Comparative analysis of natural and artificial regeneration in Nowa D?ba Forest District

摘要

New challenges related to the multifunctional role of forests in consideration of both natural environment and economy come into view sequentially. In current forestry practice, an important element is not only the quality of forest cultivations (silvicultural aspect) but also the costs incurred for their production and tending (economic aspect). The main purpose of this article is to show the prospect of increasing positive silvicultural effects depending on the method used in management of Scots pine stands under given site conditions. The comparative analysis was carried out using the study results obtained in the Forest District Nowa D?ba and those presented in other relevant studies. In the present study, we examined whether the site conditions have significant effects on silvicultural and economic effectiveness of regeneration and development of Scots pine stands or those predominated by Scots pine in the initial stages of stand growth. Significance of the regeneration method effects on growth characteristics of Scots pine regeneration as well as the costs of forest cultivation management was analysed. The study on silvicultural and economic effectiveness was carried out in the Forest District Nowa D?ba. The results obtained showed that using Scots pine natural regeneration under the conditions of fresh coniferous forest site and fresh mixed coniferous forest site was the way of management based on reason. This was supported by both the values of regeneration growth parameters and silvicultural quality along with clearly lower expenditures incurred to achieve these effects. In wet mixed coniferous site, Scots pine seedlings regenerated naturally; however, the results indicated their lower silvicultural quality and growth parameter values when compared to those artificially regenerated. In fresh mixed broadleaved forest site, equally for silvicultural and economic reasons, the more optimal option was to regenerate forest using traditional planting material as natural Scots pine regeneration showed lower silvicultural effects. The unit costs of regeneration and maintenance of stands with self-sown Scots pine in fresh mixed broadleaved forest site were higher when compared with other examined forest sites. On the basis of the results of the present study, it can be concluded that regardless of the regeneration method examined, the most differentiating factor of the final economic effect of Scots pine stand establishment and maintenance was the cost of regeneration operation. The expenditure for this purpose consumed the largest part of expenses incurred in artificial regeneration variant. The higher cost of corrections in artificially planted forest cultivations in poorer forest sites was one of the reasons behind the profitable final balance of naturally regenerating Scots pine stands. Differences between other costs analysed were not significant. The results of the present study may contribute to comprehensive assessments of natural and artificial ways of forest regeneration and indicate forest production costs that are the most closely related to site conditions.