Can management practices in rice fields contribute to amphibian conservation in southern Brazilian wetlands?

Abstract

ABSTRACT1. Rice field expansion is one of the activities associated with the disappearance of 90% of the wetlands in southern Brazil. Worldwide, rice agriculture has been recognized as having considerable potential value for many aquatic species. Nevertheless, management practices in such systems must be ameliorated and better investigated.2. This study evaluated the potential role of rice fields as refugia for amphibians, and whether different hydrologic management practices after rice cultivation could contribute to wetland amphibian conservation in southern Brazil.3. Six collections were made in six rice fields with different management practices after cultivation (three dry and three flooded) and three natural wetlands. The amphibians were sampled through six random 15-min visual transects per collection in each rice field and the natural wetlands.4. In total, 2139 anuran individuals were observed in rice fields (798) and Reserva Lake (1341), comprising 12 anuran species distributed among five anuran families. Anuran richness and abundance varied over the rice cultivating cycle, and they were higher in the growing phases than in the fallow phases. The mean anuran richness and abundance was higher in Reserva Lake than in flooded and dry rice fields.5. The different management practices adopted after the harvesting period (presence or lack of surface water) did not influence the anuran richness and abundance. It did, however, influence species composition.6. The difference in species composition between the management practices adopted is an interesting result in terms of biodiversity conservation. Rice producers could maintain part of their agricultural land flooded during the fallow phase as a strategy to preserve a higher diversity of anurans. These results should be taken into consideration in wetland conservation plans in southern Brazil; however, the percentage of each agricultural land that should be kept flooded should be decided by Brazilian agricultural and conservation policies. Such a strategy would reconcile agricultural/economic needs with the conservation of biodiversity in southern Brazil, where more than 90% of wetland systems have already been lost.

Habitat heterogeneity and anuran community of an agroecosystem in the Pantanal of Brazil

“…Wetlands throughout the world, including the Pantanal, are diminishing owing to agriculture. Natural wetlands are being functionally replaced by irrigated fields, which harbor many aquatic species, including amphibians (Duré et al 2008, Machado and Maltchik 2010, Piatti et al 2010, Piatti and Souza 2011; however, drainage activities and land management of these aquatic systems are thought to be harmful to anurans (Colombo et al 2008). Thus, any information about the relationship between anuran populations and habitat complexity is strategically important to sound environmental management practice, especially in regions with high deforestation activities.…”

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

“…Os estudos envolvendo ecologia de comunidades de anuros existentes no Bioma Pampa, historicamente, estão concentrados na região da Planície Costeira (e.g., colomBo et al, 2008;maltcHik et al, 2008;moreira et al, 2008;macHado & maltcHik, 2009;macHado et al, 2012;oliveira et al, 2013), enquanto as fisionomias campestres interioranas permaneceram pouco exploradas exceto pelos estudos de santos et al (2008) na Depressão Central, BotH et al (2011) na Serra do Sudeste e di- Bernardo et al (2002) na região da Campanha. Apesar do crescente número de estudos, o conhecimento acerca dos padrões de composição, diversidade e distribuição espacial dos anuros desta região ainda são escassos.…”

Frogs as potential biological control agents in the rice fields of Chitwan, Nepal

“…Rice field agro-ecosystems are important in terms of biodiversity conservation and provide habitat for several species of plants and animals, such as mammals, fish, birds and amphibians (Bambaradeniya et al, 2004;Machado and Maltchik, 2010). Rice (Oryza sativa L.) is the most important staple cereal crop in Asian countries and approximately 163 million hectares of land are cultivated with rice globally.…”