tailieunhanh - Báo cáo lâm nghiệp: "An economic aspect of conversion of Scots pine (Pinus sylvestris L.) stands in the Polish Lowland"

Tuyển tập những bài báo cáo nghiên cứu khoa học hay nhất được đăng trên tạp chí JOURNAL OF FOREST SCIENCE đề tài: An economic aspect of conversion of Scots pine (Pinus sylvestris L.) stands in the Polish Lowland. | JOURNAL OF FOREST SCIENCE 55 2009 6 293-298 An economic aspect of conversion of Scots pine Pinus sylvestris L. stands in the Polish Lowland A. Wẹgiel1 R. Jaszczak1 G. Rạczka1 P. Strzelinski1 D. Sugiero1 A. Wierzbicka2 -Department of Forest Management Poznan University of Life Sciences Poznan Poland Department of Game Management and Forest Protection Poznan University of Life Sciences Poznan Poland ABSTRACT Pine stands at fertile sites need conversion into broadleaved or mixed forests. Yet according to the age of stand conversion may have different economic results. Therefore in order to reduce costs of the process the analysis on the basis of the potential income from wood sale has been done. The aim of the analysis has been to find an optimal date of conversion beginning. The date of conversion beginning has been fixed on the basis of the relation of the value of wood increment from the stands which need conversion to the value of average wood increment from stands conformable to the sites. By this means three age intervals have been appointed. Keywords Pinus sylvestris pine stands oak stands forest conversion forest sites Polish Lowland In Europe in the past when forest management tried to meet the demands of industry coniferous species were preferred due to their faster increment and therefore Norway spruce in the mountains and Scots pine in the lowland were usually planted. At the present time these tendencies have changed and tree site requirements are the most important considerations taken into account in the course of the forest regeneration process. However due to the long lifetime of trees there are still many coniferous stands which grow in sites unsuitable for them. In the case of the Polish Lowland Scots pine is a dominant forest tree species. Many stands with this species growing on excessively fertile sites belong to the least stable forest formations. Therefore there is an urgent need of their conversion into adapted to the site broadleaved and .