The distribution pattern and interspecific associations of arbor seedlings were examined in two Tilia amurensis forest stands in Zhangguangcailing, with one without man-made interference (natural recovery secondary forest) and the other one being 20-year-old after selective cutting (selective cutting secondary forest). The results showed that the importance value of the seedlings of the soft broad-leaved (heliophile) and tolerant tree species was 7.9 and 64.5 in natural recovery secondary forest, and was 3.9 and 68.9 in selective cutting secondary forest, respectively. The spatial distribution pattern of arbor seedlings in natural recovery and selective cutting secondary forests showed clustered distribution at the scale of 0-18 m and 0-15 m, respectively. Most of tree species pairs were negatively correlated at large scale (14-45 m) in the natural recovery secondary forest, whereas tree species pairs at all the scales were mostly uncorrelated in the selective cutting secon-dary forest. Most of the tree pairs of T. amurensis seedlings (57%) with other tree species showed negatively correlation at large scale (31-45 m). In the natural recovery secondary forest, the proportion of negatively correlated tree pairs was higher than 60%. In selective cutting secondary forest, Acer mono seedlings were negatively correlated with other tree species at more scales (6-45 m). In the natural recovery secondary forest, the pairs of A. mono and other arbor seedlings were positively correlated at small scale (0-5 m), but not at large scale (31-45 m). Therefore, selective cutting accelerated the succession of the secondary forest of T. amurensis, which induced random distribution of the arbor seedlings at the large scale (31-45 m), promoted a more coordinated inter-specific relationship, and adjusted the spatial competition between T. amurensis seedlings. Both stands were under succession, and thus suitable artificial management should be carried out to promote tree regeneration and community restoration.
研究张广才岭林区未经人为干扰的(自然恢复次生林)和择伐后20年(择伐经营次生林)的2种紫椴次生林林分的乔木树种幼苗的分布格局及其种间关联性。结果表明: 阳性软阔叶和阴性树种幼苗在自然恢复次生林中重要值分别为7.9和64.5,在择伐经营次生林中为3.9和68.9;自然恢复次生林和择伐经营次生林中乔木树种幼苗的空间分布点格局分别在0～18 m和0～15 m尺度内呈聚集分布。自然恢复次生林中,14～45 m尺度上树种对多呈负相关;而择伐经营次生林中,所有尺度上的树种对多呈无相关性。在择伐经营次生林中,更新层中有57%的紫椴幼苗与其他乔木幼苗的树种对在大尺度上(31～45 m)呈负相关,在自然恢复次生林中该比例大于60%。在择伐经营次生林中,色木槭幼苗与其他乔木幼苗的树种对在更多尺度上(6～45 m)主要呈负相关,自然恢复次生林中的色木槭幼苗与其他乔木幼苗的树种对多在小尺度上(0～5 m)呈正相关,在大尺度上(31～45 m)无相关性。择伐加快了紫椴次生林未来的演替速度,一定程度上使得乔木树种幼苗在更大距离尺度上呈现出随机分布状态,并促使林分中乔木树种幼苗的种间关系更加协调,调整了紫椴种群幼苗种间的空间竞争关系。2个林分均处在演替进程中,在今后的林分管理中,应适当采取人工经营措施以促进林分更新及群落的恢复。.
Keywords: Tilia amurensis secondary forest; spatial association; spatial pattern; tree seedling.