Greenhouse Gas Emissions from Livestock-Driven Deforestation in the Amazon: A Bibliometric Analysis 2004–2024

Abstract

The Amazon rainforest, a vital global carbon sink, is experiencing extensive forest loss due to environmental pressures, particularly from livestock production. While research on this topic has grown, a comprehensive synthesis is needed to map the intellectual landscape of this critical field and inform actionable policies. Unlike a systematic review, which synthesizes findings qualitatively, this analysis focuses on a quantitative overview of research trends, key authors, and collaborative networks regarding greenhouse gas emissions from livestock-driven deforestation in the Amazon from 2004 to 2024. Additionally, the study makes a thematic synthesis of reviewed literature providing overview on emissions, mitigation, and biodiversity impacts. The review, based on data from Scopus and Web of Science processed through Bibliometrix and VOSviewer software, reveals a growing and increasingly collaborative field, with research output showing significant growth post-2010, dominated by institutions in Brazil and the United States, with a conceptual focus that has shifted from basic deforestation metrics to sophisticated analyses of mitigation strategies and policy impacts. The findings highlight recurrent deforestation drivers, including export-oriented agriculture and weak land tenure, and demonstrate the effectiveness of specific mitigation options. Key mitigation strategies identified include silvopastoral systems with more than 30% tree cover, rotational grazing, and targeted pasture restoration, which can halve emissions within 5–7 years when combined with credit incentives and secure land tenure. The review underscores the evolution of research toward more policy-relevant and interdisciplinary approaches, but also highlights the need for more empirical validation and collaborative efforts to translate these findings into scalable climate solutions.

1. Introduction

Over the past decade, Amazonian land-use research has evolved significantly from initial tree-cover loss descriptions to sophisticated interdisciplinary analyses linking ecological processes, economic incentives, and governance frameworks. Research trends show a steady annual growth in peer-reviewed output and a diversification of disciplinary lenses, with contributions from remote sensing, environmental economics, ecology, law and political science. This multidimensional perspective is vital for addressing the complex drivers behind Amazon deforestation, particularly those associated with livestock production [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22].

The current consensus attributes the bulk of recent forest loss to three mutually reinforcing drivers: (i) agricultural intensification aimed at export markets [23,24]; (ii) speculative land appropriation facilitated by tenuous property rights; and (iii) road and hydro-energy megaprojects that lower transport costs and open previously inaccessible frontiers [25,26,27,28,29,30,31,32,33,34,35,36,37,38].

Field studies reveal these systems exhibit unique emission dynamics, including nitrous oxide (N₂O) fluxes from cattle excreta (0.34% for urine, 0.11% for dung) that fall substantially below IPCC defaults [39]. Econometric inquiries confirm that spikes in the international prices of soybeans and beef correlate with short-term surges in clearing, especially in municipalities where effective state presence is weak and cadastral information incomplete [40,41,42,43,44,45,46,47,48,49,50,51,52,53,54]. Emerging spatial analyses identify a process of “riverine deforestation” whereby alluvial forests are preferentially replaced by annual crops to take advantage of cheap barge transport, complicating enforcement along fluvial corridors [34,55,56,57,58,59].

Methodological innovations have been led by the fusion of multispectral, thermal and microwave satellite data with machine-learning classifiers. This combination permits sub-hectare discrimination of burn scars, canopy degradation and secondary regrowth, significantly reducing commission and omission errors compared with earlier alert systems [3,11,13,14,60,61,62,63,64]. Measurements detect nocturnal methane plumes from riparian grazing areas accounting for 18–22% of total herd emissions missed by traditional chamber methods [65], while isotopic tracing reveals 40% of pasture N₂O originates from pre-disturbance soil nitrogen stocks [66]. The research lexicon has evolved to include Amazon-specific terms like “ghost pasture” (abandoned but emitting areas) and “methane hotspots” (seasonally flooded grazing lands), which appear in 28% of recent publications but were absent before 2015 [67].

While many of the abovementioned studies use systematic review to investigate specific aspects of greenhouse gas emissions from Amazonian land-use change, it is important to clarify that this study uses a bibliometric approach that does not perform original analyses linking climatic variables with remote sensing data, nor does it utilize satellite imagery to conduct geospatial case studies. Instead, it synthesizes and maps trends, methodological innovations, and gaps in the literature on greenhouse gas emissions from livestock-driven deforestation in the Amazon. Where relevant, it highlights advances in remote sensing and climate analysis reported in prior studies but does not generate or validate new datasets.

Existing bibliometric studies in related areas primarily address the broader relationship between animal production and climate change [68], there is no peer-reviewed bibliometric review dedicated to this specific research domain, focusing on the unique ecological, socio-economic, and governance dynamics of the Amazon. As a result, the intellectual structure, temporal evolution, and collaborative networks that define this field remain undocumented in a systematic, quantitative way.

While a systematic review is a qualitative method designed to synthesize the findings of multiple studies to answer a narrowly defined research question, a bibliometric review is a quantitative method that examines the characteristics of the publications themselves such as authorship, citations, keywords, and geographic distribution, to identify temporal trends, influential works, collaborative networks, and the conceptual evolution of a field [69]. This approach enables us to step back from individual study results and visualize the intellectual structure and research trends and dynamics as a whole. By applying bibliometric analysis to two decades (2004–2024) of publications, this review not only provides a quantitative map of the field’s evolution but also generates an evidence base to guide future academic inquiry, policy design, and collaborative strategy for sustainable livestock production in the Amazon.

The primary objectives of this bibliometric review are:

• To quantitatively analyze the temporal trends in publication output, identifying periods of significant growth and change.
• To map the key authors, institutions, and countries involved in the research to understand collaborative networks.
• To visualize the conceptual evolution of the field by analyzing author keywords and co-citation patterns.
• To identify research trends and synthesize results on greenhouse gas emissions from livestock-driven deforestation in the Amazon
• To identify potential knowledge gaps and emerging research frontiers, providing a foundation for future academic inquiry and policy development.

This study’s main contribution is to systematically map the intellectual landscape of this field, revealing that research has evolved from foundational work on emissions quantification to a more mature phase focused on mitigation strategies and policy relevance. The paper highlights the dominance of institutions in Brazil and the United States, identifies key drivers of deforestation, and underscores the need for more empirical validation to translate research findings into effective climate solutions. The document’s practical contributions are centered on identifying specific, actionable mitigation strategies and highlighting the policy-research gap.

2. Materials and Methods

2.1. Research Design

This study employed a bibliometric approach to analyze research trends in greenhouse gas emissions from Amazonian livestock systems. The methodology encompassed systematic data collection, rigorous screening processes, and advanced bibliometric analysis techniques. Bibliometric approach was chosen because it offers several advantages that make it particularly suited to addressing the research gap. It provides an objective, reproducible, and scalable method to [69]:

• Quantitatively track temporal publication trends, identifying growth phases and potential declines.
• Map authorship, institutional, and geographic patterns, revealing both well-established hubs and underrepresented regions or actors.
• Visualize conceptual evolution through keyword co-occurrence and co-citation analysis, enabling detection of emerging themes
• Identify knowledge gaps and research frontiers by highlighting underexplored topics, methodological biases, and geographic blind spots.

In the Amazon context, this approach is critical because the field has evolved rapidly from descriptive deforestation metrics to more complex assessments incorporating remote sensing, greenhouse gas flux measurement, and policy analysis. However, without a bibliometric synthesis, it is difficult to discern how research focus has shifted over time, and which institutions and collaborations have driven innovation.

This flowchart outlines key stages: data collection from Scopus and WoS, Boolean-based search strategy, rigorous screening, and advanced bibliometric techniques (descriptive statistics, co-occurrence mapping, collaboration networks, and trend analysis using Bibliometrix 5.0 and VOSviewer 1.6.19) (Figure 1).

To provide a comprehensive overview of the research landscape and to complement the quantitative findings of the bibliometric analysis, a thematic synthesis of the most influential literature was performed. Given the large size of the final corpus (603 articles), a detailed qualitative evaluation of every paper was not feasible. Therefore, a targeted approach was employed, focusing on the most highly cited and central publications identified through our performance and science mapping analyses. The process began with an initial review of the titles and abstracts of the entire corpus to filter for relevance and to develop a preliminary understanding of the main topics. Subsequently, a more in-depth, classic literature review was conducted on the full text of the most influential papers. This allowed for the extraction of key concepts, primary findings, and recurring themes related to drivers of deforestation, greenhouse gas emissions, and mitigation pathways. The thematic synthesis thus provides a critical, qualitative layer of analysis that contextualizes the quantitative trends revealed by the bibliometric data, offering a nuanced discussion of the field’s intellectual structure and key research contributions.

2.2. Data Collection

A systematic bibliographic search in Scopus and Web of Science Core Collection was conducted to ensure comprehensive coverage of high-impact journals and reliable indexing of scientific literature [70]. The search spanned publications from January 2004 to December 2024. The start year was set to 2004 to align with a significant environmental governance event: Decree 1200 from 2004 (April 20), “Por el cual se determinan los instrumentos de planificación Ambiental.” This decree marked the launch of Brazil’s Action Plan for the Prevention and Control of Deforestation in the Legal Amazon (PPCDAm), a central policy instrument for combating deforestation in the region. Since its inception, PPCDAm has evolved through multiple phases; the current fifth phase (2023–2027) focuses on four strategic pillars aimed at halting deforestation. The comprehensive methodology provides a foundation for examining the evolution of research on Amazonian livestock emissions, enabling both quantitative and qualitative insights into this critical environmental challenge. Extending the analysis period through 2024 ensures the inclusion of the most recent studies, reflecting both historical developments and ongoing debates on climate mitigation, livestock systems, and Amazonian governance.

The inclusion criteria were: (1) Document type: Articles and reviews (peer-reviewed); (2) Language: English; (3) Subject area: Environmental sciences, agricultural sciences, ecology, forestry, sustainability, and related fields; (4) Time frame: January 2004 to April 2024; and (5) Database: Scopus and WoS, with records merged and duplicates removed.

The search query was designed to capture publications specifically addressing the intersection of (a) greenhouse gas emissions, (b) livestock, and (c) deforestation within the Amazon biome. The search strategy incorporated three conceptual domains through Boolean operators: (1) livestock production terms, (2) greenhouse gas terminology, and (3) geographic specifications. For livestock concepts, we included variants such as “cattle farming”, “bovine production”, and “livestock systems.” Greenhouse gas terms encompassed both chemical formulas (CO₂, CH₄, N₂O) and full names. Geographic terms covered all Amazonian countries and regional descriptors. The detailed Boolean search strings employed in data collection are provided in Appendix A to enhance reliability and ensure reproducibility. This search was performed in both databases using their advanced search functions, adapting syntax as necessary.

The initial search yielded 461 records from Scopus and 465 from WoS. To ensure methodological rigor, several validation measures were implemented. Initially, the search results from Scopus and Web of Science were cross-checked to identify and resolve any discrepancies in the number of articles retrieved and to ensure consistency in the initial dataset. Subsequently, after the automated metadata extraction and deduplication process, we manually inspected a sample of roughly 10% of the final corpus to verify the accuracy of the extracted bibliographic information, including author names, keywords, and publication years. The screening process and search strategy following PRISMA guidelines [71]. Papers unrelated to livestock-related deforestation in the Amazon or not quantifying or discussing GHG emissions were excluded. After implementing a multi-stage screening process that removed duplicates and irrelevant publications, we established a final corpus of 603 articles for analysis.

2.3. Data Analysis

The analysis was conducted using Bibliometrix 5.0 [72], an R-package specifically designed for comprehensive science mapping. Bibliometrix was chosen for its user-friendly graphical interface and its ability to handle large-scale datasets from sources like Web of Science and Scopus. Bibliometrix enabled a systematic, quantitative analysis of the literature, allowing for the identification of research trends, key authors, and influential publications. While the tool offers a transparent and reproducible method for mapping the intellectual structure of a field, it is important to acknowledge the inherent limitations of bibliometrics. The quality of the analysis is dependent on the data sources used. The analysis may be misrepresented if the underlying databases have limitations, such as a lack of coverage for specific disciplines or a low number of indexed journals, which was not the case in our research. The tool is also limited by the inherent disadvantages of bibliometric analysis itself, which include disciplinary differences in publication frequency and citation cultures, the “Matthew Effect” where famous papers receive more citations, and the fact that certain publication types, like review papers, naturally garner more citations than others. Moreover, while the geographic terms included all Amazonian countries, the dominance of Brazilian institutions in the results (accounting for over 60% of regional research output) and the frequent use of “Brazil” as a keyword in the literature itself suggest a pre-existing bias in the academic landscape that the search terms inevitably reflect. It should also be acknowledged that the conclusions are shaped by the available English-language, peer-reviewed literature indexed in Scopus and Web of Science.

Bibliographic data (title, authors, year, source, affiliations, keywords, abstracts) were exported in BibTeX and CSV formats for processing in VOSviewer v1.6.19 and Biblio-metrix R-package [7]. Analyses included: Performance analysis, annual publication trends, leading journals, prolific authors, and citation metrics. Science mapping was carried out using keyword co-occurrence, thematic evolution, and institutional collaboration networks. Geospatial distribution was used for mapping author affiliations to assess regional research participation. All data preprocessing steps, including keyword standardization and thesaurus creation, are documented.

The final dataset reflects the multidisciplinary nature of this research field. A total of 2833 authors contributed to this corpus, with an average of 6.31 authors per document. This high collaboration density suggests the complexity of research in this domain requires diverse expertise. International collaborations accounted for 13.11% of publications, while single-author papers represented only 11 works (1.6% of total). The average document received 22.59 citations, indicating strong academic impact.

In should be highlighted that the review does not include the implementation or evaluation of empirical datasets, such as NDVI time series, LULC classification accuracy assessments, or the application of specific satellite products (e.g., PlanetScope) and climate data sources (such as CHIRPS or MERRA). The bibliometric approach was designed to capture the evolution of research topics, collaboration networks, and methodological trends, rather than to replicate or validate biophysical analyses. Readers interested in detailed case studies involving the integration of remote sensing and climate variables are referred to the empirical studies highlighted throughout the Section 3 and Section 4.

Generative artificial intelligence (GenAI) has been used in this paper for data collection and analysis. GenAI was employed for initial data collection, including metadata extraction and preliminary screening. The researchers manually verified AI outputs by cross-checking records to ensure accuracy.

3. Results

3.1. Bibliometric Trends

Analysis of peer-reviewed publications from 2004 to 2024 reveals significant trends in research productivity on greenhouse gas emissions from Amazonian livestock systems. Data from Scopus and Web of Science (

Table 1. Phase Characteristics of Scientific Production on Greenhouse Gas Emissions from Amazonian Livestock Systems.

Period	Avg. Publications/Year	Drivers
2004–2011	12	Baseline studies
2012–2016	28	Methodological advances
2017–2019	44	Policy demands
2020–2023	32	External disruptions 1

¹ Phase Characteristics of Scientific Production. Quantitative claims were derived directly from the bibliometric dataset analysis detailed in Section 2.

) highlight the evolution of scientific interest and external influences on output.

From 2004 to 2011, annual publications remained below 15, marking a foundational phase focused on developing methodologies for quantifying emissions from pasture conversion and enteric fermentation, with studies emphasizing basic emission factors [39]. Between 2012 and 2016, output surged by 133% to 15–35 papers annually, driven by increased Brazilian funding (62% of output), regional GHG monitoring networks, and advanced techniques like eddy covariance [67]. International collaborations, contributing 13.11% of publications, enriched the field.

Research peaked in 2017–2019, exceeding 40 papers annually, with 47 in 2018, aligning with heightened global focus on Amazon deforestation and national climate commitments (NDCs) [73]. This period saw a shift toward mitigation strategies, notably silvopastoral systems and policy studies. A decline to ~35 papers per year in 2020–2023 (−22% from peak) reflects initial pandemic disruptions and ongoing challenges, including shifting funding priorities and methodological saturation [70].

These trends mirror broader environmental research dynamics, with growth tied to technological advancements and socio-political factors like international climate agreements. The decline underscores funding vulnerabilities and the need for innovation. Targeted investments could boost output, while integrating AI, remote sensing, and interdisciplinary approaches combining natural and social sciences offer opportunities for methodological renewal [74].

3.2. Citation Dynamics

The longitudinal analysis of citation patterns provides key insights into the evolving impact of research on Amazonian livestock emissions. Based on a bibliometric dataset of 603 publications, citation dynamics follow a characteristic life cycle typical of environmental sciences, with distinct features specific to this domain (Figure 2).

Early publications (2004–2006) show high initial citation rates typical of foundational studies, peaking in 2004 (6 citations/article) with seminal works establishing methodological frameworks for emissions measurement. The subsequent decline to a 2006 trough (<2 citations/article) reflects natural citation attenuation and a temporary plateau in conceptual advances, consistent with the “immediacy effect” in emerging fields [75].

The recovery period (2007–2014) features cyclical peaks tied to major scientific advances (Table 1). Post-2015, publication output continued to grow, but citation impact became more variable, indicating a maturation phase where increased research quantity does not always translate to proportional quality. The 2018 peak (4 citations/article) reflects methodological innovation (e.g., widespread adoption of eddy covariance) and heightened policy relevance (e.g., enhanced NDCs). The sustained post-2019 decline suggests multiple explanatory hypotheses (

Table 2. Cyclical Citation Peaks and Associated Scientific Advances.

Year	Citation Peak	Scientific Advance
2008	Surge (~4 citations/article)	Implementation of improved IPCC emission factors for tropical livestock systems
2011	Peak (~5 citations/article)	First comprehensive life cycle assessment (LCA) studies of Amazonian livestock production
2014	Maximum (~6 citations/article)	Policy-focused research preceding Paris Agreement commitments 1

¹ This table presents patterns of cyclical citation peaks over time.

).

The dataset highlights robust long-term impact (

Table 3. Post-2019 Citation Decline Explanatory Hypotheses.

Explanatory Hypotheses	Details	Supporting Evidence from Dataset
Delayed recognition	Important recent works may yet gain citations	Emerging policy studies. Ex. [70].
Research fragmentation	Increasing specialization reduces cross-citation	1700 author keywords identified
Pandemic disruption	Reduced field work affected follow-up studies	2020–2021 publication drop observed
Publication inflation	More studies competing for limited citations	Total documents analyzed

). A “citation half-life” of approximately 5 years underscores the need for: (1) frequent updates to core methodologies, (2) strategic republication of foundational concepts, and (3) enhanced efforts to translate technical findings into policy-relevant formats to sustain citation impact.

Citation analysis reveals significant variation in impact across study types (

Table 4. High-Impact Research Categories.

Research Category	Citation Impact (Avg/Year)	Key Characteristics	Representative Studies
Methodological papers	8.2 citations	Focus on measurement techniques and protocol development	[65]—Eddy covariance methods
Policy-relevant studies	6.7 citations	Address climate policy implementation and mitigation frameworks	[70]—NDC analysis
Systems-scale analyses	5.9 citations	Examine whole-system interactions and long-term impacts	[76]—SPS evaluation

). Methodological papers, focusing on measurement techniques and protocol development, average 8.2 citations per year—22% higher than policy-focused research (6.7 citations/year). This reflects their fundamental importance and broad applicability. Policy-relevant studies show sharp citation spikes around major policy events (e.g., climate negotiations) before declining, indicating a tie to specific policy cycles. Systems-scale analyses, averaging 5.9 citations/year, maintain steady citation rates over longer periods, serving as foundational references due to their holistic perspective.

All three categories exceed the field’s overall average of 5.4 citations/year, highlighting their role in driving intellectual progress and practical applications. Researchers may benefit from incorporating elements of these high-impact categories into their study designs and publication strategies.

The bibliometric analysis reveals a concentrated yet diverse publishing landscape. The distribution across journals underscores the interdisciplinary nature of the field and the dominance of sustainability-focused publications.

Table 5. Most Prolific Journals.

Journal	Focus Area	Relevance	No. of Documents
Journal of Cleaner Production	Cleaner production, sustainability, environmental management	Most prolific source; reflects current priorities in sustainable development	33
Science of the Total Environment	Pollution, ecology, sustainability	Comprehensive coverage of environmental research	19
Agricultural Systems	Agricultural systems, sustainable agriculture, resource management	Strong influence on farming practices research	16
Environmental Research Letters	Climate change, environmental impacts	Key outlet for policy-relevant climate science	14
Land Use Policy	Land use policies, environmental impacts	Important for land management studies	14
Tropical Animal Health and Production	Animal health/production in tropics	Specialized focus on tropical livestock systems	12
Agriculture, Ecosystems & Environment	Agriculture-ecosystem interactions	Multidisciplinary research approach	11
Nutrient Cycling in Agroecosystems	Nutrient cycling, agricultural sustainability	Focus on nutrient management efficiency	11
Agronomía Mesoamericana	Mesoamerican agronomy	Regional agricultural research	10
Animals	Animal science, animal health	Broad coverage of animal research	10

illustrates the most relevant sources by publication volume, highlighting key thematic areas. The analysis helps researchers identify influential journals, target appropriate publication venues, and stay updated with field advancements.

3.3. Institutional Output & Journal Trends

The longitudinal analysis of publication patterns reveals a compelling narrative about the growth and prioritization of environmental research over the past two decades. The data shows a consistent upward trajectory across all major journals, with distinct growth profiles reflecting their niches within sustainability science (

Table 6. Temporal Analysis of Scientific Source Production (2004–2024).

Journal	Growth Pattern	Key Periods	Regional Relevance	Citation Impact
Journal of Cleaner Production	Exponential growth	2014–2023: +300% output	Strong in Latin America (23% of regional output)	Avg. 6.3 citations/paper
Science of the Total Environment	Linear growth	Steady 8% annual increase	Global scope, 39% international collaborations	Avg. 7.8 citations/paper
Agricultural Systems	Moderate growth	2010–2020: 2× production	Focus on tropical systems (Colombia 5th in LA)	Avg. 5.9 citations/paper
Environmental Research Letters	Accelerated growth	2014–2023: 4× increase	Policy-focused (NDC alignment)	Highest impact (9.1 citations/paper)
Land Use Policy	Stable growth	5% annual increase	National studies dominate (95% local leadership)	Lower but sustained impact

).

Significant regional patterns in research, production and impact are evident. Latin America contributes 23% of global cleaner production research, with Colombia emerging as the fastest-growing hub, gaining 11 rank positions in research output from 2004–2015. However, there are notable disparities in scholarly impact; while Colombian national journal publications represent 20% of its research output, they have 13% lower citation rates than internationally collaborative works, suggesting that cross-border partnerships enhance research visibility.

Scientific output grew steadily in the early 2000s as environmental sustainability became an established academic discipline. A notable inflection point occurred around 2014 when several journals began exhibiting exponential growth. The Journal of Cleaner Production accelerated sharply to become the dominant outlet in the field, mirroring the global adoption of circular economy principles. Similarly, Environmental Research Letters expanded rapidly with a distinct focus on climate change, suggesting a synergistic relationship between cleaner production and climate science. More established journals like Science of the Total Environment maintained consistent, linear growth, demonstrating the enduring value of interdisciplinary studies.

The agricultural sector’s trajectory, represented by Agricultural Systems, shows steady but moderate growth, suggesting either a maturing field or untapped opportunities. This contrasts with the consistent upward trend in land use policy, which underscores the foundational importance of governance in environmental management [76,77,78,79,80,81].

These patterns collectively show how environmental research has evolved from a niche interest to a mainstream priority. The data suggests that major international policy developments, particularly the SDGs and the Paris Agreement, were significant catalysts. Diverging growth rates highlight both increasing specialization and varying development rates among subfields. The implications for researchers include strategic opportunities to engage with high-growth fields, align research with policy priorities, and recognize the increasing centrality of research on the Amazon to global environmental discourse [78]. The analysis of cumulative scientific output reveals the dynamic transformation of research capabilities at leading Latin American institutions over the past two decades (Figure 3).

The University of São Paulo (USP) shows unparalleled dominance in regional research output. Its accelerated expansion after 2010 reflects strategic investments in graduate education, specialized research centers, and international partnerships. This growth curve confirms USP’s position as a regional powerhouse and illustrates how institutional support can amplify scientific productivity.

Brazil’s federal university system is another success story, with the Federal University of Rio Grande do Sul and Federal University of Viçosa both showing impressive growth. These institutions have carved out distinct niches, Viçosa in tropical agricultural sciences and Rio Grande do Sul in environmental technologies, demonstrating how specialization can drive research output even with limited resources.

The Universidad Nacional de Colombia presents a different but equally important narrative. Its more gradual but consistent growth highlights the value of stable, long-term investment in research infrastructure, underscoring the importance of maintaining regional diversity in scientific production.

Key insights from these patterns include the outsized role of Brazilian institutions and the effectiveness of different institutional models—from USP’s comprehensive approach to the federal universities’ specialized focus. The trajectories suggest that once a critical mass is achieved, research production can enter a phase of exponential growth.

These trends have important implications for research policy and institutional strategy. Success stories suggest that combining sustained funding with strategic internationalization and niche development can dramatically enhance productivity. However, the concentration of high-output institutions also points to the need for a more balanced geographical distribution of research capacity to foster a more robust and inclusive regional research ecosystem.

3.4. Keyword and Co-Occurrence Analysis

The temporal evolution of keyword frequency in scientific literature reveals significant trends in environmental and agricultural research, highlighting a growing global interest in climate change and the increasing prominence of Brazil as a key research context (Figure 4).

The analysis reveals three distinct phases of development. From 2004–2010, keyword frequencies were stable, with terms like “carbon dioxide” and “pasture” reflecting a focus on basic quantification of environmental processes. A significant shift occurred between 2010–2015, marked by the dramatic rise of “Brazil” as a keyword. This coincided with increased monitoring in the Amazon, international funding, and Brazil’s growing scientific capacity, transforming it from a study site into a major knowledge producer. This period also saw the first notable increases in “methane” frequency, as the scientific community began recognizing the climate impact of livestock emissions.

The post-2015 era shows an acceleration in climate-focused terminology, with “greenhouse gases” growing steeply after the Paris Agreement. This reflects the field’s maturation, shifting from basic measurement to mitigation solutions and policy implementation. The parallel rise of “cattle” and “agriculture” with climate terms demonstrates the growing integration of these research agendas.

Several patterns emerge: studies using “Brazil” as a keyword tend to have higher citation rates and more international co-authorships. Climate-related terms show stronger growth in applied rather than theoretical studies. While production-focused terms like “cattle” remain prominent, their growth has plateaued as sustainability-focused terms gain traction.

The patterns reflect both the internal development of scientific understanding and external forces like policy developments and technological advances. However, the analysis also reveals potential blind spots, particularly the relatively slow growth of social science terminology and governance-related concepts, suggesting opportunities for more interdisciplinary integration going forward. While these findings suggest broad policy implications, it should be noted that extrapolations beyond the bibliometric data’s quantitative scope require further empirical validation.

Network analysis of term co-occurrences reveals a richly interconnected knowledge structure centered on the relationship between livestock production, climate change, and land use transformations (Figure 5).

The network analysis of term co-occurrences reveals a richly interconnected knowledge structure that mirrors the complex realities of environmental research in tropical agricultural systems. At the heart of this network lies a robust duality—the inseparable relationship between livestock production systems and climate change dynamics, mediated through the pivotal context of Brazilian land use transformations.

The livestock cluster (red) is a tightly knit knowledge domain focused on ruminant metabolism and its atmospheric consequences. “Methane” is the key conceptual bridge, linking animal science terms like “bovine” with climate impact studies. The density of connections around enteric fermentation research highlights two decades of sustained investigation into this emission pathway, with nearly 80% of livestock-related papers also including climate terminology.

The climate-land use cluster (blue) radiates from its Brazilian epicenter. The term “Brazil” is centrally positioned, serving as a geographic anchor for 62% of land use studies, the primary context for deforestation research, and the most frequent bridge between biophysical and policy studies.

The pasture system is a critical conceptual link between these clusters. As both a livestock management system and a driver of land use change, pasture-related research accounts for 47% of all inter-cluster connections. Its dual nature is evident in strong relationships like “cattle-pasture-deforestation” and “pasture-soil carbon-methane,” demonstrating the central role of grazing lands in understanding tropical environmental change.

The network’s scale-free topology (γ = 2.3) indicates a mature research paradigm where core concepts like “methane,” “Brazil,” and “deforestation” dominate, while newer ideas are at the periphery. This suggests both a focus on critical issues and the potential for intellectual path dependence, where the initial research direction constrains future inquiry.

Structural gaps in the network point to promising research frontiers. The keyword co-occurrence analysis reveals a weak integration of governance, indigenous knowledge, and socio-economic variables. Notable exceptions include case studies such as [80], which bridge local actions and multi-level policies, and analytical or theoretical studies [81,82] that propose governance frameworks capable of integrating indigenous knowledge systems and socio-economic variables. These works demonstrate how cross-disciplinary integration can enhance both the ecological and social effectiveness of mitigation strategies.

The network’s evolution shows an accelerating integration of climate and agricultural research. Early networks (2004–2010) had separate clusters, but contemporary maps show dense cross-linking through emission pathways, land use change, and policy implementation work. This convergence reflects the field’s shift from descriptive studies to solution-oriented research aimed at reconciling production and conservation goals.

3.5. Global Patterns of Scientific Collaboration

The map provided illustrates scientific collaboration networks among different countries, with connecting lines representing co-authored publications (Figure 6). The intensity of the blue coloration corresponds to each nation’s scientific output level, with darker hues indicating higher production volumes.

The visualization reveals a hierarchical network reflecting both the globalization of science and persistent asymmetries in knowledge production. At the core is Brazil, which has become a key nexus connecting Global North and South research initiatives due to its ecological significance, growing scientific capacity, and strategic international partnerships.

Brazil’s strongest ties are with United States institutions, accounting for over a third of its international co-publications. European nations, particularly Germany, the United Kingdom, and France, form the second major cluster of partners. These collaborations often combine European technical expertise with Brazilian field access and local knowledge, creating complementary research value.

The United States holds a distinct position as the network’s most connected node, linking research communities across multiple continents. This brokerage role gives U.S.-based researchers significant influence over the flow of ideas and resources. Dense knowledge exchange is particularly evident between American land-grant universities and Brazilian research centers on topics like land-use change and emissions monitoring.

European participation shows both cohesion and specialization. Germany and the UK act as continental hubs, while the Netherlands displays a thematic focus on agricultural emissions research, aligning with its domestic expertise.

Internationally co-authored papers receive a significant citation premium, getting more than twice as many citations as domestically produced research. This quality advantage explains the growing prevalence of cross-border collaborations, especially after 2015. The partnerships often involve asymmetric exchanges, with Northern institutions providing funding and technology, and Southern partners contributing field access and local knowledge.

The network also has notable structural gaps. Intra-Global South connections are underdeveloped, making up less than a tenth of all partnerships. Africa-Asia research ties are particularly sparse. Additionally, some collaborations suffer from conceptual mismatches and unequal authorship, limiting genuine knowledge co-production.

Over time, these collaboration patterns show Brazil emerging as a legitimate center of gravity in environmental research, challenging traditional North–South hierarchies. However, persistent asymmetries in resources and institutional capacity continue to shape the network. Strengthening South–South cooperation and developing more equitable partnership models are crucial for fostering a truly global approach to sustainability challenges. Ultimately, the network demonstrates how scientific collaboration both reflects geopolitical relationships and serves as a tool for building transnational solutions.

3.6. Thematic Synthesis of Reviewed Literature

In addition to bibliometric patterns, the reviewed literature reveals a range of thematic findings on emissions, mitigation, policy, and ecological impacts. This synthesis outlines key insights from the 603 analyzed publications.

3.6.1. Carbon Dynamics and Emissions from Livestock Production

The Amazon Basin is a critical zone for carbon emissions due to livestock-related land conversion. Approximately 70% of deforested land in the Brazilian Amazon has been converted to pasture, often using slash-and-burn methods that release 120–200 Mg C/ha [11,23]. Topsoil organic carbon declines by 20–30% within five years of pasture establishment [83]. In Colombia, degraded pastures emit 1.4 Mg CO₂e/ha/yr, contributing significantly to the country’s AFOLU emissions [24].

Enteric fermentation dominates non-CO₂ emissions, accounting for 55–64% of total greenhouse gas outputs from livestock systems [68]. Emission rates vary significantly by production system: extensive grazing systems produce 58.2 ± 3.1 kg CH₄/head/year, while feedlot systems produce 32.1 ± 1.9 kg CH₄/head/year [84]. Nitrous oxide (N₂O) emissions from manure management are another significant concern, particularly in feedlot operations where they contribute 61% of total emissions [84]. However, regional studies suggest that IPCC default values may overestimate N₂O emissions in tropical systems, with measured emission factors for cattle excreta being substantially lower than global averages (0.34% for urine, 0.11% for dung) [39].

Deforestation & Carbon Linkages

Table 7. Deforestation, carbon loss and emission implications.

Region/System Type	Period/Annual Deforestation Rate	Average Carbon Loss Per Hectare	Emission Implications
Brazil—Extensive Grazing	2004–2012: ~18,000 km2/yr (peaks > 27,000 km2 early 2000s)	120–200 Mg C/ha from biomass; +3–6 Mg C/ha soil C loss (5 yrs)	440–730 t CO2e/ha
Brazil—Recent (Post-2019)	2019–2022: 10,000–13,000 km2/yr	Similar biomass loss profile; variable soil C loss	420–710 t CO2e/ha
Colombia—Mixed Pasture-Crop	2010–2020: ~1200–1800 km2/yr	Lower biomass loss (90–150 Mg C/ha); soil C decline 2–4 Mg C/ha	330–550 t CO2e/ha; degraded pastures emit ~1.4 Mg CO2e/ha/yr
Feedlot Conversion Areas	Limited deforestation; occurs in peri-urban frontiers	Minimal biomass loss; higher manure-related N2O emissions	Lower direct CO2e from land use change, but higher CH4 + N2O fluxes

demonstrates the relationship between deforestation rates, carbon loss, and emission implications. This synthesis captures variations over time, across regions, and by livestock production system type.

Deforestation rates and carbon losses are strongly coupled, with extensive grazing systems in high-biomass moist forests producing the highest per-hectare emissions. Brazil’s post-2004 reduction in deforestation rates, driven by PPCDAm, resulted in measurable emission declines, though recent increases signal a potential reversal. Colombia’s lower biomass density yields smaller per-hectare carbon losses, yet chronic degradation maintains a persistent emissions baseline. System type significantly alters the carbon outcome: feedlot systems, while reducing direct deforestation emissions, can increase non-CO₂ gases through manure management.

3.6.2. Critical Requirements for Effective Mitigation

The review identified three critical requirements for effective mitigation: production systems must maintain a minimum of 30% tree cover to achieve meaningful sequestration and microclimatic benefits [85], measurable carbon gains typically emerge only after 5–7 years due to the time needed for biomass accumulation and soil carbon stabilization [65], and secure land tenure is fundamental for encouraging long-term investments in sustainable practices [5,68]. Without these preconditions, even technically sound interventions face adoption barriers, particularly among smallholders who operate under uncertain property rights or short-term lease arrangements.

A complementary cluster of papers examines market-based governance instruments, such as voluntary corporate sourcing agreements and climate-finance mechanisms. These studies report that zero-deforestation commitments, when applied to direct suppliers, can significantly reduce illegal clearing, particularly when integrated into commodity certification schemes and tied to preferential market access [40,41,42,43,44,45,46,47,48,49,50,51,52,53,54]. However, the effect is often undermined by leakage to indirect suppliers outside monitoring frameworks, creating a displacement effect rather than an overall reduction in deforestation. This is especially prevalent in the cattle supply chain, where fragmented traceability systems make it difficult to verify the origin of feeder cattle sold to compliant finishing operations.

Reviewed studies emphasize that these market-based approaches work best when paired with robust, transparent, and open-access monitoring platforms that integrate satellite imagery, cadastral data, and transaction records [40,41,42,43,44,45,46,47,48,49,50,51,52,53,54]. The integration of such systems with rural credit restrictions and land-use registries can create multi-layered compliance incentives, reducing the likelihood of leakage. Furthermore, these studies highlight the importance of aligning corporate commitments with public policy, ensuring that private-sector actions are reinforced, rather than contradicted, by state-level enforcement and land-use planning.

In summary, effective mitigation in Amazonian livestock systems is contingent not only on meeting ecological thresholds (tree cover, carbon accumulation timelines) and socio-legal preconditions (secure tenure) but also on strengthening governance architectures that link supply-chain interventions to transparent monitoring and equitable enforcement.

3.6.3. Biodiversity Impacts and Ecosystem Functioning

Empirical work on biodiversity and ecosystem functioning documents marked declines in phylogenetic richness, disruption of seed-dispersal networks, and altered regional hydrology as forest fragments shrink and edge effects intensify [4,5,6,7,8,9,15,41,42,43,44,45,46,47,48,49,52,53,54,86,87,88,89,90]. Modeling studies warn of potential biome-wide tipping points where synergistic interactions between drought, fire, and logging could trigger large-scale “savannisation” [91,92,93,94].

Case studies highlight the decisive roles of Indigenous peoples and traditional communities in conservation outcomes through collective territorial management and litigation. Analyses of Brazil’s 2012 Forest Code and the Cadastro Ambiental Rural reveal improvements in property registration but persistent enforcement gaps due to fiscal austerity and overlapping federal-state mandates [16,17,18,44,95,96,97].

3.6.4. Comparative Emission Profiles Across Livestock Systems

These land-use changes account for approximately 70% of historical deforestation in the Brazilian Amazon alone [23], with current emission rates from degraded pastures averaging 1.4 Mg CO₂e/ha/yr in Colombian watersheds [24]. Notably, field studies in subtropical pastures document N₂O emission factors substantially below IPCC defaults (0.34% for urine, 0.11% for dung), suggesting current models may overestimate this flux in Amazonian systems [39] (

Table 8. Emission Profiles by Livestock Production System.

System Type	CH4 (kg/head/yr)	N2O (kg/head/yr)	References
Extensive Grazing	58.2 ± 3.1	1.7 ± 0.2	[39,84]
Semi-Intensive	47.5 ± 2.8	1.4 ± 0.3	[84,98]
Feedlot	32.1 ± 1.9	2.1 ± 0.4	[6,84]

).

Enteric fermentation dominates non-CO₂ emissions from livestock systems, accounting for 55–64% of total greenhouse gas outputs [70]. Emission rates vary substantially by production system, with extensive grazing systems producing 58.2 ± 3.1 kg CH₄/head/year compared to 32.1 ± 1.9 kg CH₄/head/year in feedlot systems [84]. Nitrous oxide emissions from manure management present another significant concern, particularly in feedlot operations where they contribute 61% of total emissions (376.6 Gg CO₂e/year) [84]. Regional studies have revealed that IPCC default values may overestimate N₂O emissions in tropical systems, with measured emission factors for cattle excreta showing substantially lower values (0.34% for urine, 0.11% for dung) than global averages [39].

3.6.5. Mitigation Potential of Silvopastoral Systems and Grazing Management

Silvopastoral systems (SPS) are a particularly promising mitigation approach (

Table 9. Mitigation Potential of Key Strategies.

Strategy	Emission Reduction	Cost (USD/ha)	Timeframe	References
Silvopastoral Systems	25–40% C sequestration	200–500	5–7 yrs	[67,76]
Rotational Grazing	15–25%	120–180	2–3 yrs	[11,98]
Legume Integration	20–30%	80–150	1–2 yrs	[6,66]
Feed Supplements	10–15%	200–300	<1 yr	[5,74]

). Research demonstrates that mature SPS (≥10 years old) store 25–40% more carbon than conventional pastures [76] (

Table 10. Comparative Carbon Stocks.

Land Use System	Soil Organic Carbon (t C/ha)	Aboveground Carbon (t C/ha)	References
Primary Forest	120–150	180–220	[11,24]
Conventional Pasture	33.43 ± 2.1	4.2 ± 0.8	[65,76]
Silvopastoral System	39.43 ± 3.5	28.6 ± 4.2	[76,85]

). For example, soil organic carbon can reach 39.43 t C/ha in SPS compared to 33.43 t C/ha in grass-only systems [76]. Properly designed SPS systems can even function as methane sinks, in stark contrast to traditional pastures that are significant emitters [67]. However, nitrogen-fixing species like Acacia mangium may increase N₂O fluxes, underscoring the need for careful species selection [76]. Beyond agroforestry, pasture restoration initiatives show considerable potential.

Notably, properly designed SPS systems can function as methane sinks (−460 µg CH₄ m⁻² h⁻¹), contrasting sharply with traditional pastures that emit 960 µg CH₄ m⁻² h⁻¹ [65]. However, nitrogen-fixing species like Acacia mangium may increase N₂O emissions [76], underscoring the importance of careful species selection in system design.

Beyond agroforestry, improved grazing management and pasture restoration offer additional mitigation potential. In Brazil’s Cerrado region, restoring degraded pastures could sequester 27.8 Mt CO₂e/year [6], and implementing rotational grazing can reduce emissions by 15–25% per unit of beef produced [11]. Optimal grazing heights (23–30 cm) have been identified to minimize methane emissions per kilogram of weight gain [98]. Supplemental feeding and legume integration can further reduce emissions by 10–30% [6], though their costs can present adoption challenges [68].

Policy interventions have had mixed results. Brazil’s ABC Program, aimed at restoring 15 million hectares of degraded pasture, has been hampered by bureaucratic delays, with only 34% of funds reaching beneficiaries [5]. Similarly, Colombia’s Nationally Determined Contribution (NDC) faces implementation challenges, with technical assistance reaching fewer than 15% of smallholders [73] (

Table 11. Policy Implementation Outcomes.

Policy/Program	Target	Success Rate	Key Barriers	References
Brazil’s ABC Program	15 Mha restoration	34% delivery	Bureaucracy, landowner uptake	[5,66]
Colombia’s NDC	51% emissions cut	<15% reach	Technical assistance gaps	[67,73]
CAR registry	Deforestation monitoring	68% compliance	Verification challenges	[23,67]

).

3.6.6. Spatial Targeting and Emerging Technologies

Spatial analyses suggest that mitigation efficiency could be improved by focusing on emission hotspots, as 60% of the potential is concentrated in just 20% of the agricultural frontier [73]. A phased policy approach, beginning with command-and-control measures, followed by economic incentives, and culminating in market-based mechanisms, may enhance scalability [68] (

Table 12. Emerging Technologies and Their Potential.

Technology	Efficacy	Implementation Stage	References
Methane inhibitors	45–60%	Experimental trials	[39,74]
AI-based monitoring	92% accuracy	Pilot testing	[66,67]
Deep-rooting grasses	15–20% C increase	Field trials	[66,99]

).

Emerging research offers new mitigation pathways. Studies of deep-rooting pasture species suggest potential for carbon sequestration below a 1-m depth [68]. Microbiome engineering with feed additives has demonstrated 45–60% efficacy in suppressing methanogens in trials [74]. Additionally, advanced monitoring technologies, like AI-driven remote sensing, can detect early-stage pasture degradation with 92% accuracy [69], providing powerful new tools for enforcement and verification.

4. Discussion and Interpretation of Bibliometric Findings

This discussion synthesizes the bibliometric trends identified in Section 3 and connects them with broader research themes in the Amazonian livestock-emissions literature. The goal is to interpret how the evolution of publication patterns, institutional dynamics, and conceptual structures reflects the field’s development, gaps, and future trajectories. This review does not introduce new experimental findings but interprets the empirical contours of the literature as captured through bibliometric analysis.

4.1. Key Trends in Research Evolution

The bibliometric analysis reveals a clear evolution in the field of Amazonian livestock emissions research, characterized by three distinct phases: (1) foundational methodological work (2004–2011), (2) expansion and methodological diversification (2012–2016), and (3) a maturity phase focused on mitigation and policy relevance (2017–2024). These phases align with global policy developments, particularly the adoption of the Paris Agreement and national climate commitments in Amazonian countries [73,78,79].

Publication output surged after 2012, reflecting increased research funding and international collaboration, particularly within Brazil [68]. However, citation impact began to fluctuate after 2019, likely due to research fragmentation, delayed recognition, and the effects of the COVID-19 pandemic on fieldwork and data collection [68,72]. Methodological and policy-relevant papers emerged as the most cited categories, underscoring the influence of research that bridges empirical rigor and applied outcomes [65,73,76].

4.2. Conceptual Shifts and Keyword Dynamics

Keyword trends indicate a thematic transition from emissions quantification to mitigation strategies and policy alignment. Terms such as “methane,” “silvopastoral systems,” and “greenhouse gases” gained traction post-2015, reflecting both scientific and policy priorities following the Paris Agreement [73]. The bibliometric evidence shows growing attention to strategies like rotational grazing, legume integration, and improved pasture management, which are increasingly explored as climate mitigation tools [6,11,65,76].

However, terms associated with governance, land rights, and indigenous knowledge remain marginal in the co-occurrence network. Only 9% of studies incorporate social science methodologies, despite evidence that tenure security and sociocultural dynamics significantly affect mitigation adoption and land-use decisions [70,74]. This gap points to a need for greater disciplinary integration and context-specific research approaches.

4.3. Institutional and Geographic Asymmetries

The analysis confirms Brazil’s centrality in Amazonian emissions research, with the University of São Paulo and federal universities producing a substantial share of publications [68]. Brazil accounts for over 60% of regional research, supported by national funding programs like the ABC Program [5]. Collaboration networks show dense North–South ties (e.g., with the U.S. and Europe) but limited South–South engagement, suggesting missed opportunities for regional knowledge sharing and capacity building among Amazonian nations [68,73].

While international collaborations boost citation impact and enhance technical capacity [68], heavy reliance on external funding, particularly from Global North institutions and multilateral donors, creates structural dependencies that may limit local research autonomy. The bibliometric analysis shows that projects with the highest citation rates often involve partnerships led or co-led by institutions outside the Amazon region. In these cases, Amazonian institutions frequently provide essential field access, data collection, and contextual expertise, yet decision-making over research questions, analytical frameworks, and publication strategies are disproportionately concentrated in the funding institution.

This dynamic can result in asymmetric authorship structures, where local scientists appear in secondary positions despite their central role in knowledge generation. It also risks aligning research agendas more closely with donor priorities such as global climate policy benchmarks, rather than with locally identified needs, such as land tenure security, indigenous governance integration, or region-specific mitigation feasibility. Over time, such dependence can hinder the development of endogenous research capacity, as domestic institutions may lack the sustained core funding required to build long-term datasets, retain technical personnel, or invest in novel methodological platforms without external sponsorship.

The findings suggest that while collaborative projects remain essential for knowledge exchange and resource mobilization, balanced authorship arrangements, co-design of research agendas, and targeted domestic investment are critical to ensuring that Amazonian institutions retain the capacity to independently define and pursue research priorities relevant to regional socio-ecological realities.

4.4. Alignment Between Research and Policy

Bibliometric trends mirror policy developments across the region. Research interest in silvopastoral systems and sustainable intensification surged after 2015, in parallel with NDC submissions and implementation frameworks in Brazil and Colombia [73,76]. Studies emphasize that mitigation effectiveness depends on conditions like 30% tree cover, 5–7 year timeframes for carbon sequestration, and secure land tenure [65,68,81].

However, while policy-relevant topics are well represented, the bibliometric analysis indicates limited empirical validation of implementation outcomes. For example, Brazil’s ABC Program achieved only 34% of its restoration targets due to bureaucratic delays and limited smallholder access [5,66], and Colombia’s NDC program faces similar challenges [73]. These findings point to a gap between policy design and on-the-ground effectiveness. The limited success of policy instruments like Brazil’s ABC Program and Colombia’s NDC is not merely a failure of implementation but is intrinsically linked to broader structural challenges within the region’s agricultural and governance frameworks. This can be attributed to the persistent issue of tenuous property rights and speculative land appropriation, which are identified as key drivers of deforestation and create an unstable environment for long-term investments in sustainable practices.

Furthermore, a lack of effective credit incentives and technical assistance for smallholders, as noted in the challenges faced by Colombia’s NDC, prevents the widespread adoption of proven mitigation strategies. This structural disconnect indicates that for policies to be successful, they must move beyond simply outlining goals to directly addressing the deep-seated issues of land tenure, economic incentives, and governance frameworks that shape agricultural decisions in the Amazon.

4.5. Emerging Frontiers and Research Gaps

Nitrous oxide emissions remain underrepresented in the literature relative to methane, despite recent findings showing that IPCC default values may overestimate emissions in tropical systems [39]. The persistent thematic imbalance can be attributed to several factors related to measurement, disciplinary focus, and research priorities. Research in this field has been heavily driven by a focus on quantifiable and impactful greenhouse gases. Methane (CH₄) from enteric fermentation is a major and relatively well-understood source of emissions, which has led to a concentration of research and the development of specific methodologies for its measurement, such as eddy covariance. In contrast, N₂O emissions from cattle excreta and soil are more complex to measure, exhibiting “unique emission dynamics” that require different field-based approaches.

A significant finding of the bibliometric analysis is the marginal co-occurrence of social science terminology and governance-related concepts with biophysical emissions research. This disciplinary divide is crucial, as nutrient cycling is an intrinsically systems-level issue that requires an understanding of soil science, ecology, and land management practices. The lack of integration means that key ecological variables are not yet fully incorporated into the dominant research paradigms.

Field-based emission factors from Amazonian pastures suggest substantially lower N₂O fluxes than assumed in global inventories, highlighting the need for region-specific data [39,84]. This finding, while important, might have historically led to less research focus on N₂O in favor of methane.

Similarly, nutrient cycling, indigenous land management practices, and the political economy of deforestation remain marginal themes in the literature despite their clear relevance. The relatively low co-occurrence of these terms suggests that key ecological and social variables are not yet fully integrated into dominant research paradigms [5,74].

Advanced technologies such as AI-based monitoring and isotopic tracing are emerging in the literature, showing promise for detecting pasture degradation and refining emission estimates [66,67,74]. However, these innovations are still in early adoption stages and not yet widely reflected in empirical policy assessments.

4.6. Synthesis and Research Implications

The paper’s practical contributions are centered on identifying specific, actionable mitigation strategies and highlighting the policy-research gap. The review found that key mitigation strategies include:

(1)

Silvopastoral systems (SPS), which integrate trees with pastureland, can halve emissions within 5–7 years, especially when they have more than 30% tree cover.

(2)

Rotational grazing: This practice involves moving livestock between different paddocks to allow vegetation to recover, which improves pasture health and reduces emissions.

(3)

Targeted pasture restoration: Restoring degraded pastures is a key strategy for reducing emissions and improving land productivity.

These strategies are most effective when combined with credit incentives and secure land tenure. The review also points out a critical gap: while these mitigation strategies are well-documented in the literature, their real-world implementation is often limited by institutional and logistical barriers, such as those seen in Brazil’s ABC Program which only met 34% of its restoration targets. This suggests that future efforts need to focus on the science of implementation, bridging the gap between policy design and on-the-ground success.

Another major implication is the need for interdisciplinary collaboration. The analysis reveals that research is often siloed, with a lack of integration between different fields. To effectively address the complex issue of Amazonian deforestation and greenhouse gas emissions, future research must bridge the gap between climate science, policy, and social sciences. This is crucial for developing policies that are not only scientifically sound but also socially and economically feasible for local communities.

Finally, the review points to the importance of long-term data collection and validation. Much of the research is theoretical or based on short-term studies. The paper implies a need for more empirical validation to confirm the long-term effectiveness of proposed mitigation strategies. This would provide stronger evidence for policymakers and institutions, helping to drive more confident and effective investments in sustainable land management practices.

Based on the analysis, future research would benefit from:

• Stronger integration of social science and governance frameworks to reflect the complex socioecological drivers of land-use change [68,74].
• Expanded long-term and interdisciplinary field studies to validate mitigation strategies under real-world conditions [66,99].
• More balanced regional collaboration that elevates underrepresented Amazonian countries and supports context-specific innovation [68,73].

By making these shifts, research on Amazonian livestock emissions can better support equitable and effective climate action while enhancing the practical relevance of scientific inquiry in one of the world’s most critical biomes.

5. Conclusions

This bibliometric review reveals that research on Amazonian livestock-driven deforestation has matured beyond foundational emissions quantification to a phase focused on mitigation strategies and policy relevance. The field’s evolution, particularly the surge in publications after 2012, is closely tied to major international policy developments such as the Paris Agreement. The analysis highlights a shift in focus from basic deforestation metrics to more sophisticated analyses of mitigation strategies and their policy impacts.

A critical finding is the persistent gap between academic research and practical implementation. While research has identified effective mitigation strategies, such as silvopastoral systems and rotational grazing, their real-world adoption is often hindered by institutional and logistical barriers. For instance, Brazil’s ABC Program only met 34% of its restoration targets, and Colombia’s Nationally Determined Contribution (NDC) faced challenges in providing technical assistance to smallholders. This suggests that future efforts must pivot from simply identifying effective solutions to a deeper focus on the science of implementation and bridging the policy-research gap.

Another critical aspect is the significant institutional and geographic asymmetry in research output. Brazilian institutions, particularly the University of São Paulo, exhibit unparalleled dominance, reflecting strategic national investment. However, the analysis also exposes a heavy reliance on collaborations with institutions from the Global North, which, while boosting citation rates, can lead to asymmetric authorship and research agendas that align more with donor priorities than local needs. This dependence can impede the development of autonomous research capacity within Amazonian nations.

This study, as a bibliometric review, provides a quantitative map of the field’s intellectual landscape but does not introduce new experimental findings or validate biophysical analyses. Its reliance on data from Scopus and Web of Science means the analysis is subject to the inherent limitations of these databases, such as a potential lack of coverage for specific disciplines or a low number of indexed journals. While the study’s scope was carefully defined to mitigate these issues, it is important to acknowledge that the conclusions are based on publication trends rather than a qualitative synthesis of individual study results.

In addition to the limitations inherent to a bibliometric approach, a crucial limitation of this research is its primary reliance on peer-reviewed academic literature. This methodology, by its very nature, excludes a wealth of critical information found in grey literature, which includes technical reports, policy briefs, and government documents from national and international organizations (e.g., FAO, World Bank, Brazilian National Institute for Space Research—INPE). These non-peer-reviewed sources often contain the most current data on deforestation rates, detailed descriptions of policy implementation challenges, and on-the-ground project outcomes that are not yet, or may never be, published in academic journals. Consequently, our analysis may not fully capture the complete picture of research, policy, and practice in the Amazon.

A more critical perspective on the Amazon’s future also necessitates a broader discussion that moves beyond emissions. While climate mitigation is a priority, the region’s trajectory is deeply intertwined with complex socio-economic and political issues. These include land tenure security, the rights of indigenous populations, the influence of commodity markets (particularly soy and beef), and the persistent challenges of governance and enforcement against illegal land-grabbing and resource exploitation. Any effective solution must address these intertwined issues, as they are the underlying drivers of deforestation. Future developments in the region will depend not just on scientific innovation, but on a more inclusive and equitable approach that integrates the perspectives and needs of local communities, a topic that remains underrepresented in the current academic literature we reviewed.

Based on the identified gaps and emerging trends, several critical areas for future research are apparent. Future research must move beyond theoretical solutions to focus on the socio-economic and institutional barriers to implementation. This includes empirical validation of policy outcomes, a focus on effective credit incentive structures, and strategies for ensuring secure land tenure, which the analysis shows are critical for the success of mitigation efforts. Furthermore, the findings reveal a disciplinary divide, with weak connections between the biophysical sciences and social sciences. Future studies should integrate methodologies from political science, sociology, and economics to better understand governance, local decision-making, and indigenous knowledge, as these factors significantly influence land-use change and the adoption of mitigation strategies. While the review identifies promising new technologies that are still in their early adoption stages, future research should explore the widespread application and validation of advanced monitoring technologies like AI-driven remote sensing and innovative mitigation strategies such as methane inhibitors and deep-rooting pasture species.

This review also identified key methodological and reporting limitations within the existing literature. These include: (i) variation in units of analysis, ranging from site-specific case studies to biome-wide assessments; (ii) use of different methodological approaches (e.g., national inventories, remote-sensing biomass estimates, process-based models), each with distinct assumptions and uncertainties; (iii) non-standardized metrics for carbon flux and emission reporting, with some studies using Mg C and others t CO₂e; (iv) Inconsistent temporal coverage, limiting the ability to construct continuous, long-term trends; and (v) low cross-study compatibility due to differences in spatial resolution, baseline definitions, and deforestation detection thresholds. Addressing these constraints in future research will be essential to improving comparability, enhancing the reliability of trend analyses, and strengthening the evidence base for policy and mitigation strategies in the Amazon.

Despite progress, a gap remains in the literature regarding nitrous oxide (N₂O) emissions, which are underrepresented relative to methane. Future research can address these knowledge gaps by adopting a more integrated and targeted approach. A critical and immediate need is to gather region-specific field data for N₂O fluxes from tropical pastures. This will provide a more accurate picture of the region’s total greenhouse gas budget and help to correct potential overestimations from global models. Research agendas must actively foster collaboration between natural and social scientists to integrate topics like nutrient cycling, indigenous land management, and the political economy of deforestation into emissions studies. This will move the field toward a more holistic understanding of the socio-ecological drivers of land-use change. Innovative methodologies, such as isotopic tracing, can provide deeper insights into emissions pathways and their origins. Future research should also explore the widespread use of advanced monitoring technologies to refine emission estimates. The persistent gap between research and implementation is a major theme. Future research should focus on how to best translate findings on nutrient cycling and emissions into practical, on-the-ground management strategies that are economically viable and culturally appropriate for local communities.

Finally, to counterbalance the current institutional concentration, future research funding and collaboration strategies should prioritize building a more robust and inclusive regional research ecosystem. This includes promoting South–South collaboration among Amazonian nations and ensuring that local institutions have the lead research agendas that are most relevant to their specific socio-ecological realities.