Current issue: 58(5)
Articles containing the keyword 'levinneisyys'
Category : Article
Climatological factors determining the natural northern boundary in Europe of oak (Quercus robur L.) were investigated. The natural northern boundary of oak corresponds in detail to the curve at which the growing season, beginning at +5°C in spring and ending at +10°C in autumn, is of a certain constant length. The northern boundaries for more oceanic plants can be explained by prolonged autumn activity. This is obviously the general explanation or the concept of oceanity. Oak spread markedly in Finland in the summers during 1961–1975, which on an average were as warm but much dried than those during 1931–1960. The importance of humidity for oak was discussed.
The PDF includes a summary in English.
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Solantie,
E-mail:
rs@mm.unknown
Ips acuminatus Gyll. (Coleoptera, Scolytidae) is a bark beetle that causes deep bluing in thin-barked Scots pine (Pinus sylvestris L.) pulpwood. It has been shown that this decreases pulp yield. The purpose of this study was to map the southern border of the distribution of Ips acuminatus in Finland. It was found that there have been changes in the distribution of this species during the last three decades. Ips acuminatus has now disappeared from southern Finland. On the basis of the sample plots (134 cutting areas) the southern border of this pest lies on the line running through the towns Vaasa–Seinäjoki–Äänekoski–Jyväskylä–Pieksämäki–Savonlinna–Punkaharju. A certain degree of localisation was observed in the occurrence of I. acuminatus in its distribution area, for instance, differences in its occurrence frequency in cutting areas and even in log and cutting residue piles in the sample cutting area.
It is considered that the most important reasons for these changes in distribution are the increase in logging and changes in the location of cutting sites, and resulting competition for breeding material for the increased population of bark beetles. Furthermore, the long-distance transport of unpeeled logs from the north across the present southern borders may, in the future, contribute to local changes in the southern distribution of Ips acuminatus.
The PDF includes a summary in English.
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Puukko,
E-mail:
kp@mm.unknown
The maps concerning the natural distribution of oak (Quercus robur L.) have proved most unreliable in detailed examination. In this paper, the author has collected his observations on natural oak in the westernmost parts of the province of Uusimaa and the easternmost parts of province of Turunmaa, the islands included. Furthermore, the paper includes some viewpoints which must be considered as criteria when determining the naturality of the stand in question. Future borders of oak’s distribution range must be moved farther up north to replace the earlier views of the northern limit of natural oak in Finland.
The PDF includes a summary in English.
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Rainio,
E-mail:
rr@mm.unknown
The paper describes the systematics, distribution, abundance and nest sites of Formica rufa -group in different Finnish forest types. In addition, it has been estimated the availability of Finnish ants in the biological competition.
F. polyctena, F. aquilonia and F. lugubris are distributed over whole Finland. F. rufa and F. nigricans to Southern Finland only. The relative abundace of ant nests diminish to Northern Finland. F. rufa -group prefer most forest on moist land (Myrtillus and Oxalis-Myrtillus types), mixed forests of Norway spruce (Picea abies (L.) H. Karsts), Scots pine (Pinus sylvestris L.) and birch (Betula sp.), and the silvicultural density 0.6–0.7 (good or satisfactory density), but they avoid broadleaved and pure one-tree species forests. For the biological competition the most competitive ant species seem to be F. polyctena and F. aquilonia.
The PDF includes a summary in English.
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Wuorenrinne,
E-mail:
hw@mm.unknown
Fomes annosus (Fr.) Cke. (now Heterobasidion annosum (s.str.)) has proved highly adaptable to varying conditions. Thus, the fungus is able to alter the pH as well as in alkalic as acid direction according to the original pH-grade. The fungus spreads mainly by basidiospores or by the sterile mycelium, but maybe also by the conidiospores. The fungus has spread through the temperate zone; in the tropical and sub-tropical zone it is found sporadically. There is a mention in the literature of at least 136 species in which it has been found. It is found in hardwoods but is most disastrous in conifers. The economic losses are considered biggest in England, Germany and Scandinavia.
The research has not been able to find a safe way to protect the trees growing on an infected site. The only way to limit the damage seems to be the use of mixed stands. Stump-protection has proved to be a relatively effective way to prevent the spread of the fungus to uninfected sites. The formerly used creosote has been mainly substituted by new chemicals, such as sodium nitrite. They act by altering the stump in a way that is favourable for antagonists to Fomes annosus, such as Trichoderma viride and Penicillium sp., or the recently presented Peniophora gigantea.
Although the fungus is found in many tree species, there is a difference in the relative resistance of different species. Among the conifers, the Abies-species (with exception of Abies grandis, A. alba and A. sachalienensis) are considered comparatively resistant. The species of Larix and Pseudotsuga are more resistant than those of Picea and Pinus.
The PDF includes a summary in English.
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Palmberg,
E-mail:
cp@mm.unknown
The aim of the study was to update knowledge of natural range of English oak (Quercus robur L.), European ash (Fraxinus exelsior L.), Norway maple (Acer platanoides L.), small-leaved lime (Tilia cordata Miller), wych elm (Ulmus glabra Mill.) and European white elm (Ulmus laevis Pall.) in Finland, and estimate how far north they could be grown as forest trees or as park trees. The study is based on literature and questionnaires sent to cities and towns, District Forestry Boards, districts of Forest Service, Forestry Management Associations and railway stations.
The northern borders in the natural range of the species succeed one another from south to north as follows: English oak, European ash, Norway maple, wych elm, and small-leaved lime. Occurrence of European white elm is sporadic. The English oak forms forests in the southernmost Finland, while the other species grow only as small stands, groups or solitary trees. According to experiences of planted stands or trees, the northern limits of the species succeed one another from south to north as follows: European ash, English oak, Norway maple, European white elm, wych elm and small-leaved lime. All the species are grown in parks fairly generally up to the district of Kuopio-Vaasa (63 °). The northern limits where the species can be grown as park trees reach considerably further north in the western part of the country than in the east.
The article includes a summary in English.
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Ollinmaa,
E-mail:
po@mm.unknown
Distribution of European white elm (Ulmus laevis Pallas) is on its northernmost border in Pyhäjärvi and Kokemäenjoki area. This survey describes distribution of European white elm in the flooded shores of the central lake of Pyhäjärvi and Kokemäenjoki river water system.
Both Ulmus laevis and U. montana (now U. Glabra Hudson) can be found in the area, but most of the elms qrowing in thea area are U. laevis. U. laevis occurs around the lake in two separate areas, almost entirely in flooded shores of the lake. Regeneration of elm from seeds was limited on a narrow belt on the higher part of the flooded shore. Consequently, U. laevis can be found as zones around the lake, created by the changes in water level of the lake. The trees are judged to be native for the area.
The article includes an abstract in German.
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Saarnijoki,
E-mail:
ss@mm.unknown
Occurence of buckthorn (Hippophaës rhamnoides L.) in the mainland coast and archipelago of Rauma in the Southwestern Finland was surveyed during 1934-1936. The species is coastal, growing most prominent in the islands of central zone of the archipelago, while it is rare in the outermost archipelago and loses competition to other vegetation in mainland. The main competitors in the innermost islands are black alder (Alnus glutinosa (L.) Gaertn.) and Norway spruce (Picea abies (L.) H. Karst.) and in the outermost islands black alder and common juniper (Juniperus communis L.). Seawater and ice can cause damage to buckthorn, but it resists wind well. The species grows well both on fine and coarse gravel.
The article includes an abstract in German.
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Enkola,
E-mail:
ke@mm.unknown
Category : Article
Norway spruce (Picea abies (L.) H. Karst.) is a species that becomes in Finland over time the dominant species in the sites that are suitable for it. The reason that it covers only a quarter of the forest areas in Finland depends mainly on forest fires. The aim of this review was to discuss the biological factors that affect competition between Scots pine and Norway spruce.
Especially important is the ability to regenerate and grow past seedling stage. There does not seem to be significant differences in the number of good seed and seedling years of the species. Spruce regenerates better on moss covered forest floor than pine. On the other hand, pine seedlings grow faster than spruce seedlings, and tolerate better dry conditions. Consequently, one of the defining biological differences is that Norway spruce needs more humid conditions than Scots pine. Spruce is shown to have greater transpiration than pine. Spruce also has higher site requirements, however, growing as undergrowth, it seems to be better able to compete of the nutrients with the larger trees than pine. It also tolerates shading better. Spruce is less frost tolerant than pine.
The PDF includes a summary in German.
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Aaltonen,
E-mail:
va@mm.unknown
The article discusses the thermal conditions in the northern limits of trees and some bushes in Finland. Temperature is the most important limiting factor for distribution of plant species. Precipitation variations, however, are small in Finland. The article lists the main features of thermal conditions during the different seasons in different parts of Finland. The northern limits and the thermal condition of the area are described for the following species: Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.), mezereon, buckthorn, common alder, linden, elm, maple, hazel, ash, oak, hybrid mountain ash, yew and Swedish whitebeam.
The PDF includes a summary in English.
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Keränen,
E-mail:
jk@mm.unknown
The northern range of small leaved lime (Tilia cordata Mill.) in Finland has remained the same since the end of 1800s, but according to the studies of subfossiles of lime found in peatlands, the northern limit has once been higher than at the present. The northernmost natural specimens of the species in Reisjärvi do not produce seed, and are therefore probably a relict. The article includes a review on the distribution of the species in Finland and its capacity to regenerate. The natural regeneration of lime in Finland is at present very rare. The species has lost its ability to sexual reproduction, but reproduces readily vegetatively.
The PDF includes a summary in German.
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Hertz,
E-mail:
mh@mm.unknown
Norway spruce (Picea abies (L.) H. Karst.) forests in Northern Finland are situated mainly in the state lands. The survey is based on silvicultural surveys made in the northernmost districts of the state forests. The quality of private lands of the area was deduced based on the adjacent state lands and specific observations. A map was drawn on the distribution of productive Norway spruce forest in the study area.
The continuous Norway spruce forest areas covered 1,112,000 hectares, of which 866,000 hectares were on the state lands. Especially in the northern parts of the area also more fragmented spruce forest could be found (130,000 hectares in the state lands). The estimated total volume of the wood in the forests in the state and private lands was 57.78 million m3 in the continuous spruce forest area. The spruce forests were often situated on hill and fell areas relatively high above the sea level. In the areas north of the 66th parallel, almost half of the forests were above 300 meters above the sea level. Because spruce forests of the state lands were concentrated near watershed areas, the wood harvesting was more expensive, and reduced the value of the state forests. The spruce forests grow usually on fresh mineral soil sites. However, towards north the species was found on drier sites. The stands were mostly pure spruce stands or mixed birch-spruce stands. The older age groups were the most common, but young stands were rare.
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Heikinheimo,
E-mail:
oh@mm.unknown
