Ecological interpretation of changes in the dutch flora in the 20th century

摘要: Abstract This article presents an ecological interpretation of the changes in vascular flora Netherlands during 20th century, paying attention to survey bias and impact environmental nature conservation policies from 1970 onwards. In course some 10 million records 1500 plant species were sampled on a 1 km grid scale. These data divided into three periods: 1902–1950, 1975–1988 1988–2000, for each period total national presence calculated. To interpret significance aggregated 83 ‘ecological groups’ using classification based five site factors. The these groups statistically analysed by redundancy analysis. principal change observed throughout whole century is marked decline vegetation types nutrient-poor sites, particularly those neutral soils, at same time large increase (moderately) nutrient-rich sites. second most important was saline especially between first period. Other grassland tall herbaceous woodland types. For certain pioneer nutrient-poor, soils recovery observed, probably as consequence restoration projects started 1980s. Despite measures reduce emissions, eutrophication remains major threat Netherlands.