A Study of Early Vegetation Features and Natural Succession of Phosphate Wasted Quarry in Northwest of the Sichuan Basin

In this study, vegetation types and natural succession of phosphate wasted quarry in northwest of the Sichuan Basin were researched by field investigation. The result showed that there were 46 species living in wasteland, belonging to 20 families and 37 genera, Asteraceae (12 species) and Gramineae(9 species) plants were the most. Natural succession of phosphate wasted quarry could be summarized in four stages:bareland→ grassland →brush and grass land →brushland. In early period of succession (waste time was below 10 years), Gramineae and Asteraceae plants were main vegetation comnnities in wasteland, which played an important role as pioneers.Stable grass and brush communities were found in the middle period of succession (waste time from 10 to 20 years) and a large number of brushes were formed in the late period of succession(waste time from 20 to 30 years). Diversity of vegetation in wasteland was increasing with the process of succession, diversity of grass vegetation was relatively stable during the period of succession and brush vegetation had a significant increment. It was also found that there was a similar trend between natural succession of phosphate wasted quarry and other kinds of wasteland, which proved that early natural succession were homologous in different kinds of wasteland.