Taxus baccata L. is a rare and endangered dioecious species in Europe. Species of this mating system
are considered to be the most vulnerable to extinction. It is believed that one reason for this state may be the
uneven reproductive effort and different habitat requirements of the two sexes. Silver fir and European yew
have very similar ecological requirements, but fir is a monoecious species. The aim of this study was to compare
the growth rate andthe effect of precipitation andtemperature on the annual tree-ring width of silver fir
and both sexes of European yew. The study site was the Knyazhdvir reserve in western Ukraine, located near
the limit of the geographical range of both species. Knyazhdvir reserve is the site of one of the last yew populations
in Europe with a large number of individuals (about 15,000 individuals above 1.3 m height) growing
alongside fir.Woodsamples were taken from 15 male and15 female specimens of T. baccata andfrom 15 specimens
of A. alba and were subjected to a standard dendrochronological procedure. The results showed high
positive correlation between the temperatures in February andMarch andthe tree-ring width in the studied
species and genders. The response of annual tree-ring width to the examined climatic factors was relatively similar
in yew andfir. However slight differences were foundbetween males andfemales of T. baccata. The growth
rate decreased more rapidly in females compared to males, probably following sexual maturation. Precipitation
in April hada positive effect on firs andfemale yews, but not on male yews. This confirms earlier reports of the
requirement of female specimens of dioecious species for a higher humidity than male individuals