Morpho-ecospaces, or how to measure biodiversity in a different way

Abstract

The current biodiversity crisis warrants accurate measuring of biodiversity, often achieved by counting species or higher taxonomic units, with morphological or molecular methods. Alternatively, trait-centred approaches categorise organisms into distinct ecological roles and then count the number of occupied roles to measure biodiversity. Even combinations of trait-based and taxonomic approaches are utilised. However, when investigating the theoretical aspects, all these approaches have significant shortcomings, which complicate a reliable biodiversity measurement, that is, the ignorance of polymorphic species, the sensitivity to the initial classification or the knowledge gap concerning the ecology of the organisms. We outline a non-discrete ecospace approach for which neither pronounced taxonomic expertise nor in-depth knowledge about the ecology of the organisms is required. A morphospace based on quantitative morphological properties is used as a proxy for an ecospace, thus resulting in a continuous morpho-ecospace. With this, decision-making concerning taxonomy or ecology is reduced, as morphology is directly used instead of being first interpreted. Differences usually not considered due to polymorphism or ontogeny can be included in this approach, as well as fossils without species determination. This morpho-ecospace approach is easily applicable and can be combined with already existing approaches, making it broadly applicable.