To reveal the phytoplankton species and their interspecies relationships which cause heavy algal bloom turning water surface color to strong green (aoko) or to brown (akashiwo), two-year-long monthly investigation with microscope was employed at six urban park ponds in Osaka city. Microcystis were the most abundant species, and it had not disappear in winter season (Jan. to Mar.) in many ponds. Some of then kept 1000 cells mL-1-order that is near to algal bloom. Mean phytoplankton composition of algal blooming genus or class could classify these ponds into four categories; 1) Chlorophyceae-Bacillariophyceae dominant pond which causes no heavy blooms, 2) Microcystis pond, 3) Oscillatoria pond, 4) aoko and akashiwo pond with cyanophyceae, euglenophyceae and dinophyceae. Additionally, Spearman's rank correlation analysis showed the confliction between Microcystis and Oscillatoria. Nitrogen:phosphorus ratio was suspected as a driver controlling the dominant species in the water. Also, a tendency was shown toward the co-occurrence of Microcystis and euglenophyceae or dinophyceae, this suggests that the co-occurrences of aoko and akashiwo at the same time. This phenomenon was seemed due to surface water sampling, because those species have ability for rising up in the water column when heavy algal blooms occurred. Anyhow, supplement investigations was required.
| 情報源 |
【オンライン情報源1】 環境展望台 全国環境研会誌 - JELA_2802035_2003.pdf 【オンライン情報源2】 環境展望台 全国環境研会誌 28巻2号 【オフライン情報源】 【媒体名称】 【備考】全国環境研会誌 28巻2号, 35-40, (2003) |
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| 配布形式1 |
【交換形式名称】PDF 【版】不明 |
| ファイル識別子 | 88863 |
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| 言語 | 日本語 |
| 文字集合 | |
| 親識別子 | |
| 階層レベル | 非地理データ集合 |
| 階層レベル名 | 全国環境研会誌 |
| 日付 | |
| メタデータ標準の名称 | JMP |
| メタデータ標準の版 | 2 |
