Influence of the environmental heterogeneity of breeding ponds on anuran assemblages from southeastern Brazil T.S. Vasconcelos, T.G. Santos, D.C. Rossa-Feres, and C.F.B Haddad Abstract: We hypothesized that the environmental heterogeneity of breeding ponds influences the species composition and species richness of anuran assemblages from southeastern Brazil, because it provides humidity, shelter, and breeding microhabitats for anuran species, which can result in an increasing number of species in a given habitat. To begin, we tested whether the occurrence of anuran species in each breeding pond is different from a null model of random placement of species in those ponds. We then performed two tests to evaluate which of the five environmental descriptors of breeding ponds influence (1) the species composition and (2) species richness. Species composition of the 38 breeding ponds was correlated with number of edge types, number of plant types along the edges of the breeding ponds, and the hydroperiod. Neither the percentage of vegetation cover on the water’s surface nor the size of the breeding ponds were correlated with species composition. Only the number of edge types was correlated with species richness of breeding ponds. The correla- tion of three environmental descriptors with species composition and one environmental descriptor with species richness, as well as the high beta diversity among breeding ponds, suggest that the analyses of environmental heterogeneity on spe- cies composition was more informative than was the analysis for species richness, because breeding ponds with similar species richness can have distinct species composition among them (high beta diversity). Re ´sume ´: Nous e ´mettons l’hypothe `se selon laquelle l’he ´te ´roge ´ne ´ite ´ du milieu dans les e ´tangs de reproduction influence la composition en espe `ces et la richesse spe ´cifique de peuplements d’anoures dans le sud-est du Bre ´sil; celle-ci fournit, en ef- fet, l’humidite ´, le couvert et les habitats de reproduction pour les espe `ces d’anoures, ce qui peut re ´sulter en un nombre plus e ´leve ´ d’espe `ces dans des habitats donne ´s. Au de ´part, nous avons ve ´rifie ´ si la pre ´sence des espe `ces d’anoures dans chacun des e ´tangs de reproduction diffe `re d’un mode `le nul de re ´partition ale ´atoire des espe `ces dans ces e ´tangs. Nous avons ensuite fait deux tests pour e ´valuer lesquels de cinq descripteurs du milieu des e ´tangs de reproduction influencent (1) la composi- tion spe ´cifique et (2) la richesse spe ´cifique. Il existe une corre ´lation entre la composition spe ´cifique dans les 38 e ´tangs de reproduction et le nombre de types de rivages, le nombre de types de plantes le long de la rive des e ´tangs de reproduction et l’hydrope ´riode. Il n’y a de corre ´lation entre la composition spe ´cifique ni avec le pourcentage de couverture ve ´ge ´tale a ` la surface de l’eau, ni avec la taille des e ´tangs de reproduction. Seul le nombre de types de rivages est en corre ´lation avec la richesse spe ´cifique dans les e ´tangs de reproduction. La corre ´lation entre trois descripteurs du milieu et la composition spe ´c- ifique et entre un descripteur du milieu et la richesse spe ´cifique, ainsi que la forte diversite ´ be ˆta entre les e ´tangs de repro- duction laissent croire que les analyses de l’influence de l’he ´te ´roge ´ne ´ite ´ du milieu sur la composition spe ´cifique sont plus riches en information que les analyses concernant la richesse spe ´cifique; en effet, des e ´tangs de reproduction de richesses spe ´cifiques semblables peuvent posse ´der entre eux des compositions spe ´cifiques distinctes (forte diversite ´ be ˆta). [Traduit par la Re ´daction] Introduction Anuran amphibians exhibit a wide variety of morphologi- cal structures, physiological mechanisms, and behavioral re- sponses that enable them to occupy nearly all terrestrial habitats. However, most species inhabit regions that have high moisture levels and moderate to warm temperatures owing to their skin permeability and dependence on aquatic and terrestrial habitats during their life cycles (Duellman and Trueb 1994; Wells 2007). Thus, human impact on the envi- ronment makes amphibians one of the most vulnerable ani- mal groups. Destruction of their habitats is documented as the main threat to this animal group in Brazil (Silvano and Segalla 2005). In forested areas, deforestation makes the en- Received 28 November 2008. Accepted 21 May 2009. Published on the NRC Research Press Web site at cjz.nrc.ca on 22 July 2009. Reposted on the Web site with correction on 30 July 2009. T.S. Vasconcelos 1 and T.G. Santos. Programa de Po ´s Graduac ¸a ˜o em Zoologia, Departamento de Zoologia, Instituto de Biocie ˆncias, Universidade Estadual Paulista (UNESP), Caixa Postal 199, 13506-900 Rio Claro, SP, Brazil. D.C. Rossa-Feres. Departamento de Zoologia e Bota ˆnica, Universidade Estadual Paulista (UNESP), 15054-000 Sa ˜o Jose ´ do Rio Preto, Sa ˜o Paulo, Brazil. C.F.B. Haddad. Departamento de Zoologia, Instituto de Biocie ˆncias, Universidade Estadual Paulista (UNESP), Caixa Postal 199, 13506- 900 Rio Claro, SP, Brazil. 1 Corresponding author (e-mail: zoologia@ig.com.br). 699 Can. J. Zool. 87: 699–707 (2009) doi:10.1139/Z09-058 Published by NRC Research Press