Introduction Interacting species have a tremendous influence on each other's population densities.
The various mechanisms for these biotic influences are quite different from that of abiotic factors. Biotic factors also regulate the size of populations more intensely. Finally, the influence of biotic interactions can occur at two different levels. Interspecific effects are direct interactions between species, and the intraspecific effects represent interactions of individuals within a single species. Neutralism Neutralism is the most common type of interspecific interaction.