Phenology of Cibotium taiwanense (Dicksoniaceae)
摘要
The phenology of Cibotium taiwanense Kuo in northern Taiwan, including frond emergence, expansion and senescence, and spore maturation and liberation, was monitored from June 1998 to October 2000. Each year, a first cohort of fronds emerged in late winter/early spring and a second cohort emerged during the summer. Most croziers appearing in December to May did not expand fully until June, regardless of the month they emerged. Croziers emerging in other months expanded completely in one to three months. Most fronds of the first cohort were fertile, whereas most fronds of the second cohort were sterile. Most of the fertile fronds in the latter cohort had only small numbers of spores, which were poorly developed. Spores produced on fronds that emerged from the first half year matured during the latter half of the year but were not shed until the following year. Spores produced on fronds that emerged during latter half year matured and were shed during the following year. Most of these spores were released during the warm season (May to October). On average, fertile fronds were larger and lived longer than the sterile ones (25 months vs. 16 months, on average). The phenology of C. taiwanense of this observation seems to be affected more by temperature and/or the accompanied longer photoperiod rather than by rainfall.