Articles containing the keyword 'seeding'

The aim of the present study was to collect information presented in literature concerning the development and germination of the seeds of coniferous trees with special reference to those species which thrive in the conditions prevailing in Finland. Along with the increase in the importance of direct seeding as a silvicultural means in Northern Finland, there is a growing demand for methods by means of which the germination of seeds could be promoted. According to the results obtained from previous studies, such a method can be found, provided that a practically usable and reliable pre-germination method is developed.

The PDF includes a summary in English.

• Lähde, E-mail: el@mm.unknown
• Pahkala, E-mail: kp@mm.unknown

The aim of the study was to assess, through field experiments, the possibilities of using peat briquettes in the seeding of Scots pine (Pinus sylvestris L.) in Southern Finland. The briquettes were dug into the soil in the middle of patches of mineral soil. The seeds were covered by a 2-5 mm layer of mineral soil. The seedings were inventoried in the three following autumns.

According to the results, the briquettes were clearly inferior to the control, which was ordinary drill seeding. This was mainly due to the fact that no rain was received after the seeding, and that the third summer from seeding was extremely dry. Abundant germination was observed during the second summer after seeding in both briquette seeding and the control. During more rainy summers the result might have been better.

The PDF includes a summary in English.

• Lehtiniemi, E-mail: tl@mm.unknown

The time interval between final felling and plantation means a waste of time and thus a production loss, and may lead to lush growth of ground cover and hardwood sprouts, which increases expenses in forest management. The objective of this study was to determine the length of time between final felling and artificial regeneration in private forests in the forest districts of Uusimaa-Häme in Southern Finland and Pohjois-Häme in Central Finland. The material consists of a sample of 150 plans of the 952 cutting and regeneration plans in the district of Uusimaa-Häme and a sample of 140 plans of the 1,102 plans in Pohjois-Häme.

The time lag between final cutting and seeding or planting was on average 1.4 years in Pohjois-Häme district and 0.7 years in Uusimaa-Häme. In the latter district, 56% of the logged area was regenerated in the spring immediately following the cutting, and 84% not later than in the second spring. In Pohjois-Häme, 29% of the harvested area was regenerated immediately in the first spring following cutting, and 79% not later than in the third spring following cutting.

In Pohjois-Häme, the interval was shortest in the smallest forest holdings, and longest in the largest holdings with the largest regeneration areas. The length seems to depend mainly on the size of the regeneration area. In Uusimaa-Häme district, the interval was shortest in the smallest holdings, rather short in the largest, and longest in the intermediate-size forest properties. Seeding with Scots pine (Pinus sylvestris L.) was used in almost all regeneration areas.

The forest owners had mainly carried out the regeneration work themselves. In the Pohjois-Häme area, the interval was shorter when the district forestry board regenerated the area. 35% of the regenerated areas had required supplementary planting in Pohjois-Häme, and 47% in the Uusimaa-Häme area. Supplementary planting was more common in areas regenerated later after the cutting. In Pohjois-Häme, according to the reports of the forest owners, 75% of the regenerated areas required tending during the first three years, in Uusimaa-Häme, 80%.

The PDF includes a summary in English.

• Yli-Vakkuri, E-mail: py@mm.unknown
• Autio, E-mail: aa@mm.unknown
• Vehkaoja, E-mail: jv@mm.unknown

This paper describes the preliminary results of Scots pine (Pinus sylvestris L.) seeding and planting trials on drained peat soils.

The results showed that a perpared peat surface was a better surface for seeding than the unprepared one. Planting of 2+1-year seedlings succeeded better than planting 1-year seedlings. Planting on the turf gave better survival than planting on the unprepared soil surface. The whole growing season was suitable time for planting Scots pine seedlings except May when the peat soil under the surface was still frozen.

Using fertilizers in connection with planting was surveyed in two ways. Mortality of seedlings increased when they were top-dressed with NPK fertilizer. Using a so-called spot fertilizing with several combinations of fertilizers resulted in K and N tending to increase the mortality of seedlings, but P decreasing mortality.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown
• Päivänen, E-mail: jp@mm.unknown
• Seppälä, E-mail: ks@mm.unknown

The article reviews the occurrence of damage causes by elk (Alces alces L.) in young Scots pine (Pinus sylvestris L.) stands established by direct seeding in the Ostrobothia region in Finland. The data was collected by random sampling, and consists of 110 sample plots in pine stands, established in 1930-1944.

Signs of elk damages could be observed in 20% of the stands. In more than half of the damaged stands pine seedlings were damaged by elk, on the rest of the stands the damage was targeted to hardwood saplings only. With the present density of elk population, the damage has an insignificant bearing upon the development of pine seedling stands in Ostrobothnia. The weaknesses of silvicultural state of the stands have been caused by other factors than elk.

Silviculturally weak stands were more liable to elk damage than strong ones. The occurrence of elk damage was more usual in stands with hardwood mixture than in pure pine stands. Especially goat willow, mountain ash and aspen, but also to some decree birch, seem to attract elk. Those factors that promote hardwood growth: fertility of the site, swampiness and the presence of seeding hardwoods in the area, increase the stand’s liability to elk damage.

The article includes an abstract in English and a summary in Swedish.

• Yli-Vakkuri, E-mail: py@mm.unknown

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes a field experiment on the use of herbicides to prevent growth of ground vegetation in cutting areas before sowing. The study suggests that the chemicals used in the experiment were not effective enough to prevent growth of ground vegetation in the more fertile lands, but were effective in poorer lands. However, the treatment affected also growth of tree seedlings.

• Paavola, E-mail: ep@mm.unknown

This paper aims at studying regeneration of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) by sowing and natural regeneration of birch (Betula sp.) in Western Finland.

Germination of spruce and pine seeds may be prevented by dryness and temperatures below the optimum for germination. In natural conditions, when temperature and moisture is insufficient for germination, the type of seedbed generally has en effect on germination result. Trenching of the seeding spots showed that root competition during the early stage of regeneration was not of decissive importance. It seemed to, however, improve the preservation of the seedlings later. It is common that it can take long before the seeds germinate, and during that time the number of viable seeds decrease strongly.

Also, the seedling stock quickly began to decrease in number after germination, especially during the first growing season and the following winter. The decrease was larger in intact vegetation than on mineral soil or in the humus layer. The emerging seedlings were destroyed by drought very easily, but their tolerance to drought improved later on.

The PDF includes a summary in English.

• Yli-Vakkuri, E-mail: py@mm.unknown

In this paper the development of sown Scots pine (Pinus sylvestris L.) seedling stands into forests is studied. The material was collected in stands sown in 1930–1940 in private forests in the Forestry Board districts of Central and Northern Ostrobothnia. The 119 areas, including both burned and other areas, were studied in 1955.

Most seedings had been carried out on relatively poor soils, mostly representing Vaccinium and Calluna type forests. 71% of the areas consisted of large forest fires, mostly from 1933. The most burned areas did not have seed producing trees nearby. The other sown areas were in general small, 1–2 ha, and near forests capable of producing seeds. The species of previous tree generation, in the older areas mostly pine and in the younger areas Norway spruce, affected tree species composition of the new tree generation.

Over 90% of the burned areas were in silviculturally good or satisfactory condition, while the main part of the other sown stands was in fair or poor condition. Weeding and thinning had been done only in the oldest stands. Most stands had been left untended. Natural new trees often competed with the sown pines, and cull-trees and border forest increased natural regeneration in the areas. In Calluna type the poor soil limited regeneration and growth of broadleaf trees. The worst competitors were naturally regenerated pine seedlings both on Calluna and Vaccinium type. On Vaccinium type also birch and sometimes also aspen (Populus tremula L.) competed with sown pine. On better sites and paludified areas competition by broadleaf trees increased. The rhythm of development of broadleaved trees is so different from pine that only those broadleaved trees that are formed in the stand when the pine seedlings are larger can develop harmoniously with pine. Due to the harmful competition, the seedling stands should be tended early on. In addition, it may be advisable to abandon the practise to leave trees on sowing areas.

The PDF includes a summary in Finnish.

• Yli-Vakkuri, E-mail: py@mm.unknown

Prescribed burning has been used in regeneration areas in Finland as a method to treat the humus layer and creating more favourable chemical, physical and biological conditions for the seedlings. At the same time, fire clears away seedlings and shoots of unwanted trees and other vegetation. Direct sowing or planting, mostly Scots pine (Pinus sylvestris L.), seldom natural regeneration, is used. In this paper, the initial stages of the formation of a new tree generation of Scots pine and Norway spruce (Picea abies (L.) Karst.) on prescribed burned areas is studied in Central Finland in 1956–1960.

The burned area remains almost without vegetation for about two growing seasons. Conditions on a burned area which has not been tiled are very unfavourable for germination of seeds of coniferous and deciduous trees. On the other hand, shoots of deciduous trees occur soon after burning. Conditions for regeneration were found to be better 3–5 years after burning. Removal of humus layer in spots improved regeneration. However, the patches facilitated also natural regeneration of Norway spruce and especially birch (Betula sp.), which compete with Scots pine seedlings.

Continuous rainy periods improved the germination of Scots pine and Norway spruce seeds sown on the humus layer. Pine and spruce developed more rapidly on the exposed soil, however, young seedlings were easily destroyed. Seed eaters destroyed the pine and spruce seeds sown on the humus layer of newly burned areas completely or almost completely. The viability of pine seeds sown on the burned humus layer did not decrease for three weeks, but the viability greatly weakened after six or more weeks. Spruce seeds lost their viability faster than pine seeds.

The PDF includes a summary in Finnish.

• Yli-Vakkuri, E-mail: py@mm.unknown

• Wennström, Skogforsk, Box 3, SE-918 21 Sävar, Sweden E-mail: ulfstand.wennstrom@skogforsk.se
• Bergsten, SLU, Dept. of Forest Ecology and Management, SE-901 83 Umeå, Sweden & SLU, Vindeln Experimental Forest, SE-922 91 Vindeln, Sweden E-mail: ub@nn.se
• Nilsson, SLU, Dept. of Forest Genetics and Plant Physiology E-mail: jen@nn.se

• Chantal, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: michelle.dechantal@helsinki.fi
• Eskola, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: le@nn.fi
• Ilvesniemi, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: hi@nn.fi
• Leinonen, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: kl@nn.fi
• Westman, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: cjw@nn.fi

• Stanturf, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: jstantur/srs_stoneville@fs.fed.us
• Schweitzer, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: cjs@nn.us
• Gardiner, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: esg@nn.us

• Ahnlund Ulvcrona, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: kristina.ulvcrona@slu.se
• Karlsson, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: lars.karlsson@slu.se
• Backlund, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: ingegerd.backlund@slu.se
• Bergsten, SLU, Forest Biomaterials and Technology, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se

• Backlund, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: ingegerd.backlund@slu.se
• Bergsten, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se