Factors Influencing the Diversity, Species Composition and Abundance of Phytoplankton in Twenty One Arctic and Subarctic Lakes

✍ Scribed by Dr. James W. Moore

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 972 KB
• Volume: 64
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.19790640410

✦ Synopsis

Abstract

The factors influencing the diversity, species composition and abundance of phytoplankton in 21 lakes in the Canadian arctic and subarctic were determined between 1975 and 1978. The maximum number of species (60–75). and highest diversity indices (1. 6–1. 9). were recorded from the most southerly lakes, situated at 63–64^°^ North. Since there were fewer species (40–60). and lower diversity indices (0. 7–1.0). in lakes located at 65–66^°^ North, temperature was the main factor influencing the diversity of the flora. Other parameters, including surface area, depth and the concentrations of nutrients, exerted little influence on the plankton. The maximum densities of several common species (Rhodomonas minuta var. nannoplanktonica, Kephyrion boreale, Ochromonas sphaerella, Ankistrodesmus falcatus, Oscillatoria limnetica). increased significantly in lakes with high concentrations of total phosphorus and total hardness whereas the reverse pattern was recorded for two other common species (Dinobryon bavaricum, D. sociale). Diatoms (mainly Asterionella formosa and Cyclotella glomerata). were restricted primarily to large lakes where turbulence helped keep these algae afloat.