Estudo da variação de recursos em um sistema presa-predador

Abstract

Spatial heterogeneity plays an important role in the processes that occur in ecosystems and can have a great influence on the number of species in natural environments. The distribution of resources and their use by species are important factors for ecosystem processes that generate spatial heterogeneity. In this sense, our objective was to investigate the effects of environmental heterogeneity, variation in the amount of resources and temporal variation of these resources on the dynamics and final state of the ecosystem in systems with prey-predator interactions. For this, the heterogeneity of the ecosystem is introduced with the use of fractal reliefs produced through the fractional Brownian movement and the variation of the amount of resource introduced as a function of a constant QR. We found that the species coexist for low and medium predator reproduction probabilities and that species richness is expanded to intermediate heterogeneities, regardless of the amount of resource. For a resource amount aswes at each site between 0 and 1 the species coexist for high and low probabilities of prey reproduction. Multiplying this amount, we found that for QR=0.1 the species coexist only for a high probability of prey reproduction and that for QR=10 and QR=20 the two species also coexist for low probabilities of prey reproduction. Regarding the temporal variation in the amount. of resource, we observed a similar qualitative behavior and that there is a higher prevalence of prey in the system.