Abstract:

Forest gaps and litter are two important factors which have influence on forest regeneration. Forest gaps(40 m²) were artificially created in spruce plantations in Miyaluo, Western Sichuan. In this paper, changes in environmental factors were monitored, and germination and survival of the seedlings were measured to test the effects of natural seeding and artificial seeding, as well as wiping out litter on germination and growth of seedlings. This paper also determined the effects of plantation litter aqueous extracts on germination and seedling growth. Our main purpose is to investigate the effects of forest gaps and litter on germination and survival of seedlings, which would lend evidence to clarify the effects of forest gaps and litter on plantation regeneration, explore the factors which influence regeneration of spruce plantations and provide scientific evidence for sustainable management of alpine plantations. The results showed that: 1) the environment in the forest gap was heterogeneous; 2) forest gaps and seeding treatments had effects on both germination and survival of seedlings. For natural seeding and artificial seeding without litter, germination was highest in the center of a gap, which had 2.75 seedling ·m^-2 and 21.25 seedling ·m^-2 respectively, while for artificial seeding, the highest germination was in the edge of a forest gap, which had 10.75 seedling ·m^-2. Seedling mortality was slightly lower in the area surrounding the center of a gap. Natural seeding had the lowest number of germination, while artificial seeding without litter had the highest. 3) Plantation litter aqueous extracts had significant negative effects on germination and seedling growth of Picea asperata, and the inhibition of root length and shoot length were 68.62% and 66.39%, respectively. Based on the results, it was concluded that: forest gaps were beneficial to forest regeneration; artificial seeding could be used to promote regeneration; litter had negative effects on regeneration of spruce plantations.

Key words: spruce plantation, forest gap, litter, environmental factor, germination, seedling mortality