Drosophilid assemblages as a bioindicator system of human disturbance in the Brazilian Savanna

Abstract

According to the Convention on Biological Diversity (CBD) the development of bioindicators is extremely necessary to achieve the conservation targets by 2010, and insects are considered an effective group for this goal. Drosophilids are regarded as potential indicators, although this idea remains untested. Therefore, we followed up a protocol to test the drosophilid potential indicator for human disturbance in the Brazilian Savanna, one of the richest and most threatened tropical biomes in the world. Sampling was undertaken in one urban environment and two biological reserves, representing four habitat types (undisturbed gallery forest, disturbed gallery forest, undisturbed savanna, and urban environment). We examined differences in the drosophilid assemblages among habitat types and used the Indicator Value (IndVal) method to point out the indicator species. We also tested the two-stage indicator validation, a protocol recently proposed in the literature, to validate the indicator species for undisturbed gallery forest and savannas, in independent samples. The assemblage variables varied mainly in undisturbed gallery forests, and reflected changes from an undisturbed to a disturbed stage. The IndVal associated with the two-stage protocol showed reliable characteristic species, which are very helpful for diagnostic surveys. Likewise, species that can detect changes in the habitats were also found. We found a set of indicators, which together may be very efficient for both assessing and reflecting a variety of conditions, improving the confidence of the bioindication system, expanding the taxonomic options for bioindicators, and therefore, contributing to the conservation of this region.

Drosophilids (Insecta, Diptera) as Tools for Conservation Biology

“…More recently, they have been used as models in studies on bioindication (Parsons 1991(Parsons ,1995Mata et al 2008b) and also biological invasions (Tidon et al 2003;Mata et al 2010). Here, we suggest that drosophilids are great tools for conservation biology.…”

“…The use of drosophilids as biological models in biodiversity conservation has been suggested since the 1990 decade (Parsons 1991;Tidon et al 2003;Ferreira & Tidon 2005;Mata et al 2008b;Mata et al 2010). Here, we get this proposal across by presenting a case study in the Paranã Valley, which was part of a broader inventory project supported by the Brazilian government (MMA/PROBIO).…”

Seasonal dynamics of a drosophilid (Diptera) assemblage and its potencial as bioindicator in open environments

“…Collections were performed at many ecosystems, like the Atlantic Rain Forest (MATEUS et al, 2006;TORRES & MADI-RAVAZZI, 2006;DE TONI et al, 2007), mangroves , cerrado lato sensu (the Brazilian savanna) (TIDON et al, 2003;TIDON, 2006;MATA et al, 2008b), and even urban environments (GOÑI et al, 1997;FERREIRA & TIDON, 2005;SILVA et al, 2005b;GOTTSCHALK et al, 2007). These and other studies also demonstrated the possible use of drosophilids as bioindicators of forest degradation (PARSONS, 1991;MARTINS, 2001;AVONDET et al, 2003;FERREIRA & TIDON, 2005;SILVA et al, 2005b).…”

Bioindicadores ambientais: insetos como um instrumento desta avaliação

“…Gadelha et al (2009) corroboram esse fato e sugerem que as espécies desse gênero podem auxiliar na averiguação de prováveis impactos ambientais. Assembleias de drosofilídeos também têm sido usadas para avaliar os distúrbios humanos na região do cerrado brasileiro (Mata et al, 2008). Outro exemplo são as famílias de dípteros importantes no processo de decomposição da matéria orgânica do solo (Frouz, 1999), destacando-se Chironomidae, Syrphidade, Cecidomyiidae e Sciaridae.…”