Acta Forestalia Fennica vol. 51 | 1943

The aim of the study was to develop a method for calculating a cutting budget that is adapted to the present forest management practices. The cutting budget determines the volume of annual cuttings for a forest holding in a certain period of time. Effect of fellings on the cutting budget depends on the cutting methods used. The study aimed at proving that growth of the forest can be estimated based on growing stock and structure of the forests for a certain time period. Accordingly, adequate drain can be defined in advance. The cutting budget is based on age-class distribution of the forest holding, which is most applicable for even-aged forestry. Calculation is based on area of the forest land and estimated volume of the growing stock. Also, the quality of the forest soil can be taken into account when age-class distribution is used. A suitable period for estimating a cutting budget is suggested to be 20 years, which is divided in two 10-year periods. The cutting budget it is included in a forestry plan. An example of a cutting plan based on the method is presented.

The PDF includes a summary in German.

• Lihtonen, E-mail: vl@mm.unknown

The aim of the investigation was to study natural regeneration of Norway spruce (Picea abies (L.) Karst.) in drained peatlands and frost injuries in seedlings, and to compare microclimates of the regeneration areas. The experiments included peatlands in Satakunta in Western Finland. Restocking of the areas with seedlings and their survival was followed in 1935-40 at sample plots that were mainly 1 are large.

Susceptibility to freezing was shown to be dependent on the stage of development of the shoots. Shoots that have just begun to grow contain little water, and withstand better freezing temperatures than shoots in later stages of growth. Damages to the seedlings were observed when the temperatures decreased to -2.8–-4.3 °C. The most severe damage to a seedling was caused by the death of the leading shoot by spring frost.

Norway spruce regenerates easily on moist peatlands, but peatlands with dry surface tend to have little or no seedlings. The species regenerated better in marshy sites than correspondingly fertile mineral soil sites. However, it needs shelter to avoid frost damage. On clear cut spruce swamp the undergrowth spruce seedlings that were left in the site got severe frost damage. If the site had birch (Betula sp.) coppice or undergrowth, spruce seedlings survived in their shelter depending on the height and density of the birch trees. To be effective, the protective forest should have relatively even crown cover. Young spruce seedlings could grow well even under relatively dense birch stand.

The PDF includes a summary in German.

• Multamäki, E-mail: sm@mm.unknown