Yew (Taxus baccata L.) regeneration is facilitated by fleshy-fruited shrubs in Mediterranean environments

Yew Taxus baccata is catalogued as a species endangered and prone to extinc tion in the Mediterranean mountains of southern Spain, due to the small siz e and senescent status of most populations. In this paper, we study the eff ects of herbivory and the protective role of woody shrubs in the regenerati on ability of the yew in the Sierra Nevada. The estimated density of the ye w in the study plot was 287.9 individuals/ha, more than 90% being juveniles (seedlings and saplings), which were mostly located under fleshy-fruited s hrubs. Saplings suffered serious herbivore damage when unprotected by shrub s. Thus, fleshy-fruited shrubs proved to be the best habitat fur seedling e stablishment and sapling survival and growth. The abundance of fleshy-fruit ed shrubs in our study site provides a yew population characterized by an a ctive regeneration under natural conditions. We suggest that the maintenanc e of healthy populations of yew in Mediterranean mountains is strongly depe ndent on the conservation of well-developed fleshy-fruit understories and t heir community of avian dispersers. (C) 2000 Elsevier Science Ltd. All righ ts reserved.