Ana C. M. Malhado

The drought of the century in the Amazon Basin: an analysis of the regional variation of rainfall in South America in 1926

The most severe drought in tropical South America during the 20th century occurred in 1926. This extreme El Nino year is further documented anecdotally, in an update of the river stage observations at Manaus, and in annual rainfall records. The annual rainfall anomaly is an east-west dipole over tropical South America, with drought to the west over the Amazon basin whose discharge is documented at Manaus, and with a surplus to the east and including the Nordeste region of Brazil. Speculations about a role for aerosol in aggravating the drought are discussed.

Modeling the photosynthetically active radiation in South West Amazonia under all sky conditions

Accurate estimates of photosynthetically active radiation (PAR) are critical for the development of realistic models of plant productivity. However, in many areas such as the vast Amazon region of South America, there have been few empirical studies of PAR. Here, we analyzed the relationship between PAR and broadband solar irradiance (Rs) and formulated models to estimate PAR in two experimental sites (pasture and forest) in the Brazilian Amazon. Three different models of increasing complexity were developed based on information from Rs (model 1), Rs and clearness index (kt; model 2), and Rs, kt, and water vapor pressure (model 3). Estimates of PAR were generated for each season and for the entire year. All models had very high determination coefficients and indices of agreement for both pasture and forest sites. This strongly supports the use of Rs and kt to produce robust estimates of PAR. The results obtained by annual models were close than that found by seasonal models, demonstrating that a single annual model is able to estimate PAR, albeit with lower accuracy.

Unexplored Diversity and Conservation Potential of Neotropical Hot Caves

The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot-cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat-generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism.

The influence of oceanic basins on drought and ecosystem dynamics in Northeast Brazil

The 2012 drought in Northeast Brazil was the harshest in decades, with potentially significant impacts on the vegetation of the unique semi-arid caatinga biome and on local livelihoods. Here, we use a coupled climate–vegetation model (CCM3-IBIS) to: (1) investigate the role of the Pacific and Atlantic oceans in the 2012 drought, and; (2) evaluate the response of the caatinga vegetation to the 2012 climate extreme. Our results indicate that anomalous sea surface temperatures (SSTs) in the Atlantic Ocean were the primary factor forcing the 2012 drought, with Pacific Ocean SST having a larger role in sustaining typical climatic conditions in the region. The drought strongly influenced net primary production in the caatinga, causing a reduction in annual net ecosystem exchange indicating a reduction in amount of CO2 released to the atmosphere.

Familiarity breeds content: assessing bird species popularity with culturomics

Understanding public perceptions of biodiversity is essential to ensure continued support for conservation efforts. Despite this, insights remain scarce at broader spatial scales, mostly due to a lack of adequate methods for their assessment. The emergence of new technologies with global reach and high levels of participation provide exciting new opportunities to study the public visibility of biodiversity and the factors that drive it. Here, we use a measure of internet saliency to assess the national and international visibility of species within four taxa of Brazilian birds (toucans, hummingbirds, parrots and woodpeckers), and evaluate how much of this visibility can be explained by factors associated with familiarity, aesthetic appeal and conservation interest. Our results strongly indicate that familiarity (human population within the range of a species) is the most important factor driving internet saliency within Brazil, while aesthetic appeal (body size) best explains variation in international saliency. Endemism and conservation status of a species had small, but often negative, effects on either metric of internet saliency. While further studies are needed to evaluate the relationship between internet content and the cultural visibility of different species, our results strongly indicate that internet saliency can be considered as a broad proxy of cultural interest.

Modelling Local Attitudes to Protected Areas in Developing Countries

During a time of intensifying competition for land, Protected Areas (PAs) are coming under increasing pressure to justify their status. Positive local attitudes to a PA are a potentially important component of any such justification, especially in the developing world where human pressure on natural resources is often high. However, despite numerous studies our understanding of what drives positive attitudes to PAs is still exceedingly limited. Here, we review the literature on local attitudes towards PAs in developing countries. Our survey reveals a highly fragmented research area where studies typically lack an explicit conceptual basis, and where there is wide variation in choice of statistical approach, explanatory and response variables, and incorporation of contextual information. Nevertheless, there is a relatively high degree of concordance between studies, with certain variables showing strong associations with attitudes. We recommend that PA attitude researchers in developing countries adopt a more rigorous model building approach based on a clear conceptual framework and drawing on the extensive empirical literature. Such an approach would improve the quality of research, increase comparability, and provide a stronger basis to support conservation decision-making.

Tropical Artisanal Coastal Fisheries: Challenges and Future Directions

Artisanal fisheries occur all over the tropics and provide an important source of protein and income for many coastal communities. However, varied types and magnitudes of anthropogenic impacts threaten the environmental, economic, and socio-cultural sustainability of this poorly studied fishing practice. This article reviews the scattered literature on tropical artisanal coastal fisheries, identifying key challenges to ensure future sustainability. Despite huge data shortfalls, there is considerable evidence that artisanal fisheries have a significant influence on the distribution and abundance of target and by-catch species, in addition to wider impacts on biodiversity, biomass, assemblage structure, community dynamics, and ecosystem functioning. Despite these immediate and considerable threats, regulation and management of artisanal fisheries are problematic. Local communities in the coastal tropics are frequently very poor, and families frequently rely on fishing for food security and income. Ensuring social and environmental sustainability therefore entails models of governance that are able to adaptively manage these complex socio-ecological systems. Such models are being developed, but it is unclear whether there are sufficient resources and technical capacity to widely implement them before the widespread collapse of fisheries with potentially serious consequences for the communities that rely on them.

Assessing insularity in global science

Most scientific research has some form of local geographical bias. This could be caused by researchers addressing a geographically localized issue, working within a nationally or regionally defined research network, or responding to research agendas that are influenced by national policy. These influences should be reflected in citation behavior, e.g., more citations than expected by chance of papers by scientists from institutions within the same country. Thus, assessing adjusted levels of national self-citation may give insights into the extent to which national research agendas and scientific cultures influence the behavior of scientists. Here we develop a simple metric of scientific insularism based on rates of national self citation corrected for total scientific output. Based on recent publications (1996–2010), higher than average levels of insularism are associated with geographically large rapidly developing nations (Brazil, Russia, India, and China—the so-called BRIC nations), and countries with strongly ideological political regimes (Iran). Moreover, there is a significant negative correlation between insularism and the average number of citations at the national level. Based on these data we argue that insularism (higher than average levels of national self-citation) may reflect scientific cultures whose priorities and focus are less tightly linked to global scientific norms and agendas. We argue that reducing such insularity is an overlooked challenge that requires policy changes at multiple levels of science education and governance.

The scientific value of Amazonian protected areas

Protected areas (PAs) are under increasing pressure to demonstrate their broader value and contribution to society. Scientific research and associated knowledge production comprise one such value, which has received relatively little attention in the academic literature. Here, we use the Amazon region as a case study to quantify scientific knowledge production (as measured by scientific publications in peer-reviewed journals) in PAs and identify the main biophysical, geographical and social characteristics that influence such production. We adopt a multi-model inference approach with an innovative hurdle regression model to independently assess the factors influencing the presence of research and the number of studies in PAs. Our results indicate a highly skewed pattern of scientific production, with many PAs with few or no associated scientific articles. Larger, older and more highly protected PAs in Ecuador and Peru were most likely to have scientific production, while time since first publication was most strongly associated with the number of publications from a PA. These findings provide important insights that could be used to support and strengthen policy aimed at increasing the value of Amazonian protected areas for scientific research.

Geographic trends and information deficits in Amazonian conservation research

Amazonia has an iconic status in global conservation due to its enormous area and vast stores of biodiversity. Nevertheless, much of its biodiversity remains unknown, and many of the region’s forests are under threat of habitat loss due to deforestation and climatic instability. Based on the assumption that effective management and conservation of forest resources should be supported by geographically localized scientific knowledge, we mapped the spatial and temporal distribution of Amazonian conservation research and compared it to areas under threat from deforestation or with a high probability of climate change induced savannization/transition to seasonal forest. Specifically, we created a database of 4019 spatial coordinates of research sites collated from 857 conservation science research articles retrieved from Scopus. Research sites tend to cluster along major rivers and urban areas and new research sites tend to be located near existing sites. Information deficits are particularly acute in the south and southeast regions within the so called ‘arc of deforestation’. Areas at risk of ecosystem transition due to climate instability are generally well studied with the exception of a large area of southwest Amazonia that has a high risk of savannization. Our results suggest that a more systematic approach to Amazonian conservation research is required, specifically targeting those areas most under threat from anthropogenic environmental change.