Competition in the Periphytic Algal Community during the Colonization Process: Evidence from the World's Largest Water Diversion Project.

Periphytic algal colonization is common in aquatic systems, but its interspecific competition remains poorly understood. In order to fill the gap, the process of periphytic algal colonization in the Middle Route of the South to North Water Diversion Project was studied. The results showed that the process was divided into three stages: the initial colonization stage (T1, 3-6 days), community formation stage (T2, 12-18 days) and primary succession stage (T3, 24-27 days). In T1, the dominant species were (Bory), (Kützing) and (Lange-Bertalot) belonging to Heterokontophyta; these species boasted wide niche widths (NWs), low niche overlap (NO) and low ecological response rates (ERRs). In T2, the dominant species were , (Kützing), , , (Kützing), (C.Agardh), (N.L.Gardner) and (Kuntze). These species displayed wider NWs, lower NO, and lower ERRs than those in T1. In T3, the dominant species were , , , , (Grunow), etc. Among them, Heterokontophyta such as and had a competitive advantage based on NWs and ERRs. Cyanobacteria like lost their dominant status due to the narrower NW and the increased NO. It could be concluded the interspecific competition became fiercer and shaped the colonization process; this study will be helpful in understanding the colonization of periphytic algal communities.