Mud, Microbes and Money: The Global Science of Mangrove Carbon Is Exploding

Beneath the tangled roots of the world’s mangrove forests lies one of the planet’s most efficient carbon vaults, and scientists have finally mapped how humanity has come to understand it. A new global analysis, published in Environmental Science and Pollution Research, has for the first time quantified the entire scientific literature on mangrove sediments as carbon sinks, tracing nearly four decades of research through a rigorous scientometric lens. Drawing on 4,798 articles indexed in the Scopus database between 1987 and 2023, the study reveals a field that has not merely grown but exploded, following a textbook exponential trajectory that shows no sign of slowing. The findings arrive at a critical moment, as governments increasingly look to coastal ecosystems, so-called blue carbon systems, to help meet climate targets through nature-based solutions.

The technical backbone of the analysis is a classic bibliometric toolkit. The researchers, led by Matheus Cavalcante-Silva of Fluminense Federal University in Brazil, applied Price’s Law, a foundational principle of scientometrics which holds that productive research fields grow exponentially rather than linearly. When the team fitted growth curves to the annual publication counts, the exponential model explained roughly 97.8 percent of the variance in the data, outperforming a linear fit by a factor of about 1.5. In plain terms, the number of studies on mangrove sediment carbon has been compounding year after year, much like the accumulation of the carbon itself in the waterlogged soils these papers describe. Citation dynamics tell the same story: the corpus has amassed 163,819 citations, with 88.8 percent of them accrued in just the last decade of the study window.

The recency of that citation activity is captured by the Price Index, which measures the share of citations less than five years old. A value near 50 percent signals a vibrant, current literature; this field scored 66.2 percent, placing mangrove sediment carbon research squarely at the center of contemporary environmental science rather than on its margins. For comparison, the team also ran exploratory polynomial regressions on cumulative publication counts. A third-order polynomial, with a coefficient of determination of 0.9998, projected a possible 6.7-fold increase in research output over the next two decades, though the authors are careful to frame such extrapolations as exploratory rather than deterministic forecasts. A sixth-order model produced more conservative estimates and showed signs of overfitting, capturing statistical noise around 2023 rather than genuine signal.

Geographically, the field is dominated by two scientific superpowers. The United States leads with 1,656 articles, representing 17.9 percent of country-level records, followed by China with 1,305 articles, or 14.1 percent. In total, 144 countries contributed to the literature, but the concentration at the top reflects deep institutional capacity and sustained funding. The Chinese Academy of Sciences alone accounted for 520 articles, the single most prolific institution, while the National Natural Science Foundation of China topped the funding agencies with support attached to 803 articles, ahead of the United States National Science Foundation with 534. The authors attribute this dominance to a dual relevance: mangroves in these regions are simultaneously recognized as efficient carbon sinks and as ecosystems under intense anthropogenic pressure from urbanization and hydrological alteration, a combination that keeps research dollars and policy attention flowing.

The disciplinary spread is equally telling. Publications span 25 major subject areas, led by Agricultural and Biological Sciences with 27.7 percent of records, Environmental Science with 26.5 percent, and Earth and Planetary Sciences with 19.5 percent. Journal output concentrates in outlets such as Biogeosciences, which published 265 articles, the Journal of Geophysical Research Biogeosciences, and Science of the Total Environment. Among individual researchers, Carlos M. Duarte emerges as the most prolific contributor with 47 publications, followed closely by Catherine E. Lovelock with 46 and Christian J. Sanders with 38, names that have become synonymous with the conceptual foundations of marine vegetated ecosystem carbon science.

Perhaps the most revealing part of the analysis is its mapping of collaboration networks. Using VOSviewer clustering on co-authorship links among 45 connected authors, the team identified seven distinct but interconnected thematic communities. The earliest clusters center on microbial pathways and early diagenesis, the suite of chemical and biological reactions that transform organic matter in oxygen-starved sediments, and on sedimentary carbon storage and source partitioning, where stable isotopes and elemental ratios distinguish carbon produced within the mangrove from carbon washed in from elsewhere. Other clusters address large-scale carbon cycling and climate-driven controls, ecosystem functioning and sequestration, hydrodynamic fluxes at the sediment-water interface, and finally ecosystem-scale blue carbon frameworks that tie local biogeochemistry to regional and global carbon budgets.

The temporal overlay of these networks documents a striking intellectual evolution. Early research was anchored in mechanistic studies of anoxic sediments across many wetland types, not exclusively mangroves, establishing the experimental foundations for understanding carbon turnover. As networks expanded and cross-cluster collaboration intensified, the focus shifted toward integrative perspectives in which biogeochemical reactions, sediment dynamics, and physical transport were treated as coupled regulators of carbon fluxes. In the most recent phase, the field has pivoted decisively toward climate-relevant and policy-facing work, connecting sediment biogeochemistry to carbon accounting, restoration science, and nature-based solutions. Keyword co-occurrence analysis of roughly 250 terms reinforces this arc: terms tied to microbial decomposition and early diagenesis dominated the early literature, while carbon storage, greenhouse gases, and climate change now co-occur with increasing frequency.

Why do mangrove sediments punch so far above their weight? The answer lies in a convergence of factors documented across the comparative literature the review synthesizes. Mangroves occupy less than 2 percent of global coastal area, yet their sediments can hold between 50 and nearly 100 percent of total ecosystem carbon, preserved for centuries to millennia. Soil carbon densities commonly range from about 100 to more than 300 megagrams of carbon per hectare in the upper meter, with some Amazonian and Southeast Asian sites exceeding 300 and even reaching 450 megagrams per hectare. The mechanistic explanation combines high organic carbon inputs from primary production, persistent waterlogged anoxia that suppresses decomposition, and physical and biogeochemical protection of organic matter. By contrast, river delta wetlands show more heterogeneous stocks of roughly 50 to 200 megagrams per hectare, and reef lagoon systems generally hold less, constrained by hydrodynamic exposure.

The review is candid about the complications. Sedimentary carbon stocks are highly sensitive to methodology: core depth integration, dry bulk density assumptions, and analytical protocols can swing estimates substantially, meaning shallow cores and assumed densities often lead to underestimation. Biogenic structures such as crab burrows and root systems reshape microscale redox conditions, and microbial communities operate across aerobic and anaerobic pathways, including iron, manganese, nitrate, and sulfate reduction as well as methanogenesis, mediating the delicate balance between carbon remineralization and long-term stabilization. Anthropogenic pressures, from urban organic loading to aquaculture, can tip this balance toward enhanced greenhouse gas production. The authors flag the persistent challenge of linking millimeter-scale microbial heterogeneity to ecosystem-scale carbon dynamics as the field’s central unresolved question, and suggest targeted secondary syntheses of clustering hotspots, particularly around microbial communities and methanogenesis, as the most promising next step.

What emerges from this quantitative portrait is a maturing discipline in transition. Mangrove sediment research has moved from describing how organic matter degrades to explaining how carbon persists, and from isolated process studies to frameworks that inform national carbon accounting and coastal restoration policy. With research output projected to keep climbing, and with mangroves increasingly written into climate mitigation strategies from carbon markets to national pledges, the muddy sediments beneath these tidal forests are no longer a scientific backwater. They are, by every bibliometric measure, one of the fastest-growing and most policy-relevant frontiers in environmental science, and the global research community is only beginning to excavate their full significance.

Subject of Research: Scientometric analysis of global research on mangrove sediments as long-term blue carbon sinks

Article Title: Mangrove sediments as carbon sinks: a global analysis of research patterns, trends and future directions

Article References: Cavalcante-Silva, M., Santos-Lima, A. C., Fonseca-Oliveira, A. L., Meira, V. L., Monte, C. D. N., & Machado, W. (2026). Mangrove sediments as carbon sinks: a global analysis of research patterns, trends and future directions. Environmental Science and Pollution Research, 33(30), 15211-15228. https://doi.org/10.1007/s11356-026-38224-7

Image Credits: AI Generated

DOI: 10.1007/s11356-026-38224-7

Keywords: mangroves, blue carbon, carbon sequestration, sediments, scientometrics, bibliometrics, climate change mitigation, microbial decomposition, early diagenesis, nature-based solutions, coastal ecosystems, greenhouse gases