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Our limited understanding of the climate controls on tropical forest seasonality is one of the biggest sources of uncertainty in modeling climate change impacts on terrestrial ecosystems. Combining leaf production, litterfall and climate observations from satellite and ground data in the Amazon forest, we show that seasonal variation in leaf production is largely triggered by climate signals, specifically, insolation increase (70.4% of the total area) and precipitation increase (29.6%). Increase of insolation drives leaf growth in the absence of water limitation. For these non-water-limited forests, the simultaneous leaf flush occurs in a sufficient proportion of the trees to be observed from space. While tropical cycles are generally defined in terms of dry or wet season, we show that for a large part of Amazonia the increase in insolation triggers the visible progress of leaf growth, just like during spring in temperate forests. The dependence of leaf growth initiation on climate seasonality may result in a higher sensitivity of these ecosystems to changes in climate than previously thought.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Litterfall is one of the most important pathways through which nutrients are recycled in the terrestrial biosphere. In tropical soils, which are generally low in essential nutrients such as phosphorus and cations, the flux of nutrients through litterfall is particularly important to sustaining CO2-uptake capacity; however, questions remain over the role of altitude in altering litter nutrient cycling rates among tropical forest ecosystems. Here we examine litterfall, carbon (C), nitrogen (N) and phosphorus (P) fluxes through litterfall over an altitudinal gradient in the coastal Atlantic Forest located on the northern coast of the State of Sao Paulo, Brazil. Litterfall was collected twice a month for 1 y (April 2007March 2008) using 30 litter traps placed in four different forest types arrayed by altitude coastal forest (sea level), lowland forest (50200 m asl), submontane forest (300500 m asl) and montane forest (1000 m asl). Litterfall mass-fluxes decreased with increasing altitude, from 9 Mg ha−1 in lowland forests to 7 Mg ha−1 in higher-altitude ecosystems. Contribution of reproductive organs to litterfall was significantly greater in lower than in higher altitudes. Litterfall N and P fluxes were higher in the lowland forest vs. other forest types, pointing to strong altitudinal controls over nutrient cycling. Furthermore, nitrogen-use efficiency (NUE) was lower and litter δ15N was higher in the lowland site providing additional evidence for lack of N constraints to productivity in lowland of the south-eastern Atlantic Forest.

The onset and demise of the rainy season in Amazonia are assessed in this study using meteorological data from the GoAmazon experiment, with a focus on the 2014 2015 rainy season. In addition, global reanalyses are also used to identify changes in circulation leading to the establishment of the rainy season in the region. Our results show that the onset occurred in January 2015, 23 pentads later than normal, and the rainy season during the austral summer of 2015 contained several periods with consecutive dry days in both Manacapuru and Manaus, which are not common for the wet season, and resulted in below-normal precipitation. The onset of the rainy season has been strongly associated with changes in large-scale weather conditions in the region due to the effect of the MaddenJulian Oscillation (MJO). Regional thermodynamic indices and the height of the boundary layer did not present a significant difference between the onset and demise of the wet season of 2015. This suggests that local changes, such as those in the regional thermodynamic characteristics, may not have influenced its onset. Thus, variability of the large-scale circulation was responsible for regional convection and rainfall changes in Amazonia during the austral summer of 2014 2015.

The Brazilian Amazon is being affected by the new worldwide geopolitical transformation that is tending towards an integrated global economy. In the region environmental considerations have not been adequately incorporated into long-term land use planning and this failure has partly been due to the complexities of the country’s existing inter-sectorial institutional arrangements. In this paper, we briefly explore two distinct economic development phases that have been reshaping Amazonian landscapes since the 1990s. We first focus on the role of traditional populations in conservation and land use planning (socio-environmental model). We contrast this with the post-environmental development model that currently dominates the land use dynamics of Amazonia and which is in stark contrasts with previous advances in environmental protection, whose basis was sustainable use of resources and social participation. The future of the socio-environmental model appears uncertain and its recovery and long-term maintenance to underpin sustainable development will depend on the strengthening the participation of the civil societal sectors that are able to reestablish balance to the sustainability agenda in the region.

Using a territorial and integrative approach based on ecological and socioeconomic factors, we envision innovative policies and initiatives aiming to reconcile urban economic development with rural conservation and restoration projects. The Paraíba Valley of São Paulo State represents an example of territory where the region’s urban development has affected land use and land cover changes, rural production systems, economy, and population dynamics with effects on environmental conservation. Forest restoration projects, rural tourism, urban to rural migration, and demands of urban consumers for more sustainable food production are becoming important linkages of the Valley’s coupled urban-rural system. In this study, we demonstrated how place-based policies and payment for ecosystem services may foster rural socioeconomic development allied with environmental conservation outcomes. The coupled ruralurban systems emerge as a strong concept to deal with the synergies and potential linkages among rural and urban areas, capable to promote more sustainable farming systems and improve ecosystem services.

In this study, we used the Standard Precipitation Index (SPI) to identify and to characterize the dry extreme events in the Amazon region. The results showed that the drought of 1998 was the most intense (SPI average equal to −1.69) in the period from 1979 to 2014. However, some papers have characterized the years 2005 and 2010 as the two largest droughts of the century. Thus, it was also carried out a comparative study of these droughts. The results showed that the drought 1998 was more intensive and extreme than the droughts of 2005 and 2010, although droughts of 2005 and 2010 lasted longer than 1998 due to oceanic and atmospheric conditions with influencing to cause greater social and economic impacts. Furthermore, it is suggested that the impact of the 2005 and 2010 droughts is a response from the dry occurred in 1993-1994 and 1997-1998.

This article reviews the current status, trends and challenges of land system science in Latin America. We highlight the advances in the conceptualization, analysis and monitoring of land systems. These advances shift from a focus on the relationships between forests and other land uses to include a greater diversity of land cover and land-use types and the processes and interactions that link them. We then provide a biome-level typology of social-ecological land systems (SELS) as an approach to help connect local-level realities to regional processes and we discuss how this approach can help to design more socially inclusive land systems. We also discuss the increased role of distant socio-economic and ecological interactions that connect these SELS to global processes. Combined, these insights support a research agenda for land system science in the region that can develop more accurate and integrative monitoring of land change and their social and ecological consequences, better understand different stakeholder perspectives within a context of livelihood diversification, and encourage institutional feedbacks to govern land systems influenced by distant drivers.

High-ozone concentrations currently represent the main air pollution problem in the city of São Paulo, Brazil. To elucidate the main volatile organic compounds (VOCs), which act as ozone precursors, samples from air quality monitoring stations were evaluated. Thirty-five samples were collected in AugustSeptember of 2006 and 43 in JulyAugust of 2008, when the consumption of ethanol was about 50 % of the total fuel used in the São Paulo Metropolitan Area. Samples were collected using electropolished stainless canisters. Chemical analyses were performed on pre-concentrated samples followed by gas chromatograph with flame ionization and mass spectrometry detection. The incremental reactivity scale was used to rank the ozone precursors using the Ozone Isopleth Package for Research (OZIPR) trajectory model coupled with chemical mechanism Statewide Air Pollution Research Center (SAPRC). Sixty-nine species of VOCs were quantified, and the ten main ozone precursors identified in 2008 were as follows: formaldehyde (42.8 %), acetaldehyde (13.9 %), ethene (12.2 %), propene (5.1 %), 1-methylcyclopentene (3.0 %), p-xylene (2.4 %), 1-butene (2.1 %), trans-2-pentene (1.9 %), 2-methyl 2-butene (1.7 %) and trans-2-butene (1.6 %). Volatile organic compound mass distribution showed that in 2008 alkanes represented 46 % of the total VOCs, alkenes 27 %, aromatics 14 %, alkadienes 1 % and aldehydes 12 %.

Large Amazonian rivers are characteristically subject to seasonal floods. We examine how inundation extent affects the partial pressure of carbon dioxide (pCO2) and CO2 outgassing in the Madeira River, a large tributary to the Amazon River. We show data from nine field campaigns performed between 2009 and 2011, complemented with data from one additional campaign in April 2014 that is representative of the largest flood on record. Both the pCO2 (range, 8359694 μatm) and CO2 outgassing (range, 64112,253 mg C m−2 d−1) had large seasonal variability (with peaks during high water), and fit exponential relationships with water level. CO2 outgassing per unit area in 2014 was 50% higher than the other highest rate in our dataset. Reconstruction of CO2 fluxes since 1968 indicates that extreme-flood years outgas 20% more CO2 per unit area than years without reported occurrence of extreme floods. Our findings indicate a positive feedback between climate change, extreme flooding, and CO2 outgassing from river water.

Analyzing Brazilian newspapers climate coverage leading up to 2010, this article shows that climate change was framed as an energy problem although energy is a small part of the countrys emissions compared to emissions from land use change and agriculture. Linked to well over half of national emissions, meat production is the single largest cause of national emissions. Yet discussions of meat as a problem in the context of climate change were marginal, at best. During the years 2007-2008, only 0.14% of climate change-mentioning articles – 0.02% of the total word count of climate change-mentioning articles – were dedicated to meat as a problem in the context of climate change. Counting also passages in articles not dedicated to the topic, the word count only rose to 0.13% of the total word flow of the articles. To the extent that the topic of meat as a problem appeared, it was underdeveloped and approached in ways that reduced attention, concern, and agency on the part of Brazilians to steer the country towards a new, more sustainable development path. This paper presents these findings and offers a preliminary political economic explanation for its existence.