METSÄNTUTKIMUSLAITOS PYHÄKOSKEN TUTKIMUSASEMAN TIEDONANTOJA 12 KALEVI KARSISTO PEATLAND FORESTRY EXPERIMENTS IN PYHÄKOSKI EXPERIMENTAL AREA MUHOS 1974 METSÄNTUTKIMUSLAITOS PYHÄKOSKEN TUTKIMUSASEMAN TIEDONANTOJA 12 Kalevi Karsistc PEATLAND FORESTRY EXPERIMENTS IN PYHÄKO SKI EXPERIMENTAL AREA Muhos 1974 FOREWORD An English copy, introducing the Pyhäkoski Experimental Forest and its most important points, was written for the excursion of the International Symposium on Forest Drainage. As the most recent results are also generally applicable, the copy was later worked into a report of the Pyhäkoski Research Station. On the other hand, this publication, which at the same time is an introductory guide for the experimental area, is useful especially for foreign visitors. In addition to the undersigned, Seppo Kaunisto, Lie. of Sci. in For., contributed with a paper dealing with the afforest ation of peatlands and Kimmo Paarlahti, Lie. of Sci. in For., introducing two results concerning the fertilization of swamp forests. The names are attached to their papers. The translation was performed by Leena Kaunisto, M. A. The staff of the Pyhäkoski Research Station, especially Jorma Issakainen and Kauko Kylmänen, has aided remarkably in the establishment and measurement of the experiments and in the treatment of the results. I wish to extend my best thanks to all the contributors . In Muhos December 22nd, 1974 Kalevi Karsisto Suomenkieliselle lukijalle: Kansainvälisen metsäojitussymposiumin retkeilyä varten laadittiin syk syllä 197*+ Pyhäkosken kokeilualuetta ja tärkeimpiä kohteita esittelevä englanninkielinen moniste. Koska tässä yhteydessä mitatut uusimmat koetulokset ovat käyttökelpoisia yleisemminkin ottaen, on monisteesta edelleen muokattu Pyhäkosken tutkimusaseman tiedonanto. Toisaalta tällä englanninkielisellä tuloksia sisältävällä julkaisulla, joka samalla on kokeilualuetta esittelevä opaslehtinen, on käyttöä erityisesti ulkolaisia retkeilijöitä ajatellen. Suomenkielisiä vie railijoita varten laadittu retkeilyopas tullaan uusimaan lähiaikoina. CONTENTS page EXPERIMENTAL ACTIVITY IN PYHÄKO SKI EXPERIMENTAL AREA 1 Index map of experimental forest 3 Survey map of the oldest lot 4 Experiments and results on the way to point 1 5 POINT 1. FERTILIZATION EXPERIMENTS ON ORIGINALLY TREELESS SWAMP 11. High rates of phosphorus and potassium 7 12. An experiment with different P fertilizers 9 13. A refertilized basic fertilization series (Paarlahti) 12 14. Cubic results 16 Experiments and results on the way to point 2 17 POINT 2. AFFORESTATION OF OPEN PEATLANDS 21. Afforestation with Betula species (Kaunisto) 21 22. Afforestation with Scots pine (Kaunisto) 25 Experiments and results on the way to point 3 30 POINT 3. AN OLD DRAINAGE AREA 31. An experiment with different P fertilizers 33 32. An afforestation experiment on arable peatland 38 33. Planting of spruce under birch shelterwood (Paarlahti) 40 Influence of forest improvement activity on living conditions of the game 41 POINT 4. A WOOD ASH FERTILIZATION EXPERIMENT 43 Experimental activity on fertilization of peatlands 46 Literature dealing with experiments and results in Pyhäkoski experimental area 47 1 EXPERIMENTAL ACTIVITY IN PYHÄKO SKI EXPERIMENTAL AREA The total area of Pyhäkoski Experimental Forest, after some recent enlargements, is about 4100 hectares. Prom this, more than 90 % is peatland. In the case of peatlands, the altitude varies between 70 -75 metres and in the case of mineral soils about 75 - 80 metres above sea level. This means that a comparatively even area is in question. The annual precipitation is about 550 mm, which is rather little. The average sum of daily mean temperature (>-+ 5°C) is 1020 d.d., and the duration of the growing season (■>+ 5°C) about days. The research activities in the station are characterized by problems urgent at a particular period of time. By presenting these periods, a clear picture of the development of the ex perimental activity as well as the changing of the problems within peatland forestry in the course of decades can be given. In the 1930 '5, the emphasis was put upon investigations on peatland afforestation. Besides methods of natural regener ation, artificial seeding methods, especially with pine, were studied. Yield investigations on peatlands were started in the 1930"'5, as the so-called permanent plot series were established. Among other things, the influence of different silvicultural treatments on yield has been studied on these plots. The first fertilization experiments, using wood ash as a fertilizer, were established in the The actual basic research on the fundamentals of fertilization did not start until the beginning of the 1950'5, as the use of commercial fertilizers in forests increased. 2 Investigations on new ditching methods started in the 1950's after mechanized ditching had become a common practice. At that time, the first field experiments on the use of plastic pipes in forest drainage were established in the experimental forest. Later, this work has been continued by investigations on rotary ditching and work output. Investigations on different fertilizer forms became actual at the beginning of the 1960'5. At this time, it was already known which nutrients and how much of each should be applied when fertilizing peatlands. Since nutrients are applicable in various chemical forms, extensive experiments with different nitrogen and phosphorus fertilizers were set up to find out the most profitable form for common use. In the 1960'5, the development of seeding and planting methods started again. Simultaneously, the value of different ditch types in afforestation was studied. It was found out that a good planting result and an effective drainage are achieved at the same time if the furrowing method is used. Mechanized afforestation with soil preparation has been studied, too. Good facilities for studying the need for repeated fertilir ation and supplementary ditching were provided by old fertilir ation experiments established some 20 years ago in the ex perimental forest. Soon after the activity of the research station started, old plots were divided into smaller units by ditches. The possibilities for intensive forestry by using effective ditching and frequently repeated fertilir ations have been the main object of research at the beginning of the 1970"5. 3 INDEX MAP OF PYHÄKO SKI EXPERIMENTAL FOREST Detailed excursion route on lot 2 can be seen on page 4 4 SURVEY MAP OF LOT 2 5 Experiments and results on the way to point 1 Near the forest road leading from the main road to the first excursion point there are several experimehts dealing with fertilization and liming of swamp forests* Experiment No. 20 deals with the yield of swamp forests. It is a permanent plot drained in 1932 - 33. Originally, planting and seeding (193*0 with spruce under differently thinned shelterwood were investigated. A fertilization ex periment (No. 145) with 10 treatments was established in 1971 on the other side of the road in a naturally regenerated birch (Betula pubescens) stand. The various blocks were thinned into three different densities in connection with fertilization. Experiment 155, established in 1973, like wise deals with the fertilization of Betula pubescens. After this we shall move over to a former treeless bog, which can be seen in its original state on the right beyond the influence of the main ditch on the road side. The stands left to the road have been established by seeding and plant ing pine in 1953 - 54 (fertilization and liming experiments 75 and 76). The experimental area No. 36 was originally seeded in 1936. Not until 1960 was the area fertilized, eight different nitrogen fertilizers with phosphorus and potassium were used among other things. Refertilization occurred in 1972 - 73. Experiments 120, 121, 122 were treated with PK fertilir ation in 1967- Later on the way, there are stands brought about by mere drainage (1938). The cubic volume of the stands is about 200 solid m /ha. A fertilization experiment with Betula pubescens (No. 156) was established in this stand in 1973. The experiments 78, 68 and 54 before the first stop are dealing with different seeding and planting methods with pine . 6 POINT 1. FERTILIZATION EXPERIMENTS ON AN ORIGINALLY TREELESS SWAMP The route consists of originally herbrich sedge bogs which underwent basic drainage in the 1930 's and were later afforested either by seeding or planting. The area has been redrained since in connection with the establishment of fertilization experiments. Additional drains have been employed for dividing the plots into new treatment units at the time of refertilization. 7 11. High rates of phosphorus and potassium Experiment No. 66 contains 10 plots. The acreage of all the plots is 0 = 065 haj excluding the plots 5 a and 5 *c with their ha. The area was drained in ~ 37» Supplementary drainage of the border areas and the untreated strips between the plots was performed in 1971. The tree stand was established in by planting with pine. Basic fertilizations were carried out from 12th to 16th December in 1953 on snow. Re fertilization took place on 11th June, 1973- The enclosed map shows the location of the plots. The treatments the aim was to save the stand by mere potassium fertilization. On the other hand, phosphorus was applied in three different forms. One of them was from the newest Finnish Sokli deposit. In addition, the possible nitrogen deficiency was investigated to improve the growth of quite a tall swamp stand as much as possible. 39 The results concerning the radial growth (mm) in 1971-7** are shown by the Table bel^w: The mere potassium application decisively improved the growth of trees, which was anticipated according to the symptoms of potassium deficiency. The use of phosphorus also increased growth, although the Sokli phosphorite is obviously so slowly soluble that it causes reactions resembling those received by using the Siilinjärvi apatite. Thus it will not reach its maximum until the Mth or sth year. NPK fertilizer includes besides nitrogen also a quickly soluble superphosphate, which yields a fast response. So far it is impossible to be sure whether the presence of nitrogen or phosphorus in its quickly affecting form in the NPK fertilizer has brought about the vigorous growth response. Probably both of them contribute to the outcome. The result is normal; usually the best response when only interested in growth increase in received by adding all the main nutrients. Considering the profitability, often only PK fertilization is used for swamp forests in practice. In this case the mere potassium application considerably improved the nutritional status of trees. This procedure, however, somewhat deviates from the usual practice on peatland. Year 0 K muriate of potash 75 kg K 2 0/ha PK 1 Sokli phos- phorite + muriate of potash 120 kg P0, + 75 kg K2 0/ha pk 2 raw phosphate + muriate of phosphate 120 kg P ? 0, + 75 kg KgO/ha NPK fertilizer poor in nitrogen 50 N + 75 P p 0 + 75 ? 1971* 0.86 I 1.63 2.02 2.20 1973 0.70 1.12 1.36 1.69 1972 0.95 1.28 1.23 1.37 1.U7 1971 1.03 0.9U 1.01 1.07 0.97 40 33. Planting of spruce under birch shelterwood (Paarlahti) The afforestation of swamps with spruce is not usually success ful without shelterwood, which protects seedlings against frost. Spruce, as a species susceptible to frost, is especially liable to damages by spring frosts. Birch is very often shelterwood, particularly on originally open swamps, on which birch is the first tree generation. In order to investigate the seeding and planting methods for spruce several experiments have been set up. The present experiment is one among those investigating the planting of spruce when employing different spot fertilization treatments under birch shelterwood with varying densities. The spruce seedlings were planted in the autumn of 1961 (or p 1963) and spot fertilized (by using spots of 0.25 m ) in the spring of 1962 (or 1964, plots No. 95 and 96). The experimental design was 34 factorial experiment with three levels of N, P, K and Ca fertilizers. The experiment was replicated 32 times. The experimental units amounted to 2592, and each unit was formed by five seedlings. Three different kinds of shelterwood are seen on this point: plot No. 86 overdense, plot No. 95 slightly thinned and plot No. 96 no shelterwood at all. The results indicate that the growth of spruce transplants under shelterwood had decreased with increased spot fertilir ation. The reason is supposed to be that shelterwood had developed a competitive root system on the spots capable of a vigorous uptake of nutrients. As a result the small amount of nutrients applied in spot fertilization was used up in few years. Thus the progress of transplants was impeded by in creased root competition. 41 Influence of forest improvement activity on living conditions of the game The research station and the Department of Peatland Forestry in the Finnish Forest Research Institute have initiated in vestigations on the multiple use of forests and the influence of forest improvement measures on berry and mushroom crops and the living conditions of the game. This so-called northern lot of 1550 ha, which has almost totally been drained in connection with research activities and over half of which is fertilized, is still despite normal hunting activity considerably richer in game than the other parts of the country on the average. According to the inventory carried out in the early spring of 1974 (Karsisto 1974) the stocks of game were found t* be as follows: 24 capercaillies , 60 black grouse, 15 partridges, 70 white ptarmigan and 50 snow hares. The stocks of game birds are three or four times more numerous than elsewhere in late winter. As late as in the 1930 's the lot was still mainly a treeless open swamp offering game animals little shelter or food. The black grouse, in particular, seems to have benefited from the lush clusters of birch on ditch sides. The capercaillie likes fertilized young pine stands as well. On point 13 (experiments 55 a and b/1) an inventory revealed how often the capercaillie ate on different plots. On the most favourable plots it had visited 25~30 trees in the early spring, whereas some plots were left entirely untouched. The various nutrients applied in the original or repeated fertilization treatments did not affect the outcome. The most important factor was that the stand had been fertilized and was well-growing. It was obvious that birds regarded shelter and security im portant when choosing the eating place. 42 Veijalainen (1974) has aimed at investigating the suitability of the old drainage areas on point 3 for the snow hare living place in winter. The investigation was performed by inventory ing the footprints after snow fall. A virgin privately owned land bordering the experimental area was used as a control area. The occurrence of footprints was six times higher on the area where forest improvement measures had taken place than on the virgin control area, although both areas had originally the same background. The biggest problem on the experimental area was the great number of footprints. In order to take an active part in game protection, game fields have been established in different parts of the lot. They help to judge the properties of various kinds of feeds and how game animals use them. An experiment set up in 1972 included seven different Swedish feed mixtures for the use of game fields. The name of one of them was "Delicacy of roe deer". As it is well-known that there do not occur wild roe deer in our country, we supposed that the feed was eaten by other animals. However, in December there appeared five roe deer in the field which the excursion route crossed, and immediately devoured "the Delicacy of roe deer". The roe deer, which evidently must have come from Sweden along the coast of the Gulf of Bothnia, lived for three months near the field, before possibly sensing a new delicacy else where. Food, not snow or cold weather, poses the problem for most game animals for surviving the winter. Areas improved for forestry offer shelter and food to a great number of game at the most critical time, in the early spring. 43 POINT 4. A WOOD ASH FERTILIZATION EXPERIMENT The last excursion point is not on land owned by the Forest Research Institute. When the power station on the river Oulu was being "built, the required land on both sides of the river was given to the Oulujoki Company. Efforts have been made to preserve all the established experiments. The name of the Experimental forest derives from the famous Pyhäkoski rapids, which before the building of the power station was an excellent place for salmon fishing and a beautiful tourist attraction. The official residence of the forest technician of the Research Institute was in the middle of the present dam basin on a high cape which is now covered with 12 m deep water. In the 1930 's experiments dealing with the afforestation of drained peatlands and soil improvement were established in this area which previously belonged to the Forest Research Institute. Sand with varying amounts, calcium and later wood ash were used for soil improvement. The area was drained in 1933 and afforested in 1934 and 1937. 44 An experiment investigating the effect of wood ash was set up on this originally treeless open swamp, whose nutritional status resembles cottongrass - sedge type. In 1932-34 the area was drained using 60 m wide drain spacings and afforested partly by seeding and partly by planting in 1934-36. The afforestation failed so that in 1947 there was an uneven, less than 0.5 m tall young stand. Including the wood lost in thinnings the total wood production (inc. 1974) on the plot was 145 solid xt? without bark/ha and on the plot c about 180 solid nrVha. The yield surpasses that obtained on the best mineral soils (the Oxalis-Myrtillus type) in southern Finland in the same period of time. With the aid of these experimental plots, serving mainly as demonstration plots, the following things may be observed: - The amount of radiation energy from the sun is not, in these latitudes (65°), the main growth limiting factor. By soil improvement measures it is possible to reach a very high production level per hectare. - The present results do not yet represent the maximum possible leve, since the employed drain spacing, 60 m, is too wide. This is demonstrated by a. distinct decrease in the total height of trees when moving towards the middle of the strip. The experimental plots do not touch the ditch side, which would be the best site. - By draining a nutritionally poor swamp the desired result will not be achieved. While the nutrient deficiency is limiting the growth, mere drainage is inadequate. If nutritionally poor swamps are drained, the task should be completed by fertilization as well. 45 - Despite the high nutrient rates used, running of nutrients into ditches and thus contributing to pollution has not been detected. Even 26 growing seasons after the fertilization there is a clearly discernible difference in ground vegetation, even on borders running in the direction of the ditches. Furthermore, the nutrients have not penetrated deep into the soil. The investigations show that in 15 years the change brought about by ash have affected only the surface peat layer down to 13 cm. - When the nutritional status and water relationships are well maintained, the present recommendation for pulp production, 1600 stems/ha, can be considerably exceeded. At the moment plot c contains 4200 stems fulfilling the requirements for pulp wood. - The long-lasting influence has been produced by adding nutrients and by improving the soil, which have ensured a continuous nutrient mobilization. The large amounts of ash have not, in fact, contained high nutrient rates. For example, plot b received 240 kg/ha of phosphorus. In another ash fertilization experiment (Ho. 14) within the experimental area 3000 kg of ash/ha produced the same yield. -If other virgin swamps in corresponding climatic conditions were made as productive as on plot c, it would be possible to provide the large wood processing industry in Oulu, for example with the needed 1.2 million from the distance uf only 20 km. (Now the wood is partly brought even from the distance of 200 km.) The example set by the ash fertilization experiment shows that the biological possibilities for wood production, not utilized today, are boundless. 46 Experimental activity on fertilization of peatlands Since the Research Station began its operation in the autumn of 1969 till the present day, the cooperation between the Department of Peatland Forestry and the Experimental Forest Office, which operates among practical forestry, has pro duced 45 fertilization experiments on the experimental area in liuhos. The experiments include 1742 plots with a net area of 432 ha. At the same time 50 refertilization experiments including 1748 plots with the net area of 336 ha have been established. At present there are altogether 154 different fertilization experiments and 4368 plots with various treat ments at the Pyhäkoski Experimental Forest. The total net area amounts to 1192 hectares. The activity is not limited to the forests owned by the Research Institute in Muhos, but 47 experiments, nut of which 15 deal with refertilization, have been established in other experimental forests possessed by the Research Institute. Moreover, 204 hectares of privately owned forests in liuhos have been used for establishing 133 fertilization experiments. Recently also many fertilization experiments have been set up on land owned by the State Forest Service. For example, in the Pohjanmaa district 55 experiments totalling 180 hectares will be ready in 1974. The projects mentioned above have been realized by linking the experimental activity with the practical work of various organizations. The problem will be the measurement and treatment of the results. 47 Literature dealing With experiments and results in Pyhäkoski experimental area Huikari, 0. 1973. Koetuloksia metsäojitettujen soiden lannoituksesta. Summary: Results of fertilir ation experiments on peatlands drained for forestry. Metsäntutkimuslaitoksen suontutkimusosaston tiedon antoja 1971/1. Karsisto , K. K. 1968. Eri fosforilannoitelajien soveltuvuus suometsien lannoitukseen. Summary: Using various phosphatic fertilizers in peatland forests. Suo 19: 104-111. 1971. Metsäntutkimuslaitoksen Pyhäkö sken tutkimus asema ja kokeilualue. Retkeilyopas . (Finnish- English dictionary). 1972. lannoituksen vaikutuksen kestoajasta suo metsissä. Pyhäkosken tutkimusaseman tiedonantoja 2. -n- 1972. Ravinteiden huuhtoutumisesta lannoitetuista suometsistä. Pyhäkosken tutkimusaseman tiedonantoja 2. -n- 1972. Lannoituksen vaikutuksen kestoajasta suomet sissä. Summary: On the duration of the effect of fertilizer application to peatland forests. Suo 23: 49-36. 1973. Esituloksia suometsien fosforilannoitelaji kokeista. (Resultat av gödlingsförsök med olilca fosforgödselmedel. ) Pyhäkosken tutkimusaseman tie donantoja 4. 48 Karsisto , K. K. 1973* Kokeita typpilannoitteiden häviämisestä säkeistä» Summary: llow do the nitrogen fertilizers disappear from the sacks. Pyhäkosken tutkimusaseman tiedonantoja. 6. 1974. Metsänparannusalueet riistan kannalta Summary: Forest ameliaration and the stocks of game. Suo 25: 35-40. 1974. On the duration of fertilization influence in peatland forests. (With special reference to the results obtained from experiments with different phosphorus fertilizers.) Proceedings of The Inter national Symposium On Forest Drainage 2nd-6th September, 1974, Jyväskylä - Oulu, Finland. Karsisto, K.K. & R a v e 1 a , H. 1971. Washing away of phosphorus and potassium from areas drained for forestry and topdressed at different times of the year. Acta Agr. Fenn. 123: 54-69. 1971. Eri ajankohtina annettujen fosfori- ja kali lannoitteiden huuhtoutumisesta metsäojitusalueilta. Summary: Washing away of phosphorus and potassium from areas drained for forestry and topdressed at different times of the year. Suo 22: 39-46. Paarlahti, K. & Karsisto, K.K. 1968. Koetuloksia kaliummetafosfaatin, raakafosfaatin, hienofosfaatin ja superfosfaatin käyttökelpoisuudesta suometsien lannoituksessa. Summary: On the usability of potassium metaphosphate, raw phosphate, rock phos phate and superphosphate in fertilizing peatland forests. Folia For. 55: 1-17. 49 Paarlahti , K., Reinikainen, A & Vei ja lainen, H. 1971. Nutritional diagnosis of Scots pine stands by needle and peat analysis. Comm. Inst. For. Perm. 74.5. Paavilainen, E. 1971. The effect of various nitrogen fertilizers on the leader growth of pine on peatlands. Acta Agr. Penn. 123- 197-205. 1972. Reaction of Scots pine on various nitrogen fertilizers on drained peatlands. Comm. Inst. Por. Penn. 77.3. Veijalainen, H. 1974. Metsänparannettu ja luonnontilainen suo eläinten talvisena elinympä ristönä. Summary: Winter habitat preferences of wild animals on improved and virgin peatland. Metsäntutkimuslaitoksen suontutkimusosaston tiedonantoja 3/1974. FOREWORD CONTENTS EXPERIMENTAL ACTIVITY IN PYHÄKOSKI EXPERIMENTAL AREA INDEX MAP OF PYHÄKOSKI EXPERIMENTAL FOREST SURVEY MAP OF LOT 2 Experiments and results on the way to point 1 POINT 1. FERTILIZATION EXPERIMENTS ON AN ORIGINALLY TREELESS SWAMP 11. High rates of phosphorus and potassium 12. An experiment with different phosphorus fertilizers 13. A refertilized basic fertilization series (Paarlahti) 14. Cubic results Experiments and results on the way to point 2 POINT 2. AFFORESTATION OF OPEN PEATLANDS 21. Afforestation with betula species (Kaunisto) 22, Afforestation with Scots pine (Kannisto) Experiments and results on the way to point 3 POINT 3. AN OLD DRAINAGE AREA 31. An experiment with different phosphorus fertilizers 32. An afforestation experiment on abandoned arable peatland 33. Planting of spruce under birch shelterwood (Paarlahti) Influence of forest improvement activity on living conditions of the game POINT 4. A WOOD ASH FERTILIZATION EXPERIMENT Experimental activity on fertilization of peatlands Literature dealing With experiments and results in Pyhäkoski experimental area