A Study On Restoration Dynamics And Pattern Of Sub-alpine Bamboo-Fir Forest In Western Sichuan Province

Restoration dynamics and pattern of bamboo-fir forest, mainly including the dynamics of plant species diversity and water retention function of the forests with restoration time of 10 years, 20 years, 30 years, 40 years and 50 years and the spatial pattern of Abies faxoniana population at the restoration stage of 40 years were studied in this paper. The main results are as the following:1) There were abundant species in bamboo-fir forest at different restoration stages, and the important values of dominant species in each layer changed dramatically with the restoration time. The important values of sunny species tended to become fewer and the important values of shady species tended to become more, shady species took place of sunny species gradually with the restoration time. For example, the important value of Rubus rubrisetulosus was 27.9, 20.3, 5.4, 0 and 0 at different restoration stages respectively.2) The total species richness were 54, 49, 33, 54, 59 in the forests with restoration time of 10 years, 20 years, 30 years, 40 years and 50 years respectively. Herb species richness decreased, while tree and shrub species richness increased with the restoration time. Generally, the species diversity indices of tree layer, shrub layer and herb layer at the different restoration stages had similar trends, herb layer > shrub layer > tree layer. The differences of evenness index for shrub layer and herb layer among five restoration stages were obvious, and the evenness index of tree layer increased with the restoration time. The differences of dominance index for tree layer were obvious among five restoration stages and that of shrub and herb layer increased with the restoration time.3) The soil bulk density of 0-10cm, 10-20cm, 20-30cm and 30-40cm 0-40 cm soil layers was 0.64-1.15 g/cm~3, and the soil bulk density of 0-10 cm layer increased with the restoration time. The cumulated mass of moss and litters also increased with the restoration time. The maximal water holding capacity of litters and moss both increased from 10 to 30 years restoration stages and then decreased little till to 50 years restoration stage. The maximal water holding capacity of litters was 345.1%-780.8% and that of moss was 469.6%-1152.5%...