Model‐based ordination for species with unequal niche widths

Bert van der Veen, Francis K.C. Hui, Knut A. Hovstad, Erik B. Solbu, Robert B. O'Hara
2021 Methods in Ecology and Evolution  
One of the key topics addressed by community ecology is the exploration of community composition. To that end, species communities are surveyed at locations along environmental gradients. The ecological niche is then reflected in the observed distribution of a species. A species exhibits its maximum abundance, or has the highest probability of occurrence, at the optimum of the niche. The limits of a species distribution correspond to the limits of the niche, controlled by a species' tolerance
more » ... a range of environmental conditions. Different species vary in their ability to tolerate deviations from the optimum, reflecting differences in niche width, and indicating different places on the specialist-generalist spectrum. Correspondence analysis (CA) is often used to estimate the optima of species niches with quadratic response curves. It implicitly approximates the fit of a quadratic model, which functions best under the assumptions of equally spaced optima, sites being well within the range of species optima, equal tolerances and equal or independent maxima (ter Braak, 1985) . The combination of assuming equally spaced optima, equal maxima and equal tolerances gives an early niche model called the species packing model (MacArthur & Levins, 1967) . The relationship of the species packing model to
doi:10.1111/2041-210x.13595 fatcat:geubqi42g5aonmqavp7hgferw4