Abstract:

Aims Wolong Nature Reserve is the largest reserve for the endangered wild panda. Owing to historical factors, much of the forest has been disturbed and poorly restored, even in many sections of the core protection area. The relative importance of determinants for species recruitment after disturbance is poorly known. We investigated factors affecting regeneration of conifer-broadleaved mixed forest in forest gaps near Wuyipeng, an observation station for pandas.
Methods We examined environmental factors, gap characteristics and recruitment of new individuals in every forest gap along three line transects and analyzed the data using principal component analysis and correlation analysis in SPSS.
Important findings A range of natural and human disturbances influenced the pattern and characteristics of forest gaps in this area. Richness was higher for seedlings than for gap makers, but the ranking of species dominance was different between seedlings and gap makers. The establishment success of dominant species was affected by a variety of factors. For instance, the establishment of Betula spp. was correlated significantly with topographic factors, while that of Abies faxoniana was affected heavily by soil characteristics and that of Rhododendron spp. was correlated significantly with topographic factors and gap-maker characteristics. Moreover, all biodiversity indexes of regenerating seedlings were significantly correlated to principal components mostly reflecting soil characteristics. Therefore, soil characteristics appear to be the most important factor influencing regeneration of dominant species and seedling richness following gap disturbance.

Key words: gap regeneration, gap maker, biodiversity index, principal component analysis, correlation analysis