The role of spatial and temporal descriptors for neotropical tadpole communities in southern Brazil

Abstract

We evaluated tadpole communities of temporary and permanent ponds, in order to understand how community richness varies monthly in a subtropical humid climate, to interpret the community structure in relation to biotic and abiotic environmental variables related to the temporary and permanent ponds. The study site was the Pró-Mata Research and Nature Conservation Center, a private reserve in southern Brazil. The climate is classified as Temperate Superhumid, with no dry season. We sampled three temporary and three permanent ponds. We compared the richness of tadpole assemblages of permanent and temporary ponds through individual-based rarefaction curves, and tested for possible differences using a MANOVA test. Tadpole richness was related to temporal environmental descriptors through General Regression Model. Relationships between the tadpole assemblages and possible predictors of their spatial variation were measured using a partial Canonical Correspondence Analysis. Analysis of rarefaction curves indicated higher expected richness for the temporary ponds. The mean values of richness were significantly different between the two hydroperiods across all months. Monthly richness showed the same tendency of variation for both pond types. Only temperature was related to tadpole richness. The pCCA analysis was significant. The most important predictors on the first pCCA axis were vegetation cover, conductivity, depth, and predator diversity. In this study, vegetation cover, conductivity, predator diversity, and water depth explained the spatial variation of tadpoles between ponds, with tadpole richness and diversity being higher in temporary than in permanent ponds. Our results suggest that different spatial-seasonal patterns operating in temporary and permanent ponds are related to maintaining the species diversity of pond-breeding anurans.

Estrutura e organização espacial de duas comunidades de anuros do bioma Pampa

“…Foram registradas 24 espécies de anuros para as duas áreas estudadas, sendo um número esperado dado que outros estudos na região dos campos sulinos como santos et al (2008), BotH et al (2009BotH et al ( ), trindade et al (2010, registraram riqueza semelhante de espécies, aproximadamente 25% de riqueza conhecida para o estado do Rio Grande do Sul (Quintela et al, 2009;iop et al, 2011). No entanto, das 24 espécies registradas apenas duas são endêmicas do bioma Pampa (Phyllomedusa iheringii e Physalaemus gracilis) (kwet & di-Bernardo, 1998;maneyro & langone, 2001;santos et al, 2008;BotH et al, 2011;moreira & malticHik, 2012).…”

“…BotH et al, 2009;oda et al, 2009;iop et al, 2011;gamBale et al, 2014) e alguns descritores ambientais estudados (e.g. hidroperíodo, condutividade elétrica, pH, presença de predadores e cobertura vegetal) vem revelando um padrão recorrente de influência direta e/ou indireta na estrutura das comunidades (Bastazini et al, 2007;vasconcelos et al, 2010;Xavier & napoli, 2011;, logo, a diferença já reconhecida (geologia, uso da terra, altitude, clima, dentre outros) entre as duas regiões amostradas pode, de alguma forma refletir uma estrutura diferente de anurofauna em cada uma delas.…”

Climatic variables and altitude as predictors of anuran species richness and number of reproductive modes in Brazil

“…Significance of the first canonical axis was tested using 999 Monte Carlo permutations, which were constrained by the covariable matrix. We also performed a variation partitioning analysis (Borcard et al 1992, Both et al 2009) in order to verify (1) the contribution of environmental variables alone (without spatial effect, i.e. geographic position); (2) the contribution of geographic position alone; and (3) the contribution of spatially structured environmental variables (i.e.…”

“…The sum of all canonical eigenvalues represents the part of total inertia explained by RDA. To transform these measurements into percentages of the total variation of biotic data, one divides the sum of all the canonical eigenvalues by the total inertia (Borcard et al 1992, Both et al 2009). All permutation tests and pRDA were performed using CANOCO 4.5 for Windows software (ter Braak & Smilauer 2002).…”

Distribuição temporal e diversidade de modos reprodutivos de anfíbios anuros no Parque Nacional das Emas e entorno, Estado de Goiás, Brasil

“…Outros estudos realizados no Brasil também encontraram relação entre a riqueza de girinos com a temperatura da água e precipitação (e.g. VASCONCELOS & ROSSA-FERES, 2005;BOTH et al, 2008). A falta de relação com a abundância das espécies de girinos pode estar relacionada a fatores tais como a competição, a predação e a disponibilidade de alimentos.…”