ABSTRACT

Despite numerous studies there are still uncertainties regarding regeneration strategies that are optimal for productivity and profitability. Thus the aim of this study was to establish effects of three regeneration methods (planting, direct seeding and natural regeneration) on the production and profitability of Scots pine (Pinus sylvestris L.) stands in southern Sweden. Long-term stand development was simulated, with the StandWise application of the Heureka decision support system, starting from short-term regeneration outcomes observed in several field experiments at sites with relatively high productivity (H100 site indices, i.e. heights of dominant pines at 100 years: 27–30 m). Financial and production results of each approach were assessed in terms of Land Expectation Value (LEV) and Mean Annual Increment (MAI), respectively, across a whole rotation. Planting on clear-cuts with 1600–3265 seedlings per hectare resulted in the highest profitability and production, whereas high-density planting (10,000 seedlings per hectare) resulted in negative LEV. However, sensitivity analysis showed that the results depended on the interest rate. Retention of seed-trees incurred additional costs relative to single-operation clear felling. In contrast, retention of shelter-trees had good financial results (at 0% and 2.5% interest rate), although they depended on the site index and average tree size.

摘要

尽管进行了大量研究，但对于生产力和盈利能力的最佳再生策略仍然存在不确定性。因此，本研究的目的是确定三种再生方法（种植、直播和自然再生）对苏格兰松（Pinus sylvestrisL.) 位于瑞典南部。使用 Heureka 决策支持系统的 StandWise 应用程序模拟了长期林分开发，从在生产力相对较高的地点（H100 地点指数，即 100 年优势松树的高度）的几次实地试验中观察到的短期再生结果开始: 27–30 m)。在整个轮换期间，分别根据土地预期价值 (LEV) 和平均年增量 (MAI) 评估每种方法的财务和生产结果。以每公顷 1600-3265 株幼苗的净地种植获得最高的盈利能力和产量，而高密度种植（每公顷 10,000 株幼苗）导致 LEV 为负。然而，敏感性分析显示结果取决于利率。相对于单一操作的砍伐，种子树的保留产生了额外的成本。相比之下，保留庇护树具有良好的财务结果（利率为 0% 和 2.5%），尽管它们取决于场地指数和平均树木大小。