Abundant, diverse, unknown: Extreme species richness and turnover
despite drastic undersampling in two closely placed tropical Malaise
traps
Abstract
Arthropods account for a large proportion of animal biomass and
diversity in terrestrial systems, making them crucial organisms in our
environments. However, still too little is known about the highly
abundant and megadiverse groups that often make up the bulk of collected
samples, especially in the tropics. With molecular identification
techniques ever more evolving, analysis of arthropod communities has
accelerated. In our study, which was conducted within the Global Malaise
trap Program (GMP) framework, we operated two closely placed Malaise
traps in Padang, Sumatra, for three months. We analyzed the samples by
DNA barcoding and sequenced a total of more than 70,000 insect
specimens. For sequence clustering, we applied three different
delimitation techniques, namely RESL, ASAP, and SpeciesIdentifier, which
gave similar results. Despite our (very) limited sampling in time and
space, our efforts recovered more than 10,000 BINs, of which the
majority are associated with “dark taxa”. Further analysis indicates a
drastic undersampling of both sampling sites, meaning that the true
arthropod diversity at our sampling sites is even higher. Regardless of
the close proximity of both Malaise traps (< 360 m), we
discovered significantly distinct communities.