Lake ecosystems exist in many alternative states with respect to their species composition and ecosystem functioning for providing free services and goods. Each state of smaller shift is stable for short-term but greater shifts change the ecosystem from one state to another. Such state shifts are important to record the ecosystem health and for ecorestoration. Thresholds in the relationship between phytodiversity and ecosystem functioning are hypothetical but plausible. In lake Chilika, high phytodiversity during the winter increases the ecophysiological process rate and low phytodiversity during the summer decreases the ecophysiological process rate. Aquatic plant threshold values and curves are determined to record the Chilika lake ecosystem behaviour. It is observed that to restore the Chilika ecosystem,   the phytodiversity must be raised above the threshold value of upper range and not the lower range. The values   have significant implications for bioresource recovery, ecosystem restoration and sustainability of ecosystem services. Adaptive management techniques for detection and avoidance of thresholds and the desirable state for long-term stability of the aquatic ecosystem are needed to ecorestore the lake Chilika.

Plant Physiology and Biochemistry Laboratory,
P.G. Department of Botany,
Berhampur University,
Berhampur-760007, Orissa, India.
E-mail: pcac-b@yohoo.com