Articles containing the keyword 'clear cutting'

Pine swamps are easily regenerated by natural regeneration of Scots pine (Pinus sylvestris L.). Usually seeding felling is used, but also strip system or clear cutting and regeneration along stand edge has been suggested. This article discusses the regeneration by clear cutting and sparing the existing undergrowth. The article focuses on pine swamps to be drained and the ones in natural state.

Pine swamps in natural state usually have plenty of trees of smaller diameter classes, that can be trusted to form the future tree generation after the felling. This shortens the rotation by 20-30 years. The undergrowth has been shown to recover quickly. The method suits for regeneration of drained peatlands but could fit also for regeneration of pine swamps in natural state.

The seedlings in the pine swamps are mainly 1-5 years old, and the stock is changing. It seems that larger trees produce a wider selection of age groups, but the seedlings survive longer under smaller mother trees. Part of the younger generations of seedlings seem to be destroyed when the peatland is drained. Further studies are needed to investigate how the draining and felling are to be performed to spare the young 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.

• Heikurainen, E-mail: lh@mm.unknown

The purpose of this paper was to determine the proportions of nutrients remaining in the forest and removed from the forest as a result of cutting. The Norway spruce (Picea abies (L.) H. Karst.) phytomass remaining after clear cutting was studied in the categories of tree-top waste, branches, twigs, needles and cones. The bole wood, measured in solid cubic metres, was converted to kilogrammes on the basis of relative density determinations, and the amount of stump and root material estimated from the known amount of bole wood and comparable data presented in the literature. The nutrients studied were N (Kjeldahl), P (colour reaction), K, Ca, Mg, Fe and Mn (atomic absorption spectrophotometer). The wood and bark were studied separately. Details of the mineral composition of the bedrock are also presented.  

The harvested timber was found to account for 46 % of the total phytomass, or 58 % of the aerial phytomass, while the stump and root material represented one fifth of the total phytomass. The needles and bark contained the highest proportions of nutrients, especially in the case of nitrogen and phosphorus, the needles containing 32 % of total nitrogen and 26 % of total phosphorus. The surface waste wood contained on average more than double the amount of nutrients compared with the harvested bole wood, including more than six times the amount of phosphorus. Approximately one fifth of the nutrient contained in the total phytomass was removed on cutting. The high proportion of basic rocks in the area is suggested as an explanation of the nutrient status at the site, which is in many ways better than that described in the results of other investigations.  

The PDF includes a summary in Finnish. 

• Kubin, E-mail: ek@mm.unknown