Die Rolle extensiv gepflegter städtischer Grünflächen zur Erhaltung bedrohter Pflanzenarten: Der St. Johanns-Park in Basel

Abstract

In the last few decades there has been an increasing loss of natural and semi-natural habitats in urban areas. The remaining semi-natural areas may play an important role for the preservation of many plant and animal species. In the present study the abundance and distribution of plant species was recorded in extensively managed lawns in the newly-created public garden St. Johann in Basel and compared with earlier records at the same locality. Effects of environmental factors and differences in life-history parameters of the involved plant species were examined and discussed. Out of the total of 170 recorded plant species, 13 species belong to the Red List of Switzerland and another 20 plant species are threatened in the region of Basel. In comparison with earlier plant records a considerable loss of ruderal plant species was observed. Today, soil moisture and soil nutrients are the key factors determining plant species richness in the public garden. In addition, life-history characteristics such as the type of seed bank, the life and growth form of the involved species play an important role for the successful establishment of plant species in extensively managed areas. Problems occurring with the management of extensively cultivated areas and the restoration of indigenous flora are discussed.