|
English summaries 8/1999
Slime moulds (Myxomycetes) are an ancient group of organisms
by Marja Härkönen
Pages 4-11
Slime moulds have remained virtually unchanged for at least 300 million years. Almost 1000 species have been described from places ranging from the equator to north of the North Pole. A total of 190 species have been encountered in Finland.
Slime moulds have no separate cells, the organism consisting of a mass of cellular slime surrounded by a membrane. The slime contains large numbers of nuclei, which divide simultaneously, the amount of cellular slime then also increasing. This enables the mould to spread blob-like over an area of several square centimetres, or even square metres.
Slime moulds are able to move bodily. This ability is due to flowing of the cellular mass, enabling the organism to slowly creep across surfaces. Movement is towards suitable food or moisture. Attracted by a succulent mass of bacteria, a "branch" of the slime mould may break off completely from the "parent", forming a new individual. If the two later meet, they may coalesce. What, then, is an individual slime mould?
Finland's original cattle breeds are appreciated again
by Helena Romppanen
Pages 24-27
Finland has three indigenous cattle breeds: one from western Finland, one from eastern Finland, and one from Lapland. The most common breed nowadays is the light brown western variety, totalling some 4000 individuals. When, in 1987, a start was made on determining the present status of the brown and white breed from eastern Finland, only 25 cows were discovered in this country. Fortunately, some of the breed's sperm was stored frozen in a sperm bank. Later, some more pedigree eastern cows were located on a few farms and at the moment there are around 130 of this variety in existence here.
Even fewer entirely white cows had survived. When the population of the Lappish breed was surveyed, researchers found only 20 genetically pure individuals. There were neither any bulls left nor sperm stored in a sperm bank. From this original stock, it has been possible to increase the number of Lappish cows to over a hundred.
The indigenous Finnish breeds rapidly declined as the Ayrshire, and later the Friesian, breeds spread. These dominant breeds gave far more milk than the traditional Finnish ones. During the first half of this century, Finnish cows were turned into effective and hardy producers. These efforts resulted in the Ayrshire breed eventually dominating cowsheds.
Genetic studies have revealed that the indigenous Finnish breeds are as distant from each other as the Friesian breed is from the Ayrshire. Finnish cows generally have no horns and are markedly smaller than, for example, Ayrshires. They are very hardy and also require much less food (which may be of poor quality) than the dominant breeds. Milk from the eastern Finnish and Lappish cow breeds curdles for cheese making, etc, better than Ayrshire milk, for example.
Ähtäri and Ranua animal parks in Central and North Finland
by Juha Valste
Pages 30-33
Ähtäri zoo, in central Finland, was opened in 1973 and Ranua zoo, in southern Lapland, ten years later. Both animal parks are specialised in breeding northern mammal and bird species and displaying these to the public. Both also possess some endangered animals like the European mink and European bison. Injured and sick animals are also cared for at both establishments.
Ähtäri attracts over 200,000 visitors a year, while Ranua sees around half of this number. The number of visitors varies rather a lot according to the weather; for instance, there were far fewer visitors during the wet 1998 summer.
Finnish zoos are popular places with nature conservationists, too. The healthy animals are kept in large enclosures and visitors are able to observe many species they would not otherwise have a chance to see in the wild. In addition to wolves, bears, lynx and wolverines, there are wild boar, European elk, wild forest reindeer, otters, pine martens, raccoon dogs, foxes, swans, owls, hawks, and even eagles. Altogether the animal parks display 50-60 different mammalian and bird species.
White eyes on the water: Finland's three different water-lilies
by Seppo Vuokko
Pages 34-37
Water lilies are aquatic plants that are familiar to all of us. In Ancient Egypt the blue and white water-lily, or lotus (blue lotus, Nymphaea caerulea and Egyptian
lotus, N. lotus) were depicted in paintings and jewellery. After the time of the Pharaohs the Indian lotus, which is not related to the water lilies, was brought to Egypt. Since then, these plants have interbred.
Three kinds of water lilies occur in Finland. Two of them, Nymphaea alba alba and N. alba candida, formerly held to be separate species, are nowadays considered to be subspecies. N.alba has long been known as the European white water-lily. The smaller N.tetragona has been relegated to its own species and has no English vernacular name.
Water-lilies are common in Finland's numerous lakes, pools and small rivers. Many animals eat them, from muskrats and elk to several species of beetles. Water-lilies protect themselves by forming toxic alkaloids in their leaves. Larvae of the beetle Galerucella nymphaeae, which feed on the leaves, store up the toxin in their own bodies, making them inedible to predators.
Sosnovyi Bor nuclear power station's problems remain unresolved
by Jan Kunnas
Pages 42-43
Standing just 150 km southeast of Helsinki, the Sosnovyi Bor nuclear power station has four 1000-MW Chernobyl type reactors. The first reactor, which has been in operation since 1973, is supposed to be in service up to 2003, while the service life of all four reactors should cease by 2011. However, the Russians intend not only extending the life of the present reactors, but also increasing the plant's output. Since the Finns purchase electricity from Russia, they are helping to support the new construction.
The fuel store used by the power plant has been filled up to 130 %. This has been achieved by packing more submersed rods in! There are 5000 tons of spent fuel stored just 90 metres from the Baltic Sea. In 1997, the Finnish Centre for Radiation and Nuclear Safety found a score of fractures in the storage vessels.
Burning peat causes global warming and heated reactions from antagonists
by Jani Kaaro
Pages 38-40
Almost one third of Finland's surface area is covered with peatlands (bogs and mires). It is averred that peat is an especially Finnish and harmless source of energy. However, the extraction and combustion of peat both cause harm to the environment.
A peat bog has to be dried out ready for peat extraction. Bogs act as natural "sponges" for storing up water. Due to the open drains excavated for draining the bog there is a sudden heavy runoff of acid bog water, which also contains a large amount of humic substances. As a consequence of drying, the bog is completely destroyed as a habitat for animal and plant species, and also as a site from which to gather berries (cloudberries, cranberries, etc).
Peat is an extremely slowly renewing natural resource. Our present peat bogs have formed over centuries, or even millennia. The carbon dioxide bound up in the peat for up to thousands of years is released into the atmosphere during combustion within the space of a few years. During peat combustion, more carbon dioxide per energy unit is released than from coal.
Peat is a poor source of energy. Its combustion accelerates the greenhouse effect, its production causes other environmental problems, and its energy density is so small that it cannot be profitably transported for long distances. Instead of peat, Finland ought to start using the energy contained in wood (energy wood) grown for the purpose, since the carbon dioxide released by burning the wood is reassimilated by the next crop.
|
|