Articles containing the keyword 'taimettuminen'

This paper reports spot sowing experiments of Scots pine (Pinus sylvestris L.). The seeds were either covered with coarse sand, tramped in the substrate or sowed without any covering, 30 seeds in each treatment in 70 replications. The site was of Vaccinium type with sandy soil. The germination percentage was 81 and 91 on the respective years. The development of seedlings was observed for 3–4 years.

The results indicate that both tramping and covering the seeds to some extent increased the number of seedlings and improved the early development. The highest numbers of seedlings were recorded in the first growing season, after which there was 23 seedlings/100 seeds in the uncovered spots, 27 seedlings in the covered spots and 31 seedlings in the tramped spots in the experiment sowed in 1965.

Mortality of the seedlings was highest between the first and second growing season, and empty spots increased with the time. There was no difference in mortality between the sowing methods, but the number of seedlings after first growing season affected the result. Under favourable conditions four seedlings per spot seemed enough to secure the survival of minimum one seedling per spot during the three first growing seasons. In poor conditions seven seedlings was needed.

The PDF includes a summary in English.

• Yli-Vakkuri, E-mail: py@mm.unknown
• Räsänen, E-mail: pr@mm.unknown

The aim of this study was to establish the need of treatment of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seeds to be sown in greenhouse. 3 x 100 seeds of each treatment (soaking in water, treatment with Pb₃O₄, treatment with tiram-containing coating substance) were sown in a glasshouse on a fertilized garden peat, and covered with peat layer of 6 mm thickness. The development of seedlings was followed for 100 days before the final measurement.

Soaking the seeds with water made germination somewhat faster. In spruce the germination percentage increased, but the opposite was observed in pine. No difference could be observed between the results from soaking with acid water from peat soil and lake water. Drying the soaked seeds for a week before sowing had no harmful influence on the germination or the early development of the seedlings. Treatment with Pb₃O₄ did not affect the germination speed or the seedling percentage of pine or spruce, but increased the germination percentage of spruce. Coating decreased germination and seedling percentages in pine. However, the differences between the treatments were so small that their practical significance is negligible.

Germination of both the species initiated on an average in 8 days, and 16 days after sowing 80% of the seeds had germinated. Seedling mortality was about 10% of the total number of seedlings, the most common reason being damping-off.

The PDF includes a summary in English.

• Löyttyniemi, E-mail: kl@mm.unknown

Prescribed burning has reported to avail forest regeneration, for instance, by releasing nutrients for the use of seedlings, changing the pH of the soil and decreasing competition of ground vegetation. The aim of the study was to find out if the effects could be verified. Sample plots were measured in the experimental area of Tuomarniemi, in Central Finland, both in previously burned and untreated seedling stands and young forests. The main species in the sample plots was Scots pine (Pinus sylvestris L.).

According to the results, prescribed burning prepares the soil for regeneration. Germination percentage of the seeds is higher on the burned soil. All the species, Scots pine, Norway spruce (Picea abies (L.) Karst.) and birch species (Betula sp.) grow faster. Prescribed burning increases the amount of birch seedlings by improving its regeneration compared to unburned sites. The seed trees survive burning better if they are tall and have short crown, and have thick bark. In general, prescribed burning improves regeneration in seed tree stands.

The article includes a summary in German.

• Kolehmainen, E-mail: vk@mm.unknown

Finland has a long tradition of grazing cattle in the forests and common land. There are also reports of degradation of forests by grazing already in 1600th century. The aim of the survey was to study which positive and negative effects grazing has in forests.

The study concludes that grazing has caused considerable economic losses through damages to forests. In addition, woodland pastures cannot give the yields required in modern animal husbandry. The quality of woodland pastures have decreased after the woodlands used in slash and burn culture have become wooded.

Grazing has also some positive effects to forests. It increases the diversity of vegetation in the woodland pastures and spreads species to new areas. This is supported by the lists of species found in different woodland pastures. Cattle destroy large grasses like Calamagrostis, which may avail growth of tree seedlings in the pastures. Grazing can also prepare the site for tree seedlings. On the other hand, prolonged grazing destroys tree seedlings and prevents regeneration.

The article includes a German summary.

• Lampimäki, E-mail: tl@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. 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 inspection of forest regeneration of mineral soil forest types and drained peatlands, and inspection of ditches. 

• Ahola, E-mail: va@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

Natural regeneration of Scots pine (Pinus sylvestris L.) by leaving a seed tree stand on a cutting area has long been the most popular regeneration method in Finland. Results of the method have, however, been unsatisfactory. The aim of the investigation was to study the basic problems of natural regeneration of Scots pine. Regeneration success was studied in 144 sample plots in pine stands at different stages of regeneration in Southern Finland. In addition, the data included information of 42 previously investigated areas.

According to the results, Scots pine can be successfully regenerated naturally on sandy and gravelly soils in Southern Finland. Preparing the ground surface by breaking or burning considerably facilitates the establishment of a seedling stand. The number of seedlings was considerably lower in the ground vegetation than in the mineral soil. Considering growth of the seedlings, root competition of the mother trees was heavy in dense stands, but insignificant in thin stands. The stand density did not affect germination of the seeds. In regeneration areas proper, where the density of mother trees usually is under 50 per hectare, there was in average 4,700 seedlings per hectare in Calluna type forests and 5,200 in Vaccinium type forests.

The PDF includes a summary in English.

• Lehto, E-mail: jl@mm.unknown

Root systems of a Scots pine (Pinus sylvestris L.) stands of seed trees on a Vaccinium sites in Southern Finland were studied by taking soil samples around the seed trees. The results show that root system of an old Scots pine spreads relatively evenly around the tree up to at least 10 meters from the stem. The densest part of the root system is near the stem, which part is often acentric. This is probably due to root competition in the early stages of growth of the tree.

Root systems of the seed trees affect stocking of the site with seedlings and the growth of the seedlings. The root competition can cause, for instance, uneven grouping of the seedlings. It seems that the largest trees of a stand have the most even root system. It is therefore recommended to choose the strongest trees of the stand as seed trees, to ensure even distribution of seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m³/ha (ranging from 80 to 428 m³/ha) and after the cutting 120 m³/ha (39–220 m³/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

• Leinonen, E-mail: kl@mm.unknown
• Leikola, E-mail: ml@mm.unknown
• Peltonen, E-mail: ap@mm.unknown
• Räsä­nen, E-mail: pr@mm.unknown