Authors: Nandakumar Kanavillil Debbie Balika Sreekumari Kurissery
Publish Date: 2014/10/07
Volume: 744, Issue: 1, Pages: 77-90
Abstract
This manuscript tests the hypothesis that the ‘edge effect’ during microalgal colonization on small substrata results in spatial heterogeneity and that the edge effect does not disappear over time The study has been carried out in a boreal lake Lake Simcoe ON Canada Multiple glass slides of size 10 × 3 × 01 cm were exposed at 05 m below the water surface for a maximum period of 30 days with intermittent sampling Biofilms on glass slides were analyzed for diatom density species richness and diversity and biofilm thickness at center and edges Diatoms with long stalks eg Gomphonema sp were common at edges and center locations while those with short stalks eg Achnanthes sp preferred center over edges Loosely attached or motile forms Aulacoseira granulata were found more at center than edges The species richness and biofilm thickness were significantly higher at center than edges however the species diversity was higher at the center during the first half of the study only A significant negative correlation between the species richness at center and edges further illustrated the variability in colonization on glass slides The results thus demonstrated ‘edge effect’ in natural biofilms leading to spatial heterogeneity which was persistent throughout the study period
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