EFFECTS OF GAP SIZE AND LOCATIONS ON THE REGENERATION OF CASTANOPSIS KAWAKAMII IN A SUBTROPICAL NATURAL FOREST, CHINA

Castanopsis kawakamii is an endangered tree species due to its low population in the middle stage of development and low percentage of seedlings in natural conditions.The present study explored whether a forest gap has the potential to promote the regeneration of C. kawakamii seedlings, and examined favourable locations for seedling regeneration within the gap.Nine sampling gaps were classified into small, medium and large sizes.The number of C. kawakamii, their basal areas and height at four stages (tree, sapling, shrub and seedling) in five locations within the gap (center, south, east, north and west) were determined during the growing season.A significant positive relationship was found between the number of C. kawakamii and gap area (r = 0.815, p = 0.007), with higher numbers in large gap size (p = 0.031) compared with small gap size.The number of C. kawakamii was predicted by a linear regression model: Number of C. kawakamii = 0.124 × gap area + 10.597, R 2 = 0.664.Moreover, the number and size of seedlings in the center of the gap were significantly different (p = 0.041, p = 0.017) from other locations within the gap.Management for C. kawakamii should move forward to provide suitable conditions for regeneration by focusing on the centre and large gap areas.