Publicações

Environmental disturbances affect ecosystem functioning through changes in organisms’ metabolism (direct effect) and biodiversity loss (indirect or biodiversity-mediated effect). It is still a challenge to separate direct and biodiversity-mediated effects of environmental changes on ecosystem functioning due to the difficulties in isolating ‘true’ biodiversity loss effects. Furthermore, it is still unclear whether biodiversity-mediated effects are as important as direct effects. In this study, we performed an experiment in artificial microcosms to disentangle biodiversity-mediated and direct effects of two major environmental disturbances on the functioning of aquatic ecosystems: increases in temperature and salinity. The ecosystem function analyzed was the microalgae predation by the zooplankton community (zooplankton grazing rates). Temperature and salinity increases affected the zooplankton grazing rates due to changes in community composition and abundance, as well as organism performance. The impact of salinity changes on community structure was higher than that of temperature; however, the importance of biodiversity-mediated and direct effects was similar to regulating the ecosystem functioning, albeit they have presented different directions and magnitude across the treatments. At a moderate level of temperature increase, we observed that the biodiversity-mediated effect was more relevant than the direct effect, with negative effects on the overall grazing rates. Our results suggest that disturbances can affect the functioning of aquatic environments through a set of complex biological mechanisms that balance direct and biodiversity-mediated effects. We concluded that the relative importance of biodiversity-mediated effects depends on the type and intensity of the disturbance.

Concerns regarding water scarcity, food security, and land/soil degradation are increasing, and these issues are far from being independent of bioenergy production. The competing need for land and water resources in food and bioenergy production have been at the forefront of policy debates. In this study, we examined policy debates related to land, food and water use in sugarcane ethanol production, and the challenges to integrated landwaterenergy-food policies. We analyzed large amounts of data obtained from governmental and business documents, Brazilian newspapers, and the bulletins of non-governmental organizations over the last ten years by combining an unsupervised probabilistic latent Dirichlet allocation (LDA) model with sentiment analysis. The results show that land, energy and water are managed in isolation by separate and disconnected institutional entities. Although the discourses of actors have evolved over time in response to certain events (e.g., expansion of sugarcane and water scarcity), the discussions and resultant public policies have failed to consider the interdependence among various sectors. To achieve sustainable resource use, sugarcane ethanol expansion should be considered by decision-makers and companies within a wider governance framework based on nexus dynamics; specifically, trade-offs in land and water use with sectors beyond bioenergy must be acknowledged.

Roughly 60% of all deforested lands in the Brazilian Amazon are covered with pastures, putting cattle raising in evidence as a major driver of deforestation and also of forests’ regrowth. Still, the role of cattle raising diversity in the landscape dynamics of this region remains poorly understood. To contribute to this discussion, we combined data from semi-structured interviews and quantitative spatially explicit methods to characterize and spatialize cattle raising systems and explore the effects of this diversity over secondary vegetation between 2004 and 2014 in Para, a hotspot of deforestation and core region of cattle production. We quantified the use of different pasture management strategies to classify small- and large-scale operations into systems with high or low impact against pastures’ degradation. High-impact systems were mapped in regions with consolidated infrastructure and high accumulated deforestation, where they expanded. On the contrary, low-impact systems were more widespread and found near forest frontiers, shrinking over time. High-impact systems had less secondary vegetation, while under low-impact systems, as a result of strategies with little or no effect against degradation, the historical pattern of concentration of this cover prevailed. Better infrastructure and access to markets as well as higher accumulated deforestation are underlying conditions related to the emergence of intensification and, as it is still unclear whether intensification is indeed capable of sparing land, the expansion of intensive cattle raising systems has the potential to configure landscapes with reduced forested areas, either primary or secondary.

In this study, the erosion of the nocturnal boundary layer (NBL) was analyzed in the central Amazon during the dry season of 2014, using data from the GoAmazon 2014/5 Project and high-resolution model outputs (PArallelized Les Model PALM). The dataset consisted of in situ (radiosonde) and remote sensing instruments measurements (Ceilometer, Lidar, Wind Profiler, microwave radiometer, and SODAR). The results showed that the NBL erosion occurred, on average, two hours after sunrise (06:00 local time), and the sensible heat flux provided more than 50% of the sensible heating necessary for the erosion process to occur. After the erosion, the convective phase developed quickly (175.2 m h-1). The measurements of the remote sensors showed that the Ceilometer, in general, presented satisfactory results in relation to the radiosondes for measuring the height of the planetary boundary layer. The PALM simulations represented well the NBL erosion, with a small underestimation (≈ 20 m) at the beginning of this phase. In the final phase of NBL erosion and in the initial stage of the development of the convective boundary layer (CBL), the model presented satisfactory results, with heights of CBL ranging from 800 m to 1,650 m, respectively.

Roughly 60% of all deforested lands in the Brazilian Amazon are covered with pastures, putting cattle raising in evidence as a major driver of deforestation and also of forests’ regrowth. Still, the role of cattle raising diversity in the landscape dynamics of this region remains poorly understood. To contribute to this discussion, we combined data from semi-structured interviews and quantitative spatially explicit methods to characterize and spatialize cattle raising systems and explore the effects of this diversity over secondary vegetation between 2004 and 2014 in Para, a hotspot of deforestation and core region of cattle production. We quantified the use of different pasture management strategies to classify small- and large-scale operations into systems with high or low impact against pastures’ degradation. High-impact systems were mapped in regions with consolidated infrastructure and high accumulated deforestation, where they expanded. On the contrary, low-impact systems were more widespread and found near forest frontiers, shrinking over time. High-impact systems had less secondary vegetation, while under low-impact systems, as a result of strategies with little or no effect against degradation, the historical pattern of concentration of this cover prevailed. Better infrastructure and access to markets as well as higher accumulated deforestation are underlying conditions related to the emergence of intensification and, as it is still unclear whether intensification is indeed capable of sparing land, the expansion of intensive cattle raising systems has the potential to configure landscapes with reduced forested areas, either primary or secondary.

This study applies three different methods to assess the flood risk and damage from the strongest high-pressure cold front (locally known as ‘Norte’) event in terms of the residual tide from 30 years (1979-2008) of data for Progreso, Yucatan. The most important difference between the three methods is the estimation of flood vulnerability for Progreso. The first method, proposed by Mexico’s National Center for the Prevention of Disasters (CENAPRED) and used by the Mexican government is based mostly on economic asset (household goods) values and flood impacts. The second (CENAPREDv2) and third (FRI) methods are proposals for assessing risk that include 17 socioeconomic indicators. The former includes economic asset values, as is the case for CENAPRED, while the latter does not. The main results of this study show that the modeled ‘Norte’ event flooded 25% of Progreso’s city blocks, with an estimated economic flood risk of $USD 16,266 (CENAPRED) and $USD 223,779 (CENAPREDv2), and flood damage of $USD 48,848 and $USD 671,918, respectively. When calculating flood risk (FRI) and flood damage (FRI_FD) without monetary terms, the risk categories along the back-barrier behind Progreso varied spatially from ‘very low’ to ‘high’, while areas along the coastal side presented a ‘low’ and ‘very low’ risk. These categories increased for the flood damage because the exceedance probability of the flood was not considered as it was for flood risk in the three methodologies. Therefore, flood damage provides the losses caused by a given flood event without considering how probable that loss may be. In conclusion, this study proposes that the selection of the applied method depends on the main objectives and specific interests when assessing flood risk. For instance, if economic damage is the main concern, then the CENAPRED method should be used as it identifies where the larger economic impacts could occur; when a socioeconomic approach is needed then the FRI should be applied, but if both economic damage and socioeconomic aspects are needed, the CENAPREDv2 is recommended. Besides considering economic aspects, the FRI method also includes social variables that can help to map the most vulnerable population in terms of mobility, education, communication access and others. Therefore, the proposed FRI method is very relevant for disaster risk managers and other stakeholders interested in disaster risk reduction.

We investigated the importance assigned to forest extractive resources (FR) for subsistence and income generation by colonist and Caboclos populations in the Brazilian Amazon. Key informants in 114 settlements (82 Caboclos and 32 colonists) in the southwest region of Pará classified on a four-level ordinal scale the importance of fruits, medicinal plants, hunting, fishing, and wood for both subsistence (FRI-s) and income generation (FRI-i). FRI-s was higher than FRI-i, which had a lower importance overall, except for fishing among Caboclos. The differences and similarities found both within and between the social groups refuted this social dichotomy as a major factor mediating the relationship with FR. We discuss possible socioeconomic factors as probable causes to explain the importance values found. The low importance for income generation may reveal the constraints on FR extraction in the Amazon, which can jeopardize the role of forest extractive reserves for economic development in the region.

Animal synchrony is found in phylogenetically distant animal groups, indicating behavioral adaptations to different selective pressures and in different signaling modalities. A notable example of synchronous display is found in fiddler crabs in that males wave their single enlarged claw during courtship. They present species-specific signals, which are composed of distinctive movement signatures. Given that synchronous waving has been reported for several fiddler crab species, the display pattern could influence the ability of a given species to sufficiently adjust wave timing to allow for synchrony. In this study, we quantified the wave displays of fiddler crabs to predict their synchronous behavior. We combined this information with the groups phylogenetic relationships to trace the evolution of display synchrony in an animal taxon. We found no phylogenetic signal in interspecific variation in predicted wave synchrony, which mirrors the general nonphylogenetic pattern of synchrony across animal taxa. Interestingly, our analyses show that the phenomenon of synchronization stems from the peculiarities of display pattern, mating systems, and the complexity of microhabitats. This is the first study to combine mathematical simulations and phylogenetic comparative methods to reveal how ecological factors and the mechanics of animal signals affect the evolution of the synchronous phenomena.

This paper presents a dataset of yearly land use and land cover classification maps for Mato Grosso State, Brazil, from 2001 to 2017. Mato Grosso is one of the worlds fast moving agricultural frontiers. To ensure multi-year compatibility, the work uses MODIS sensor analysis-ready products and an innovative method that applies machine learning techniques to classify satellite image time series. The maps provide information about crop and pasture expansion over natural vegetation, as well as spatially explicit estimates of increases in agricultural productivity and trade-offs between crop and pasture expansion. Therefore, the dataset provides new and relevant information to understand the impact of environmental policies on the expansion of tropical agriculture in Brazil. Using such results, researchers can make informed assessments of the interplay between production and protection within Amazon, Cerrado, and Pantanal biomes.

Demand for agricultural exports in Brazil has stimulated the expansion of crop production and cattle raising, which has caused environmental impacts. In response, Brazil developed public policies such as the new Forest Code (FC) and supply chain arrangements such the Soy and the Cattle Moratoriums. This paper analyzes the effectiveness of these policies, considering the trajectories of agricultural expansion in the state of Mato Grosso in three years: 2005 (pre-moratorium and before the new FC), 2010 (post-moratorium and before the new FC) and 2017 (post-moratorium and post-new FC). Our analysis uses a detailed land use change data for both the Amazon and Cerrado biomes in Mato Grosso. In all the years considered, soybean expansion occurred in consolidated production areas and by conversion of pastures. Pasture expansion is influenced by existence of pastures nearby, by areas of secondary vegetation and deforestation. Our data and models show the effectiveness of public policies and private arrangements to reduce direct conversion from forests to crop production. However, our results also provide evidence that soybean expansion has caused indirect impacts by replacing pasture areas and causing pasture expansion elsewhere. Evidence from our work indicates that Brazil needs broader-ranging land use policies than what was done in the 2010s to be able to reach the land use goals stated in its Nationally Determined Contribution (NDC) to the Paris Agreement.

Important features of the Atlantic meridional mode (AMM) are not fully understood. We still do not know what determines its dominant decadal variability or the complex physical processes that sustain it. Using reanalysis datasets, we investigated the influence of the North Atlantic Ocean variability on the dominant decadal periodicity that characterizes the AMM. Statistical analyses demonstrated that the correlation between the sea surface temperature decadal variability in the Atlantic Ocean and the AMM time series characterizes the Atlantic multidecadal oscillation (AMO). This corroborates previous studies that demonstrated that the AMO precedes the AMM. A causal inference with a newly developed rigorous and quantitative causality analysis indicates that the AMO causes the AMM. To further understand the influence of the subsurface ocean on the AMM, the relationship between the ocean heat content (0300 m) decadal variability and AMM was analyzed. The results show that although there is a significant zero-lag correlation between the ocean heat content in some regions of the North Atlantic (south of Greenland and in the eastern part of the North Atlantic) and the AMM, their cause-effect relationship on decadal time scales is unlikely. By correlating the AMO with the ocean heat content (0300 m) decadal variability, the former precedes the latter; however, the causality analysis shows that the ocean heat content variability drives the AMO, corroborating several studies that point out the dominant role of the ocean heat transport convergence on AMO.