Amazon Frontier Research Articles

Influence of precipitation and temperature on burned areas in the agricultural and cattle ranching frontier of the Brazilian Amazon.

Fire occurrence, intensity, and spread are highly influenced by climatic variables. This study investigates the correlation between burned area, precipitation, and temperature in Rondônia, an agricultural frontier in the southwestern Brazilian Legal Amazon, from 2001 to 2022. The analysis utilized climatological data from the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) and MODIS product MOD11A1.061 for temperature, along with MODIS product MCD64A1 for burned area. The study was conducted on a monthly scale, employing the cross-correlation function to determine the lagged effects of temperature and precipitation on burned areas. Trend analysis was performed using the Mann-Kendall test, with the magnitude of trends estimated by Sen's Slope. Results indicated a significant negative correlation between burned areas and precipitation, with a 2-month lag and an R2 of - 0.51. In contrast, temperature exhibited a significant positive correlation with burned areas, showing a 1-month lag and an R2 of 0.55. Trend analysis revealed a decrease in precipitation by - 0.0542mm.month-1, temperature increased by 0.006°C.month-1, while burned areas decreased by - 111.13 km2.month-1. These findings underscore the intricate relationship between climate variables and fire occurrences, highlighting the urgent need for policies addressing climate change and environmental degradation in the Amazon.

Bayesian spatio-temporal modeling to assess the effect of land-use changes on the incidence of Cutaneous Leishmaniasis in the Brazilian Amazon

Cutaneous Leishmaniasis (CL) is a vector-borne disease caused by a protozoan of the genus Leishmania and is considered one of the most important neglected tropical diseases. The Brazilian Amazon Forest harbors one of the highest diversity of Leishmania parasites and vectors and is one of the main focuses of the disease in the Americas. Previous studies showed that some types of anthropogenic disturbances have affected the abundance and distribution of CL vectors and hosts; however, few studies have thoroughly investigated the influence of different classes of land cover and land-use changes on the disease transmission risk. Here, we quantify the effect of land use and land-cover changes on the incidence of CL in all municipalities within the Brazilian Amazon Forest, from 2001 to 2017. We used a structured spatiotemporal Bayesian model to assess the effect of forest cover, agriculture, livestock, extractivism, and- deforestation on CL incidence, accounting for confounding variables such as population, climate, socioeconomic, and spatiotemporal random effects. We found that the increased risk of CL was associated with deforestation, especially modulated by a positive interaction between forest cover and livestock. Landscapes with ongoing deforestation for extensive cattle ranching are typically found in municipalities within the Amazon Frontier, where a high relative risk for CL was also identified. These findings provide valuable insights into developing effective public health policies and land-use planning to ensure healthier landscapes for people.

Drivers of functional diversity in small-bodied mammals across a deforestation frontier in the Southern Brazilian Amazon

Deforestation remains the most pervasive driver of biodiversity erosion across tropical forests. Understanding how species can cope with such habitat changes is particularly important along the rapidly expanding agricultural frontiers. To do so, we used a functional perspective examining small mammal responses to habitat loss, fragmentation, and degradation across the ‘Arc of Deforestation’ in the Southern Brazilian Amazon. Small mammals were surveyed using a combination of conventional and pitfall traps across 20 forest fragments—ranging from 42 to 4743 ha—in addition to two relatively continuous forest sites (> 7000 ha). These fragments lie isolated by a cattle pasture matrix of varying grazing intensity. We then analysed taxonomic and functional diversity patterns—represented by Simpson Diversity and Rao Quadratic entropy indices—in Generalised Linear Models containing local- to landscape-scale predictors of variation. Further, we used a functional trait composition approach based on community-weighted mean trait values to depict and predict small mammal functional variations across this degradation gradient. From a total of 847 individuals recorded belonging to 24 taxa, functional responses tended to follow the taxonomic diversity, both increasing with fragment area. The functional dimension further was promoted by low fire-related disturbance. Functional trait composition was mainly driven by habitat quality, represented by tree density, arthropod biomass, and fire-related disturbance. Our results reinforce that small forest fragments sustain depauperate small mammal assemblages both taxonomically and functionally. Accounting for habitat quality further allows for boosting the persistence across functional groups. Our findings can be used to improve the efficiency of management practices thereby maximising the multiple dimensions of small mammal diversity and their associated ecosystem services across tropical deforestation frontiers.

Valuing conservation and socio-environmental services on an Amazon frontier: the Extractive Reserves of the Terra do Meio

In the Brazilian Amazon, forest conservation has relied on the presence of 'traditional communities' and Indigenous peoples to secure legally demarcated protected areas from deforestation and biodiversity degradation. Facing pressures for land-use change from a rapidly encroaching frontier of resource extraction and commodity production, there is no guarantee that Indigenous peoples or traditional communities will continue to occupy these forests or continue to fulfill the role of forest protectors except under certain conditions. In this article, we detail the case of the extractive reserves of the Terra do Meio and consider what conditions would be needed for traditional communities to continue to occupy and protect protected areas. Employing an agrarian political ecology approach, we draw on years of ethnographic research in this area to argue that forest peasant livelihoods, which revolve around the forest areas of use, produce both ecological and cultural diversity in the forest. We term this socio-ecological arrangement the productive system of the colocação, the system and geographies of forest peasant livelihoods that upholds and is upheld by diverse socio-ecological relationships. Contemporary forest conservation regimes, however, have largely failed to incentivize and value these forest peasant livelihoods in ways that would sustain them in the face of commoditizing frontier pressures. Any mechanisms that pay for forest conservation should remunerate communities for their entire socio-ecological relationships, those relationships that are upheld through forest peasant livelihoods, not simply their products. We propose an approach to valuing forest communities' socio-environmental services, and we argue that such valuation would be more effective for conservation and cultural/ecological diversity than existing proposals for payments for ecosystem services (PES).

Peripheral or strategic? The border condition of the amazon frontier in Brazil

The objective of this article was to discuss the border condition of the Brazilian Amazon between the 20th and 21st centuries from its peripheral and strategic behavior. The guiding question was: how is the border condition configured through the peripheral/strategic behavior of frontier spaces in the Amazon region of Brazil? The methodological approach was the hypothetical-deductive based on three investigation strategies; qualitative analysis of documents, review of specialized literature and fieldwork observations. The results indicate that the Amazon frontier cannot be considered peripheral or strategic in isolation. These two adjectives qualify specific historical, political and economic uses that need to be considered together to understand the border condition of the Brazilian Amazon. We conclude that the peripheral/strategic behavior reveals not only the historical-economic construction of the border, but also the choice of national decision-making centers, reflected in the public policies implemented in the region.

Land grabbing in the Brazilian Amazon: Stealing public land with government approval

We estimate the magnitude of land grabbing - the illegal appropriation of public land - on an active Amazonian frontier, the associated deforestation, and the rates at which these claims were legalized due to changes in the law and downsizing of settlements. Of all land claimed in Brazil's Rural Environmental Register (CAR) in our 300,689-km2 study area, 90.5% is non-compliant with Brazilian law and 45.8% is in protected areas. Changes in the law by 2017 reclassified as licit 4.2% of the illicit CAR land claims ) in 2014 (901 km2 yr-1). Downsizing settlements made 5266 km2 available for illegal appropriation. Deforestation in land claims accounted for 35% of the total, and this percentage is likely to grow. Planned future changes in land law will further jeopardize Amazon's natural and cultural heritage legalizing at least 10% of the area in this frontier. Importers of beef, soybeans and other commodities should bar products from land that has been grabbed as a result of changes in Brazil's land laws, reducing the outsourcing of deforestation.

Contemporary slave labour on the Amazonian frontier: the problems and politics of post rescue solidarity

ABSTRACT This paper addresses the deepening vulnerability of both domestic and international migrant workers to contemporary slave labour and the challenges for its eradication in the Brazilian Amazonian state of Mato Grosso. Drawing upon the experiences of 40 workers ‘rescued’ from contemporary slave labour, the paper shows that the repetitive experiences of contemporary slave labour by subjects and the authoritarian turn in Brazil evokes a conceptual reinterpretation of solidarity and its operationalization. It must move away from the distinct liberal approach in the state paradigm to focus on class and agrarian based solidarity and their understanding of liberation. The paper redefines solidarity as structural and relational notion that engages with the epistemic insight of unfree workers to define the terms of their own freedom, pointing towards humanizing, and self-emancipating alternatives that challenge roots of class oppression and slave labour.

MULTIVARIATE MIXED MEMBERSHIP MODELING: INFERRING DOMAIN-SPECIFIC RISK PROFILES.

Characterizing the shared memberships of individuals in a classification scheme poses severe interpretability issues, even when using a moderate number of classes (say 4). Mixed membership models quantify this phenomenon, but they typically focus on goodness-of-fit more than on interpretable inference. To achieve a good numerical fit, these models may in fact require many extreme profiles, making the results difficult to interpret. We introduce a new class of multivariate mixed membership models that, when variables can be partitioned into subject-matter based domains, can provide a good fit to the data using fewer profiles than standard formulations. The proposed model explicitly accounts for the blocks of variables corresponding to the distinct domains along with a cross-domain correlation structure, which provides new information about shared membership of individuals in a complex classification scheme. We specify a multivariate logistic normal distribution for the membership vectors, which allows easy introduction of auxiliary information leveraging a latent multivariate logistic regression. A Bayesian approach to inference, relying on Pólya gamma data augmentation, facilitates efficient posterior computation via Markov Chain Monte Carlo. We apply this methodology to a spatially explicit study of malaria risk over time on the Brazilian Amazon frontier.

Farm Knowledge Co-Production at an Old Amazonian Frontier: Case of the Agroforestry System in Tomé-Açu, Brazil

This paper addresses how co-producing knowledge can assist local farmers in reshaping their territories into sustainable farming systems. We describe the emergence and consolidation of an agroforestry system in an Eastern Amazon forest frontier, unpacking the co-production of a new farming system over recent decades. Instead of assuming pre-defined categories (e.g., traditional/technical, local/external), the analysis focuses on interactions among knowledge holders and how multiple knowledge sources are intercalated. The analysis is based on long-term ethnographic research, comprising of over 70 interviews, visits to 40 farm fields, and participation in several local meetings and four annual seminars. The agroforestry system – locally called SAFTA – has emerged from a farming crisis experienced by mid-scale farmers of Japanese descent. Grounded in traditional Amazonian farming practices, SAFTA has been enriched by scientific and organizational knowledge from various sources to become a local solution that reconciles economic, social and environmental demands. Built on a few basic principles, this new farm system enables flexibility in crop field designs according to each farmer’s preferences and available resources. SAFTA knowledge has spilled over to other farmer groups and has helped develop an innovative agroforestry system for oil-palm cultivation. The SAFTA model has been consolidated, legitimized by a range of national and international actors, and gradually institutionalized in policy and commercial circles. This case sheds light on the potential of knowledge co-production to transform complex rural landscapes featuring cultural diversity, asymmetrical relationships and history of land-use change. Analysis of social interactions and knowledge integration mechanisms give insight into how co-production under local cultural diversity and asymmetrical relations may yield mutual benefits among local farmer groups.

‘Everything peasants do is illegal’: Colombian coca growers’ everyday experiences of law enforcement and its impacts on state legitimacy

For decades, Colombian governments have imposed a narrative linking illegal crops with statelessness and presenting ‘more state’ and specifically ‘more law enforcement’ as the solution to a swathe of problems in drug-producing regions. We draw on coca growers’ own accounts of law enforcement to critique this narrative. Their accounts – specifically from Putumayo in Colombia’s Amazonian frontier – refer to persecution for many of the things they do in their everyday lives, not just those directly related to the coca economy. Their livelihoods are constantly under threat from state forces as a result of counternarcotics operations but also due to the imposition of (phyto)sanitary and environmental norms. This generates resentment towards the state, undermining its efforts to establish authority in these territories. Thus, building on coca farmers’ accounts, we argue that state weakness in drug-producing areas is a problem of quality and not only quantity. Improving quality means transforming the way lawmakers and enforcers relate to rural citizens. If the Colombian state continues to wage war against the peasantry, it will hardly achieve effective governance of the coca frontier. Supplemental data for this article is available online at https://doi.org/10.1080/01436597.2021.1971517 .

Who knows, who cares? Untangling ecological knowledge and nature connection among Amazonian colonist farmers

Abstract Conservationists often assume that connection with and caring about nature's well‐being is strongly linked to ecological knowledge. Existing evidence on the link between ecological knowledge and psychological nature connection is mixed, geographically limited to countries in the Global North, and does not scrutinise potential differences in determinants of ecological knowledge and nature connection. We investigate the relationship between psychological nature connection and ecological knowledge of local bird species, and assess their associations with potential drivers, including access to, contact with, and reliance on nature and socio‐demographic characteristics. Our study is carried among a novel participant population of colonist farmers living along a major deforestation frontier in the Brazilian Amazon. Our study context has high conservation relevance and provides an ideal setting to assess the extent to which conservation psychology's insights from the Global North hold true elsewhere. Tropical farm‐forest frontiers suffer from intense habitat and biodiversity loss, and farmers with migrant origins are important yet rarely studied conservation stakeholders. Importantly, farmers' experiences of nature are likely to vary considerably due to the wide range of socio‐demographic, economic, geographical and cultural diversity. Interviewees scored highly on two indices of nature connection, but scores were higher among older people and those with greater contact with nature. Bird identification knowledge was generally low to moderate, and higher among men and younger people. Species more frequently recognised were regionally common, larger‐bodied or associated with non‐forest habitats. Ecological knowledge of birds and nature connection were not correlated, and they did not have any predictors in common. Our results indicate that colonist farmers are capable of forming strong connections with nature, even if they rarely possess detailed knowledge of local forest biodiversity. Considering the complex and apparently context‐dependent relationship between knowing and caring about nature, it is unwise to assume that changing one would automatically affect the other. A free Plain Language Summary can be found within the Supporting Information of this article.

New evidence of the Formative in the Amazon: A stilt village culture in Maranhão, Brazil

The Formative period (c. 4000 to 2000 BP) in the Latin-American continent was characterized by human occupations along the sea coast, rivers, and lakes as well as in the interfluves and highlands. In Brazil, there is a tendency nowadays to deny the existence of the Formative due to an alleged Amazon population vacuum in this period. Studies in the precolonial stilt villages in the Baixada of Maranhão, along with earlier research elsewhere in Brazil, confirm that the Formative did indeed exist in Brazil and suggest these sites in Maranhão were the last Amazon frontier of the Formative of its eastern portion.

Deforestation Trajectories on a Development Frontier in the Brazilian Amazon: 35 Years of Settlement Colonization, Policy and Economic Shifts, and Land Accumulation.

We examine deforestation processes in Apuí, a deforestation hotspot in Brazil’s state of Amazonas and present processes of land-use change on this Amazonian development frontier. Settlement projects attract agents whose clearing reflects land accumulation and the economic importance of deforestation. We used a mixed-method approach in the Rio Juma Settlement to examine colonization and deforestation trajectories for 35 years at three scales of analysis: the entire landscape, cohorts of settlement lots divided by occupation periods, and lots grouped by landholding size per household. All sizes of landholdings are deforesting much more than before, and current political and economic forces favoring the agribusiness sector foreshadow increasing rates of forest clearing for pasture establishment in Apuí. The area cleared per year over the 2013–2018 period in Apuí grew by a percentage more than twice the corresponding percentage for the Brazilian Amazon as a whole. With the national congress and presidential administration signaling impunity for illegal deforestation, wealthy actors, and groups are investing resources in land grabbing and land accumulation, with land speculation being a crucial deforestation factor. This paper is unique in providing causal explanations at the decision-maker’s level on how deforestation trajectories are linked to economic and political events (period effects) at the larger scales, adding to the literature by showing that such effects were more important than aging and cohort effects as explanations for deforestation trajectories. Additional research is needed to deepen our understanding of relations between land speculation, illegal possession of public lands, and the expansion of agricultural frontiers in Amazonia.

O avesso da nação: a recorrência de relações de trabalho escravo na fronteira amazônica no final do século xx e século xxi

O presente artigo visa tratar da recorrência de relações de trabalho degradantes, conhecidas no Brasil como Trabalho Análogo ao de Escravo ou Trabalho Escravo Contemporâneo, ao longo do século XX, com ênfase em sua presença na fronteira amazônica brasileira. Discutindo a permanência dessas relações de trabalho após o fim do escravismo, predominantemente entre os trabalhadores rurais, analisamos suas reconfigurações até o final do século quando os projetos de Integração da Amazônia foram desenvolvidos pelos governos militares, sob o pretexto de levar homens sem terra para terra sem homens, produzindo degradação ambiental à custa de mão de obra de migrantes, explorados e sem garantias de direitos.

Forever Working on the Whiteman: Agency, Vulnerability, and Hope in the Interstices of an Amazonian Frontier

ResumenEste artículo presenta un estudio de caso de término medio entre una comunidad indígena en el sur de Guyana y un grupo de mineros itinerantes de Brasil cuyo jefe era percibido como un hombre blanco. Un elemento central para la aparición de este término medio fue el sentido de agencia creativa de cada parte en relación con la otra, su vulnerabilidad mutua en relación con factores circunstanciales más grandes y su malentendido mutuo de los motivos de compromiso de la otra parte. De este estudio de caso, sostengo que las condiciones que proporcionan un punto medio en los espacios fronterizos de extracción de recursos en la Amazonía son raras, de corta duración y es más probable que surjan en contextos donde una disminución en el valor de mercado de los recursos ha reducido la escala y la intensidad de contacto. El término medio surge en estas condiciones, en parte porque ciertas técnicas indígenas para negociar relaciones de poder florecen cuando la escala de contacto es más interpersonal desde el punto de vista gastronómico.

Chinese-driven frontier expansion in the Amazon: four axes of pressure caused by the growing demand for soy trade

Chinese demand for the world’s commodities has the capacity to shape agricultural frontiers in many parts of the world, including the Amazon. This article is a preliminary report on findings concerning the expansion of the agricultural frontier in the Brazilian Amazon driven by increases in soybean production, extension of cropped area, cross-referenced with satellite data on deforestation rates at the smallest possible scale: the municipal level. The study identifies 21 municipalities forming fours axes of frontier expansion in the Amazon, where soycrops may be the cause for displacement deforestation, as it is the case of cattle ranching. Despite the Soy Moratorium, frontiers in the Amazon keep shifting. The article advocates that further research in those four axes is needed to better understand the relationship between those two industries in terms of land use as well as the socio-environmental on the ground impacts. Furthermore, the connections between those areas with present and future infrastructure development in the Amazon, many counting with direct Chinese investment, will be key to the expansion of the soy value chain, bypassing the initial goal of zero-deforestation.***Expansão de fronteira impulsionada pela China na Amazônia: quatro eixos de pressão causados pela crescente demanda pelo comércio de soja***A demanda chinesa por commodities tem capacidade para moldar fronteiras agrícolas em muitas partes do mundo, incluindo a Amazônia. Este artigo é um relatório preliminar sobre a expansão da fronteira agrícola na Amazônia brasileira, impulsionada por aumentos na produção de soja, extensão da área cultivada, cruzadas com dados de satélite sobre as taxas de desmatamento na menor escala possível: o nível municipal. O estudo identifica 21 municípios formando quatro eixos de expansão de fronteira na Amazônia, onde a lavoura de soja pode ser a causa do desmatamento indireto por deslocamento de outras atividades, como é o caso da pecuária. Apesar da Moratória da Soja, as fronteiras na Amazônia continuam mudando. O artigo defende que mais pesquisas nesses quatro eixos são necessárias para entender melhor a relação entre essas duas indústrias em termos de uso da terra, bem como os impactos socioambientais in loco. Além disso, é fundamental traçar as conexões entre esses eixos com o desenvolvimento presente e futuro de obras de infraestrutura na Amazônia, muitas delas com investimento direto chinês, para antever a expansão da cadeia de valor da soja, que pode estar ignorando de fato a intenção inicial de uma cadeia de valor de desmatamento zero.Palavras-chave: Amazônia. Fronteiras agrícolas. Desmatamento. Soja. Demandachinesa.

Acoustic space occupancy: Combining ecoacoustics and lidar to model biodiversity variation and detection bias across heterogeneous landscapes

Abstract There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a habitat, or soundscape, contains information about multiple taxa and may circumvent species identification, but robust statistical technology for characterizing community-level attributes is lacking. Here, we present the Acoustic Space Occupancy Model, a flexible hierarchical framework designed to account for detection artifacts from acoustic surveys in order to model biologically relevant variation in acoustic space use among community assemblages. We illustrate its utility in a biologically and structurally diverse Amazon frontier forest landscape, a valuable test case for modeling biodiversity variation and acoustic attenuation from vegetation density. We use complementary airborne lidar data to capture aspects of 3D forest structure hypothesized to influence community composition and acoustic signal detection. Our novel analytic framework permitted us to model both the assembly and detectability of soundscapes using lidar-derived estimates of forest structure. Our empirical predictions were consistent with physical models of frequency-dependent attenuation, and we estimated that the probability of observing animal activity in the frequency channel most vulnerable to acoustic attenuation varied by over 60%, depending on vegetation density. There were also large differences in the biotic use of acoustic space predicted for intact and degraded forest habitats, with notable differences in the soundscape channels predominantly occupied by insects. This study advances the utility of ecoacoustics by providing a robust modeling framework for addressing detection bias from remote audio surveys while preserving the rich dimensionality of soundscape data, which may be critical for inferring biological patterns pertinent to multiple taxonomic groups in the tropics. Our methodology paves the way for greater integration of remotely sensed observations with high-throughput biodiversity data to help bring routine, multi-taxa monitoring to scale in dynamic and diverse landscapes.

New Scholarship

New Scholarship

A spatiotemporal natural-human database to evaluate road development impacts in an Amazon trinational frontier

Road construction and paving bring socio-economic benefits to receiving regions but can also be drivers of deforestation and land cover change. Road infrastructure often increases migration and illegal economic activities, which in turn affect local hydrology, wildlife, vegetation structure and dynamics, and biodiversity. To evaluate the full breadth of impacts from a coupled natural-human systems perspective, information is needed over a sufficient timespan to include pre- and post-road paving conditions. In addition, the spatial scale should be appropriate to link local human activities and biophysical system components, while also allowing for upscaling to the regional scale. A database was developed for the tri-national frontier in the Southwestern Amazon, where the Inter-Oceanic Highway was constructed through an area of high biological value and cultural diversity. Extensive socio-economic surveys and botanical field work are combined with remote sensing and reanalysis data to provide a rich and unique database, suitable for coupled natural-human systems research.

Intensification in agriculture-forest frontiers: Land use responses to development and conservation policies in Brazil

Abstract Deforestation associated with agricultural expansion, particularly that of extensive cattle ranching, remains a pressing challenge for sustainable development and climate mitigation efforts in South America. In response to these challenges, national and local governments, as well as private and non-governmental actors, have developed new forest conservation governance mechanisms. In addition to reducing deforestation for agricultural expansion, it is hoped that these policies may lead to the intensification of existing agricultural regions, thereby contributing to global food availability and continued rural development. The objective of this study is to understand the timing and spatial patterns of crop and pasture intensification in agriculture-forest frontiers in the context of changing conservation policies and rural development. We focus on Mato Grosso, the largest soy and cattle producing state in Brazil, which spans the Cerrado and Amazon biomes and has experienced among the highest levels of deforestation for agricultural expansion globally. Using econometric analysis of remotely sensed and agricultural survey data, we find that cropland and pasture intensification are both linked to increasing forest conservation restrictions and broader supply chain development. However, the effect of conservation restrictions on intensification is lower in regions where there is more forest remaining. While crop and pasture area dynamics are often coupled in agriculture-forest frontiers, crop intensification does not appear to have contributed to pasture intensification through animal feed production. Intensification of crop and pasture areas was associated with temporary, immediate reductions in local deforestation, but crop intensification was associated with increased deforestation over longer time periods. These results suggest that targeted investments in supply chain infrastructure in the Amazon frontier could promote intensification and relieve pressure to clear forests, but must be coupled with substantial, long-term negative incentives for deforestation, including more effective public forest governance and private zero-deforestation commitments.