Abstract: Employing sampling method,this paper studied the niche breadth,similarity and overlap of the dominant populations in Cyclobalanopsis glauca forest in Gutian Mountain Nature Reserve.The results showed that the niche breadths of C.glauca,Rhododendron ovatum,Schima superba,Castanopsis eyrei and R.latoucheae were much greater,with the Levins and Hurlbert's niche breadths 0.7974,0.6435,0.6272,0.5908,0.5783 and 0.7770,0.4012,0.4745,0.4171,0.4303,respectively.While those of Photinia glabra and Caslanopsis fargesii were smaller,with the Levins and Hurlbert's niche breadths 0.3966,0.2716 and 0.1441,0.0825,respectively.The niche similarity between the species with broad niche breadths was greater than that between the species with narrow niche breadths,e.g.,it was 0.6134 and 0.6056 between C.glauca and R.ovatum,and C.glauca and R.latoucheae,respectively,but was 0.1039 between Photinia glabra and Caslanopsis fargesii.Similar trend was observed for the niche overlaps.

Key words: Bryophyte, Nutrient content, Phosphorous pool