Effect of changing habitat on species: application to Keoladeo National Park, India

Abstract

In this paper, a mathematical model is proposed to study the effect of ecological changes caused by the excessive growth of wild grasses such as Paspalum distichum on the existence of various species in the Keoladeo National Wetland Park, Bharatpur, Rajasthan, India. In the model the growth rate of several species, such as floating vegetation ( Nymphoides indicum, Nymphoides cristatum, Nymphaea nouchali and Nymphaea stellata), fishes, waterfowl, etc. and the corresponding carrying capacity of the wetland are assumed to decrease with the increase in biomass density of wild grasses. By analysing the model it is shown that if the wild grasses are not controlled, the existence of various other species will be threatened. It is shown through the model study that if the growth of wild grasses is controlled, either by allowing a managed number of buffaloes to graze them or by using some other mechanism to remove them, then the other species in the wetland will boom. Keeping in view the growth of Paspalum distichum and using the corresponding parameters for this wetland in the model, the number of buffaloes to be permitted for grazing has also been calculated for management purposes.