Symposium Introduction

Species composition within the community of organisms and the quantitative ratio species population is one of the most important indicators of the structure community. In the study of communities most abundant species is given focus, but rare species are often the best indicator state of the environment, total number of species is an indicator of the conditions of existence living organisms. Species diversity - a sign of ecological diversity: more species, the more ecological niches, ie higher richness of the environment.

Species diversity is associated with a sustainable community for the simple reason that the greater the diversity, the greater the possibility of adapting community to the changed conditions, be it climate change or other factors.

The explanation for this is that the presence of different organisms with different requirements of the environment increases the fitness community as a whole. Thus, rare in existing species under altered conditions may be in pole situation and become numerous, and vice versa. Thus, by species diversity of community as it provides a reserve of survival in case of unexpected changes in the conditions of life .