Abstract: Using continuum index(CI) and collective habitat gradient(Gc) as quantitative indexes of plant community succession and habitat quality, this paper studied the β diversity of forest communities in east Heilongjiang Province. The β diversities of plant species(β_Z) and insect species(β_K) were increased with increasing of habitat gradient, i.e. the species turnover rate between communities declined as habitat quality increased, and β_K lagged behind β_Z. The relationships between β_Z and CIand between β_K and CI were close nonlinear. At initial succession stage, the species turnover rate between communities was higher, while at middle and end succession stages, it was the lowest. The peak value of β_K lagged behind β_Z, showing that the change of insect species diversity depended upon that of plant species.

Key words: &beta, diversity, Continuum index, Collective habitat gradient, Forest community