Presence of an urban gradient demonstrated for carabid associations.

Using carabid associations from Leipzig (GDR) as an example, the effect of an urban gradient("arborealeremial") is demonstrated. Equations for calculation of gradient values are given. Furthermore the associations are characterized by an index of temporal homogeneity as a measure of balance during the year. Species diversities for small time intervals are used to calculate homogeneity. A more or less linear correlation between gradient value and homogeneity was demonstrated for the associations investigated.