Algal Community Structure in Artificial Ponds Subjected to Continuous Organic Enrichment

• Published in: The American midland naturalist 1970-04, Vol.83 (2), p.565-582
• Main Authors: Ewing, Margaret S., Dorris, Troy C.
• Format: Article
• Language: English
• Subjects: Algae; Ammonia; Community structure; Lagoons; Nitrates; Phytoplankton; Ponds; Population growth; Species diversity; Zooplankton
• ISSN: 0003-0031; 1938-4238
• DOI: 10.2307/2423963

Nine artificial ponds each subjected to one of three experimental treatments of organic enrichment exhibited no significant differences in mean concentration of dissolved nitrate, nitrite, ammonia or phosphate. Phytoplankton communities were dominated by Chlorophyta. Communities differed considerably in population size and in pattern of fluctuation among ponds treated similarly. Population variations generally were not correlated with nutrient variations. Development of large algal populations began concurrently with sharp increases (25 μg/liter or more) in nitrate concentration in some ponds. In zoo-plankton communities a shift occurred in dominant forms from rotifers in June, to cladocera in July, and copepods in August. In general, algal species diversity (H̄) was not positively correlated with nutrient concentrations. Redundancy (R) was closely parallel in the ponds. Among ponds supporting very large algal populations, only one exhibited consistently high R values for that period. The expected inverse relation between P/R ratio and H̄ among autotrophic communities was not observed. The correlation coefficient for these two parameters was -.09. Vertical mixing of algal communities in all ponds was indicated by comparison of surface and deeper samples.