The vegetation dynamics of the monsoonal wetland of the Keoladeo National Park, India: a reassessment

As a result of a field trip in 1980 to the monsoonal wetland of the Keoladeo National Park, India, which was organized by Dr. Brij Gopal, a study of the vegetation dynamics of this wetland was initiated. The original hypothesis for this study was that the seasonal vegetation changes caused by the annual summer monsoon was a compressed habitat cycle. Habitat cycles are a characteristic of prairie potholes in North America. Habitat cycles are the result of wet–dry cycles that last from 5 to 25 years during which the vegetation of a pothole changes from dense emergent vegetation (dry years) to open water with only submerged vegetation (wet years). In retrospect, our field studies were not consistent with our hypothesis. The increase in water level caused by the monsoon was not large enough to kill the emergent vegetation, as happens during prolonged high-water years in prairie potholes. However, both wetland types have significant seed banks that allow their plant species to survive adverse conditions. We now believe that the vegetation dynamics of monsoonal wetlands are best described as seasonal shifts between a wet marsh phase when the wetland is flooded and a dry grassland phase when it is not.