An update on the knowledge of aquatic macrophytes in Northeast Brazil

We updated the first checklist of aquatic macrophytes from Northeast Brazil (First Flora), which included data collected up to 2010, with a new checklist based on data from works published between 2011 and 2017 (New Flora). Together, these checklists record 637 species of 89 families, with an emphasis on strictly amphibious or emergent species, with 392 and 115 species, respectively. We found differences in observed richness between New Flora and First Flora, with an increase of 106 species in the New Flora. The rarefaction curve shows that a considerable increase in collection effort is necessary to determine the aquatic flora of the studied region. From the compiled data, we suggest new perspectives for floristic inventories of aquatic macrophytes, highlighting the prioritization of poorly studied areas; the exploration of ecological information of the species (e.g., endemism, rarity, threat of extinction or invasive potential); and the promotion of projects on a regional scale.

Herpetofauna of protected areas in the Caatinga V: Seridó Ecological Station (Rio Grande do Norte, Brazil)

We provide a list of lizards, snakes, chelonians, and amphibians collected during a 30-day expedition to the Seridó Ecological Station (ESEC Seridó), Rio Grande do Norte state, Brazil. We sampled species using thirty-seven pitfall trap stations composed of four buckets each, along with glue traps and active searches. We recorded 13 species of lizards, eight snakes, 19 amphibians, and one chelonian. Rarefaction curves suggest local biodiversity is still underestimated. Sampling during rainy season was crucial to stabilize rarefaction curve for amphibians. Comparisons of our results with data from literature show we did not capture some arboreal and semifossorial lizards known for the area. Seridó Ecological Station fauna is characterized mainly by generalist species common to lowland Caatinga sites. Still, several Caatinga endemics species are found, which underscore the importance of this small but representative protected area.

The Arctiini (Lepidoptera, Erebidae, Arctiinae) fauna of the Serra do Pardo National Park, Pará, Brazil

This study evaluated the Arctiini fauna of the Serra do Pardo National Park (Pará, Brazil) between 22 September and 3 October 2011. Light traps were left one night in each sampling site (SS) from 18:00 h to 6:00 h of the next day. The following parameters were evaluated: richness (S), abundance (N), diversity index (H’), Shannon uniformity (U) index, and Berger-Parker dominance (BP). Richness was estimated using the non-parametric methods Chao1, Chao2, ACE, ICE, Jackknife1, Jackknife2 and Bootstrap. A total of 3,247 specimens were captured, belonging to 221 Arctiini taxa; 32 of these are new records for the state of Pará and, of these, six are new records for the Brazilian Amazon. The Arctiini fauna is very rich and uniform. The richness estimator and rarefaction curve indicated the need for increased sampling efforts in the area.

Rarefaction and rarefiction—the use and abuse of a method in paleoecology

Rarefaction is a method for comparing community diversities that has consistently been abused by paleoecologists: here its assumptions are clarified and advice given on its application. Rarefaction should be restricted to comparison of collections from communities that are taxonomically similar and from similar habitats: the collections should have been obtained by using standardised procedures. The rarefaction curve is a graph of the estimated species richness of sub-samples drawn from a collection, plotted against the size of sub-sample: it is a deterministic transform of the collection's species-abundance distribution. Although rarefaction curves can be compared statistically, it may be more efficient to compare the species-abundance distributions directly. Both types of comparison are discussed in detail.