Robustness of relative diversity metrics to inventory incompleteness: Could we estimate the near-imponderable?статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 30 августа 2018 г.
Аннотация:ABSTRACT
Aim: Relative diversity metrics (RDMs), such as local:global or regional:global diversity ratios and percentage of endemics, are widely applied in biodiversity studies. This approach, however, is flawed because the actual global diversity of many taxa is still largely unknown, especially for rare species. This potential inconsistency of RDMs has not been proven (or disproved) thus far. Here, I use simulation models to explore the efficiency of RDM estimations from incomplete inventories.
Location: world-wide.
Methods: three simple models of species distribution have been used:
- The “everything is everywhere” model (unlimited dispersal, i.e., equal probability for a species to occur at every point),
- The “environmental selection” model (each species can occupy only a portion of randomly distributed “suitable localities” according to its ecological preferences), and
- The “endemicity” model (most species are restricted to a few regions each).
To parameterize these models, the worldwide datasets on ciliates, flagellates and harpacticoid copepods were used. The RDMs were estimated by simulating equal-effort sampling and by varying the full number of species and number of sampled individuals per cell.
Results: Estimated species richness at any scale was heavily influenced by the sampling effort and was greatly underestimated with small sample sizes. The estimated RDM values also depended on the sampling effort (being either upward- or downward-biased) but were only slightly influenced by the unrecorded part of actual global diversity (ignorance). The predictions of the first two models were generally close to each other but differed noticeably from those of the third model.
Main conclusions: The relative metrics, though influenced by undersampling, are nevertheless more robust to inventory incompleteness than absolute measures and therefore can be a reliable tool in comparative biodiversity studies, even if the true number of species cannot be estimated overall. Their estimated values, however, must be interpreted with caution.