In recent decades, the traditionally diverse range of trees and shrubs in Helsinki's parks has come under threat from cutbacks and conventionality. Old individual plants and trees are ageing, and they disappear with new construction, renovation, maintenance, large-scale events or digging. The plants in parks and green areas have become more consistent as oldfashioned species are replaced by widely used, readily available common plants. Thus the cultural-historical and visual value of the old species is lost, as are their excellent cultivated characteristics. This decrease in the range of species also makes the parks more vulnerable to diseases and pests.