Conversion of second-growth Nothofagus forests in Chile into managed stands

摘要

The second growth Nothofagus forests of Central Chile show a very favourable species composition and suitable silvicultural parameters for conversion into managed stands for production of high value timber. For lack of information this opportunity has not been fully utilized up to now. The natural and economic results of conversion of second growth Nothofagus forests were analyzed in the Cordillera de los Andes (Fundo Jauja, Malleco Province, Region IX) with the purpose of improving the data base for management decisions. On the basis of a group tree oriented inventory 8 forests types with distinct silvicultural parameters were defined. Depending on forest type between 40 and 140 potential crop trees (trees of superior quality) were found per hectare with a dbh range from 10-25 cm. Because of the uneven distribution of crop trees enrichment planting is recommended. Linear stimulation models indicated that crop trees can reach 55-60 cm dbh in 40-60 years. Under a "high thinning" regime a two storey forest can be expected to develop. The first silvicultrual intervention in these stands resulted in removals of very poor quality; however, the high volume of these removals covered the cost of the operation. A financial analysis showed that a conversion of natural Nothofagus into managed stands can result in some cases in high financial gains, but still is less profitable than a conversion into pine or eucalyptus plantations.