Silva Fennica vol. 24 no. 3 | 1990
Category : Article
Coniferous timber imported by rail from the Soviet Union in Finland was studied for the presence of potential forest and timber pest beetles. Systematic samples of fourteen lots of pine pulpwood were examined. Seven of the lots originated from the European parts of the Soviet Union and seven from Siberia. 23 species of Scolytidae and about 18 other phloeophagous species were found including three species new for Finland: Phaenops guttulata (Buprestidae), Ips subelongatus and Orthotomicus erosus (Scolytidae).
The PDF includes an abstract in Finnish.
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Siitonen,
E-mail:
js@mm.unknown
Shoot elongation of Pinus kesiya Royle ex Gordon was studied using 2-year old grafts in a clonal seed orchard of the Pine Improvement Centre, located at the Huey Bong Experimental Station near Chiangmai, Thailand (19° 17’ N, 99° 15’ E, 900 m a.s.l.).
The seed orchard had a completely randomized block design with 30 blocks and 80 single-tree plots (clones) in each block. Eleven clones in four blocks were selected out of the total of 80 grafts (clones). From each graft, three lateral branches at the height of 1.6 m from the ground level were selected. Thus, total of 109 branches were measured. Shoot length of branches was measured between July 3, 1983 and March 11, 1984 at approximately bi-weekly intervals. Method of classical growth analysis were used in describing the shoot growth.
The annual shoot growth pattern of P. kesiya exhibited two consecutive sigmoid growth curves, i.e. it consisted of two flushes of shoot elongation, both formed by free growth. Thus, the pattern of shoot growth resembled the caribaea pattern. However, the annual shoot was composed of summer and winter shoots. These could be distinguished from each other by the reproductive organs, which always occur on winter shoot. The shoot contributed 61% of the total annual shoot length.
There were significant differences in the pattern of shoot elongation between the studied clones, which may reflect differences in the adaptation to different environmental conditions.
The PDF includes an abstract in Finnish.
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Sirikul,
E-mail:
ws@mm.unknown
- Kanninen, E-mail: mk@mm.unknown
Five ploughed research areas from Finnish Norther Karelia were selected for comparison studies of plough ridges and untouched soil. Measurements were made at a depth of 10 cm in sample plots on both mineral and paludified mineral soil and peatland parts of these areas. In summer 1987 daily soil water matric potential was measured using tensiometers, and volumetric soil moisture content and density were determined from soil samples at two dates during the summer. Water characteristics of the core samples were also determined. On paludified mineral and peat soils the water table depth from the soil surface was measured.
The results indicated that in plough ridges matric potential was lowest. Plough ridges were also seen to dry and wet faster and to a greater degree than untouched soils. In untouched soils, soil water relations and aeration were not affected by the distance to the furrow. The effect of the plough ridge was smallest on peatland, where there was a good capillary connection from plough ridge to the ground water, if the ditches were not very effective. The soil in the ridges did not dry too much to restrict seedling growth. The untouched surface soil in poorly drained peat and paludified minear soil was, at least in a rainy growing season, often and also for long times so wet that 10% minimum air space required for good seedling root growth was not available.
The PDF includes an abstract in English.
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Mannerkoski,
E-mail:
hm@mm.unknown
- Möttönen, E-mail: vm@mm.unknown
Four dispersal stages of the nematode Bursaphelenchus mucronatus (Nematoda: Aphelenchoididae) were surveyed in Finland during the summers 1989 and 1990 examining field collected conifer beetle (Coleopterea) adults of the following species: Monochamus sutor, M. galloprovincialis, Acanthocinus aedilis, Rhagium inquisitor, Asemum striatum, Spondylis buprestoides and Hylobius abietis. All but the last one (Curculionidae) belong to genus Cerambycidae. The two Monochamus species were the only ones carrying B. mucronatus fourth dispersal stages, total number of nematode larvae per beetle being higher in M. galloprovincialis. The frequency of infestation was 24% in M. galloprovincialis and 14% in M. sutor but the difference eas not statistically significant.
The PDF includes an abstract in Finnish.
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Tomminen,
E-mail:
jt@mm.unknown