Elmo B A Koch

The state of Pará in northern Brazil is located entirely within the Amazon Basin and harbors a great diversity of landscape and vegetation types that support high levels of biodiversity. Here, we provide a comprehensive inventory of ant species and their distribution in Pará. This regional list is based on an extensive review of species records from published and unpublished sources covering a period of 134 years (1886–2020) and includes the five most representative ant collections in Brazil. In total, we documented 12 subfamilies, 90 genera, and 753 ant species, including 97 species recorded for the first time in Pará and 12 species newly reported in Brazil. Sampling effort across the state is highly uneven, and most records may be associated with research areas near the state capital, mining areas, hydroelectric dams, and research field stations run by the state or universities. In addition, our results suggest a strong bias in ant collection in Pará in terms of proximity of sampled sites to access routes, such as roads and rivers. We also found that species records were highly unevenly distributed based on areas of endemism within the Amazon, vegetation type, and protected areas within the state. Ant surveys are still lacking from most protected areas of Pará, and further sampling is urgently needed in view of the current trend of expansion of major infrastructure projects and natural resource harvesting within protected areas of Pará. Our database represents an extremely valuable and rich source of information for further studies on ant biodiversity and conservation in the Amazon Basin.

tEcologists often seek sampling protocols that are both effective and relatively simple, i.e. those thatprovide a balance between the advantages obtained through sampling completeness and the costsinvolved in species sorting. Here we explored ways of simplifying a protocol devised for assessing geo-graphic patterns of ant species richness and composition in the savanna-dominated Cerrado landscapeof central Brazil. This protocol, which retrieved up to 88.5% of the expected number of species, wasemployed in five different sites located up to 1200 km apart from each other. In each site three transects(>1 km apart) were established, and within each transect 80 arboreal and 80 ground pitfall traps wereinstalled. We then evaluated the degree of congruence in species richness and composition between dataoriginated from the full data set and various subsets of the data, that either contained a reduced numberof samples (in different spatial configurations) or potential surrogates of the entire ant fauna. Our mainfindings show that by sorting specimens from just a subset of the ant genera we retrieved most of theinformation existing in the full data set, even though the amount of work involved in ant sorting wasreduced by about 50%. Reducing the number of samples taken in each site, as expected, also reducedthe amount of work involved in ant sorting. However, in most of our analyses the level of congruencewith the full data set was lower and/or became more erratic when sampling intensity was reduced toone-third or less of the original number of samples. More species were retrieved when samples werespread over multiple transects than when they were located in only one or two transects, indicating thateven at relatively small scales (a few kilometers) there is a turnover of ant species within the same typeof habitat. Based on these results we suggest that at least half of the samples from our original protocolare necessary to adequately describe large-scale patterns of ant species richness and beta diversity inNeotropical savannas. We also suggest that, whenever possible, sampling within a given site should bedone in multiple locations in order to maximize the number of species collected.