[Effects of selective cutting on the distribution pattern and inter-specific association of arbor seedlings in secondary forest].

The distribution pattern and interspecific associations of arbor seedlings were examined in two 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 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, seedlings were negatively correlated with other tree species at more scales (6-45 m). In the natural recovery secondary forest, the pairs of . 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 . , 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 . seedlings. Both stands were under succession, and thus suitable artificial management should be carried out to promote tree regeneration and community restoration.