Articles containing the keyword 'oja'

Young Norway spruce (Picea abies (L.) H. Karst.) are susceptible to early summer frost damage. Birch (Betula pubescens Ehrh.) naturally colonize rich or fairly rich drained peatlands after clear cutting, and can provide protection for developing seedlings. The report describes the development of spruce stands after various types of handing of the birch nurse crops.

Different proportions of birch and spruces did not have any influence on the spruce stand production. In cases where the nurse crop stand is removed when the spruce stand age was 20 years and height 4 m the spruce suffered badly but recovered with time, reaching the spruce stand growing under a nurse stand within the next 20 years. The height growth of spruce depends on the density of the nurse stand, especially on fertile sites. The development of diameter growth also depends on the density of the nurse trees. Removal of the nurse stand in spruce stands on the sites concerned should be done when the spruce stand is 20 years old and at the height of 4 m.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

Peat industry is rapidly expanding in Finland. Consequently, during next decades peat will be removed from thousands of hectares. Because timber production probably is the most rational use of this area after the peat production has ended, some experiments of afforestation of such areas have already been conducted. This article reports results of two experiments which were started in Kihniö, Western Finland, in 1953 and 1964.

In the first experiment fertilization with wood ash proved very effective whereas seeding and planting without fertilization resulted in almost complete failure. In the second experiment, interplanting with grey alder (Alnus glutinosa L. Gaertn.) greatly promoted the growth of Scots pine (Pinus sylvestris L.). The effect of slight fertilization lasted a few years only. The reasons for the remarkable effect of alder need further research. Although alder is known as a nitrogen-fixing plant, its beneficial effect was most clearly seen in the K and P contents of pine needles. Inoculation with mycorrhizal fungi was beneficial but not necessary. Experiments hitherto show that afforestation of bogs after peat removal is possible although some additional measures like fertilization or interplanting with alder may be needed.

The PDF includes a summary in English.

• Mikola, E-mail: pm@mm.unknown

It is possible to show that many of the after-effects resulting from the disappearance of forest cover were well known already in ancient times. The invigorating effect of moving around freely in the forest and its artistic creative ability were also recognized as well as the healing effect of coniferous forest on people suffering from consumption. Hunting and the use of forests for cattle grazing is also an extremely old practice. The so-called by-products of the forest such as tree bark and leaves, as well as berries and fruits, have played an important role in the history of mankind from the very earliest beginnings.

The PDF includes a summary in English.

• Makkonen, E-mail: om@mm.unknown

The changed in size and shape of ditches made by draining plows and tractor diggers were followed over a one-year period after the draining in four different peatland types. The material consists of 51 ditches made with each method in dwarf-shrub pine bog, herb-rich spruce swamp, in herb-rich sedge bog and sedge pine bog. The measurements were made immediately after the digging, and one month and a year later.

Ditches made by plowing and surrounded by peat became shallower quickly during the first 2–3 days after plowing due to the pressure of the surrounding peat. Ditches made with tractor diggers did not become shallower as fast, and their bottom did not widen to the same extent than plown ditched. During the first year, machine-made ditches change in a same way as handmade ditches, especially when compared to ditches made by tractor digger.

Immediately after digging the ditches made by tractor digger were 10 cm deeper and 0.13 m³ larger than plown ditches. One year later the values were 7,5 cm and 0.09 m³, respectively. Plown ditches made in the peat were 14.4 cm deeper than ditches that penetrated into the subsoil, for tractor digger the value was 13.2 cm. Ditches made with a tractor digger were deeper than plown ditches both in soils with deep and shallow peat layer.

The changes were largest and fastest in the wettest peatland type herb-rich sedge bog. In herb-rich spruce swamps, which have a shallow peat layer, the shallower plown ditches kept their form better than ditches dug by tractor digger.

The PDF includes a summary in English.

• Timonen, E-mail: et@mm.unknown

This paper reports spot sowing experiments of Scots pine (Pinus sylvestris L.). The seeds were either covered with coarse sand, tramped in the substrate or sowed without any covering, 30 seeds in each treatment in 70 replications. The site was of Vaccinium type with sandy soil. The germination percentage was 81 and 91 on the respective years. The development of seedlings was observed for 3–4 years.

The results indicate that both tramping and covering the seeds to some extent increased the number of seedlings and improved the early development. The highest numbers of seedlings were recorded in the first growing season, after which there was 23 seedlings/100 seeds in the uncovered spots, 27 seedlings in the covered spots and 31 seedlings in the tramped spots in the experiment sowed in 1965.

Mortality of the seedlings was highest between the first and second growing season, and empty spots increased with the time. There was no difference in mortality between the sowing methods, but the number of seedlings after first growing season affected the result. Under favourable conditions four seedlings per spot seemed enough to secure the survival of minimum one seedling per spot during the three first growing seasons. In poor conditions seven seedlings was needed.

The PDF includes a summary in English.

• Yli-Vakkuri, E-mail: py@mm.unknown
• Räsänen, E-mail: pr@mm.unknown

The objective of this investigation was to study the influence of stand density of white birch (Betula pubescens Ehrl.) on the minimum temperatures in the stand during the growing season, and the actual minimum temperatures of the leading shoot of Norway spruce (Picea abies (L.) H. Karst.) seedlings growing in the open. The 40-year-old uniform white birch stand was situated in 142 m above the sea level in Southern Finland. The stand was treated with thinnings of three different densities in 1961.

Air temperature was recorded in four sample plots at heights of 0.1 m, 0.5 m, 1.0 m, 2 m and 4 m. In the stand of moderate density, temperatures were measured at heights of 6.0 m, and in the stand of full density at 6.0 m, 8.0 m and 10.0 m.

The temperature differences between stands of various densities proved to be rather small. Especially the thinnest stand differed very little from the open area. The soil surface has in all cases been warm compared with the higher air layers indicating meadow-fog-type by Geier (1965). On cloudy or windy weather all the temperature profiles in the various stands resembled each other. The difference between the air temperature and temperature of the spruce shoot was greatest at midnight and decreased steadily thereafter.

The problem in using shelter stands for spruce regeneration areas is that optimum shelter stand density is difficult to define. Already a thin shelter stand causes drawbacks to the young seedlings, but in order to be effective enough against early frosts, the shelter stand should be comparatively dense.

The PDF includes a summary in English.

• Leikola, E-mail: ml@mm.unknown
• Pylkkö, E-mail: pp@mm.unknown

The present paper is a preliminary report of a project designed to determine the order of profitability of various forest improvement measures – seeding and planting, drainage, and fertilization – in various types of stands and in different parts of the country on drained peatlands. Sample plot data on the effect of draining on increment was derived from areas drained 28– 36 years ago. The study was carried out in the southern half of Finland.

The observations on increment changes are based on two measurements of the sample stands 12 years apart. Supplementary calculations indicate that the stands on drained peatland, depending on site quality and tree species, have either continued to grow like mineral-soil sites of similar fertility or have somewhat increased their growth rate.

The effect of draining intensity was studied using strip measurements. It was found that both the total amount of wood produced (current stand + cutting removal + natural removal) and the current annual volume increment for the 5-year period systematically decrease as the ditch interval increases. The decrease is, however, relatively slight. In Eriophorum vaginatum pine swamps, the total amount of wood produced and the increment show a decrease of ca. 20% with an increase in ditch interval from 20 to 60 metres. In other sites, the decrease is ca. 5-10%

It can be concluded that if the increase in ditch interval do not result in considerably poorer timber assortment distributions than indicates by stand production and increment, it is profitable to pan for a relatively large ditch interval and a slightly smaller than maximum wood production. Supplementary data and check calculations may cause some changes in these preliminary results.

The PDF includes a summary in English.

• Seppälä, E-mail: ks@mm.unknown

The article is a proposal of a committee, appointed by the government of Finland, to expand the forest education of landowners, concerning use and management of forests. The proposal also outlines a program for a youth association dedicated to forests. The committee proposes that present organizations are used as a basis for the expanding education. The main forms of education suggested were education in public and agricultural colleges, education in forest colleges, forest clubs, forestry study groups and self-study, courses, excursions, exhibitions, competitions and rising of general awareness. Different age groups would be given education adapted to their needs.

The report includes statistics about rural population of Finland in 1938 and detailed description of how the education would be arranged in different parts of the country.

The article includes an abstract in German.

• Metsäopetuskomitea, E-mail: –

The article deals with forest ditches dug by manual labour in drained peatlands in Central and Southern Finland, ranging in age from 16 to 25 years. The ditches have been allowed to develop in a natural state. A total 1,160 of randomly selected sample plots were studied.

The results show that the originally dug ditch depth has not been the decisive factor from the viewpoint of maintaining the ditch repair. Ditches dug in thick peat layer have maintained their repair better than those dug in thin peat layer. Apparently, the influencing factor is the type of soil, to a certain extent parallel to the thickness of peat layer. In ditches dug mainly in mineral soil, the type of soil has essentially contributed to maintaining the ditch repair. Ditches in coarse-grained soils maintained a better repair than those in fine-grained soils. Also, the steeper the gradient of the ditch the better the ditch repair has been maintained. There was no relationship between the thickness of peat and the filling up of ditch bottom, because of the influence of mineral soil. Filling up of a ditch seems to be mainly due to the sinking of peat. The filling up of ditch bottom was more pronounced in clay-silt soil than in other soil types. The filling up of ditch bottom by varying gradient is due to the fact that with a small gradient the speed of water is so slow as to permit the soil particles to sink to the bottom. Another factor affecting filling up of the ditches is wetness of the peatland. Deepening of ditches happens mainly through erosion, if the gradient is large enough. The study suggests that a 50-m spacing with about 60-cm ditchc depth would be most profitable.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

The purpose of this investigation was to obtain a preliminary picture of the composition of the microbial population in some virgin soils on forest land in Finland. Four different forest types were studied, Oxalis-Myrtillus type birch (Betula sp.) stand, Oxalis-Myrtillus type Norway spruce (Picea abies (L.) Karst.) stand, Vaccinium type Scots pine (Pinus sylvestris L.) stand, and drained pine bog. In addition, a flood meadow was selected as a comparison.

The methods used captured only part of the fungi growing in the soil. Rapidly growing types, especially Mucor and Penicillium species, were mainly isolated. In addition, fungi showing activity of decomposition, such as Fusarium, Monosporium and Spicaria, as well as an ascomycete of the genius Ascobolus, were isolated. Autochthonous bacteria were most abundant in the soils of Oxalis-Myrtillus type forests and in the flood meadow. In the birch stand 90% of the autochthonous bacterial flora were gram-negative bacteria, in the Oxallis-Myrtillus spruce and Vaccinium type pine stand 60% were gram-negative, while the share was only 25% in the pine bog. Nitrogen-fixing bacteria of the type Clostridium pasteurianum were found in all soils. Actinomycetes were found in all sites. The numbers of protozoa were highest in the soils of Oxalis-Myrtillus type forests.

There were no big differences between the forest soils and the flood meadow. Some groups of micro-organisms seem to be absent from the forest soils, which is probably due to the more favourable pH in the meadow. The occurrence of myxobacteria is interesting since no earlier data exist of this organism in Finnish soils.

The PDF includes a summary in English.

• Gyllenberg, E-mail: hg@mm.unknown
• Hanioja, E-mail: ph@mm.unknown
• Vartiovaara, E-mail: uv@mm.unknown

The aim of the investigation was to study natural regeneration of Norway spruce (Picea abies (L.) Karst.) in drained peatlands and frost injuries in seedlings, and to compare microclimates of the regeneration areas. The experiments included peatlands in Satakunta in Western Finland. Restocking of the areas with seedlings and their survival was followed in 1935-40 at sample plots that were mainly 1 are large.

Susceptibility to freezing was shown to be dependent on the stage of development of the shoots. Shoots that have just begun to grow contain little water, and withstand better freezing temperatures than shoots in later stages of growth. Damages to the seedlings were observed when the temperatures decreased to -2.8–-4.3 °C. The most severe damage to a seedling was caused by the death of the leading shoot by spring frost.

Norway spruce regenerates easily on moist peatlands, but peatlands with dry surface tend to have little or no seedlings. The species regenerated better in marshy sites than correspondingly fertile mineral soil sites. However, it needs shelter to avoid frost damage. On clear cut spruce swamp the undergrowth spruce seedlings that were left in the site got severe frost damage. If the site had birch (Betula sp.) coppice or undergrowth, spruce seedlings survived in their shelter depending on the height and density of the birch trees. To be effective, the protective forest should have relatively even crown cover. Young spruce seedlings could grow well even under relatively dense birch stand.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown

The shared forests of the villages were generally parceled out to farms in the general parceling out of land (isojako) in Finland, that begun in 1775. The state established also jointly owned forests, mostly in the beginning of 2000^th century when land was donated for landless population. Some have been established voluntarily. Act on Jointly Owned Forests was enacted in 1925 to ensure proper management of the forests. It contains instructions of administration of the forests.

A survey was conducted to study the conditions of the jointly owned forests. The forests, a total of 37,843 ha, are distributed evenly over the country. Average size of settlement jointly owned forests in Southern Finland are 314 ha, initial jointly owned forests in Southern Finland 1,726 ha, settlement joined forests in the county of Oulu in Northern Finland 592 ha, and initial joined forests in Northern Finland 1,268 ha. The forest lands are poorer than in other private forests. The most common age class is 41-80 years in Southern Finland and 61-120 years in the north. The forests resources were larger in the initial joined forests than in the settlement joined forests when the joined forests were established. In settlement joined forests fellings were smaller than the increment, while in initial joined forests fellings were slightly larger than the increment. Joined forests have given the owners rather good and regular income, which has probably been larger than if the forests had been managed as farm forests. Joined forests have, therefore, met their objectives.

• Metsäpelto, E-mail: em@mm.unknown

The drained peatlands regenerate usually well, and artificial regeneration by sowing or planting has been rare. Field trials of Norway spruce (Picea abies (L.) H. Karst.) were established in northern Satakunta in Western Finland in three drained peatlands in 1934. Sowing trials of Norway spruce consisted of patch and broadcast sowed sample sites in treeless bogs and under protective forest. The seedlings of spruce were planted either under protective forest or in treeless peatland.

The results show that artificial regeneration of Norway spruce succeeds best under protective forest. The best tree species for upper storey is Betula sp. which grows fast and controls growth of ground vegetation. The peat is relatively decomposed on those peatlands that are suitable for spruce, and breaking of the surface of the peat is not recommended. In the sowing trials, breaking of the upper layer of the peat caused frost heaving, cracking of the dried surface and sticking of mud in the seedlings in the patch sown sample site. The shoot and root growth of seedlings of the broadcast sown site was better than seedlings of the patch sown site. The planted spruce seedlings seemed to be more susceptible for spring frost than the seedlings in the sown site. The plants of seed origin succeeded in general better than the planted seedlings.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown

The aim of the study was to investigate how the drain network and dimensions of ditches change after the drainage. The studied drained peatlands were situated in the municipalities of Parkano and Virrat in Central Finland. The ditches were in average 15 and 17 years old. The depth and width in the surface of the peatland were in average one quarter smaller than after the drainage. The width at the bottom of the ditch has, however, almost doubled. Peat had sunken more in peatlands with thick peat layer and higher humidity. Sinking of peat influenced the depth of the ditches. The volume of the ditches decreased about 30%. The decrease of the ditches by the drying and sinking of the peat was greater than the increase caused by erosion.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown

Approximately 320,000 hectares of peatlands and paludified lands had been drained for agriculture and forestry purposes in Finland by 1920. The ditch network was not optimal in the early drained areas, and the condition of the ditches declined over time. In this study, the condition of drainage system, and the natural processes that affect them, was inspected in 18 drained peatlands.

Several processes can reduce of the size of the ditches. The process of crumbling of soil in the sides of the diches can last up to three years after the draining. Erosion of the main drains, caused by water flow can, however, continue longer. The ditches also sink when the peat dries. Soil frost can affect the ditches, but as the vegetation grows its effect gradually decreases. The vegetation that grows in the ditches may finally block the ditch completely.

The PDF includes a summary in English.

• Kokkonen, E-mail: pk@mm.unknown

The article is a detailed review on the problems in the general parceling out of land (isojako) in Kuusamo, Kemijärvi and Kuolanjärvi counties from the context of forest policy. The disputes about division of the land originate from military tenure contracts (knihtikohtrahti) made with the local tenants in 1700s. Later some counties got alleviations in the contracts concerning taxation and partition of land. These alleviations delayed the parceling out of land in the area. According to the article, from the forest policy point of view, the inhabitants in Kuusamo, Kemijärvi and Kuolanjärvi were conveyed disproportionately large forest properties from the state due to the military tenure contracts. This gave them undue benefits from the state compared to the neighbouring counties.

The PDF includes a summary in German.

• Pekkala, E-mail: mp@mm.unknown

The article aims to give a proposal on how to organize a protection forest system to protect the pine timber line in the northernmost Finland. In this first part of the six-article series is described the range and biology of Scots pine (Pinus sylvestris L.) in the timber line area, and human actions influencing the species in the area. The southward shift of Scots pine timber line cannot be explained by change of climate. The main factors are too intensive fellings, reindeer husbandry and forest fires. The poor reproduction of pine in Lapland makes it vulnerable to disturbances. The trees produce viable seeds in average only every 100 years. Thus, effective measures are needed to protect the existing pine forests in the area.

The article is divided in six parts. A German summary is in a separate PDF.

• Renvall, E-mail: ar@mm.unknown

An extensive field-based survey was conducted to establish the distribution of site types on drained peatlands, the condition of the drainage networks, the post-drainage development of the tree stands, their structure and silvicultural condition and the corresponding requirements for operational measures. The data is based on sampling of the forest drainage undertaking during 1930–78 and consists of 1,312 km inventory transect, 6,030 relascope sample plots and 21,700 studied ditches.

Of the studied peatlands more than 60% were Scots pine (Pinus sylvestris L.) mires, slightly under 20% Norway spruce (Picea abies) mires, and under 10% each treeless mires and paludified upland forest sites. The remaining peatland area that is to be considered suitable for forest drainage according to criteria used by Heikurainen (1960) now consists mainly of spruce mires and paludified upland forest types; about 1 million ha both groups still remain undrained.

The proportion of ditches in need of ditch cleaning was estimated to be under 10% in the youngest drained areas and under 30% in the oldest. The mean tree stand volumes of the drained peatlands of different site types show the same dependence on the trophic level as in earlier studies but the volumes seem to be some 5–10% lower. These results compare favourably with those of the 7th national forest inventory.

Trends in the post-drainage development of tree stand volumes and increment are also, generally, in accordance with earlier findings but have somewhat lower values. The development of the nutrient-poor site type stands, especially in Northern Finland, seems to be significantly poorer than was earlier assumed.

The PDF includes a summary in English.

• Keltikangas, E-mail: mk@mm.unknown
• Laine, E-mail: jl@mm.unknown
• Puttonen, E-mail: pp@mm.unknown
• Seppälä, E-mail: ks@mm.unknown

The aim of this investigation was to examine the dependence of stand volume and increment on different growth factors on drained peatlands drained 20 years ago. Measurements were made in 1977-79 on 35 sample plots in Central Finland on relatively poor pine bogs with a thick peat layer.

It became evident that the stand volume, increment and radial growth and growth development are primarily functions of groundwater depth. Groundwater depth is dependent, in the first place, on ditch depth and ditch condition. With regard to the variation in ditch spacing (ca. 35-70 m) under examination, the effect of ditch spacing on the stand was insignificant. As a practical recommendation it was concluded that ditches should be kept deep enough (> 70 cm) in order to maintain undisturbed stand development.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

The study deals with the development during the 1950s and 1960s of a stand growing on peatlands which had been drained in the 1930s. The following characters were determined by measurements: the volume of the growing stock, the volume increment, the relative increment, the increment percent and the increment curves. Moreover, the possible changes taking place in the difference between tree growth along the ditches and in the middle of the strip between ditches were studied. In addition, the regional variation in increment was studied; this question was studied as the regression between the relative growth and the temperature sum. The results were compared with other Finnish investigations into the regional variation of increment.

The volumes of the growing stock had increased during the course of twelve years by 70–10 m³ /ha depending on the site type and climatic zone concerned. The relative increment had dropped in each case studied. As a matter of fact, this is only to be expected because the volumes had increased and the absolute growth had remained more or less unchanged. The development of the increment percent was compared with mineral soil stands in the case of Southern Finland, both uncut stands and stands treated with cuttings. According to the results obtained, the development of the increment percent was better in the present material than in uncut forests, but in some cases it did not reach the level of tended stands. The revival of the tree crop after draining takes place at different rates in the vicinity of and, on the other hand, at greater distances from the ditches and that this relationship is dependent on the fertility of the site.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown
• Seppälä, E-mail: ks@mm.unknown