Natureza & Conservacao最新文献

The unrestrained ongoing construction of dams in rivers of high-priority for conservation represents a common threat to environment and surrounding societies. In Brazil, despite several known negative impacts assigned to poorly planned construction of dams, Federal and State Governments maintain the policy of expansion of the hydroelectric matrix. The outcome includes impoundments of remaining rivers that are extremely important for biodiversity conservation. Here, we suggest strategies to prevent dams in remaining rivers proven to be of high priority for conservation or with potential to social disruption. Besides, we report a successful case study in areas of two important remaining tributaries of the Paraná River (the most dammed river in the Neotropics), Brazil, where the enactment of municipal laws protecting areas of the basins, initiatives to indicate features of the rivers as heritages and the creation of protected areas are among the effective measures to prevent new dams. Distinctive features in this effort have been the exchange of information among different stakeholders and the consequent empowerment of local actors. The strategies presented here are indicated to halt projects of new dams and are applicable and encouraged to be adopted throughout Brazil, provided that some features found in Paraná State may occur elsewhere.

The relevant scales over which specific communities vary must be identified to address fundamental ecological questions and to advance the conservation of biological diversity. In this study, the variation among drosophilid assemblages associated with forests was quantified at a large temporal–spatial scale. Our results are based on data collected in four conservation units (CUs) in the Brazilian savanna across four seasons and two years. The primary component of variation occurred at the temporal scale: it was three times greater than that of the spatial scale. Significant variability was also found in the interaction between seasons and CUs. Measuring the temporal and spatial variability of drosophilid diversity in forests contributed to the improvement of the methodological framework supporting such assemblages as bioindicators and provided important insights into the mechanisms behind the dynamic patterns in time and space that ultimately can improve our understanding of Cerrado biodiversity.

Species response to land-use changes are usually assessed by investigating factors affecting distribution, with a single snapshot in time. However, several processes can lead to a same pattern. Focusing on observed, short-term patterns limits our ability to make inferences about ecological processes and responses to environmental change over time. In this study, we assessed changes in occupancy of two primate species in southeastern Brazil, following a major habitat loss due to implementation of a hydroelectric dam. Occupancy was assessed before dam construction and 11 years after, while explicitly accounting for imperfect detection. We assessed the effect of forest patch size and isolation on occupancy and rates of extinction and colonization, driven by landscape modification. Then we calculated occupancy under metapopulation equilibrium and expected time-lags resulting from non-equilibrium. We compared two primate species inhabiting forest patches, the black penciled marmoset Callithrix penicilatta and the black-fronted titi monkey Callicebus nigrifrons, with markedly different ecological characteristics. Those differences may explain why occupancy dynamics were driven by distinct elements. A fast response to habitat changes was observed only for marmoset, an opportunistic species. However, non-equilibrium states and the possibility of time-lag effects were observed for titi monkey, a species dependent on forest habitat. Our analyses support the need to establish long term monitoring and assess system vital rates over time. A single snapshot in time may lead to erroneous interpretations of a species response to habitat alteration.

The protected areas are essential for the conservation of native biota. However, only the protected area establishment does not guarantee the persistence of threatened species. Here, we assessed the efficiency of the Cerrado protected areas in maintaining viable populations of giant anteater and analyzed the impact of roadkills. We used the software VORTEX to model the viability of giant anteater populations in 18 Cerrado protected areas. We evaluated the impact of roadkills through three mortality scenarios (2.5%, 5% and 10% of the initial population). Our results show that in the pessimistic scenario, only three protected areas are able to maintain viable populations of the giant anteater. In the optimistic scenario, 11 protected areas out of the 18 protected areas are capable of maintaining viable giant anteater populations in the next 100 years. Three protected areas are not able to maintain viable populations in any scenario. The roadkills have had a major negative impact on the long-term persistence of giant anteater populations. We suggest that management actions to counteract the negative effects of roadkills are necessary to maintain populations of giant anteater in protected areas affected by this threat.

Miscanthus sinensis-dominated semi-natural grassland is one component of a typical Satoyama landscape. M. sinensis most notably forms ring patches as a result of human management, which includes the removal of aboveground stems by burning. In this study, I hypothesized that M. sinensis aids the coexistence of several plant species under managed conditions because of its notable ring patches. To test this hypothesis I monitored the richness of plant species inside and outside M. sinensis ring patches for 5 years, which included one non-managed year, and compared richness between managed and non-managed years. Results showed that species richness was higher inside than outside patches in all cases, but that this effect was more prominent in managed years than in the non-managed year. Consequently, human management is promoting the coexistence of plant species in M. sinensis-dominated semi-natural grassland. Human management will likely play an important role in conserving plant species diversity in semi-natural grasslands by changing relationships among plants.

Brazil is the third largest market for new investments in wind power in the world and thousands of turbines will become operational in the coming years. Wind power is necessary but, as any other source of energy, it has environmental impacts, especially on bats. Due to such rapid expansion and the volume of investiments on course, an analysis of the current environmental licensing of wind farms in Brazil is necessary. Here we compared normatives from Brazil with similar ones from Portugal, the United States and Canada. By using 21 driving questions, we detected that there is no an international standard in the licensing of wind farms, ranging from simplified to rigorous approaches, from mandatory to voluntary normatives. Despite having specific and mandatory legislation dated from 2014, Brazil's federal and state normatives have a vague and relaxed approach regarding the possible impacts of wind farms on bats. Larger wind parks can be fractioned in smaller units, licensed based on simplified and less rigorous studies, but with no explanation on how or when such fractionating may occur, neither details on when adopt it. Only Brazilian legislations do not clearly specify the procedures and the minimum necessary effort for pre and post-installation, and which should be the mitigation measures adopted for the impacts of wind farms. The Brazilian federal and state normatives must be revised and until that, the current EIA procedures should be seen as insufficient to accurately determine the real impact of wind farms on the Brazilian bat fauna.