, the mire water table and daily precipitation was monitored. The annual growth of S. fuscum was about 10 mm, which was quite the same as in several previous studies around the Baltic sea. The importance of immediate moisture for S. fuscum growth was revealed. The correlation between growth and water table was r = 0,59, periods of zero-growth caused by low temperatures excluded. The periods when the growth was dependent only on the water table were grouped linearily on the upper margin of a correlation graph (fig. 2). Thus, they showed the possible maximum growth on different water tables when not restricted by any other factor. The points deviating from the regression line B (fig. 2) have different explanations. Partly they are due to low temperatures in spring and autumn, partly they depict the periods of unfavourable temperature or radiation conditions. Only in one case (1977, 10. fig. 1) the importance of direct seepage water from heavy rains was revealed. The results showed uninterrupted connection between water table and growth medium of S. fuscum. The mosses in general have been supposed to have quite an opportunistic strategy of growth. During the two growing periods studied this was seen concerning S. fuscum, too. There is in the background clear regulation, but, whether this is internally or externally governed, is not possible to conclude from this material and analysis.

• Lindholm, Sähköposti: ei.tietoa@nn.oo

On the basis of case material collected in the studies of Kosonen (1976), Ouni (1977), Vasander (1981a) and Solmari (unpubl.) and with references to Paavilainen's (1980) material a review was made on the primary production patterns of mires ameliorated for forestry (Fig. 1). The available data represented poorly the variation of mire types, fertility classes, improvements and succession time. As first examples from c. 5,3 million hectares of ameliorated mires in Finland the results were published. The total biomass and tree-biomass increased parallelly being dependent on site type, original tree stand, treatment and time (Fig. 1, Table 1). The biomass of lower vegetation layers developed more irregularly. The field layer with changing species composition maintained its biomass better than the ground layer, which suffered most from the decreasing moisture and increasing canopy shadow. Along all the succession the proportions of lower vegetation in biomass decreased steeply. In 40—60 years the biomass distribution reached appr. the state of pine forests on mineral soils. Higher biomass of field layer was a reminder of mire succession. Above ground production (Fig. 1, Table 1) changed less than the biomass, but mainly increased. The total efficiency of the community was after drainage 103— 187 %, and after additional NPK fertilization 150— 230 %, of that in virgin mire type. The distribution of primary production changed so that the proportion of tree biomass increased. However, the amount of stem growth did not increase in the same degree.

• Reinikainen, Sähköposti: ei.tietoa@nn.oo

The vegetation of a small kettle hole mire, which is situated near Lammi biological station in southern Finland and which has many different habitats, was mapped and a habitat map was constructed. The bio-mass and production of the vegetation in 13 different habitats was analyzed and measured. Moreover, some environmental parametres as fluctuation of ground water table was monitored. The vegetation of the mire consist of open and wooded habitats. The nutritional variation has eutrophic and ombrotrophic ends. There are also some special features due to the flooding and percolating water. An eutrophic habitat is VL. Mesotrophic habitats are TuSN, LuSN, RhNR, LuRhK. Oligotrophic habitats are SN, NR, KR, NK, KgK, Clear tendency to ombrotrophy have LkN and TR. Of these SN (almost), TuSN, LuSN, RhSN, VL and LkN are treeless habitats. The dry weight distribution from tree layer to ground layer mosses from all 13 habitats is presented. The material from field and ground layer was also grouped so that it illustrated the life form spectrum, trophic spectrum and spectrum of mire ecological factors, which can be seen in the dry weight relationship of the flora in different habitats. The greatest plant dry weight was found from dry and moderately fertile habitats. Ombrotrophy limits the production, but it does not prevent trees from growing. Wet habitats are treeless, but a moderately fertile substrate increases production. The eutrophic habitat was not the most productive one.

• Lindholm, Sähköposti: ei.tietoa@nn.oo

The vegetation as well as the biomass of the field and ground layers was described and the production of the field layer was determined in the following mire site types in 1979: LkN (ombrotrophic), SN (oligotrophic), RiN, RhSN (mesotrophic), VL, RiL, WaL (eutrophic). The total biomass was highest in RhSN (606.5 g/m2) and lowest in RiL (252.6 g/m2) due to the small cover of both layers. The production of the field layer was highest in those site types (RhSN, VL, SN) dominated by Carex rostrata. The highest biomass of the ground layer was found in the ombrotrophic LkN and the lowest in the eutrophic site types. Only in RiL this could be explained by the sparseness of the cover. When the total production was calculated by summing the field layer production with half the ground layer biomass, it was found to be highest in RhSN and lowest in the eutrophic site types RiL and RiN. The ombrotrophic LkN was placed in the middle of this series. It was concluded that high trophy which is partly correlated to wetness does not signify high production. It is, however, seen in the number of plant species and in the versatility of the production.

• Liedenpohja, Sähköposti: ei.tietoa@nn.oo

The total aboveground biomass and production of four mire site types (English names, see Ruuhijärvi & Reinikainen 1981) with rather stout tree stands were studied in Lammi, southern Finland. The o.b. volume of the stands was as follows: MK 251, MkK 167, LhK 120, MrK 83 m3/ha. The tree layer was proportionally the most significant component of the total biomass composing correspondingly 99,3, 98,3, 98,2 and 96,6 % of it. Among the spruce swamp sites the proportion of the ground layer increased as the shading of the tree layer decreased and the moistness of the site increased. At the same time the significance of the field and shrub layers decreased. The proportional annual production was highest in LhK (20,4 % of the biomass) where the tree stand consisted of hardwood species and the field layer of herbs. For this reason the absolute production also was higher there than in the spruce swamp sites where the production percentage of the communities was 3,4—5,8 %.

• Solmari, Sähköposti: ei.tietoa@nn.oo
• Vasander, Sähköposti: ei.tietoa@nn.oo

An example of this very common pine bog site type was analyzed in Vilppula, Central Finland in the zone of eccentric bogs in 1973 and 1974. The mean above-ground biomass and net-production of different layers and plant species was determined (Table 1 and Fig 1). The total above-ground biomass on this sample plot of IR pine bog was 1872 g/m2 and the total production 234 g/m2. The biomass was dominated by tree stand (80,5 %), but in the production the lower layers were better represented (field layer 38,5 % and ground layer 14 %). The distribution of biomass and production was rather similar to that of different ombrotrofic bog types studied (see Vasander 1981 c). The most prominent distinguishing feature was the smallnes of moss biomass and production in the IR site type.

• Kosonen, Sähköposti: ei.tietoa@nn.oo

The total plant biomass and production was studied in the eccentric raised bog Laaviosuo, Lammi, southern Finland in 1977 and 1978. For the study of field and ground layers the surface of the bog was divided into different plant communities: high hummocks, low hummocks, upper hollows, moist hollows and wet hollows with the proportions of 56.9, 17.3, 8.5, 10.5 and 6.8 % of the studied area (21 ha). For the material and methods see Lindholm & Vasander 1979, 1981, Vasander 1981 a, b. The total biomass of the bog was 1170.5 g/m2 and the total annual production 381.8 g/m2. The proportions of aboveground parts were 61 and 62 % respectively. Biomass proportions were: trees and seedlings 41 %, field layer 39 % and ground layer 20 %. Corresponding values for the total annual production were 10, 55 and 35 % (Fig. 1). In the hummocks the dominating species were dwarf shrubs and in the hollows, different Sphagnum species (Table 1). The total production of the studied bog was of similar magnitude as measured earlier in ombrot-rophic mire site types (Bacilevich 1967, Kosonen 1981) or somewhat smaller (P'yavchenko 1967, Kozlovskaya et al. 1978) due mainly to the differences in the ground layer values.

• Vasander, Sähköposti: ei.tietoa@nn.oo

The background, establishment, organisation, study strategy and topics of a project carried out from 1973 to 1981 was described (for more details, see Ruuhijärvi et al. 1979). Initially the Finnish Forest Research Institute supported the project. Since 1978 it has been financed by the Academy of Finland, and working facilities and equipment were provided by the Forest Research Institute, Lammi Biological Station, and the Institutes of Botany and Zoology at the University of Helsinki. The studies concentrated on the primary production and the decomposition of mire ecosystems mainly in the virgin state, but examples of amelioration successions were also analysed. The study sites (Table 1) were selected from the area of southern boreal mires, mainly within the zone of eccentric raised bogs (Fig. 1). This number of the periodical ""Suo"" contains the main results and summaries of the separate studies made within the project. The classification of site types was the Finnish one and the type names were used in the Finnish form. Therefore, it is essential to study the Table 2 in this article. "

• Ruuhijärvi, Sähköposti: ei.tietoa@nn.oo
• Reinikainen, Sähköposti: ei.tietoa@nn.oo

Soiden metsäojitusta on kritisoitu lähinnä sen vuoksi, että on katsottu sen aiheuttavan tulvariskin kasvua vesistön alapuolisissa osissa. Tulvan esiintyminen on suorassa yhteydessä ylivirtaamiin. Täten oleellisimmaksi kysymykseksi muodostuu, lisääkö metsäojitus ylivirtaamia? Selvityksessä tarkastellaan metsäojituksen vaikutusta ylivirtaamiin eräiden viimeaikaisten tutkimusten perusteella. Metsäojituksen havaitut hydrologiset vaikutukset vaihtelevat valuma-alueen koon ja virtaaman mittausaseman sijainnin mukaan. Tarkastelun kohteena on erityisesti ollut ojitusalueelta purkautuva virtaama; vähemmälle huomiolle on jätetty tässä yhteydessä koko valuma- tai vesistöalue. Virtaamatapahtumia kuvataan yleensä virtaaman aikakäyrän avulla, jossa voidaan erottaa nousukäyrä, huippu- eli yli virtaa-ma, resessiokäyrä sekä pohjavirtaama (ks. Kuva 1 ja Anon. 1976, s. 137). Ojitetun ja ojittamattoman suon virtaamien aika-käyrien analysointiin pohjautuvat tutkimukset ovat tuottaneet toisistaan melkoi-sestikin poikkeavia tuloksia. Eräiden tutki-musten perusteella ojitus lyhentää huippu-virtaaman esiintymisaikaa, nostaa huippu-virtaaman ja alentaa pohjavirtaaman tasoa (Malli A Kuvassa 2; ks. Mustonen ja Seuna 1971, Ahti 1980). Toisaalta on havaittu ojituksen pidentävän huippuvirtaaman esiintymisaikaa sekä alentavan huippuvirtaaman ja nostavan pohjavirtaaman tasoa (Malli B Kuvassa 2; ks. Multamäki 1962, Burke 1972, Heikurainen 1976 ja 1980). Edelleen voidaan olettaa, ja tämän suuntaisia havaintojakin on tehty, että edellä esitettyjen virtaaman aikakäyrien yhdistelmätyyppikin on olemassa (Malli C Kuvassa 2; ks. Seuna 1974 ja 1980). Kirjoituksessa pohdiskellaan valuma-alueen ominaisuuksien (topografia, kaltevuus, koko, kasvupaikka, turvelaji, pinta-turpeen vedenvarastoimiskyky, ojituksen tehokkuus, ojatyyppi jne.) ja sadetapahtu-man ominaisuuksien (sateen intensiteetti, puustopidäntä) vaikutuksia virtaaman aika-käyrään. Eri tutkimuksissa saadut toisistaan poikkeavat tulokset selittynevätkin ainakin osaksi edellä mainittujen tekijöiden avulla. Tarkastelun perusteella on pääteltävissä, että ojitus ilmeisestikin lisää virtaamien suurenemisen mahdollisuutta. Virtaamien todelliset muutokset riippuvat kuitenkin oleellisesti sadetapahtuman (tai lumen sulamisen) luonteesta, ojituksen tehokkuudesta ja alueen kasvillisuudesta, erityisesti puustosta. Vaikka metsäojitettu pinta-ala on maassamme suuri verrattuna suoviljelystä ja tur-peenkorjuuta varten kuivatettuun alaan, metsätaloudessa käytettyä ojitusta on kuitenkin pidettävä tehokkuudeltaan suhteellisen alhaisena. Edelleen otettaessa huo-mioon vuotuinen kokonaisvalunta ja ojitusalueen elpyvä puusto, ojituksen vaikutuksesta mahdollisesti lisääntyvä valunta tulee aikaa myöten pienenemään ja jopa asettumaan ojittamattoman vertailualueen valunnan alapuolellekin.

• Starr, Sähköposti: ei.tietoa@nn.oo
• Päivänen, Sähköposti: ei.tietoa@nn.oo

In the highlands of Burundi are mires more than 20 m deep. The great depth results either from high growth rate of deposits or from long accumulation time. Samples for radiocarbon datings have been taken from the depths of 5, 10, 15 and 20 meters (Table 1). The investigated mire is in the valley of the Buyongwe river, at an altitude of 1 400 m, where the mean annual temperature is about 18°C and precipitation about 1 150 mm (Lebedev 1970). The lower part of the peat deposit (10— 20 m) consists of well-humified (H 7—8) woody peat. The upper part (0—10 m) is formed of less humified (H 5—6) papyrus peat. Many undecomposed logs are at a depth of 5 to 10 m. 14C-age of the deepest sample is 8 650±120 years. Average long-term growth rate is 2.31 mm per year. The increase in growth rate from bottom to surface is partly apparent, partly real. The apparent increase comes from the fact that the lower part has been compressed. The real increase results from changes in the peat-forming vegetation. In its earlier phase the mire had tree cover. Later the vegetation changed to papyrus with a richer yield. The long-term growth rate in this mire has been about five times higher than in Eurasian mires (Zurek 1976). The 20 m thick peat deposit has accumulated during the last 8 700 years. The climate has been rather constant all the time. The absence of logs in the top meters is the result of human acitivity. Altitude effects peat formation. In low lying areas the decomposition of plant matter is faster than its production. There-fore peat cannot form. Plants with the richest yield cannot grow on mires at high altitude. The most favorable altitude for high growth rate seems to be from 1 300 to 2 300 m. The depth of this mire results from high growth rate rather than from long accumulation time.

• Pajunen, Sähköposti: ei.tietoa@nn.oo

Olemme tutkineet termogravimetristen suureiden merkitystä määritettäessä kuuman auman (A) ja kylmän auman (B) välisiä eroja. Totesimme, että reaktiokineettiset suureet poikkeavat huomattavasti toisistaan, mikä voidaan varsin selvästi todeta kuvasta 1., josta ilmenee kuuman auman reaktioiden nopeuksien huomattava ero eri kaasuatmos-fääreissä tapahtuvissa reaktioissa. lnfrapunaspektroskopia paljastaa myös sen tunnetun asian, että hydrolysoituvien aineiden määrä vaikuttaa huomattavasti aumojen itsepalamiseen. Näitä alustavia tutkimuksia on tarkoitus jatkaa ensi tuotantokautena siten, että pystyisimme suoraan kenttänäytteestä ennus-tamaan auman itsepalamisominaisuuksia. Myöskin tältä alueelta tehdyt alustavat kokeet ovat olleet rohkaisevia.

• Tummavuori, Sähköposti: ei.tietoa@nn.oo
• Venäläinen, Sähköposti: ei.tietoa@nn.oo
• Nyrönen, Sähköposti: ei.tietoa@nn.oo

The ground vegetation on three peatland sites in Ilomantsi (eastern Finland), drained for forestry some four decades ago, was investigated. The cover data were analyzed with principal component analysis (PCA) and detrended correspondence analysis (DECORANA) in order to see the main community types and major ecological gradients. The original peatland site type was identified by studying peat stratigraphy. The vegetation, especially on the Eriophorum vaginatum-dominated pine bog, is diverse including several types of plant communities. The communities form a mosaic that is differentiated by changing physical environment and biological effects, for example hummock-forming processes. Some communities are of heath forest character due to the influence of former drainage; some are kind of "relicts" from original quite wet and mesotrophic vegetation. The main community type is almost pure Eriophorum vaginatum-surface consisting of vital tussocks. It is probably not originally dominating community type but have become widespread due to the influence of incomplete forest drainage. Because the vegetation structure is a mosaic of diverse kinds of community types and successions, it is difficult to define major successional trend for the site as a whole. The classical generalizations of succession and climax are not very usable to explain the successional processes of peatland vegetation. On such kind of previously drained areas it is also difficult to define the original bog type and to estimate the site fertility for practical forestry purposes. Peat stratigraphy may give more information on this question.

• Kuusipalo, Sähköposti: ei.tietoa@nn.oo
• Vuorinen, Sähköposti: ei.tietoa@nn.oo

A pine afforestation experiment was set up on a peat cut-away area at Aitoneva, Kihniö (62°12'N, 23°19'E, elev. a. 160 m) in the spring of 1979. By the autumn of the same year the area had been naturally stocked with a great number of Betula pendula and B. pubescens seedlings. In the spring of 1980 an inventory was carried out to find out the effect of the various fertilization and soil amelioration treatments on the number of Betula pendula and pubescens seedlings and on their growth during the first growing season. There were 96 sample plots (20 m x 15 m). On each plot 16 systematically chosen plots, sized 0.25 m2, were measured. The number of normal, leader damaged and dead seedlings were recorded on each circular plot as well as the height of the tallest Betula pendula and pubescens seedling. The various fertilization and soil amelioration treatments are presented in Table 1. The birch row along the road on the western side of the experimental field (Fig. 1 and Table 2) was the main seeding tree stand. The number of birch seedlings was very high near the seeding trees. Even 100 metres from the row there were far more seedlings than are required by practical forestry (Fig. 2, Table 3). By adding phosphorus, potassium, nitrogen and wood ash, the number of seedlings increased (Tables 4 and 5, Fig. 3). Liming had an adverse effect and the fertilization with micronutrients affected sometimes negatively, sometimes positively (Table 5). In their first growing season the seedlings grew the better, the more they received phosphorus and potassium (Table 6 and Fig. 4). Similarly, nitrogen fertilization improved the growth of, seedlings. The best growth was achieved on wood ash fertilized plots and the poorest on limed plots (Table 7). A very good Betula pendula and B. pubescens seedling stand was naturally reproduced with the aid of quite few seeding trees on a peat cut-over area. Such seedling reproduction, as it entails no costs, should be further studied and considered as one of the alternatives in producing wood material for energy production.

• Kaunisto, Sähköposti: ei.tietoa@nn.oo

This paper deals with the mineral exploration with the help of mire vegetation, its trophic level (geobotanic) and peat chemistry (biogeochemistry). The study area (Fig. 1) consists of 1. aeroelectrical anomaly zones (6970 ha), where the bedrock potentially contains limestone or skarnrocks with zinc ore, but is without outcrops and covered by peatlands and 2. some granite (1170 ha), quartz diorite (240 ha), gabbro (1210 ha) and amphibolite (270 ha) regions for comparison. The so called calcium influence of differed clearly from others having meso-through the peat. The anomaly region differed clearly from others having meso-and eutrophic mire types 37 % of the area. On amphibolite base there were 15 % and on gabbro base 12 % of rich mire types. Neither granite nor quartz diorite regions had mire types above mesotrophic level, the corresponding percentages being 9 and 4 (table 2). Some properties of peat were measured from 228 surface peat samples, (5—10 cm below the surface, from the first slightly humified peat layer) and from 236 borer samples through the peat horizon (106 points). The correlation analyses (Table 4) and t-tests (Table 3) certified that pH, conductivity, ash and Ca content of peat indicate the trophic level of a mire type and that the type is influenced by the bedrock. Plant species and mire types they form can thus reliably be used as measurement for the nutrient status of mire and peat. The distribution of Ni, Cu, Zn and Pb were studied. The vertical distribution of those heavy metals and Ca resembled more or less the letter c (fig. 2 and 3). The minimum contents were generally in the middle layers, about 150 cm from the bottom of mire, where the correlation (table 4) between the measured properties were also weakest. Ni contents in the surface peat were very significantly positively (+ + +) correlated to the trophic status of mire vegetation. Rich, mire-margin effected types got the greatest values. Ni was the only metal which had a very significant correlation with Ca in the surface and in the bottom layers. The correlation analyses did not show any meaningful relationships between Cu contents and other parameters except for the ash content in 50 cm layer from the bottom and other metals. The highest individual contents in the surface peat were analysed from the samples of meso- and eutrophic types with mire-margin effect. Zn distribution was the most irregular. It has significant correlation only with Cu and Pb. Zn content had sharp variations in peat profiles. The maximum contents were often in the surface peat of oligotrophic types. Pb had a very clear maximum value on the surface peat. In this material, which contains a great amount of samples from the area probably with skarn ore, Pb had a very significant correlation to ash and other heavy metals in the surface. The correlations declined and disappeared in intermediate layers but came out as significant with Ca, Cu and Zn at the bottom. In general the highest contents in surface were often analysed on mire-centre-effected types as with Zn, too. Classifying and mapping vegetation is a useful method before all when locating limestone and skarnrock deposits. It has to be remembered that mire types reflect the bedrock in accordance with the characteristic nutrient situation. The peat of mire-margin effected type might have importance being an accumulator and binder of nutrients and heavy metals coming from the nearest surroundings of the mire. The minerotrophic types with mire-centre effect reflect very locally the mineral soil and bedrock below the mire and are suitable for mineral exploration. When prospecting heavy metals on areas without outcrops of bedrock and covered with peatlands the peat chemical method can be used in connection with other methods like geophysical and -chemical ones. Also then it is relevant to take into account the information given by plants and vegetation units. The results published of the vertical distribution of heavy metals do not always agree and the pnenomenon has to be studied in more detail. One has to consider, also here, the effect of mire characteristic nutrient status (mire-margin and -centre effect). Investigating both vertical and horizontal distributions of heavy metals in peat of different mire types we get, as I understand, important information for mineral exploration. This information would also greatly help to plan a well serving peat sample collecting.

• Elomaa, Sähköposti: ei.tietoa@nn.oo

The effect of water content and degree of humification on dry density of peat has been shortly dealt with. Term dry density of peat is being used here to express the quantity of dry matter of peat held in a unit of volume of peat in situ. The material was collected from different parts of Finland both from virgin and drained mires (Fig. 1). Figures 3 and 7 are based on material collected from Eastern-Canadian raised bogs (Korpijaakko 1975). Sampling was conducted using a piston sampler designed for taking volumetric peat samples (Korpijaakko 1981). To determine water content and dry density peat samples were dried at 105 °C. Water content is given as per cent of fresh weight except for Canadian material as per cent of volume. Dry density is expressed as kg/m3 or g/cm3. Ash content of Sphagnum peat samples varies between 1 and 2 % and Carex peat between 3 and 4 %. It is not substracted from the weight. There is a clear positive correlation between the degree of humification and dry density of Sphagnum peat (comp. e.g. Päivänen 1969, Korpijaakko ja Radforth 1972, Tolonen ja Saarenmaa 1979, Mäkilä 1980). This is deliniated by a straight regression line for Finnish peats in Figure 2 and for Canadian peats in Figure 3. The slight difference on the course of the lines is due to the fact that Finnish samples come from the conditions that regularly prevail in Finnish mires where as part of Canadian samples are obtained from a exceptionally dry and consolidated deposite near a five meters high peat cliff in Point Escuminac, New Brunswick. For sedge peat there is no significant correlation between degree of humification and dry density (Fig. 4). This comes from the fact that sedge peat differently from Sphagnum peat is rather dence in its structure already in low degree of humification. Thus only minor changes of weight per volume takes place when humification advances. There is a strong negative correlation between water content and dry density of both Sphagnum and Carex peat. Within the limits of water content met in Finnish peatlands (80—95 %) the correlations can be depicted with straight regression lines (Figs. 5 and 6). When the water content of peat in situ gets still much lower than this, the regression lines will curve to the left closing to certain maximum values of dry density. As to Sphagnum peat there would be several curves representing different degrees of humification as is shown in Fig. 7. For Carex peat, because of the lack of correlation between the degree of humification and dry density, there will still be only one curve, that would follow at its wet end the data points shown in Fig. 6. The evaluation of the content of dry matter and further the energy content of a peat deposit can not be based on the knowing of peat types and degrees of humification alone. Dry density values of different kinds of peat in the deposit have to be determined. The most reliable results are obtained if the calculations are based on a sufficient quantity of volumetric samples. If they are not available the diagrams such as in Figures 5 and 6 could be utilized. The preassumption is that good enough peat samples are available for correct determination of water content on weight bases.

• Korpijaakko, Sähköposti: ei.tietoa@nn.oo
• Häikiö, Sähköposti: ei.tietoa@nn.oo
• Leino, Sähköposti: ei.tietoa@nn.oo

Turpeen pH:ta mitattaessa on huomioitava aika. Jos mittaamme pH:n liian nopeasti, saamme kalkitsemattomalle turpeelle liian korkean pH-arvon, kun taas kalkitulle turpeelle saamme liian alhaisen pH:n. Yleensä kalkitus stabiloittaa pH:n mittausta (kuva 1). Metalli-ionien määrityksissä tarvitaan suhteellisen vahvat happoliuokset. Vasta 1M happoliuokset liuottavat ja irroittavat turpeesta kationiset hivenravinteet riittävän tehokkaasti. Vasta näin vahvoilla hapoilla voidaan myös eliminoida turpeen erilaiset ominaisuudet kationisten hivenaineiden pidättäjänä. Edellä esitetyistä syistä ei esim. ammoniumasetaatti sovellu uuttoliuokseksi nyt kyseessä olevia ioneja määritettäessä. (Vertaa taulukko 3). Menetelmän hitainta työvaihetta (2—3 h) ei voida nopeuttaa sillä, että suodatuksesta otettaisiin vain osasuodos ennenkuin suodatettava on huolellisesti pesty. Totesimme, että osasuodoksista saadut metallimäärät olivat vain 25—70 % todellisista kokonaispitoisuuksista.

• Tummavuori, Sähköposti: ei.tietoa@nn.oo
• Kaikkonen, Sähköposti: ei.tietoa@nn.oo
• Pennanen, Sähköposti: ei.tietoa@nn.oo

The protection of peatland complexes has been the starting point of peatland conservation planning. This level of consideration has been completed by investigating the different characteristics of mires (vegetation types, flora, fauna etc.) as well as their ecological and regional variation. The present condition of the most threatened peatland types and flora has been surveyed in the last few years. A particular inventory has been undertaken e.g. in Kainuu, northern Finland, where the drainage has decreased the are of natural rich fens approximately to one tenth. The inventory of rich fens in Kainuu was started by examining the literature, flora register and bedrock maps with explanations. The natural state of the areas was judged by using aerial photographs, and many sites were excluded from further studies as they were already drained. In the field work main attention was paid to each mire complex, mire types, meso-eutrophic and eutrophic flora, landscape and natural state. The ranking of rich fens was performed on the basis of the following criteria: quantity and variety of types and subtypes, number of meso-eutrophic and eutrophic plant species, species under threat, natural state of peatland complexes, stage of drainage and importance of regional situation of rich fens. At the moment only two of the rich fens in Kainuu are under protection, but in the basic peatland conservation programme there are seven new sites included. A supplementary plan of the basic programme contains 20 further rich fens, which are very remarkable according to this ranking system (Table 1). Therefore, the rich fen inventory in Kainuu has proved to be necessary.

• Kaakinen, Sähköposti: ei.tietoa@nn.oo
• Kukko-oja, Sähköposti: ei.tietoa@nn.oo

Chemical analyses of anaerobic ombrotrophic Sphagnum peats are presented from four southern Finnish raised bogs. Some characteristics of the study sites and samples are outlined in Table 1. Ranking of the elemental concentrations in Table 2 indicates that among the "trace metals", iron (380 ppm = 0.38 mg/g of dry peat) shows a greater mean concentration in deep ombrotrophic peat layers than the "macronutrients"" phosphorus (160 ppm) and potassium (100 ppm). The lowest averages were found for zinc (8.5 ppm), lead (6.0 ppm), manganese (5.7 ppm) and copper (1.3 ppm). Estimates of long-term accumulation rates of elements in peat (Table 2) are based on volume samples from radiocarbon or pollen-dated profiles (cf. Tolonen 1971, 1977). The average rate of nitrogen accumulation (3.6 kg ha-1 yr-1) appears to be somewhat lower than the corresponding values from Denmark (Jörgensen 1927), Sweden (Mattson & Koutler-Andersson 1955) and Germany (Aletsee 1967). A tentative comparison to watershed studies (Verry 1975, Kauppi 1979) suggests that roughly equal amounts of phosphorus are accumulated by ombrotrophic peat and lost by runoff waters, while in the case of nitrogen the retention by peat is relatively greater. The mean rate of past peat accumulation in the study material (50 g m-2 yr-1, cf. Table 1) is approximately 1/4 of the current mean annual production of Sphagnum fuscum (195 g m-2 yr-1, cf. Pakarinen 1978a) in the same area. A similar comparison of the past accumulation rates of chemical elements (Table 2) with the current retention (consumption) rates by the living moss layer (Pakarinen 1978a,b) gives the following order of elements (peat/moss % ratio in parentheses): N(26.4) > Mg(16.7) > Fe(14.5) > Ca(14.4) > P(11.9) > Zn(8.1) > Pb(7.2) > Cu(5.0) > Mn(0.8) > K(0.6). This comparison suggests that manganese and potassium are to a great extent depleted from peat (by recycling or leaching), while nitrogen is accumulated at about the same relative rate as organic matter. The relatively low percentage values of some elements (Zn, Pb, Cu) probably indicate an increase in atmospheric metal deposition in this century (cf. Aaby & Jacobsen 1979). Detailed budget calculations may not be possible, because no direct information is available on the atmospheric fallout or on the leaching rates 1000 or 2000 years ago. In any case it appears that on annual basis the past accumulation rates of chemical elements (exc. N) in ombrotrophic bogs are quite small. This study has been supported by the Natural Science Research Council, Academy of Finland (macronutrients) and by the Nessling Foundation (trace elements). "

• Pakarinen, Sähköposti: ei.tietoa@nn.oo

Kasvuturpeen ravinteiden analysoimisella on suuri merkitys sekä sen valmistajille että käyttäjille. Ravinneaineiden analysoiminen sinänsä ei ole kovinkaan vaikea tehtävä. Vaikeudet ovat näytteen otossa ja sen esikäsittelyssä analyysiä varten. Tässä työvaiheessa syntyvät suurimmat virhemahdollisuudet ja erot eri analyysimenetelmien vä-lillä. Suurimmat erot aiheutuvat seuraavista seikoista. 1. Eri menetelmissä analyysiin käytettävän turvenäytteen fysikaalinen tila voi poiketa huomattavasti, sillä käytetään ilmakuivaa, kuivattua sekä kostutettua turvetta ja lisäksi näytteet voivat olla joko sellaisenaan tai hienoksi jauhettua. 2. Analyysiin käytetty turvemäärä voi olla joko paino- tai tilavuusyksikköön perustuva. 3. Ravinteiden uutossa käytetään eri uutto-liuoksia, erilaisia uuttoliuosten ja turve-määrän suhteita ja erilaisia uuttoaikoja. Tässä työssä olemme selvittäneet kahden ehkä yleisimmin käytössä olevan menetelmän väliset erot ja vaikutukset pääravin-teiden analysoinnissa. Nämä menetelmät eroavat toisistaan käytetyn uuttoliuoksen (90 ml vettä tai 200 ml 0.5 M ammonium-asetaattia), turvenäytemäärän (40 ml tai 60ml) ja uuttoajan osalta (0.25 h tai 2 h). Osoittautui, että fosfaatin, nitraatin ja natriumin osalta ei menetelmällä ollut vaikutusta. Ammoniumasetaatti oli noin 30 % tehokkaampi kuin vesi uuttoliuoksena kaliumille ja 12—15 kertaa tehokkaampi kalsiumille ja 10 kertaa tehokkaampi magnesiumille. Kokeissa pyrittiin käyttämään turvetta, jonka kosteusprosentti oli 80 %. Silmämääräisessä kostutuksessa päästiin ±1.5 %:n tarkkuuteen. Lyhimmäksi riittävästi uuttavaksi uutto-ajaksi osoittautui 15 min., mutta suosittelemme 30 min. uuttoaikaa, jolloin eliminoituvat ajanottovirheet. Jos jatkuvasti analysoidaan tasalaatuista turvetta, jonka tiheys on vakio, niin tilavuusmitta voidaan korvata painomitalla analyysin tarkkuuden kärsimättä. Tämä nopeuttaa työskentelyä. Suosittelemme, että ammoniumasetaatti-uutosta siirrytään vesiuuttoon, jolloin saavutetaan useita etuja: voidaan hyvin käyttää 30 min. uuttoaikaa, laboratorio rea-genssikustannukset ja jätevesikuormitus pienenevät sekä vältytään ihottumalta, jota ammoniumasetaatti aiheuttaa joillekin henkilöille.

• Tummavuori, Sähköposti: ei.tietoa@nn.oo
• Kaikkonen, Sähköposti: ei.tietoa@nn.oo
• Nyrönen, Sähköposti: ei.tietoa@nn.oo

Dry density of peat — the quantity of dry matter of peat held in unit of volume of peat in situ — depends on several factors, the most important of which are peat type, degree of humification (comp. e.g. Päivänen 1969, Korpijaakko and Rad-forth 1972) and water content (Korpijaakko 1975). Thus knowing of peat types and their degree of humification is not enough for accurate evaluation of the amount of dry matter contained in a peat deposit. Undisturbed samples of known volume from different depths and sites are needed. A piston sampler for this purpose has been developped and applied in the Geological Survey of Finland. The sampler is a modified version of the stationary piston sampler used mainly for palynologieal studies in the Geological Survey. When the coring is performed the piston-cone component of the sampler is kept stationary while the sharpened cylinder is pushed down. Thus the vacume caused by the piston helds peat core on its place while the cylinder cuts it off from the surrounding matter. Because of the strong vacuum effect good samples are obtained also from wett deposit. The diameter of the new sampler is 10 cm (Fig. 1). The cylinder component is devided into three parts. The one in the center is the sample cylinder proper. Its length is 20 cm. The lowest part is 10 cm long. The peat held in this part prevents water from running out from the sample cylinder while the sampler is hoistened. The length of the topmost part of the cylinder is 20 cm. Its function is to hold at the end of the sampling procedure the piston- cone component plus the peat which was disturped while the sampler was pushed down. The cylinder parts are jointed with nuts, which are rotated on to the upper part when the sample is removed. Cylinders are made off stainless steel. Transparent plastic cylinders have been used, too. They are good only in the peat deposits with no sunken logs. The sample cylinder is driven into peat with a rammer. The sampler is hoisted with tongs, which are also used to keep piston-cone component stationary while taking a sample. The equipment is portable. 3—4 men are needed in sampling.

• Korpijaakko, Sähköposti: ei.tietoa@nn.oo

As a result of draining and fertilization, the numbers of a few mushroom species native to moist Sphagnum mosses have decreased while mycorrhizal mushrooms commonly found on mineral soil sites have become frequent. The material was collected in 1975—1976 from 38 experimental plots (comprising a total area of 1,16 ha) at the Alkkia experimental area of Parkano Forest Research Station (Salo 1979). The highest total mushroom yield, 528,3 kg/hectare (fresh weight, Table 1) on an average in 1975—1976, was obtained from the Sphagnum fuscum-Calluna plot treated with NPK fertilizer. High total yields were also obtained from plots fertilized with urea only. The mushroom yield was poorest in the virgin pine bog. Lactarius rufus was the most common mushroom species in this investigation. Its fruit bodies formed 86,8 % of the dry weight of the total mushroom yield. The fruit bodies of Paxillus involutus amounted to 8,3 % of the total mushroom yield. The largest amounts of mushrooms were found on plots fertilized in June 1975 with urea and NPK (Table 3). Other mycorrhizal species amounted to 3,5 % and the fruit bodies of saprophytic mushrooms to 1,4 %. Saprophytic mushrooms were common, for they formed 34,7 % of the fruit bodies collected. The total number of all collected fruit bodies was 27 205 in 1975—1976. During the growing seasons investigated the weather conditions differed greatly especially as regards the precipitation and the mean temperatures in September (Table 4). 1975 was a good mushroom year on peatlands. The production of fruit bodies on mineral soils was very poor in that year. 1976 was exceptional owing to the cold autumn and the dry spell in August. The growing season in 1976 was nearly one month shorter than that in 1975 with the result that the mushroom yield remained poor (Fig. 1.).

• Salo, Sähköposti: ei.tietoa@nn.oo