红松天然林种内和种间竞争关系的研究

基于穆棱林业局3块红松天然林标准地调查数据，采用竞争区域动态半径的概念确定了林分中有效竞争木，并利用Hegyi竞争指数对红松天然林的种内、种间竞争强度进行了定量分析。研究结果表明：红松的种内和种间竞争强度分别占总竞争强度的18.0%和82.0%，说明红松天然林种内竞争小，主要竞争来自种间。色木、云杉、冷杉林木个体高大，数量较多，在群落中占据一定优势，对红松的竞争压力较大。红松对象木胸径与竞争指数之间呈幂函数关系，随着红松胸径的增大，受到的竞争强度逐渐减小。当红松胸径小于25 cm时，所受到的竞争压力较大；当胸径大于25 cm时，竞争指数较小，并维持稳定。

Relationship Between Intraspecific and Interspecific Competitions of Natural Pinus koraiensis Forests

Based on the investigation data of 3 sample plots in Muling Forestry Bureau, the effective competitive trees were identified by using the concept of dynamic radius in competition zone. The intraspecific and interspecific competition intensities for natural Korean pine(Pinus koraiensis) forests were quantitatively analyzed based on Hegyi competition index. The results showed that intraspecific and interspecific competition intensities of Korean pine were 18%, 82% of total competition intensity, respectively. Hence, competition pressure of Korean pine mainly came from interspecies rather than intraspecies. Some species, such as Acer mono, Picea koraiensis and Abies nephrolepis, which were in a dominant position because of their big size and large quantity, gave a high competition pressure to Korean pine. The relationship between DBH and CI for competitive trees of Korean pine was negative power function and the competitive intensity decreased gradually as DBH increasing. When DBH of Korean pine is smaller than 25 cm, it is under higher competition; on the other hand, that above 25 cm was under lower and steady competition.