Ecological Diversity: Measuring the Unmeasurable

• DOI: 10.3390/math6070119
• Publication Date: 2018-07-10T13:24:01Z
• Authors: Aisling J. Daly; Jan M. Baetens; Bernard De Baets
• Keywords: 0106 biological sciences; POPULATION-SIZE; estimators; CONSUMERS GUIDE; CONSISTENT TERMINOLOGY; 01 natural sciences; diversity; FUNCTIONAL DIVERSITY; effective numbers; PHYLOGENETIC DIVERSITY; NONPARAMETRIC-ESTIMATION; EVENNESS MEASURES; QA1-939; mathematical ecology; RAOS QUADRATIC ENTROPY; SPECIES-DIVERSITY; Biology and Life Sciences; 15. Life on land; Mathematics and Statistics; Earth and Environmental Sciences; GENETIC DIVERSITY; evenness; richness; Mathematics

Diversity is a concept central to ecology, and its measurement is essential for any study of ecosystem health. But summarizing this complex and multidimensional concept in a single measure is problematic. Dozens of mathematical indices have been proposed for this purpose, but these can provide contradictory results leading to misleading or incorrect conclusions about a community’s diversity. In this review, we summarize the key conceptual issues underlying the measurement of ecological diversity, survey the indices most commonly used in ecology, and discuss their relative suitability. We advocate for indices that: (i) satisfy key mathematical axioms; (ii) can be expressed as so-called effective numbers; (iii) can be extended to account for disparity between types; (iv) can be parameterized to obtain diversity profiles; and (v) for which an estimator (preferably unbiased) can be found so that the index is useful for practical applications.