Fractal geometry and scaling in benthic ecosystems

Although fractal geometry has been applied on various aspects of ecology such as patterns of plant and landscapes, applications on benthic freshwater environments and patterns of community structure have only recently emerged. Fractal models can be used to summarise the response of organisms to environmental heterogeneity that may be independent of differences in species composition and body size distribution. Few studies have considered spatial scale-dependent aspects of distribution pattern of different-sized organisms, particularly in lotic systems. Body size influences an organism`s energetic requirements, its potential resource exploitation, and its susceptibility to predation. The existence of a general relation, between population density and body size in benthic animal assemblages may be attributed to non-metabolic constraints such as habitat complexity. We aim to examine the implications of substratum surface heterogeneity and its fractal characteristics for the body-size distribution of benthic communities. In eight geographically separated streams we shall explore if scaling of population density to body size converges across communities. Furthermore, we aim to examine if the relation between body-size and population density in benthic animal assemblages may be influenced by local, regional and geographic scales of observation.

Although fractal geometry has been applied on various aspects of ecology such as patterns of plant and landscapes, applications on benthic freshwater environments and patterns of community structure have only recently emerged. Fractal models can be used to summarise the response of organisms to environmental heterogeneity that may be independent of differences in species composition and body size distribution. Few studies have considered spatial scale-dependent aspects of distribution pattern of different-sized organisms, particularly in lotic systems. Body size influences an organism`s energetic requirements, its potential resource exploitation, and its susceptibility to predation. The existence of a general relation, between population density and body size in benthic animal assemblages may be attributed to non-metabolic constraints such as habitat complexity. We aim to examine the implications of substratum surface heterogeneity and its fractal characteristics for the body-size distribution of benthic communities. In eight geographically separated streams we shall explore if scaling of population density to body size converges across communities. Furthermore, we aim to examine if the relation between body-size and population density in benthic animal assemblages may be influenced by local, regional and geographic scales of observation.