Seasonal Variations of Primary Productivity in a Freshwater Pond, Tamilnadu, India
Vaidehi. J
Department of Zoology, Annamalai University, Annamalai Nagar, Chidambaram, Tamil Nadu-608002, India.
R. Sivakami *
P.G. and Research Department of Zoology, Arignar Anna Government Arts College, (Affiliated to Bharathidasan University), Musiri-621 211, Tiruchirappalli, India.
V. Babu
Mangalam College of Arts and Science, Affiliated to the University of Madras, Thirumullaivoyal, Chennai, Tamil Nadu - 600062, India.
A. Rajendiran
P.G. and Research Department of Zoology, Arignar Anna Government Arts College, (Affiliated to Bharathidasan University), Musiri-621 211, Tiruchirappalli, India.
*Author to whom correspondence should be addressed.
Abstract
The Gross Primary Productivity (GPP) was found to range between 33.6 and 64.4 g O2/m2/day while Net Primary Productivity (NPP) ranged between 15 and 37.4 g O2/m2/day and Community Respiration (CR) from 12.6 to 29.2 g O2/m2/day during the period of study. The minimal levels of NPP and CR were recorded in November while the minimum NPP was recorded in October. However, the maximal levels of GPP, NPP and CR were uniformly recorded in June throughout the period of study. It is suggested that apart from the influence of physicochemical factors on phytoplankton population, the grazing rate of zooplankton is one of the major factors that influence the size of the standing crop of phytoplankton and thereby the rate of production. In addition they also reported that the production rate of phytoplankton will vary from place to place depending on geographical location and enrichment of water bodies. According to respiration as percent of gross production may be used as a measure of the eutrophic nature of the water body and many workers suggested that in a productive aquatic ecosystem respiration accounts for a large proportion of Gross Primary Productivity (GPP).
Keywords: Freshwater pond, gross primary productivity, net primary productivity, community respiration