동해 덕산항에 생육하는 포기거머리말 (Zostera Caespitosa Miki) 군집의 생물계절학과 형태 변이

Abstract

From March 1998 to August 2000, the phenology and morphometrics change of Zostera caespitosa Miki were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics (shoot height, leaf length, sheath length, leaf width, and number of leaf per shoot), size and number of reproductive structures (spathe, spadix, and seeds), shoot density, biomass and physiochemical parameters (water temperature and nutrient concentration) were measured. Significant differences between months(p<0.05) existed for morphometric characteristics except for sheath length. The sequence of shoot heights clearly showed cyclical annual variation with water temperature. Vegetative shoots of Z. caespitosa were present throughout the year, but reproductive shoots were rarely occured from mid January to early April in water temperature of 9∼12℃. Flowering in the spathe began in mid February, and seed maturing was occured in early April. Water column nitrate and phosphate concentration showed seasonal variation, but ammonia concentration was variable with season. Relationship between shoot morphometrics and physiochemical parameters were not significantly correlated but water temperature seemed to regulate the reproductive phase and annual life cycle. The mean shoot density and above biomass of the populations were 511.6±25.6 shoots m-2 and 413.4±19.8 g dry wt m-2, respectively.