Current issue: 54(2)
Soil of open and forest covered lands have different properties. Forest devastation has negative effect on forest soil, for instance, through leaching of nutrients. There are different views on how forest fire influences chemical properties of the soil. Burning of forests can have both positive and negative consequences.
The article publishes partial results from a study that aimed to find out how shifting cultivation affects the soil, and how it may change natural regeneration and forest growth of the stands. Soil samples were collected from four burnt-over sites. Of the samples, size classes of the soil particles, volatile solids and nutrient contents were determined. According to the results, the burning increased soluble nutrients, but the effect was not long-lasting. However, more sample sites would be needed to give definitive results of the differences.
The article is a review on shifting cultivation, its methods and use in Finland, and its effect on the condition of forests. Shifting cultivation decreases forest reserves not only by burning large amounts of wood. Of the area used for shifting cultivation, 10-50% can be open land. The older age classes of forests are often missing, and range of tree species shift towards deciduous trees. This causes lack of large timber. The shorter the rotation, the less well the most valuable trees survive on the area. One reason is lack of seed trees. Of the coniferous trees, Scots pine (Pinus sylvestris L.) is able to survive in the burnt-over lands better than Norway spruce (Picea abies (L.) H. Karst.), because it can produce seeds at a relatively young age. Betula sp. and especially grey alder (Alnus incana (L.) Moench) regenerate well on burnt-over lands. Also the frequency of good seed years determine which tree species become the dominant species on a burnt-over site.
When shifting cultivation is abandoned, deciduous trees keep their advantage over coniferous trees, because the wood of coniferous trees is used more in the surrounding villages. Pine and spruce spread to the burnt-over areas from the poorer sites that often had remained unburned. In densely populated areas in some counties in Savo in eastern Finland, where shifting cultivation was practiced intensively, Norway spruce became rare. Dominant tree species in the burnt-over areas became birch and pine.The article is divided in two parts. A German summary is included in a separate PDF
The earliest local records of lack of timber in Finland are from the 1600th century when Finland belonged to Sweden. The causes vary from burning of tar and shifting cultivation to local factories using fuel wood. Best preserved were forests in Lapland and Kainuu in Northern Finland and those parts of Karelia where shifting cultivation was not practiced. Especially harmful was shifting cultivation, because it made it impossible to grow valuable timber. The state did not intervene in the use of forests until it itself began to need more wood. Shipbuilding was the first cause to limit the use of wood, especially need of mast trees of pine and oak. Also the use of timber by private sawmills began to raise general concern in the 16th century. They influenced the decrease of forests in the 1800th century, due to the limited wood procurement areas and selection felling of timber trees. The establishment of sawmills became regulated in 1700th century. Collective forest ownership by the farms was seen at the time one of the reasons to forest devastation. In 1654 the state of Sweden forbade the burning of mast or in timber forests. Mining industry needed much fuel wood, and shifting cultivation was forbidden near the mines in 1734. Regulations and instructions were also on given on use of wood, for instance, in building, in fences, leaf fodder, fuel wood and tar burning.
Despite of many efforts, the government of Sweden could not prevent devastation of forests in Finland. The many wars of the state hindered economic growth, the regulations were sporadic and often difficult to apply, there was little supervision, the understanding of forestry was poor, and the remote Finland was often neglected in Sweden.The PDF includes a summary in German.
The Jokioinen Estate was established in 1562 when king Erik XIV of Sweden granted a large area around Jokioinen in the southwest Finland to Klas Kristersson Horn. The estate had several landlords until it was acquired in 1872 by Jokkis Stock Company, and finally sold to the government in 1918. The forestry of the estate was influenced by complications concerning the ownership of the land. A part of the tenants of the estate had originally been independent and owned their farms, but some farms were so-called family-right-farms, which were inherited from father to son, but the farmer did not own the land. A third type of farmers were ordinary tenants, who were directly dependent on the landlord. Especially ambiguous was the family-right-farmers’ right to harvest timber from the forests. The Finnish government acquired the estate to solve the problems and gave the tenants right to buy their farms.
Until the 18th century most of the farmers in Jokioinen area practiced shifting cultivation. This method of farming influenced strongly the forests, and continued until the increased market price of timber made it unprofitable. The forests were also the source of fuel wood for both the farmers and the landlord. The estate had own saw-mill industry since the 18th century. In 1871 a trained forester was hired for the estate. When the government acquired the estate, it comprised 32,000 hectares of land. The state retained 7,000 hectares of the forests. They were managed by a trained forester and administrated under the Board of Agriculture.
The PDF includes a summary in English.