Changes of species composition as affected by the replacement of broad-leaved community by Chines fir community

The changes of species composition in a 76-year-old Chinese fir community , which was originally occupied by a broad-leaved community , were studied based on the data collected from sample plots with an area of 1 200 m2 in Ancaoxia , Nanping , Fujian Province .The results showed that the changes of species composition affected by slope location were greater than by forest type .The old-growth Chinese fir community in the hillside and broad-leaved community had higher percentage of species in common (46.84 %)than Chinese fir community in the hillside and Chinese fir community in the low-land (42.46 %).The old-growth Chinese fir community still had only one dominant tree species , while the broad-leaved community was secondary community with dominant tree species of Pinus massoniana , Castanopsis fargesii , and Schima superba .Percentage , relative density and importance values of tree species and intolerant tree and shrub species increased while slope gradient from lower to upper.Herb layer of Chinese fir community in the low-land were mainly shade-tolerant species , and had more shade-tolerant fern species than broad-leaved community which were mainly intolerant herb species .