Population ecology and conservation status of the last natural population of English yew Taxus baccata in Denmark

English yew Taxus baccata L. has become extinct or rare in many parts of Europe. Here we investigate the status of the only natural population persisting in Denmark. While many other yew populations are declining, the Danish population increased from < 200 individuals in 1925 to > 2000 in 1998. This was most likely due to the thinning of the tree stand at this site, as reproductive activity, strobilus production, and recruitment were enhanced at better lit microsites. The declining status of other populations is probably often caused by succession from open woodland to dense forest. The light dependency is consistent with the Quaternary history of yew. The sex ratio of the Danish yew population was female-biased, probably due to chance. Yew invaded forest areas neighbouring source populations at rates of less than or equal to 3 m yr(-1), but forest management impeded this process. (C) 1999 Elsevier Science Ltd. All rights reserved.