Evaluation of different similarity indices as measures of succession in arthropod communities of the forest floor after clear-cutting.

Communities of spiders (Araneae) and beetles (Coleoptera) living in the soil and litter of clear-cut areas were compared with those of intact forest stands. Sixteen different indices of similarity were tested on three sets of material: spiders and beetles examined during one year in three clear-cut areas felled 3, 6 and 9 years earlier, and spiders in one clear-cut area examined during 7 successive years after felling. Other sources of evidence showed that succession in the spider community was divergent for at least 7 years after felling.The indices that seemed to express the changes best were: (1) Kendall's rank correlation test, (2) the Bray-Curtis measure, (3) Renkonen's percentage similarity, (4) the correlation coefficient r (2 to 4 after logarithmic transformation of data), (5) the Canberra metric, and (6) the diversity overlap (R 0). The properties of the indices are discussed.