Articles containing the keyword 'Symposiums'
Category : Article
The symposium of ’Air pollutants as additional stress factors under northern conditions’ was held in Oulu in Northern Finland during November 11–13, 1980. The symposium had four sessions: 1) the ecophysiology of air pollution effects and long-term risks of air pollution effects, 2) bioindication in forest ecosystems, 3) particle and metal problems, and 4) a general poster session mainly related to current research, and the results of the research programme on the dispersion and effects of air pollutants in forest environments financed by the Academy of Finland. Most of the posters and papers presented at the symposium have been included in the proceedings. The rest of the results presented are reviewed in research report of the programme and in the related scientific papers.
The PDF includes a summary in Finnish.
The paper discusses the theoretical basis of quantitative analysis of the effect of genotype and environment in forest trees. Perhaps the main problem in the understanding of the laws of intrapopulation variability of the species of woody forest plants is the study of the structure of their populations. It may be characterized by a number of parameters. The intrapopulation variability of quantitative characteristics appears as a result of environmental and genetic factors, but to determine the relative weight of these factors in a concrete case is not easy. The study of the structure of a population by its quantitative characteristics has a wider task: to establish the relevance of the hereditary differences of the individuals of a population. Also, the differences caused by diverse growth conditions and how they are reflected in the level of general phenotypic variability of the quantitative characteristics in a given population has to be identified. The author gives examples of assessment of heritability in forest trees.
The PDF includes a summary in Finnish.
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Petrov,
E-mail:
sp@mm.unknown
Establishment of seed orchards to produce genetically improved seed started in the USSR in the 1960’s. The aim is that within 10–15 years the total seed production will reach 50% of the seed used. The paper describes seed production in seed orchards of Scots pine (Pinus sylvestris L.) in the forest-steppe of the European part of the USSR. The orchards have been established either by grafting or by planting of seedlings originating from plus trees. The grafts begin flowering relatively early, however, only at the age of 8–10 years seed crops become relatively regular and abundant. The cone yield in young seed orchards have great variability, and the yield of cones varies between clones. Cone yield does not always correlate with a good seed yield. One of the reasons for high amount of empty seeds is the difference in the periods of flowering between the clones.
The seed crops can be improved by establishing optimal conditions for the growth of the trees. Also, when a seed orchard is founded, the peculiarities of the generative activities of the clones and their reactions to changes in the environmental conditions must be taken account by taking an individual and selective measure approach to improvement measures. The orchards can be established with clones for their genetic combining ability and their requirements for the stimulation of seed-bearing.
The PDF includes a summary in Finnish.
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Efimov,
E-mail:
je@mm.unknown
Planting of forest trees takes place in USSR on millions of hectares but without permanent forest seed bases having yet been established in every region of the country. Consequently, local seed does not suffice the need, and it is necessary to secure it from other geographical regions. To avoid negative consequences of seed transfer it is necessary to study geographic variation of the genetic characteristics of forest trees and construct scientifically based division into seed zones. Geographic transfer of seed can also be regarded as a breeding measure. A large research program is being carried out in the USSR on the subject. Most of the existing trials are provenience tests of Scots pine (Pinus sylvestris L.). Over 2,000 hectares of new provenience experiments is to be established in near future.
The PDF includes a summary in Finnish.
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Prokazin,
E-mail:
ep@mm.unknown
The study concerned with variations in the density of the wood of different provenances in provenance test series of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) RH. Karst.), established in 1931. Increment cores were collected from 10 sample trees from each sample block. The density of the pine wood was noticeably higher than that of spruce. The basic density was in average 450 kg/m3 for Scots pine, and the variation between different origins was 3–9%, while the average basic density of spruce was under 400 kg/m3 and the variation 3–10%. Statistically significant differences were found between the mean basic densities of different provenances in all sub-experiments for spruce, but only in one pine sub-experiment. However, these differences were not due to the altitude or latitude of the place of the origin. Volume growth seems to be the dominant component in the formation of dry matter yield.
The PDF includes a summary in Finnish.
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Velling,
E-mail:
pv@mm.unknown
The productivity and several morphological features of Estonian Norway spruce (Picea abies L. Karst.) show significant geographical variation. This is no doubt because of differences in the climatic and soil conditions, which in spite of the small area of the country is quite large. In order to check the possible geographical variability of the gene pool, preliminary experiments were carried out in 1969, when seeds from 93 spruce stands originating from 14 forest enterprises were sowed in a nursery. After two years, the seedlings originating from south-eastern Estonia were the tallest. The seedlings from northern origins were smallest. However, it cannot be maintained that spruces from Southern Estonia are of better genotype than genotype from Northern Estonia since the genotypes are evaluated on the basis of ecological conditions under which the experiments are carried out. Another study suggests that an average shift of 7° to the east of the territory for spruces are suitable for cultivation in Estonia.
The PDF includes a summary in Finnish.
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Etverk,
E-mail:
ie@mm.unknown
Ecological investigations have shown that Norway spruce (Picea abies (L.) H. Karst.) reached Western Finland about 1,500–1,000 years B.C. and did not reach Åland islands before around the year 0. The species spread into Finland from the east and north-east, having survived the glaciation somewhere in the central parts of the Asian continent. Geographical variation has provided foresters with provenances of better growth and higher economic yield. In Finland, provenances, for instance, from Austria, Eastern Germany, Romania, Southern Poland and Slovakia have been planted in experiments, mostly in various parts of Southern Finland. According to the results of the experiments, it seems that for the more northern parts of Finland and Sweden the best material was to be obtained from north-east Europe.
The Scandinavian countries decided in 1975 to make a common assessment of all the provenance experiments with Norway spruce. The synthesis confirms the earlier view that provenances from the most north-eastern parts of Central Europe are of the greatest value for Finland.
The PDF includes a summary in Finnish.
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Hagman,
E-mail:
mh@mm.unknown
The development of the scientific basis for the production of high-quality seed led to the introduction of a large part of the research findings in forest genetics and forest tree breeding into practical forest seed production in the USSR. Since 1971, work has begun in forest enterprises on the establishment of a permanent seed supply for the main tree species – Pinus sylvestris, Picea ssp., Larix ssp. Quercus robur, Haloxylon ssp. and nut trees.
The basis for forest tree improvement is a gene pool which is built up using mass and individual selection of valuable forms in natural populations. In accordance with a long-term programme up to 1990, an inventory of 13.2 million ha of the best high-productive stands has been carried out for breeding purposes in the state forests. About 7,000 ha of plus stands have been selected, and a total of 9,453 ha of seed orchards and 141,253 ha of seed collection stands have been established. The first stage of the programme is planned to be complete in 1980, and in the second stage clonal high-quality seed orchards will be established.
The PDF includes a summary in Finnish
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Novoselceva,
E-mail:
an@mm.unknown
The Nordic working group for forest fertilization is a group of research workers from the Nordic countries Denmark, Finland, Norway and Sweden, which has been working on plant nutrition questions and forest amelioration problems. The group has met annually to discuss current problems, hitherto mostly concerning forest fertilization. In 1976 the question of future working forms came up, and the group decided to arrange a symposium on the subject Nutrient cycle in tree stands in 1977.
This symposium took place in Harjavalta and Ikalis in Finland from the 29th of August to 1st of September 1977. During the symposium 12 papers were presented, which are published in the following, either in full or as summaries of a given lecture. Part of the lectures are in English and part in Swedish.
The paper includes the following titles:
A bioelement budget of an old Scots pine forest in Central Sweden
Mobilization of plant nutrients in a Scots pine forest Mor in Central Sweden
Accumulation of organic matter and nitrogen on sand dunes following sand fixation and planting of dwarf mountain pine
Sambandet mellan torvmarkstyp och yttorvens näringshalt
Changes in the amounts of inorganic nutrients in the soil after clear-felling
Plant nutrient balance in decoration greenery cultivation
The effect of forest fertilization on primary production and nutrient cycling in the forest ecosystem
Förändringar i humuslagret efter skogsgödling
Balanserad näringsupptagning och behovet av gödsling i trädbestånd på näringsfattiga torvmarker
Of fertilization on nutrient contents in needles and litter fall of Scots pine on dwarf shrub pine swamp
Micro-nutrient deficiencies cause growth disturbances in trees
Tallarnas växtstörningar, markens näringsbalans och micronäringsbrist
The paper is a review on the topics of Symposium on forest types and forest ecosystems, held in connection to the IX internal botanical congress in Montreal in August 1959, the chairman of which was Ilmari Hustich. The article includes 18 preparatory papers that were distributed among the participants of the symposium. The common theme of the papers was the question of finding common platform for the different schools of forest types and forest ecosystems. In addition to the papers, the article includes a summary of the proceedings and discussions of the symposium.
The following papers were presented in the symposium:
Aichinger, E. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?
Arnborg, T. Can we find a common platform for the different schools of forest type classifications?
Dansereau, P. A combined structural and floristic approach to the definition of forest ecosystems.
Daubenmire, R. Some major problems in vegetation classification
Ellenberg, H. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?
Hills, G.A. Comparison of forest ecosystems (vegetation and soil) in different climatic zones
Kalela, A. Classification of the vegetation, especially of the forest, with particular reference to regional problems
Krajina, V.J. Can we find a common platform for the different schools of forest type classifications?
Kühler, A.W. Mapping tropical forest vegetation
Linteau, A. Y. a-t-il. Un terrain d’entente possible entre les différentes écoles au sujet de la classification de types forestiers?
Medvecka-Kornaś, A. Some problems of forest climaxes in Poland
Ovington, J.D. The ecosystem concept as aid to forest classification
Puri, G.S. The concept of climax in forest botany as applied in India
Rowe, J.S. Can we find a common platform for the different schools of forest type classifications?
Scamoni, A. Können wir eine gemeinsame Grundlage für die verscheidenen Schulen in der Waldtypenklassifikationen finden?
Sukachev, V.N. The correlation between the concept ’forest ecosystem’ and ’forest biogeocoenise’ and their importance for the classification of forests
Webb, L.J. A new attempt to classify Australian rain forest
