S. Mahunka szerk.: Folia Entomologica Hungarica 56. (Budapest, 1995)
ried out. For establishing species dominance the Berger-Parker dominance index in percentage distribution was applied (Southwood 1978), D%= N max /N T xlOO, where D%= dominance index in percentage distribution, Nmax= tota l number of individuals of a species, NT= total number of the individuals of the communities. In calculation the Shannon-Wiener index (Ff) was used (Southwood 1978). H'= - X Pi logepi, where pi= proportion of the ith species, log e = natural basic logarithm. Four different similarity indices were used to determine the similarities between the grasshopper communities of the three sites. Renkonen's percentage similarity (Krebs 1989): R= minimum (pi,, p2 ( ) where R= Renkonen index, percentage similarity between sample 1 and 2, pu= percentage of species i in the community of sample 1, p2r= percentage of species t in the community of sample 2. Jaccard's coefficient: J= K7(A+B-K) where J= coefficient of Jaccard, K= number of the common species in the community of sample 1 and 2, A= total number of species in the community of sample 1, B= total number of species in the community of sample 2. Coefficient of S0rensen: S= 2K/(A+B) where S= coefficient of S0rensen, K, A and B= same as above. Coefficient of Bray-Curtis: C= 2N K /(NA+NB) where C= coefficient of Bray-Curtis, NK= sum of the lesser abundance of the common species in sample 1 and 2, NA= total abundance in the community of sample 1, NB= total abundance in the community of sample 2. To establish the similarity level between the groups Chi-square test was carried out, and among the groups (3x3 samplings) and between the groups oneway analysis of variance was made, by the SPSS/PC+ program (Norusis 1990).
