藻類群聚的組成與回復，會影響淡水生態系的基礎生產力。本研究目的為瞭解播遷與拓殖效應對淡水藻類群聚組成初期演替的改變與對藻類生長所產生的影響，以及對溪流藻類生物多樣性的影響。本研究於南投縣蓮華池地區的火焙坑溪進行，以自然溪流與模擬人工溪流中進行微生態系實驗，研究共進行四十一天，於研究期第八天時將自然溪流內的磁磚移置模擬人工溪流，並且定期採集磁磚上藻類樣本與漂流藻樣本，進行藻類的鑑定與分析。 實驗結果顯示，自然溪流與人工溪流磁磚上藻類細胞密度皆隨時間而增加，而自然溪流磁磚上矽藻藻種數目在研究初期即達到最高，並隨時間的增加而有歧異度下降，優勢度上昇的趨勢。自然溪流磁磚上藻類生物量與有機物重，皆比人工溪流要高，並且自然溪流細胞密度比人工溪流要高，顯示在播遷與拓殖效應的影響下自然溪流藻類生物量的累積速率比人工溪流要快。在自然溪流與人工溪流的磁磚上，矽藻藻種有生長速率上的差異，大部份自然溪流矽藻藻種密度隨研究時間增加而上升，人工溪流中部份矽藻藻種與時間為正向關係，部份矽藻藻種與時間為負向關係。優勢藻種為生長速率快的曲殼藻屬（Achnanthes），可能是因為此屬藻種體型小，生長速率快，為好的拓殖者。群集分析結果顯示，自然溪流與人工溪流磁磚上矽藻群聚組成屬於不同的集群，降趨對應分析結果顯示自然溪流與人工溪流磁磚上矽藻群聚組成有不一樣的發展方向。自然溪流中播遷的漂流藻與自然溪流磁磚上的附著藻大部份為相同的藻種。自然溪流磁磚上藻類群聚組成因為漂流藻播遷與拓殖而產生演替，人工溪流磁磚上藻類群聚組成因藻種的生長與競爭能力而產生演替。 The recovery and composition of algal assemblages affected the primary production of freshwater ecosystems. The goal of this research was to understand the effects of dispersal and colonization on algal diversity, algal growth, and early succession of algal assemblages. The study site is located at the Huo-Bei-Keng Creek in Lian-Hua-Chi area of Nantou County. I used tiles to study dispersal and colonization of algae in natural and artificial streams. The duration of the experiment was 41 days and the transfer of tiles from natural to artificial streams was on day 8. Algae were collected on 9 dates and analyzed. Results showed that algal densities increased with time in both natural and artificial streams. Algal diversity reached the highest value in early days, then decreased with time, and dominance increased with time. Algal biomass and AFDM were higher on tiles of natural streams than in artificial streams through time, indicating higher algal growth rates in natural streams than artificial streams. Some diatom species had different growth rates in natural and artificial streams. Most diatom species increased with time in the natural system, some increased in the artificial system, while some decreased with time in either of two systems. Most dominant species belonged to Achnathes because small sizes rendered them high growth, dispersal, and colonization rates. Multivariate analyses showed that diatom assemblages of natural and artificial systems belonged to different clusters and had different development routes. Diatom species composition in the natural system was similar to that in the drift assemblage. The succession of diatom assemblages in the natural system was driven by the dispersal and colonization of drift algae, while the succession of diatom assemblages in the artificial system was driven by the growth rate and competition capacity.
