Flowering in concrete jungles

-- It's not time yet to write the obituary of urban biodiversity. A recent study by Czech ecologist Pavel Pysek reveals that European cities host a large number of wild plants. Berlin tops the list with 1,432 species, while Polkowice, a small city in western Poland, is at the bottom.

Pysek theorises that big cities with large populations have more flora. However, he points out that this does not always hold good. For instance, Amsterdam with its 1 million residents has less species because it lacks enough parks and open spaces.