How Habitat Change and Rainfall Affect Dung Beetle Diversity in Caatinga, a Brazilian Semi-Arid Ecosystem

Abstract

The aim of the present study was to evaluate how dung beetle communities respond to both environment and rainfall in the Caatinga, a semi-arid ecosystem in northeastern Brazil. The communities were sampled monthly from May 2006 to April 2007 using pitfall traps baited with human feces in two environments denominated “land use area” and “undisturbed area.” Abundance and species richness were compared between the two environments and two seasons (dry and wet season) using a generalized linear model with a Poisson error distribution. Diversity was compared between the two environments (land use area and undisturbed area) and seasons (dry and wet) using the Two-Way ANOVA test. Non-metric multidimensional scaling was performed on the resemblance matrix of Bray-Curtis distances (with 1000 random restarts) to determine whether disturbance affected the abundance and species composition of the dung beetle communities. Spearman's correlation coefficient was used to determine whether rainfall was correlated with abundance and species richness. A total of 1097 specimens belonging to 13 species were collected. The most abundant and frequent species was Dichotomius geminatus Arrow (Coleoptera: Scarabaeidae). The environment exerted an influence over abundance. Abundance and diversity were affected by season, with an increase in abundance at the beginning of the wet season. The correlation coefficient values were high and significant for abundance and species richness, which were both correlated to rainfall. In conclusion, the restriction of species to some environments demonstrates the need to preserve these areas in order to avoid possible local extinction. Therefore, in extremely seasonable environments, such as the Caatinga, seasonal variation strongly affects dung beetle communities.

Dung beetles in a Caatinga Natural Reserve: a threatened Brazilian dry-forest with high biological value

“…Hence, such species typical of the Caatinga biome can be excluded locally due to an inadequate management of these zones. Deltochilum verruciferum Felsche, 1911 is common in dry environments and was also registered in studies carried out in the Caatinga areas (Lopes & Louzada, 2005;Hernández, 2007;Liberal et al, 2011;Vieira & Silva, 2012 Silva, 2012). Both species are indicators of management (D. calcaratum) and preservation (D. verruciferum) zones which mean that their presence should be considered.…”

Hexapod decomposers of Serra de Santa Catarina, Paraíba, Brazil: an area with high potential for conservation of Caatinga biodiversity

“…In addition to new records for science, the species richness of springtails (S=26), saprophagous flies (S=30) and termites (S=38) of SSC are among the highest recorded for an area of Caatinga in Northeast Brazil , Santos-Rocha et al 2011, Ferreira et al 2013, Alves et al 2014, Vasconcellos & Moura 2014, Vasconcelos & Salgado 2014. For the dung beetles, the total richness observed (S=20) was greater or close to that found in other areas of Caatinga in Northeast Brazil (S=4-23) and identical to two other areas of Caatinga in the state of Paraíba (Hernández 2005, Lopes et al 2006, Liberal et al 2011, Salomão 2012, Salomão & Iannuzzi 2017.…”

Changes in the dung beetle community in response to restinga forest degradation

“…Previous studies suggest the maintenance of abundance in degraded restinga areas, a finding that might be explained by the unchanged regular distribution of available resources and the maintenance of limiting conditions for the species (Louzada et al 1996;Vieira et al 2008). The same was reported for beetle and butterfly communities in areas with different levels of vegetation covers in other biomes (Harvey et al 2006;Gardner et al 2008;Liberal et al 2011). Since disturbed areas promote the formation of new niches for generalist species or species from similar ecosystems, Vieira et al (2008) suggested that total richness and abundance of dung beetles are insufficient indicators of habitat quality in restinga areas.…”