OLM10.5. Niche segregations
While niche and niche-segregation are defined in a model-independent way (Ch10Niche) it is far from being an easy task to understand coexistence of natural populations in terms of their niches. Identification and characterization of the regulating feed-back loops is a complex task that would require field-experiments and large-scale comparative studies of population growth. The technical difficulties as well as conceptual ambiguities (Ch10Niche) may explain why niches are usually determined with other methods. Besides functional-trait based approaches, the realised relative abundances of the species are studied in relation to the suspected limiting environmental conditions (like studies of adaptations within populations; Ch5Toler) instead of population dynamics and feed-backs. Studies in small communities of extreme habitats like deserts or comparisons of closely related species or ecotypes provide some examples in which the mechanisms of coexistence or the drive for niche segregation are well understood.