Beta diversity can provide insights into the processes that regulate communities subjected to frequent disturbances, such as flood pulses, which control biodiversity in floodplains. However, little is known about which processes structure beta diversity of amphibians in floodplains. Here, we tested the influence of flood pulses on the richness, composition, and beta diversity of amphibians in Amazonian floodplain environments. We also evaluated indicator species for each environment. We established linear transects in three environments: low várzea, high várzea, and macrophyte rafts. Species richness decreased and beta diversity increased according to the susceptibility of habitats to flood pulses. Indicator species differed among environments according to forest succession promoted by the flood pulse. The decrease in species richness between high and low várzea is due to non‐random extinctions. The higher rates of species turnover between várzeas and macrophyte rafts are driven by the colonization of species adapted to open areas. Our results highlight that the maintenance of complex environments is needed to protect biodiversity in floodplains.

Despite the historical knowledge on amphibians of the Purus River basin, basic information on assemblages is fragmented, with gaps in knowledge existing at various scales, which limits conservation strategies. This study provides information on the composition, richness and abundance of the amphibian fauna in varzea environments and floating meadows of the oxbow lakes of the Middle Purus River between the Boca do Acre and Pauiní municipalities, Amazonas, Brazil. We sampled six oxbow lakes using forty-seven 200-meter transects, distributed among the ''floating meadows,'' ''high varzea'' and ''low varzea,'' from April to January 2014. We recorded 59 species, with the family Hylidae being predominant. This amphibian fauna represents approximately 19% of the species known for the Amazon, 28% for Amazonas State and 45% of the species recorded so far in the Purus River, increasing the richness of the basin to 132 species. Eight species were considered rare, and 29 are endemic to the Amazon. This study adds to the knowledge on the amphibian species of the Amazonian lowlands, including the expansion of known distributions, as well as increases the knowledge of several species that are locally rare, endemic and/or that are data deficient regarding distribution and ecology. Keywords: Amazon, floodplain, flood pulse, diversity, conservation. Resumo: Apesar do histó rico conhecimento sobre anfíbios ao longo da bacia do rio Purus, informac¸õ es bá sicas sobre as taxocenoses encontram-se fragmentadas, formando lacunas no conhecimento do grupo em diversas escalas e restringindo estratégias de conservac¸ã o. Este estudo apresenta a composic¸ão, a riqueza e a abundâ ncia da fauna de anfíbios em ambientes de vá rzea e bancos de macró fitas de lagos de meandro do médio Rio Purus, entre os municípios de Boca do Acre e Pauiní, Amazonas, Brasil. Conduzimos amostragens em seis lagos de meandro, através de 47 transectos de 200 metros, distribuídos entre os ambientes ''banco de macró fitas'', ''vá rzea alta'' e ''vá rzea baixa'', entre abril de 2013 e janeiro de 2014. Registramos 59 espécies, com predomínio de espécies da família Hylidae. Essa fauna de anfíbios representa aproximadamente 19% das espécies conhecidas para a Amazô nia, 28% para o estado do Amazonas e 45% do registrado até o momento para o rio Purus, elevando a riqueza da bacia para 132 espécies. Oito espécies foram consideradas raras e 29 sã o endêmicas da Amazô nia. Este estudo contribui para o conhecimento das espécies de anfíbios das terras baixas na Amazô nia, incluindo a ampliac¸ão da distribuic¸ã o e aumento do conhecimento sobre diversas espécies localmente raras, endêmicas e/ou com deficiência de dados sobre distribuic¸ã o e ecologia. Palavras-chave: Amazônia, planície de inundac¸ão, pulso de inundac¸ão, diversidade, conservac¸ão.

ABSTRACT. Local diversity and infl uence of seasonality on amphibians and reptiles assemblages in the Reserva Extrativista Chico Mendes, Acre, Brazil. Despite the high richness of amphibians and reptiles known for the southwestern portion of the Brazilian Amazon, the knowledge of these is punctual and few studies have evaluated the temporal variations in the occurrence and abundance of species. The goals of this study were to present the amphibians and reptiles assemblages in a locality of the Chico Mendes Extractive Reserve, verify which climate variables infl uence the temporal fl uctuations in richness and abundance, and identify the main species of the amphibians and reptiles infl uenced by them. The study area is located in the Seringal Etelvi region, southwestern portion of the Reserve, municipality of Brasiléia, state of Acre. Data collection took place between October 2011 and September 2012, for 48 sampling days, using the methods of searches limited by time and pitfall traps. There were recorded 978 specimens of 31 amphibians and 54 reptiles. Higher richness and abundance of amphibians occurred during the rainy season, with the monthly abundance positively associated with the mean temperature. Only the abundance of reptiles was higher during the rainy period. However, both richness and abundance were positively associated with mean temperature. Four amphibians, Allobates gr. marchesianus, Hamptophryne boliviana (Parker, 1927), Boana geographica (Spix, 1824) and Rhinella marina (Linnaeus, 1758), and two reptiles, Kentropyx pelviceps Cope, 1868 and Norops fuscoauratus (D'Orbigny, 1837), had their monthly abundances positively associated with the mean temperature. The lizard Dactyloa punctata (Daudin, 1802) had the monthly abundance associated with precipitation. It was possible to verify the increase of richness and abundance of amphibians and reptiles during periods when the availability of resources is favorable for many species. Species can react diff erently to climatic variations, whereas others are sensitive to fl uctuations, others seem answer easily or not reduce their abundances in periods theoretically unfavorable.KEYWORDS. Richness, abundance, Southwestern Amazonia, seasonality, temporal variation.RESUMO. Apesar da elevada riqueza de anfíbios e répteis conhecida para a porção Sul-Ocidental da Amazônia brasileira, o conhecimento sobre estes é pontual e poucos estudos avaliaram as variações temporais na ocorrência e abundância das espécies. Os objetivos deste estudo foram descrever as taxocenoses de anfíbios e répteis em uma localidade da Reserva Extrativista Chico Mendes, verifi car quais variáveis climáticas infl uenciam as fl utuações temporais na riqueza e abundância e identifi car as principais espécies de anfíbios e répteis infl uenciadas por elas. A área de estudo está localizada na região do Seringal Etelvi, porção sudoeste da Reserva, município de Brasiléia, estado do Acre. A coleta de dados ocorreu entre outubro de 2011 e setembro de 2012, num total de 48 dias de amostragem, com os mét...

In this paper we discuss the impact on conversion degraded pasture areas into an integrated crop, livestock and forest system (ICLFS). We collected 30 soil samples at 0-0.1 m depth in five agroforestry systems, degraded pasture and native areas along Brazilian Cerrado biome. We analyzed the influence of chemical variables on microbial biomass carbon and enzyme activity using multivariate statistic analysis. The land use explained only the variation of microbial biomass carbon and seasonality explained the variation in glycine aminopeptidase activity. The sample controls differ from the other soil areas due to their greater biological activity (MBC). The enzymatic indicators showed that the biological activity is lower in degraded pasture. It was observed that the ICLFS system had a positive effect on the microbial activity (MBC and soil enzyme) when compared to pasture. This reinforces the importance of adopting more sustainable practices to improve soil quality.

The production of forest species that present seedlings with exogenous dormancy is limited by low germination rates, which can be overcome by rupturing or weakening the tegument. This study aimed to evaluate the efficiency of low-cost methods of overcoming dormancy and determine the effect of storage on the seeds of Enterolobium contortisiliquum. Four storage periods were used, freshly collected seeds (0), stored for 6, 12 and 18 months, and four methods were applied, mechanical scarification and immersion in water (EI), mechanical scarification (ES), immersion in water (IM) and control (TE). We obtained the percentage values of seedling emergence (EP) and the mean emergence time (TME). Conductivity and moisture were obtained as indicators of the physical and physiological quality of seeds, respectively. Variations in moisture content and electrical conductivity during storage did not have effect on the percentage of germination. EI treatment was more efficient for overcoming dormancy than the ES was, regardless of storage time. IM and TE treatments did not lead to germination. EI was the most efficient treatment for decreasing the TME. The results indicate that alternative and low-cost methods are efficient at overcoming exogenous dormancy and thus can be used to optimize the process of seedling production.

ResumoGrande parte da biodiversidade de anfíbios e répteis conhecida para o Brasil está representada nas regiões sob domínio do Cerrado, que tem sofrido intensa ação antrópica, causando elevada perda de espécies. Estratégias para conservar a diversidade biológica necessitam de estudos com ênfase em sua quantificação e distribuição em pequena e larga escala. Neste trabalho, caracteriza-se a herpetofauna da porção média do rio Aporé, localizada nos Estados de Goiás e Mato Grosso do Sul, Brasil, através de um inventário realizado entre outubro de 2009 e julho de 2011. Registramos 28 espécies de anfíbios, distribuídas em seis famílias, e 33 espécies de répteis, distribuídas em 14 famílias. A herpetofauna na região do médio rio Aporé apresentou riqueza correspondente a 13,4% das espécies de anfíbios e 14% das espécies de répteis conhecidas para o Cerrado, sendo endêmicas duas espécies de anfíbios e cinco espécies de répteis. A distribuição da riqueza e abundância de anfíbios e répteis não foi homogênea entre os ambientes amostrados e o elevado grau de heterogeneidade espacial provavelmente influenciou as diferenças de diversidade entre os ambientes. Similarmente a outras áreas de Cerrado, a herpetofauna do médio rio Aporé possui diversas espécies endêmicas, especialistas de hábitat e com poucos registros em outros biomas.Palavras-chave: Cerrado, hotspot, inventário, herpetofauna, diversidade. AbstractMuch of the biodiversity of amphibians and reptiles known to Brazil is represented in the regions under the domain of the Cerrado, which has suffered intense anthropogenic activities and, thus, threatened by loss of species. Strategies for conserving biological diversity require studies with emphasis on its quantification and distribution both in small and in large scale. In this paper, we characterize the herpetofauna along the middle portion of the Aporé river, localized in the States of Goiás and Mato Grosso do Sul, Brazil, through an inventory carried out between October 2008 and July 2011. We recorded 28 species of amphibians, represented by six families and 33 species of reptiles, distributed in 14 families. The herpetofauna sampled in the mid river Aporé has a richness corresponding to 13.4% of amphibians and 14% of reptile species known to biome, being endemics two species of amphibians and five reptiles. The distribution of richness and abundance of amphibians and reptiles was not homogenous among the sampled sites and the high degree of spatial heterogeneity probably influenced the difference in diversity between environments. Similarly to other areas in Cerrado, the herpetofauna along the mid river Aporé has many endemic species, habitat specialists and with few records in other biomes.

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The degradation of riparian vegetation in low-order streams can cause irreversible environmental damage, biodiversity loss and alter the structure of communities. In this context, the present study evaluated how the level of degradation of riparian vegetation influences the fish assemblage in three low-order streams in the Brazilian Amazon. In each stream, three different stretches were delimited, distributed in the environments of forest, edge and pasture, and the samplings were conducted in three hydrological regimes using dip nets. Influences of the stretches and streams on richness and abundance were tested with GLMM, on the composition with PERMANOVA and on indicator species with IndVal. Species richness was higher in forest environments and lower in pasture; while abundance was higher in pasture and lower in forest. Species composition differed between stretches, streams and in the interaction between stretches and streams, with a strong difference between stretches of forest and pasture environments. Six species dependent of the riparian vegetation were classified as indicators of forest environments; while a generalist species was indicator of pasture. These results reinforce the negative influence of riparian vegetation removal on biological communities and provide subsidies that can help in the conservation and management of these systems.