Publicações

Understanding how Amazonian rainforests deal with extended droughts is critical in the face of changing climate. This research analyze the physical properties and the soil water dynamics of a deep soil profile in an area of primary forest in central Amazonia to elucidate these processes under drought and nondrought conditions. Physical soil properties derived from soil cores exhibited a distinctive layer between 480 and 880cm deep, characterized by higher microporosity and low plant water availability. In situ soil moisture measurements collected during the period from January 2003 through February 2006 and for depths ranging from 10 to 1,430cm suggest that, in the study site, the top 480cm of the soil profile satisfied most of the transpirational demands in normal climatological years. However, during exceptionally dry periods, such as the 2005 drought, root uptake occurs below 480cm. As concluded by previous studies, most of the uptake is concentrated in the first meter of the soil profile: More than 40% of the total demand for transpiration is supplied by the top meter of soil. Because deep root uptake occurred at greater depths than normal during the 2005 drought, our results suggest that this is a fundamental mechanism to cope with prolonged droughts.

Background Climate change is arguably a major threat to biodiversity conservation and there are several methods to assess its impacts on species potential distribution. Yet the extent to which different approaches on species distribution modeling affect species richness patterns at biogeographical scale is however unaddressed in literature. In this paper, we verified if the expected responses to climate change in biogeographical scale-patterns of species richness and species vulnerability to climate change-are affected by the inputs used to model and project species distribution. Methods We modeled the distribution of 288 vertebrate species (amphibians, birds and mammals), all endemic to the Amazon basin, using different combinations of the following inputs known to affect the outcome of species distribution models (SDMs): 1) biological data type, 2) modeling methods, 3) greenhouse gas emission scenarios and 4) climate forecasts. We calculated uncertainty with a hierarchical ANOVA in which those different inputs were considered factors. Results The greatest source of variation was the modeling method. Model performance interacted with data type and modeling method. Absolute values of variation on suitable climate area were not equal among predictions, but some biological patterns were still consistent. All models predicted losses on the area that is climatically suitable for species, especially for amphibians and primates. All models also indicated a current East-western gradient on endemic species richness, from the Andes foot downstream the Amazon river. Again, all models predicted future movements of species upwards the Andes mountains and overall species richness losses. Conclusions From a methodological perspective, our work highlights that SDMs are a useful tool for assessing impacts of climate change on biodiversity. Uncertainty exists but biological patterns are still evident at large spatial scales. As modeling methods are the greatest source of variation, choosing the appropriate statistics according to the study objective is also essential for estimating the impacts of climate change on species distribution. Yet from a conservation perspective, we show that Amazon endemic fauna is potentially vulnerable to climate change, due to expected reductions on suitable climate area. Climate-driven faunal movements are predicted towards the Andes mountains, which might work as climate refugia for migrating species.

Dietary guidelines urge Brazilians to increase their consumption of raw vegetables. Yet key issues must be tackled by the government and civil society, not only to foster consumers’ appetite for healthier food, but more importantly to diminish the gaps between local demand and production, determined by food and land accessibility. We examine whether vegetable production in Brazil meets the demand to provide Brazilians the daily amount of fresh food recommended by the World Health Organization (WHO).We developed demand scenarios in Brazil for 2008 and 2030, based on demand density maps built at the district level using production census surveys, household acquisition data, and population growth estimates. Results reveal an inherent inequality in vegetable consumption between the southern and central northern regions of Brazil that follows food insecurity regional indicators. Even in more urbanized regions and metropolitan areas, where the best balance between vegetable production and acquisition is found, simulated demand is far fromWHOrecommendations. A complementary discussion regarding land distribution and fresh food production supports our outlook on the weaknesses of existing rural policies for land reform and sustainable local fresh food production that directly affect demand and nutritional security. This work was the foundation to the Delivering Food Security on Limited Land (DEVIL) project in Brazil supported by Belmont Forum consortium.

Despite the dangers associated with tropical cyclones and their rainfall, the origin of the moisture in these storms, which include destructive hurricanes and typhoons, remains surprisingly uncertain. Existing studies have focused on the region 40400 km from a cyclone’s center. It is known that the rainfall within this area cannot be explained by local processes alone but requires imported moisture. Nonetheless, the dynamics of this imported moisture appears unknown. Here, considering a region up to three thousand kilometers from cyclone center, we analyze precipitation, atmospheric moisture and movement velocities for severe tropical cyclones North Atlantic hurricanes. Our findings indicate that even over such large areas a hurricane’s rainfall cannot be accounted for by concurrent evaporation. We propose instead that a hurricane consumes pre-existing atmospheric water vapor as it moves. The propagation velocity of the cyclone, i.e. the difference between its movement velocity and the mean velocity of the surrounding air (steering flow), determines the water vapor budget. Water vapor available to the hurricane through its movement makes the hurricane self-sufficient at about 700 km from the hurricane center obviating the need to concentrate moisture from greater distances. Such hurricanes leave a dry wake, whereby rainfall is suppressed by up to 40% compared to the local long-term mean. The inner radius of this dry footprint approximately coincides with the hurricane’s radius of water self-sufficiency. We discuss how Carnot efficiency considerations do not constrain the power of such open systems. Our findings emphasize the incompletely understood role and importance of atmospheric moisture stocks and dynamics in the behavior of severe tropical cyclones.

Niche conservatism, i.e. the retention of a species’ fundamental niche through evolutionary time, is cornerstone for biological invasion assessments. The fact that species tend to maintain their original climate niche allows predictive maps of invasion risk to anticipate potential invadable areas. Unravelling the mechanisms driving niche shifts can shed light on the management of invasive species. 2. Here, we assessed niche shifts in one of the world’s worst invasive species: the wild boar Sus scrofa. We also predicted potential invadable areas based on an ensemble of three ecological niche modelling methods, and evaluated the performance of models calibrated with native vs. pooled (native plus invaded) species records. By disentangling the drivers of change on the exotic wild boar population’s niches, we found strong evidence for niche conservatism during biological invasion. 3. Ecological niche models calibrated with both native and pooled range records predicted convergent areas. Also, observed niche shifts are mostly explained by niche unfilling, i.e. there are unoccupied areas in the exotic range where climate is analogous to the native range. 4. Niche unfilling is expected as result of recent colonization and ongoing dispersal, and was potentially stronger for the Neotropics, where a recent wave of introductions for pig-farming and game-hunting has led to high wild boar population growth rates. The invasive potential of wild boar in the Neotropics is probably higher than in other regions, which has profound management implications if we are to prevent their invasion into species-rich areas, such as Amazonia, coupled with expansion of African swine fever and possibly great economic losses. 5. Although the originally Eurasian-wide distribution suggests a pre-adaptation to a wide array of climates, the wild boar world-wide invasion does not exhibit evidence of niche evolution. The invasive potential of the wild boar therefore probably lies on the reproductive, dietary and morphological characteristics of this species, coupled with behavioural thermoregulation.

Este estudo presta-se à detecção de conglomerados espaciais (clusters) que representem fontes e sumidouros da malária. O estudo foi aplicado ao Município de Manaus (AM) e o método utilizado foi o da Estatística Scan, também conhecido como varredura espacial de Kulldorff. Dados epidemiológicos referentes ao ano de 2011 foram utilizados, 14.282 novos casos de malária, atribuídos a um conjunto de 831 Localidades devidamente georreferenciadas, foram analisados. Os casos foram tabulados conforme Local provável da infecção cli, Local de residência clr, importados ci e exportados ce. Para gerar clusters fonte foi utilizada a probabilidade ce/cli, enquanto que para sumidouro ci/clr. O método gerou três cluster com significância acima de 99,99%, dois do tipo fonte e um do tipo sumidouro. ABSTRACT: – This study aims to the detection of spatial clusters that represent malaria sources and sinks. The analysis was applied to the Manaus Municipality (Brazil) and the method used was the Scan Statistical, also called Kulldorff space sweep. Epidemiological data of 2011 were used, 14,282 new malaria cases attributed to a set of 831 geo-referenced Localities were analyzed. This cases were tabulated according to Local of probable infection cli, Local of residence clr, imported ci, and exported ce. To generate source clusters was used the probability “ce/cli”, while for sink “ci/clr”. The method generated three cluster with significance above 99.99%, two source and one sink.

The main source of electricity in Brazil is from hydro, which has about 65.2% share of the country’s electric energy matrix. However, over the last decade the wind energy increased from 19 MW to 2.2 GW. Since wind is an intermittent energy source, heavily determined by the weather and climatic conditions, and important effects on wind power generation can be expected in the mid and long term, in particular related to the impacts of extreme winds. The IPCC AR5 (Intergovernmental Panel on Climate Change) indicates changes in wind speed at the surface in some regions of the world, and increased wind strength in mid-latitude regions. This study scrutinizes future scenarios of extreme winds in Brazil by applying trend analysis techniques on a 50-year historical series of observational wind speed and meteorological parameters at 10 m height in Brazil. Embracing techniques of cluster analysis it was possible to characterize six main regions with macro climatic similarities. To assess the goodness fit distribution, we designate two stations per homogenous region, taking as criteria the stations with better performance in the qualification process to determine the wind distribution pattern in each region applying the Kolmogorov-Smirnov test (KS) and the lowest standard error (SE). After evaluating the frequency distribution of wind speed, the best fit result for the frequency distribution of maximum wind speed is the Gumbel model. The analysis of climatic trends performed by Mann-Kendall test revealed that in minimum wind speed series is not conclusive because it shows disparate results between homogeneous regions. On the other hand, the analysis of climatic trends of maximum wind speed presents 100% positive trends in Group#1, an equal number of stations with not significant trends and positive trends for Group#2, 36.8% more stations with positive trends than negative trends for Group#3 and 20% of stations with more negative trends than stations with positive trends for Group#4. This way, based in these results, is possible assert that there are an increase in the maximum extreme wind in Brazil, mainly in mid-latitudes.

This study provides an overview of the drought situation in Northeast Brazil for the past, present, and future. Droughts affect more people than any other natural hazard owing to their large scale and long-lasting nature. They are recurrent in the region and while some measures have been taken by the governments to mitigate their impacts, there is still a perception that residents, mainly in rural areas, are not yet adapted to these hazards. The drought affecting the Northeast from 2012 to 2015, however, has had an intensity and impact not seen in several decades and has already destroyed large swaths of cropland, affecting hundreds of cities and towns across the region, and leaving ranchers struggling to feed and water cattle. Future climate projections for the area show large temperature increases and rainfall reductions, which, together with a tendency for longer periods with consecutive dry days, suggest the occurrence of more frequent/intense dry spells and droughts and a tendency toward aridification in the region. All these conditions lead to an increase in evaporation from reservoirs and lakes, affecting irrigation and agriculture as well as key water uses including hydropower and industry, and thus, the welfare of the residents. Integrating drought monitoring and seasonal forecasting provides efficient means of assessing impacts of climate variability and change, identifying vulnerabilities, and allowing for better adaptation measures not only for medium- and long-term climate change but also for extremes of the interannual climate variability, particularly droughts.

Aim Conservationists have been using ecological niche modelling (ENM) to understand how climate change impacts species, estimate their extinction risk and assess species conservation status in the future. However, most ENMs are built using just current species occurrences. As short-term observations are naturally biased and incomplete in both geographical and climate spaces, palaeontologists have recommended the use of fossil data to improve species vulnerability assessments. Here, we used a time structured data set of the jaguar Panthera onca (Linnaeus, 1758) to test the implications of fossil data on distinct distribution dynamics and conservation status predicted by ENMs under future climate change scenarios. LocationThe New World. MethodsWe built two classes of ENMs, (i) using only current occurrences of P.onca and (ii) combining current and fossil information. Models were then projected onto current and future climates. ResultsNiche models calibrated using fossil data broadly predicted more optimistic conservation statuses, with larger suitable areas for the species in the future, which are geographically nearest to its current distribution and better represented within protected areas (current network of protected areas will hold significant suitable areas). Main conclusionsFossils provided complementary information about different climate conditions that species experienced though time and filled empty spaces in currently unoccupied fundamental niche. Our analyses reinforce the idea the fossil record is a valuable source of alternative information to increase the reliability of ENMs when assessing biodiversity risk. Combining ecological and palaeontological data for niche modelling increase our understanding about species responses to changing climates. Consequently, it potentially improves our knowledge on how to manage biodiversity by more reliably anticipating the effects of climate change and proactivelyrather than reactivelyplanning conservation actions over longer periods going forward.

AimTo propose and compare priority sites for conservation and restoration of woody plants under diverse climate and land use scenarios, considering socio-economic costs, presence of protected areas and distribution of forest remnants. LocationThe Atlantic Forest Biodiversity Hotspot, Brazil. MethodsWe used ecological niche modelling to estimate geographical distributions for 2,255 species under current and future climate scenarios, which we analysed in relation to spatially explicit land use projections, maps of forest remnants derived from remote sensing and socio-economic variables for each municipality within the Atlantic Forest region. We identified spatial priorities that complement the current network of protected areas under three different prioritization scenarios: (1) conservation of existing forest remnants only; (2) conservation of remnants followed by restoration of degraded habitat; and (3) unconstrained actions, in which management location is not defined a priori. We compared our results under different levels of land protection, with targets of 10%, 17% and 20% of the Atlantic Forest extent. ResultsCurrent forest remnants cover only 12% of the Atlantic Forest, so targets of 17% and 20% were achieved only through active restoration. Targets of 17% and 20% captured most species and represented on average 26%-34% of species’ distributions. The spatial pattern of degraded habitats negatively affected representation of biodiversity and implied higher costs and reduced efficiency of planning. We did not observe major differences between conservation prioritizations based on contrasting climate change scenarios. Main conclusionsProtection of forest remnants alone will not suffice to safeguard woody plant species under climate and land use changes; therefore, restoration actions are urgently needed in the Atlantic Forest. With integrated management actions and multicriterion nationwide planning, reaching the 17% of land protection of Aichi biodiversity targets will constitute an important step towards protecting Atlantic Forest biodiversity.

O presente estudo objetiva determinar Regiões homogêneas do SPI-6 na Amazônia Oriental e analisar as principais características dos eventos secos e chuvosos em cada região. Para o cálculo do SPI, utilizou-se dados de precipitação de 72 postos pluviométricos distribuídos na Amazônia Oriental. Além disso, aplicou-se o Agrupamento Hierárquico de Ward para determinar as Regiões Homogêneas e a Análise Fatorial em Componentes Principais (ACP) para determinar os principais padrões de variabilidade climáticas associados aos eventos secos e chuvosos. Os resultados obtidos pela Análise de Agrupamento mostraram a existência de três Regiões Homogêneas em relação ao SPI-6: RH-1 (litoral), RH-2 (central) e RH-3 (sul). De modo geral a região do litoral apresentou mais eventos secos que chuvosos. Nas demais regiões (central e sul) a situação é inversa, isto é, existem mais eventos de chuva, porém com pouca duração. Por meio da ACP verificou-se que os eventos secos e chuvosos na Amazônia Oriental estavam associados, principalmente, a variabilidade climática dos oceanos Atlântico (Gradiente do Atlântico) e Pacífico (ENOS).