The objective of this study was to examine the eff ects of temperature and light intensity on growth of female gametophytes of Eisenia bicyclis and Ecklonia cava and responses of these female gametophytes to Fe additi...The objective of this study was to examine the eff ects of temperature and light intensity on growth of female gametophytes of Eisenia bicyclis and Ecklonia cava and responses of these female gametophytes to Fe addition and daylength. Female gametophytes of each species were cultured at four temperatures (10, 15, 20, and 25°C) and under a combination of four light intensities (10, 20, 40, and 80 μmol photons/(m^2 ·s)) with two temperatures (15 and 20°C for E i . bicyclis;20 and 25°C for E c . cava ) to clarify their optimal growth conditions. Growth and maturation of female gametophytes of these two species under a combination of five Fe-EDTA concentrations (0, 1, 2, 4, and 8 μmol/L) and three daylengths (10, 12, and 14 h) were also examined. The growth of E i . bicyclis gametophyte was maximal at approximately 15–20°C, 20 μmol photons/(m^2 ·s), Fe-EDTA concentration of 8 μmol/L and daylengths of 12–14 h. While E c . c ava gametophytes showed optimal growth at approximately 20–25°C, 20 μmol photons/(m^2 ·s), Fe- EDTA concentration of 8 μmol/L and daylength of 14 h. Maturation of gametophytes was enhanced at Fe-EDTA concentration of 4 μmol/L for E i . bicyclis and at 2 μmol/L for E c . c ava . In conclusion, optimal growth temperatures and Fe-EDTA concentrations for maturation of E i . bicyclis and E c . c ava gametophytes were diff erent. Higher optimal growth temperature for E c . c ava gametophytes may contribute to its wider geographical distribution compared to E i . bicyclis which has restricted habitats in Korea. This suggests that addition of Fe ion could be used to recover beds of these two species in barren grounds of Korea.展开更多
Spatial biomass variation and community structure of epilithic biofilms were examined using cell counts, chlorophyll a extraction, and remote-sensing techniques. Samples were collected at two levels of wave exposure a...Spatial biomass variation and community structure of epilithic biofilms were examined using cell counts, chlorophyll a extraction, and remote-sensing techniques. Samples were collected at two levels of wave exposure along the Yellow and East Coasts of Korea in December 2010. Cyanobacteria were dominant, occupying about 88% of biofilm, irrespective of wave exposure levels. The cyanobacteria species, Aphanotece spp. was abundant in the Yellow Coast location and Lyngbya spp. was abundant in the East coast location. The representative diatoms were Navicula spp. and Achnanthes spp. on the rocky shores of all study sites. Average Normalized Difference Vegetation Index (NDVI) was significantly greater in the Yellow Coast (mean 0.46) than that in the East Coast (mean 0.21);a similar pattern was observed in Vegetation Index (VI). Chlorophyll a content was three times greater on the Yellow Coast (20.50 μg/cm2) than that on the East Coast (8.21 μg/cm2), and it was greater at the Gosapo and Bangpo shore sites than that at the Gyeokpo site, on the Yellow Coast. However, chlorophyll a contents were not different between 23.33 and 17.66 μg/cm2 at exposed- and sheltered-shores of Yellow Coast, and were 9.62 μg/cm2 and 6.80 μg/cm2 on the East Coast. Vegetation indices were positively correlated with chlorophyll a contents. In conclusion, biofilm of Korean upper rocky shore was mainly composed of cyanobacteria and biofilm biomass that differed between the Yellow and East Coast.展开更多
文摘The objective of this study was to examine the eff ects of temperature and light intensity on growth of female gametophytes of Eisenia bicyclis and Ecklonia cava and responses of these female gametophytes to Fe addition and daylength. Female gametophytes of each species were cultured at four temperatures (10, 15, 20, and 25°C) and under a combination of four light intensities (10, 20, 40, and 80 μmol photons/(m^2 ·s)) with two temperatures (15 and 20°C for E i . bicyclis;20 and 25°C for E c . cava ) to clarify their optimal growth conditions. Growth and maturation of female gametophytes of these two species under a combination of five Fe-EDTA concentrations (0, 1, 2, 4, and 8 μmol/L) and three daylengths (10, 12, and 14 h) were also examined. The growth of E i . bicyclis gametophyte was maximal at approximately 15–20°C, 20 μmol photons/(m^2 ·s), Fe-EDTA concentration of 8 μmol/L and daylengths of 12–14 h. While E c . c ava gametophytes showed optimal growth at approximately 20–25°C, 20 μmol photons/(m^2 ·s), Fe- EDTA concentration of 8 μmol/L and daylength of 14 h. Maturation of gametophytes was enhanced at Fe-EDTA concentration of 4 μmol/L for E i . bicyclis and at 2 μmol/L for E c . c ava . In conclusion, optimal growth temperatures and Fe-EDTA concentrations for maturation of E i . bicyclis and E c . c ava gametophytes were diff erent. Higher optimal growth temperature for E c . c ava gametophytes may contribute to its wider geographical distribution compared to E i . bicyclis which has restricted habitats in Korea. This suggests that addition of Fe ion could be used to recover beds of these two species in barren grounds of Korea.
文摘Spatial biomass variation and community structure of epilithic biofilms were examined using cell counts, chlorophyll a extraction, and remote-sensing techniques. Samples were collected at two levels of wave exposure along the Yellow and East Coasts of Korea in December 2010. Cyanobacteria were dominant, occupying about 88% of biofilm, irrespective of wave exposure levels. The cyanobacteria species, Aphanotece spp. was abundant in the Yellow Coast location and Lyngbya spp. was abundant in the East coast location. The representative diatoms were Navicula spp. and Achnanthes spp. on the rocky shores of all study sites. Average Normalized Difference Vegetation Index (NDVI) was significantly greater in the Yellow Coast (mean 0.46) than that in the East Coast (mean 0.21);a similar pattern was observed in Vegetation Index (VI). Chlorophyll a content was three times greater on the Yellow Coast (20.50 μg/cm2) than that on the East Coast (8.21 μg/cm2), and it was greater at the Gosapo and Bangpo shore sites than that at the Gyeokpo site, on the Yellow Coast. However, chlorophyll a contents were not different between 23.33 and 17.66 μg/cm2 at exposed- and sheltered-shores of Yellow Coast, and were 9.62 μg/cm2 and 6.80 μg/cm2 on the East Coast. Vegetation indices were positively correlated with chlorophyll a contents. In conclusion, biofilm of Korean upper rocky shore was mainly composed of cyanobacteria and biofilm biomass that differed between the Yellow and East Coast.
