Distribution pattern of flora and vegetation in a small industrial town: an effect of urban zones

Flora and vegetation of a small industrial town (Horažďovice, Czech Republic) was analysed with respect to its spatial distribution in particular urban zones (historical town centre, industrial zone, periphery). Ellenberg indicator values were used to express the relationship of flora and vegetation to soil nitrogen, moisture, reaction and light. Flora of particular zones did not differ with respect to nitrogen and moisture. The town centre harboured more species tolerant to shade and drought. No differences in the distribution of life forms, life strategies and origin (i.e. native/alien status) were found between particular zones. It is concluded that the response of the flora to the inner town-periphery gradient of human impact in the area under study is less obvious than in large urban agglomerations . The comparison of vegetation revealed that the occurrence of particular community types is differentiated with respect to the urban zones. The communities were arranged along gradients of ecological conditions, among which the soil nitrogen appears to be most responsible for vegetation differentiation . During the last 24 years, the proportion of thermophilous species decreased and that of acidophilous species increased, a trend which appears to be related to retreat of calcium rich sites harbouring seminatural vegetation (mostly due to building activities and changes in land use management). Proportion of archaeophytes decreased during that period, presumably as a consequence of changes in life style and land use management having occurred in the last decades.