Suo - Mires and peat 29 (1978)

In this work we have investigated the possibilities of the thermogravimetry (TG) to be applied to the peat research as well as to the rapid quality control of the peat products. It is shown, that the moisture content, the volatile matter and the ash content of the peat can be easily determined from the TG curves. Further, the pyrolysis of the peat in various atmospheres can be investigated. The effect of the temperature rate and the carbonization time to the coke yield was also a subject of this study. Further investigations involve the calculations of the rate constants and the activation energies. Also, the products during the pyrolysis are of interest.

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

Concentrations of five metals — Mn, Fe, Zn, Pb, Cu — were determined in samples of a common dwarf shrub, Ledum palustre, collected from seven S. Finnish raised bogs (between 60 and 61 °N) in September-October 1977. The analyses were made separately for the twigs (stems) of last four years and for the leaves of last two years. The material was dry-ashed at 450°C, dissolved in cone. HC1 on hot plate, filtered and diluted to 50 ml with deionized H2O which solution was finally analyzed with an atomic absorption spectrophotometer (Varian Techtron AA-1200). Ash percentage and manganese showed identical distributions with maximum values on second-year leaves and a decrease of concentrations in stems with age (Figs. 2 and 3). Also the concentrations of Fe, Zn and Pb (but not Cu) increased from first- to second-year leaves. In stems, there was a fairly regular increase in Fe and Pb levels from first to fourth year, while Zn and Cu changed little or decreased with age (Fig. 3). Average concentrations in Ledum (leaves + stems of last two years) were compared with those in the substrate (Sphagnum fuscum peat). The results (Table 1) showed that manganese was the most favoured metal and iron the least. The relative enrichment of metals from the peat substrate to Ledum followed the order Mn >Cu >Zn >Pb >Fe.

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

According to the investigations of Kaila, the phosphorus content in Finnish peat-lands varies at the range from 190 ppm to over 2000 ppm. (Kaila 1955, 1956). The amount of organic phosphorus lies between 55 % and 95 %. The determination of the phosphorus from the matrix of organic matter is a tedious process. (Haiman 1972, John 1970, Alexander and Robertson 1968, Kaila 1955). The aim of our study was to develop a method for the phosphorus determination in which the metals also could be determined after the same sample treatment. The most common digestion method for the organic matter is the Kjeldahl wet digestion. It cannot, however, directly be employed to the metal determination with the atomic absorption technique. We used a small autoclave ( ~ 25 cm3) made from teflon in the sample digestion. The amount of the sample was 0.5—1.0 g and then 11.7 cm3 of perchloric acid (70 %), 6.7 cm3 of nitric acid (65 %) and 10 cm3 of hydrogen fluoride (40 %) was added. The sample was heated for five hours at 140 °C. The phosphorus was determined according to the method by Lueck and Boltz with the difference, that the absorbance of the solution was measured exactly after one hour since the last reagent addition. The results are presented in Table 1 and Figs. 1 and 2. The comparative determinations were made after the Kjeldahl digestion with the method by Kaila. The results were in agreement. The advantage of the autoclave method is its suitability to the routine work in the phosphorus determinations of peat, peat coke and wet carbonized peat, for instance. The same solution can be used to the metal determinations and the use of the autoclave improves the analytical accuracy and reduces the amounts of poisonous gases in the laboratory air.

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

Kirjoituksessa tarkastellaan Skotlannin viljelymetsätaloutta, osaksi kirjallisuuden, osaksi omakohtaisten tutustumiskäyntien pohjalta. Kirjoittajalla on ollut tilaisuus tutustua Skotlannin metsätalouteen kahteen otteeseen; British Councilin stipendin turvin keväällä 1967 ja IURFO:n (International Union of Forest Research Organizations) division l:n viljelymetsien ekologiaa käsittelevän kokouksen yhteydessä syyskuussa 1978.

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

The lead (Il)-electrode has been recognized as a reliable and rapid tool for sulfur determinations. Its use is based on the detection of the lead ions while titrating with lead perchlorate. The range of applications varies from the waste water sulphate determinations to the microdeterminations of sulfur in petroleum products (Goertzen, 1972, Ross 1969, Heistand, 1972, Hicks, 1974). In this study, we have employed the lead (Il)-electrode to the sulfur determination of peat. The principal idea was to connect the sulfur determination of peat to the calorific value measurement performed according to the DIN 51900. The main interference for the lead (II) -electrode is the phosphate ion. Since phosphorus-sulfur weight ratio in finnish peat usually lies between 0.1—0.2, we investigated with known samples the interference caused by the phosphate. The results show that no significant errors are involved. The comparative determinations of sulfur in peat samples were performed at VTT (The State Technical Research Center, Helsinki). The method, either used solely to the sulfur determinations or combined with the calorific value measurement offers a rapid and reasonably precise way to determine the sulfur content of peat.

• Korhonen, Sähköposti: ei.tietoa@nn.oo
• Nyrönen, Sähköposti: ei.tietoa@nn.oo
• Lehtovaara, Sähköposti: ei.tietoa@nn.oo

The paper deals with berry and mushroom yields on a dwarf-shrub pine swamp site, drained in 1922—23. The experimental field was laid out 12 years ago, in 1966— 67, and its forty sample plots were randomly divided into the following four treatment groups: — untreated (control)(1) — dwarf shrubs killed-off (herbicide treatment)(2) — NPK (14—18—10) fertilization (500 kg/ha)(3) — dwarf shrubs killed-off + NPK fertilization(4) Each treatment was thus replicated 10 times and the size of a sample plot was 0.08 ha. The results of treatments on stand development have been published earlier (Saras-to & Seppälä 1977). The berry yields were inventoried three times during the summer. 1978, i.e. in the middle of July, beginning of August, and at the end of August. The changes in the coverage of berry producing plants after treatments are shown in Fig. 2 and the amounts of berries suitable for picking and edible mushrooms found are presented in Fig. 3. It seems probable that the amounts of cloudberry (Rubus chamaemorus) and lingonberry (Vaccinium vitis-idaea) that were picked nearly equal the total yields and the amounts of blueberry (V. myrtillus) and bog bilberry (V. uliginosum) about four fifths of the total yield. The corresponding quantities of edible mushrooms were only a fraction of the total yield. Eliminating the competition from dwarf-shrub vegetation has more than doubled the cloudberry yield, but reduced the yield of bilberry to almost nothing. Simultaneous fertilization and herbicide treatment have decreased the yield of lingonberry to about one half of that in the other treatments. On nutrient poor pine swamps fertilization (NPK) seems to increase the yield of edible mushrooms. It is noticeable that cloudberry can grow and produce berries on these kinds of sites for decades after drainage and that the dwarf-shrub vegetation has only slightly been able to reappear during 12 years after herbicide treatment, on the soil from which it disappeared.

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

The research work of the pyrolysis of the fossil fuels before the increase of the oil consumption was mainly directed to the tar, coke and gas obtained from the coal and to their use as energy and material sources of the industry. The interest to the further investigations has revived with the increase in the oil price. This is shown, for instance, with the thermogravimetric investigations lately performed by several scientists. The thermogravimetric investigations of wood and its components are performed in order to improve the fire re-tardant properties of wood, but forgetting the possibilities to use wood as an energy source or to refine its pyrolysis products. The comparison between various investigations is difficult due to the different instrumental and technical methods involved. The sample materials differ markedly by the virtue of their geographical locations. This is why we have performed the investigations of some domestic solid fuels in equal conditions in order to get comparable results. During the pyrolysis peat acts as an inhomogenous material making it difficult to monitore the pyrolysis products without a careful selection of the starting material. The pyrolysis of willow, alder and birch in different conditions are very identical and the whole pyrolysis is quite simple, since e.g. the tar content is very low. The preparation of liquid fuels (e.g. methanol) from hard wood species is easier than from peat. Also, the low ash content of the wood in an advantage.Fig 4 shows that the organic components in the mixture pyrolyze independently. The wet carbonization of peat makes it burn faster but pyrolyze slower.

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

Kirjoitus selostaa metsäojituksen seurausvaikutuksia koskevia tutkimuksia, joita Helsingin yliopiston suometsätieteen laitoksessa on tehty vuodesta 1972 alkaen. Vesien laatua koskevat tutkimukset on tehty yh-teistyössä Vesihallituksen vesientutkimus-laitoksen kanssa. Kirjoittajat ovat esitelleet tässä julkaistavia tuloksia Suoseuran kokouksessa 18. huhtikuuta 1978. Julkaisua on syytä pitää edeltävän tiedonannon luontoisena. Yksityiskohtaiset tutkimusjulkaisut tulevat ilmestymään myöhemmin. Tutkimukset osoittivat, että metsäojitus ei aiheuta ojitusaluetta lähellä olevilla kangasmailla kasvavien metsien kasvussa haitallisia vaikutuksia. Ojien lähettyvillä vaikutus on metsien kasvua lisäävä, eräissä tapauksissa samaa havaittiin kauempanakin ojasta. Pelko siitä, että ojituksen vaikutuksesta kasvuolosuhteet huonontuisivat ympä-röivillä kankailla näyttää siis aiheettomalta (vrt. Laine ja Seppälä 1977). Metsäojituksella sinänsä ei näytä olevan selviä pysyviä vaikutuksia alueelta purkautuvien vesien laatuun. Orgaanisen hiilen pitoisuuksissa ei ole merkitseviä eroja yli kaksikymmentä vuotta vanhojen, jo metsittyneiden ojitusalueiden ja luonnontilaisten suoalueiden välillä. Samoin on asian laita kaliumpermanganaatin kulutuksen ja kokonaistypen suhteen. Ojituksen aikana ja jonkin aikaa sen jälkeen lisääntyy vesien mukana huuhtoutuva orgaaninen aines merkittävästi, mutta jo parissa kuukaudessa näiden epäpuhtauksien määrä laskee. Onkin ilmeistä, että liuenneen orgaanisen aineen huuhtoutuman kasvu rajoittuu nopeaan vesivaraston muutoskauteeni Sen sijaan lähinnä ojaeroosiosta johtuva kiintoainehuuhtoutuma jatkuu pitempään keskittyen ylivirtaamakausiin. Tämä tutkimus antaa selviä viitteitä siitä, että ojituksen haitalliset vaikutukset veden laatuun ovat ajallisesti rajoittuneita. Ojituksen vesistövaikutukset tulisivat siis vähitellen pienenemään nykyisestä tasosta uudisojitusten vähentyessä ratkaisevasti ja 1980-luvulla. Ojituksen välitön vaikutus hydrologisissa olosuhteissa näkyy kesän alivalumien erittäin voimakkaana kasvuna, myös sateiden aiheuttamat ylivalumat suurenivat. Valumien suureneminen on osittain suon vesivaraston pienenemisen seurausta, joka tapahtuu valtaosaltaan parin ensimmäisen ojituksen jälkeisen kuukauden aikana. Ojituksen pitkäaikaiset hydrologiset vaikutukset näyttävät yleisesti ottaen olevan vaihteluita tasoittavia, maksimivalumat pienenevät ja kesän kuivien kausien minimivalumat suurenevat. Kuivina kausina vähintä jatkuu ojitetuilta alueilta pitempään kuin luonnontilaisilta alueilta. Kevään lumensu-lamiskauden aineisto on pieni, eikä siten anna aihetta pitkälle meneviin yleistyksiin. Näiden lähinnä edullisina pidettävien muutoksien syyt ovat ilmeisesti seuraavanlaiset: Ojituksen vaikutuksesta valuntakynnys alenee, josta seuraa veden varastoimis-kyvyn lisääntyminen. Toinen vaikuttava tekijä lienee pidännän voimakas kasvu ojituksen vaikutuksesta lisääntyneen puuston ansiosta. Ilmeisesti myös evaporaation pieneneminen ojituksen vaikutuksesta on merkittävä tekijä. Näyttää siis siltä, että metsäojitus, ainakin sellaisena kuin sitä Suomessa ja Suomen ilmasto-oloissa harjoitetaan, on omiaan aiheuttamaan lähinnä positiivisia hydrologisia seurausvaikutuksia. Tällaisiin tuloksiin ovat aikaisemmin päätyneet useat muutkin tutkijat (esim. Baden ja Eggelsmann 1964, Ferda 1966, Bay 1971, Pyavtsenko 1976). Päinvastaisiakin käsityksiä on esitetty (esim. Masing 1976, Shaposhnikov 1976), osaksi kuitenkin enemmän tai vähemmän aridisilla alueilla saatujen tulosten perusteella (Klueva 1973). Ojituksen aikaiset ja välittömästi sitä seuraavan lyhyen aikajakson vaikutukset ovat sen sijaan haitallisia. Vesien mukana kulkeutuvalla orgaanisella ai-neksella saattaa olla ainakin tilapäisesti vesien laatua laajemmaltikin pilaava vaiktus. Lopuksi on syytä todeta, että ojitusalueiden jatkuva hoito ja käyttö tuovat omat erikoispiirteensä edellä tarkasteltuihin tekijöihin. Voidaan päätellä, että ojitusalueilla suoritettavat hakkuut lisäävät valuntaa (esim. Heikurainen & Päivänen 1970) ja ojien perkaukset sekä ojituksen uusiminen vaikuttavat vesien laatuun saman suuntaisesti kuin uudisojitus. Varsinaisia tutkimuksia näistä seikoista ei ole riittävästi olemassa, eivätkä nyt selostetut tutkimustulokset ole sellaisenaan sovellettavissa näihin ongelmiin.

• Heikurainen, Sähköposti: ei.tietoa@nn.oo
• Kenttämies, Sähköposti: ei.tietoa@nn.oo
• Laine, Sähköposti: ei.tietoa@nn.oo

In this study samples of both flark and forest peat from nutritionally similar sites were compared. Flark peat was found to be richer in nearly all nutrients, including the exchangeable ones, than the forest peat (Table 1). The most important reason for the difference may be that the trees and ground vegetation on a pine fen have taken up and retained a considerable part of nutrients. Microbes may, however, have fixed more nutrients on flark fen than on pine fen, for there were four times as many aerobic bacteria in flark peat than in forest peat. The peat required for the experiments came from Alajärvi fen in the Kivalo experimental area belonging to the Forest Research Institute. Peat was taken from two points, 30 metres apart. One sampling point was located on a flark fenlike bog and the other on a pine fen. Peat from the former will be called flark peat, from the latter forest peat. Thirty pots were filled with two peat types. Three pine seedlings grown in unfertilized garden peat were planted in every other pot and birch seedlings in the rest of the pots. Pine seedlings were grown in their pots in a greenhouse for about 12 moths and birch seedlings for about 10 months. At the end of the experiment the shoots were weighed, the length of roots measured and the root tips counted. Every fifth birch root branch in each pot was measured; while each pine root from every other pot was chosen for measurements. Results from the analysis lead to the assumption that flark peat, because of its richer nutrient content, may be better than forest peat as a substrate for the growth of Betula verrucosa and Scots pine. The final measurements showed that the growth of birch shoots and roots was much stronger on flark than on forest peat (Table 2). The growth of pine shoots showed a similar trend, although the difference was smaller. The investigation also included the forming of mycorrhizae in seedlings and corresponding nutrient uptake. A microscopic study of the slices from root tips revealed a rather weak ability of birch and pine to form mycorrhizae (Fig. 1). There^ were no marked differences in mycorrhizaf development of seedlings grown on flark or forest peat. Scanning electron microscopy showed that some root tips were enveloped by mycelium and that pines grown on flark peat displayed unidentified cell formations (Fig. 2). When comparing the influence of peat extracts and mixtures of nutrient solution on the growth of mycorrhizal fungi, it was detected that a fungus important for birch, Paxillus involutus, grew better in a solution containing extract from forest peat rather than flark peat (Table 3). Tricholoma flavo-brunneus yielded the opposite result in two experiments, in one of which the difference was statistically significant. The fungi important for pine, Cenococcum grani-forme and Boletus variegatus, grew better in a nutrient solution containing extract from forest peat. The growth of other involved mycorrhizal fungi (Amanita muscaria umbrina, E-57) was not significantly dependent on peat types. The examination of seedlings grown in 32P isotope solution showed that the phosphorus uptake was better from a pure nutrient solution than from a solution containing either of the two peat extracts (Table 4). The extract from flark peat, as compared to that of forest peat, harmed the phosphorus uptake of birch less; whereas pine reacted in the opposite way. Pine could on a peat substrate, however, take up phosphorus, applied at watering, better from flark peat than from forest peat. According to the results, peat from a flark fen was a good substrate for the initial development Betula verrucosa. The initial development of Scots pine was relatively much weaker on this peat substrate. The experiments utilizing peat extracts even imply that peat from a flark fen may contain, in its natural state, substances that harm the growth of mycorrhizal fungi on pine and the nutrient uptake of seedlings. More investigations, however, are necessary for any final conclusions.

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

This study involves the determination of some kinetic parameters of the various peat samples. Also, the effect of the peat type and the degree of the humification to the kinetics of the pyrolysis was of interest. These experiments were performed both in the inert gas and in the air nitrogen gas mixture. The energy of the activation as well as the rate constant clarify the changes of the matter during the pyrolysis. These facts are met, if we want to distinguish the nature and the behaviour of the products formed in the pyrolysis. The kinetic parameters were calculated using two different methods, both giving the similar results. The reference substance employed was cellulose since it is one of the main components of the peat and its pyrolysis is well studied. We conclude, that the pyrolysis of the peat can be investigated assuming the first order kinetics. Further, the differences between the peat types were considerable which leads to the fact, that the selection of the peat type reflects the gaseous products formed during the pyrolysis and is important e.g. in the gasification studies.

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

The article presents results of an experiment in which different sowing and planting methods were compared. The experi-ment was carried out in two experimental areas in Central Finland, the Lylynsuo and the Nuijaneva. The Lylynsuo area has been drained in 1969 and its pre-drainage peatland site type was an ordinary sedge bog. The Nuijaneva area has been drained in 1963 and its site type was a small-sedge bog. The experimental layout was the same in both areas: four planting and four sowing methods on five blocks. An experimental unit consisted of a pair of rows with 100 transplants or sowing spots. The methods used were. 1. Planting on intact peat surface 2. Planting on top of the furrow ridge made by a reforestation plow (see Fig. 1) 3. Planting on the side of the ridge nearest to the furrow 4. Planting on the other side of the ridge 5. Sowing on intact peat surface 6. Sowing on a 50 x 50 cm2 spot, from where the living moss had been removed 7. Sowing on a foot-pressed spot, on chopped peat spread out with Kopo spiral trencher 8. Sowing with sowing machine (see Fig. 2). The afforestation was made with Scots pine in the spring 1969. After planting and sowing, spot fertilization (30 g/trans- plant or sowing spot) was applied with compound fertilizer (15 % N, 25 % P2O5, 10 % K2O). Living transplants and sowing spots with seedlings were counted in the autumn 1969, in the spring 1970, in the autumn 1971, and in the autumn 1974. The height and the height growth of the transplants and seedlings were measured in 1971 and 1974, the height of the seed-lings in the machine-sown group only in 1971. The results are presented in the Figures 3— 5. Planting was successful with all the methods applied, with no significant differences between the methods. Sowing succeeded better in the Nuijaneva area than in the Lylynsuo. As can be seen, the results of sowing correlate with the competition from the surface vegetation, which is greater in the Lylynsuo area. The transplants were significantly higher and their height growth greater in the three turf planting methods (2—4) than in the method of planting on intact peat surface. Height growth of seedlings was the best on the chopped peat (method 7) and the poorest on the intact surface. Results from the two experimental areas are quite similar. Taking into account the age diffe-rence of the seedlings and the transplants, the seedlings are either growing almost as well as the transplants or are only a year or two behind in development.

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

The material for this study was collected during summer 1974 in Siurua district, near Pudasjärvi, N-Finland (65°30'N/26° 30'E). Sample squares were marked out at regular intervals along the study lines crossing peatlands of different site type. The number of the plants and the berries in each square was then counted. The average weight of the single berries was calculated separately for cloudberry growing in spruce swamps (1,76 g) and for cloudberry in pine and open peatlands (1,30 g). The average weight for cranberry has been calculated using the individual weights of Vaccinium oxycoccos and V. microcarpon (0,756 and 0,293 g respectively) and the average value obtained from the ratio in which they occur in different peatland site types as presented by Ruuhijärvi (1960). The frequency of cloudberry shoots was at its highest in spruce swamps (MrK), in Sphagnum fuscum pine swamps (RR) and in S. fuscum peat banks (S. fuscum-jänne) (Fig. 1). The best yields, about 6—7 kg/ha, were found in the same peat-land site types (Table 1). It is most likely that the beetles and beetle larvae of the Galerucella (Col., Chrysomelidae) had the greatest effect in cutting down the cloudberry yield in Siurua district in 1974. The frequency of occurrence of cranberry shoots was highest in S. fuscum pine swamps, in S. fuscum cotton grass pine swamps (RTR) and in small-sedge bog (LkN) (Fig. 2). The best yields, in turn, were observed in S. fuscum cottongrass pine swamps and in mesotrofic sedge fens (RhSN), being about 40 kg/ha (Table 2). These cranberry yields are much lower than those observed by e.g. Ruuhijärvi (1974). Possible explanations for the difference in the results lie in the methods used and in the large temporal and regional variation in the yields. The total annual cranberry yield in Finland has been estimated at 25—50 mill. kilos and the cloudberry yield at 25—30 mill, kilos. According to the present results the total cranberry yield in nearly 50 mill. kilos and the total cloudberry yield about 5 mill, kilos, which, however, can be at least 3—4 times more in favourable years

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

It is known from earlier studies that many different types of peatland become afforested or naturally reforested fairly rapidly after drainage has been carried out. Peatlands, which initially develop into birch stands are common in the Ostrobothnian drainage areas. The occurrence of under-storey seedlings their species distribution and development potential in such Betula pubescenis stands 15—35 years after drainage are examined in this study. Details of the study material, which consisted of 204 sample plots, are given in Table 1., and the location of the sample plots is shown in Fig. 1. Fifteen circles, each one square meter large, were systematically marked out in each sample plot and the number of seedlings of different tree species growing in the circles subsequently counted. One seedling per circle, which was found to be the best as regards size and development potential, was chosen as the dominant seedling. The tree species, height, age and degree of development potential of the dominant seedlings were all noted. In addition, the ground vegetation in each circle was analyzed. The means for the number of seedlings at each sample plot were calculated in groups according to drainage age, site fertility and geographical area (Table 1). The results show that the ability of a site to produce seedlings has been retained rather well, in places where drainage had even been carried out a long time ago, if the conditions otherwise have been favourable. The number of seedlings capable of development appears, on average, to be satisfactory. The number of coni-feroys seedlings capable of development in sites of the southern part of the studied area in sufficient for the formation of new stand. However, in northern Ostrobothnia, the number, on average, was so small, that a fully stocked seedling stand could only be obtained by resorting to a large admixture of birch seedlings. The variation in the data is large and thus the means give only limited information about the phenomena studied. Table 2 shows the proportion of sample plots where the number of seedlings capable of develop-ment satisfies the accepted minimum requirements. It can be seen that in the southern part of the research area understorey seedling growth capable of development is found in two sites out of three. The reasons for the great differences between the areas did not become apparent in this study.

• Seppälä, Sähköposti: ei.tietoa@nn.oo
• Keltikangas, Sähköposti: ei.tietoa@nn.oo

A number of peatland conservation programmes have been drawn up in Finland during the last ten years, to date, however, only those programmes covering state-owned land have been carried through to completion. The total area of peatlands either protected by nature conservation legislation or by decision of the State Board of Forestry is 193 000 ha. Completion of the network of protected areas is especially urgent in the southern parts of the country owing to the rapid increase in the utilization of peatlands for forestry purposes and peat extraction. The working group set up by the Ministry of Agriculture and Forestry has just completed its proposed basic peatland conservation programme. Methodology required in the determination of the conservation value of peatlands has also been developed during the drawing up of this programme. The starting point of conservation is the protection of peatland complexes. An attempt has been made to find sufficient representative peatland complexes, which are still in a natural state, from all the Finnish climatological peatland areas (Fig. 1.). Peatland plant community conservation is being carried out both within the framework of larger peatland areas and peatland complexes and in addition by means of different conservation sites representing rare peatland types. Eutrophic fens and eutrophic spruce and birch swamps are especially threatened. As far as the protection of peatland wild-life is concerned, special attention has been paid to peatland bird-life, which better describes the quality and variety of peatland sites than any other group of fauna. Threatened peatland flora have also been documented. The most important criterion used in the determination of the value of a site in the basic peatland conservation programme, is determination of the representability of the peatland complex in question. Peatland complexes have been classified into three groups on the basis of aerial photography interpretation and other data. Classification based on the abundance of different peatland site types required field work. The occurrence and abundance of 28 different major peatland site types have been examined in the basic programme. Conservation sites have been divided on the basis of their peatland type abundance into four classes. If the area in question includes more than 16 different peatland types, then it belongs to Class I. With 15—11 types it belongs to Class II, with 10—6 to Class III and with 5—1 to Class IV. Corresponding conservation site classification has been carried out on the basis of the relative frequency of 51 species of peatland birds. If over 22 species of bird nest on a peatland it belongs to Class I. The number of bird species in Class II sites varies from 22—15, in Class III sites from 14 to 8 and in Class IV sites from 7 to 1. The above-mentioned three classification systems have finally been combined to form a general classification system for peatland conservation sites. Threatened animal and plant species, educational and research use of the peatland, geological structure and in some cases also scenic value are used as additional bases. The final result is a four-class classification system. 0. Internationally important peatland area, which represents the peatland complex type typical in Finland but rare in other countries. There are at most 1 or 2 such peatlands in each peatland complex type area marked on the map (Fig. 1). 1. A nationally important peatland is a larger and complete peatland complex, which should be preserved as an example of the ecological variation of peatland complexes. The most important bird sanctuaries, threatened peatland types and sites of rare peatland fauna and permanent research areas belong to this category. II. Regionally important peatlands are examples of the local scenery, habitats of regionally threatened plant and animal species or important educational sites. III. Locally important peatlands are usually small conservation sites for peatland complexes or individual peatland types. Their preservation would satisfy the needs of education, nature study, berry picking and the protection of peatland fauna. Only sites belonging to Classes 0 and 1 have been included in the basic peatland conservation programme. 337 of them lie to the south of the Arctic Circle (Fig. 1). The conservation sites have been listed in order of importance for each area. The basic programme covers a total of 290 000 ha of peatland. Of this, 58 000 ha of peatland have earlier been protected. The total area of peatlands in Finland lying below the Arctic Circle has originally been about 6,7 mill. ha. Thus 4,7 % of the total area of peatlands is included in the basic programme, rising to 5 % when peatlands protected at the regional and local level are included. The working group is at present involved with the part of the basic programme which covers Lapland, where relatively large conservation areas (90 000 ha) have earlier been established. Attention is also being paid to the protection of rare peatland types and threatened flora and fauna throughout the country.

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