How habitat change and rainfall affect dung beetle diversity in Caatinga, a Brazilian semi-arid ecosystem

Carolina Nunes Liberal1a*, Ângela Maria Isidro de Farias2b, Marcos Vinicius Meiado3c, Bruno K. C. Filgueiras1, Luciana Iannuzzi2d

1Programa de Pós-Graduação em Biologia Animal, Universidade Federal de Pernambuco, Av. Professor Moraes Rego s/n, Cidade Universitária, 50670-901, Recife, Pernambuco, Brazil
2Departamento de Zoologia, Universidade Federal de Pernambuco, Av. Professor Moraes Rego s/n, Cidade Universitária, 50670-901, Recife, Pernambuco, Brasil
3Programa de Pós-Graduação em Biologia Vegetal, Universidade Federal de Pernambuco, Av. Professor Moraes Rego s/n, Cidade Universitária, 50670-901, Recife, Pernambuco, Brazil

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.

Keywords: dry season, human impact, Scarabaeinae

Correspondence: a carolinaliberal@gmail.com, b amif33@hotmail.com, c marcos_meiado@yahoo.com.br, d lucianaiannuzzi@gmail.com, *Corresponding author

Received: 3 July 2010 | Accepted: 26 July 2011 | Published: 6 September 2011

ISSN: 1536-2442 | Volume 11, Number 114

Liberal CN, Isidro de Farias ÂM, Meiado MV, Filgueiras BKC, Iannuzzi L. 2011. How habitat change and rainfall affect dung beetle diversity in Caatinga, a Brazilian semi-arid ecosystem. Journal of Insect Science 11:114 available online: insectscience.org/11.114


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