Spatial synchrony in host-parasitoid populations

The ubiquity of spatial synchrony and its influences and causes have attracted the interest of ecologists. Spatially correlated environmental noises, dispersal, and trophic interactions have been considered as the causes of spatial synchrony. In this study, we developed a spatially implicit host-parasitoid model. Beside the above three mechanisms, correlation of environmental noise on different trophic levels was also included. Patterns of spatial synchrony was considered for stable, quasi-periodic, periodic, and chaotic population dynamics, respectively In the stable region, a theoretical exploration based on a linearized 2-patch model was firstly done. Theoretical prediction shows that trophic correlation of environmental noises is another mechanism causing spatial synchrony. Numerical simulations of 2-patch and multi-patch models also verified the prediction. More simulations in other region show that periodic and quasi-periodic populations could be synchronized, while chaotic populations are hard to synchronize. The importance of our research is enriching the theory of potential causes of spatial synchrony. (C) 2006 Elsevier B.V. All rights reserved.