A stochastic ecological model

By including under the name ‘niches’ all the beneficial and adverse factors or attributes for an ecological system that contribute or affect the biomasses of the species in that system, the contributory functions of these factors, together with their distributions in spatial region, have been proposed. From the random nature of these functions, termed as ‘random causes’ for the ecosystem, the stochastic evolution equations for the biodensities of the spreading species have been deduced. These equations are found to be very general in nature and also describe the nonlocal contributions of the biodensities. They can produce stochastic partial differential equations for the biodensities of the species for various ecological systems. y, it has been discussed how the experimental values of the population growth and spread over a region with the niche distribution therein, can determine the ecological niche-contribution functions to the species of the system. The stationary or equilibrium transition probabilities for the general ecological systems are also given.