Warsaw

Abstract

As in the case of other metropolitan areas, the size and the structure of land use in Warsaw have changed substantially both spatially and temporally. Areas of natural and semi-natural habitats and agricultural land have declined, especially in the peripheral parts of the city. At the same time, new habitats have appeared, such as industrial areas, tramlines and railways. After 1945 a considerable part of the central area of the city was occupied by rubble that was initially devoid of vegetation but which was soon to be colonised by many plant species. The area of rubble decreased as the city was re-constructed. As a result of spatial planning policies gradual changes occurred in the structure of the spontaneous and cultivated flora. Future trends in the flora of the city can be predicted based on the observations made so far. The establishment of protected areas within the city has only limited success in preventing the disappearance of native species. The conversion of agricultural land to urban uses has led to the elimination of some native weed species and archaeophytes (especially segetal species). It appears, therefore, that the importance of alien species in the flora of Warsaw will continue to increase as will the number, frequency and abundance of thermophilous and xerothermic species with short life cycles.