Journal of Environmental Biology

Microbial biomass at land water interface and its role in regulating ecosystem

properties of a fresh water dry tropical woodland lake

J. Pandey*

Department of Environmental Sciences, M.L.Sukhadia University, Udaipur - 313 001, India

(Received: January 09, 2006; Revised received: November 12, 2006; Accepted: December 31, 2006)

Abstract: This study was aimed at determining microbial biomass at land water interface and the role it plays in regulating ecosystem properties of a fresh water dry tropical woodland lake. Four microbial variables namely biomass-C (C_mic), fumigated CO₂ –C, substrate induced respiration (SIR) and basal respiration (BR) were measured in humus samples collected from land water interface over a period of one year. Microbial biomass (C_mic) was maximum during February (718 µg CO₂ –C g^-1).Similar was the case of fumigated CO₂ –C (560 µg CO₂ –C g^-110 d^-1), SIR ( 2900 µg CO₂-C g^-1) and BR (480 µg CO₂ –C g^-1). Humus- N appeared maximum (1.60 %) during November and phenolics (204 µg g^-1) during December. Gross primary productivity (GPP) was found maximum (3.30 g C m ^-2 d^-1) during March. Almost similar trend appeared for chlorophyll and phytoplankton density. Variation in microbial biomass at land water interface can be explained by seasonality and the quality of substrate material. Asynchrony in the peaks of microbial variables with phytoplankton pulsation and GPP suggested that the microbial biomass through nutrient mineralization regulates ecosystem functioning of a fresh water woodland lake. This has relevance for evaluating the nature of anthropogenic perturbations and for maintenance of fresh water lakes void of human disturbances.

Key words:    Land water interface, Ecosystem, Phytoplankton, Humus, Microbial biomass

PDF of full length paper is available with author (jiten_pandey@rediffmail.com)

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