Assessing the efficacy of higher-taxon approach for ant species surveys to improve biodiversity inventories

Abstract

Understanding the distribution of species is essential for the conservation and management of biodiversity. But the availability of this kind of information is still scarce for the most diverse regions. The higher-taxon approach (i.e. use of coarser taxonomic levels to represent species) as an easier and efficient method in representing species patterns can be one way to overcome these constraints. However, there is a general lack of information about the taxonomic stability of surrogate taxa across space and time. We investigated the predictive power and stability of taxonomic identification at the genus level as a predictor of ant species (Hymenoptera: Formicidae) distribution throughout ˜1000 km along the Amazon Basin, using taxonomy over the past 120 years. Using intervals of 10 years, from 1900 to 2020 we generated a genus and species matrix based on actual data from our sampling sites for each decade over a total of 120 years. We tested the predictive power of genera as a surrogate of species for approximating species-level richness, composition and distribution-based measures along topographic gradients at local (within site) and regional (between sites) scales. We detected a strong correlation between genera and ant species richness in the current database. There was also high congruence between genera and ant species composition over the time period studied. Genera were also efficient at detecting patterns of species distribution along topographic gradients. Despite changes in ant taxonomy over the past 120 years, our data indicate that such revisions did not affect the ability of ant genera to predict general patterns of ant species in our study area within the Amazon Basin. This reinforces the potential of genera to serve as surrogates for ant species elsewhere, which may significantly decrease the cost of surveying ants in environmental monitoring programs because of the time saved from identifying collected specimens to genus rather than species level. © 2021 The Zoological Society of London