Never ending story: a lesson in using sampling efficiency methods with ground beetles

Abstract

Biological inventory is a crucial activity in life sciences field research. However, it is sometimes timeconsuming and laborious to take representative samplings of communities, especially in the case of invertebrates. In this paper, we address the issue of sampling efficiency and its influence on obtained results. As a study system, we used data on epigeic carabid beetles (Carabidae) collected in 1999-2001 in the Warta River valley of western Poland. We trapped a total of 17,722 individuals belonging to 108 species. However, due to rarefaction methods, the expected number of species was estimated at 134-140, suggesting that from 26 to 32 species are missing from the material, even expressed as a huge number of collected specimens. The estimated probability that another captured individual will represent a new species (i.e. a species that was not already recorded) is 0.0010. In order to record all the species present in the study area, another 193,338 individuals need to be sampled (abundance-based approach) or another 1,871 samples need to be collected (incidencebased approach). This means that the collected material should be 10.9 times greater (or 7.9 times greater for incidence-based data) than what was actually collected in order to record all the species present in the study area. The results show that, in practice, full inventory is simply nearly impossible to achieve, and this knowledge should be included in inventory planning. Therefore, we argue that species accumulation curves and unseen species estimators need to be carefully examined and threshold probability of detecting a new species should be built into the design of inventory science. The ratio between recorded and estimated species richness and the estimated efficiency of further sampling can be easily computed with available freeware software and should be incorporated when performing biological inventories.

Guidelines on sampling intensity of bees (Hymenoptera: Apoidea: Apiformes)

“…Our study shows that the identification of all bee species inhabiting a study area is very difficult, time-consuming and uneconomical in practice. This seems to be the general pattern in entomological studies ( _ Zmihorski et al 2012; Novotny and ;Chao et al 2009). However, sampling at a frequency of nearly four times a month yielded 108 bee species, i.e.…”

Bees (Hymenoptera, Apoidea, Apiformes) in the Agricultural Landscape of Bulgaria: Species Diversity

“…As Gotelli and Colwell (2010) observed, lack of independence between samples can be neglected if rarefaction curves are functions of the number of samples. Comparison of species richness with unequal sampling effort, which incorporates sample-based rarefaction curves, is often used (Calvillo et al, 2010;Banaszak-Cibicka and Żmihorski, 2012;Żmihorski et al, 2013). To estimate the true species number, we applied 2 estimators: Chao2 (Chao, 1984) and Jackknife2 (Burnham and Overton, 1979).…”

Estimación de la riqueza de coleópteros epigeos de la Reserva Nacional Pingüino de Humboldt (Regiones de Atacama y Coquimbo, Chile)

“…Sin embargo, a la fecha siguen siendo métodos bastante utilizados y su uso se extiende en diversos grupos de artrópodos, tanto insectos como arácnidos (Fattorini et al 2013b;Zmihorski et al 2013;Jiménez-Valverde et al 2015;Wei et al 2016).…”