We used standard periphyton samplers to examine the colonization pattern of periphytic algae on artificial substrates (glass slides) in Lam Tsuen River, Hong Kong, in dry (winter) and wet (summer) seasons. In each sea...We used standard periphyton samplers to examine the colonization pattern of periphytic algae on artificial substrates (glass slides) in Lam Tsuen River, Hong Kong, in dry (winter) and wet (summer) seasons. In each season, six replicated slides were retrieved randomly and replaced by new slides at weekly intervals over a period of 6 weeks. We thus obtained two batches of slides, both with a series of different exposure times (1 to 6 weeks): one batch was set up at the same time (start of the sampling) and the other was harvested at the same time (end of the sampling). Changes in taxonomic composition, species diversity (Shannon-Wiener diversity index), standing crop (in terms of cell density and cell biovolume), and abundance of the abundant algal species were monitored and compared between the two batches of slides. The succession patterns of the periphytic algae were similar between the two batches in each season, while more remarkable differences were observed between the two seasons, suggesting that either batch would be suitable for a colonization study of periphytic algae. The cell density was dominated by diatoms in both seasons, while the cell biovolume was dominated by diatoms in winter and by green algae in summer. The cell density and biovolume attributed to blue green algae was relatively small. Most of the diatom species exhibited similar colonization patterns throughout the experiment, while green algae showed different succession patterns in different seasons or sampling methods, indicating that diatoms are better bio-indicators than green algae for a periphyton colonization study. In general, the diversity indices and the standing crops reached their maximums at around week 4, and they were higher in summer than in winter.展开更多
基金Supported by the National Natural Science Foundation of China (Nos.30770393 30770340)+1 种基金the National Major Program of Science and Technology for Water Pollution Control and Restoration in China (Nos.2009ZX07423-003,2009ZX07101-011)the Natural Science Foundation of Guangdong Province,China (No.06301361)
文摘We used standard periphyton samplers to examine the colonization pattern of periphytic algae on artificial substrates (glass slides) in Lam Tsuen River, Hong Kong, in dry (winter) and wet (summer) seasons. In each season, six replicated slides were retrieved randomly and replaced by new slides at weekly intervals over a period of 6 weeks. We thus obtained two batches of slides, both with a series of different exposure times (1 to 6 weeks): one batch was set up at the same time (start of the sampling) and the other was harvested at the same time (end of the sampling). Changes in taxonomic composition, species diversity (Shannon-Wiener diversity index), standing crop (in terms of cell density and cell biovolume), and abundance of the abundant algal species were monitored and compared between the two batches of slides. The succession patterns of the periphytic algae were similar between the two batches in each season, while more remarkable differences were observed between the two seasons, suggesting that either batch would be suitable for a colonization study of periphytic algae. The cell density was dominated by diatoms in both seasons, while the cell biovolume was dominated by diatoms in winter and by green algae in summer. The cell density and biovolume attributed to blue green algae was relatively small. Most of the diatom species exhibited similar colonization patterns throughout the experiment, while green algae showed different succession patterns in different seasons or sampling methods, indicating that diatoms are better bio-indicators than green algae for a periphyton colonization study. In general, the diversity indices and the standing crops reached their maximums at around week 4, and they were higher in summer than in winter.
