Seasonality in the primary growth of Cupressus sempervirens L. from western Crete

摘要

The primary growth increment of 48 seedlings from 9 natural provenances of Cupressus sempervirens from western Crete was measured from January 1994 to August 1995 at 10-day-intervals. On the basis of the collected data, parameters characterizing theseasonal pattern of apical shoot growth were defined and analysed. The study showed that the species provenances exhibited height elongation all year around, except during the dry summer. In addition, short growth cessation occurred for some of the trees during winter. All provenances were consistent in their growth pattern during the two observed spring seasons. The duration of the spring growth period and the date of growth cessation in summer varied significantly among the provenances and genotypeswithin them. The results indicate strong genetic control of these parameters and the presence of differential adaptation to summer drought. On the other hand, variation in the spring and the autumn growth resumption dates and the durations of the summerand winter rest periods were small and not significantly different among the provenances due to the high variation they contained. The northern provenances and those located on the northern aspects had shorter cessation in summer, while provenances fromthe lower altitudes had a shorter winter rest period. The altitude of the provenance seems to affect the date of the peak in the spring growth: it was earlier in provenances growing at lower altitudes than those growing at higher altitudes.