title: Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories.
abstract: Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D1), Simpson's dominance (D2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P. lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.
authors.affiliation: Institute of Biology, Dahlem Center of Plant Sciences, Freie Universität Berlin Altensteinstr 6, Berlin, 14195, Germany ; Department of Biology, Xavier University 3800 Victory Parkway, Cincinnati, Ohio, 45207.
authors.forename: E Kathryn
authors.initials: EK
authors.lastname: Morris
authors.affiliation: School of Biological Sciences, Queen's University Belfast 97 Lisburn Road, Belfast, BT9 7BL, Northern Ireland.
authors.forename: Tancredi
authors.initials: T
authors.lastname: Caruso
authors.affiliation: Department of Soil Ecology, UFZ- Helmholtz Centre for Environmental Research Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany ; Institute of Biology, University of Leipzig Johannisallee 21-23, Leipzig, 04103, Germany ; German Centre for Integrative Biodiversity Research (iDiv) Deutscher Platz 5e, Leipzig, 04103, Germany.
authors.forename: François
authors.initials: F
authors.lastname: Buscot
authors.affiliation: Institute of Plant Sciences, University of Bern Altenbergrain 21, Bern, 3013, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Fischer
authors.affiliation: Department of Animal Ecology and Tropical Biology, University of Würzburg Am Hubland, Würzburg, 97074, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Hancock
authors.affiliation: Department of Chemical Ecology, Bielefeld University Universitätsstr. 25, Bielefeld, 33615, Germany.
authors.forename: Tanja S
authors.initials: TS
authors.lastname: Maier
authors.affiliation: Institute of Biology, Applied Zoology/Animal Ecology, Freie Universität Berlin Harderslebener Strasse 9, Berlin, 12163, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Meiners
authors.affiliation: Department of Chemical Ecology, Bielefeld University Universitätsstr. 25, Bielefeld, 33615, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Müller
authors.affiliation: Department of Animal Ecology and Tropical Biology, University of Würzburg Am Hubland, Würzburg, 97074, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Obermaier
authors.affiliation: Institute of Plant Sciences, University of Bern Altenbergrain 21, Bern, 3013, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Prati
authors.affiliation: Institute of Plant Sciences, University of Bern Altenbergrain 21, Bern, 3013, Switzerland.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Socher
authors.affiliation: Institute of Biology, Dahlem Center of Plant Sciences, Freie Universität Berlin Altensteinstr 6, Berlin, 14195, Germany.
authors.forename: Ilja
authors.initials: I
authors.lastname: Sonnemann
authors.affiliation: Institute of Biology, Applied Zoology/Animal Ecology, Freie Universität Berlin Harderslebener Strasse 9, Berlin, 12163, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Wäschke
authors.affiliation: Department of Soil Ecology, UFZ- Helmholtz Centre for Environmental Research Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany ; German Centre for Integrative Biodiversity Research (iDiv) Deutscher Platz 5e, Leipzig, 04103, Germany.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Wubet
authors.affiliation: Institute of Biology, Dahlem Center of Plant Sciences, Freie Universität Berlin Altensteinstr 6, Berlin, 14195, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Wurst
authors.affiliation: Institute of Biology, Dahlem Center of Plant Sciences, Freie Universität Berlin Altensteinstr 6, Berlin, 14195, Germany ; German Centre for Integrative Biodiversity Research (iDiv) Deutscher Platz 5e, Leipzig, 04103, Germany ; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB) Altensteinstr 6, Berlin, 14195, Germany.
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Rillig
keywords: Arbuscular mycorrhizal fungi; Berger–Parker; Hill’s powers; Plantago lanceolata; Shannon index; Simpson’s index; arthropods; chemical diversity; molecular diversity; plant diversity