Phenological study of Sargassum thunbergii (Fucales,Phaeophyta) in Lidao Bay, Rongcheng, China

摘要

We conducted a phenological evaluation of Sargassum thunbergii,a common algal species,along the coast of Lidao Bay,Rongcheng,China.The local S.thunbergii population entered a maturation period from early June to mid-August,when seawater temperature was 14.4 to 25.1 ℃C.Our results suggest an increase in temperature and day length during this period initiated thalli maturation.Inhabitants of the low tidal zone had higher thalli length and biomass compared with those from the mid-and high tidal zones.We observed a switch in the length frequency distribution and contribution of length classes to biomass between the small (＜20 cm) and long (20-79.9 cm) length classes at the time of thallus maturity.This suggests there is a trade-off between sexual reproduction and vegetative regeneration.